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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
361

A critical analysis and study of the problems of intonation in the band ensemble

Bartlett, Harold H. 01 January 1958 (has links) (PDF)
The purpose of this treatise is not so much to discover heretofore unknown facts through original research; however, certain research is planned to assist in deleting the obvious handicaps one might encounter from using faulty instruments or mouthpieces, but rather to assemble under one cover practical data that may be of value in improving intonation in the band ensemble. Various definitions of terms will be established, purposes determined, opinion and methods of teachers evaluated, conclusions reached, and highlights of other persons’ experiments that may bear upon the subject will be presented.
362

Topological properties of flat bands in generalized Kagome lattice materials / Topologiska egenskaper hos platta band i generaliserade Kagome gittermaterial

Pinto Dias, Daniela January 2021 (has links)
Topological insulators are electronic materials that behave like an ordinary insulator in their bulk but have robust conducting states on their edge. Besides, in some materials the band structure presents completely flat bands, a special feature leading to strong interactions effects. In this thesis we present a study of the edge states of three particular two-dimensional models presenting flat bands: the honeycomb-Kagome, the $\alpha$--graphyne and a ligand decorated honeycomb-Kagome lattice models. We extend earlier work done on these lattice models by focusing on the topological nature of the edge states involving flat bands. We start by giving a review of the band structure theory and the tight-binding approximation. We then present several main topics in two-dimensional topological insulators such as the notion of topological invariants, the Kane-Mele model and the bulk-edge correspondence. Using these theoretical concepts we study the band structure of these lattices firstly without taking into account the spin and spin-orbit interations. We finally add these interactions to get their bulk band structures as well as the edge states. We observe how these spin-orbit interactions relieve degeneracies and allow for the emergence of edge states of topological nature. Since the lattices studied have an arrangement based on the honeycomb-Kagome lattice, two-dimensional materials having the structures of these lattices can be designed assembling metal ions and organic ligands. Therefore the results obtained could be used as a first hint to create new two-dimensional materials presenting topological properties. / Topologiska isolatorer är elektroniska material som uppför sig som en vanlig isolator i sin bulk men har robusta ledande stater på kanten. Dessutom presenterar bandstrukturen i vissa material helt platta band, en speciell egenskap som leder till starka interaktionseffekter. I denna avhandling presenterar vi en studie av kanttillstånden för tre speciella tvådimensionella modeller som presenterar platta band: bikakan-Kagome, $\alpha$-grafynen och en liganddekorerad honungskaka-Kagome modeller. Vi utökar tidigare arbete med dessa gittermodeller genom att fokusera på den topologiska karaktären hos kanttillstånd som innefattar platta band. Vi börjar med att ge en genomgång av bandstruktursteorin och den tätt bindande approximationen. Vi presenterar sedan flera huvudämnen i tvådimensionella topologiska isolatorer såsom begreppet topologiska invarianter, Kane-Mele modellen och bulk-kant korrespondensen. Med hjälp av dessa teoretiska begrepp studerar vi bandstrukturen för dessa gitter först utan att ta hänsyn till spinnen och spinnsorbital interaktioner. Vi lägger sedan till dessa interaktioner för att få sina bulkbandstrukturer såväl som kanttillstånden. Vi observerar hur dessa spinnsorbital interaktioner lindrar degenerationer och möjliggör uppkomsten av kanttillstånd av topologisk naturen. Eftersom de undersökta gitterna har ett arrangemang baserat på honungskaka-Kagome gitteren, kan tvådimensionella material med strukturerna hos dessa gitter utformas genom att montera metalljoner och organiska ligander. Därför kan de erhållna resultaten användas som en första ledtråd för att skapa nya tvådimensionella material med topologiska egenskaper.
363

Development of a trans-rotational temperature diagnostic for vibrationally-excited carbon monoxide using single-photon laser-induced fluorescence

Leiweke, Robert John 30 March 2004 (has links)
No description available.
364

Raman spectroscopy as a non-destructive screening technique for studying white substances from archaeological and forensic burial contexts

Schotsmans, Eline M.J., Wilson, Andrew S., Brettell, Rhea C., Munshi, Tasnim, Edwards, Howell G.M. January 2014 (has links)
No / Raman spectroscopy was evaluated as a non-destructive analytical tool for the characterisation of white substances in burials. In addition, Fourier transform Raman spectroscopy was used to assess the conversion of hydrated lime into calcium carbonate. Fourteen samples of white substances from archaeological and forensic sites were analysed and characterised. The results show that not all white residues in burials are lime. Lime can easily be mistaken for other building materials (gypsum), for minerals (brushite) or degraded metal (cerussite). This study highlights the need for chemical analysis of white residues when encountered in burials. Analytical information derived from Raman spectra of white substances can further assist in the interpretation of the taphonomic processes of burials and their funerary context. Copyright (c) 2014 John Wiley & Sons, Ltd.
365

The West Point Band's Wind Commissioning Project in Celebration of the Bicentennial of the United States Military Academy

Morse, Matthew C., 1967- 05 1900 (has links)
The United States Military Academy Band, also known as the West Point Band is the oldest active band in the United States Army and the oldest unit at the United States Military Academy, and is considered to be one of the finest military musical organizations in the world. The band has also been instrumental in facilitating the creation of new works for wind band.As the commissioning of new music has been essential to the expansion of the wind band's repertoire, several major commissioning projects were undertaken in the mid-twentieth century by various organizations, including the West Point Band, the Goldman Band in conjunction with the League of Composers and later the American Bandmasters Association, Kappa Kappa Psi and Tau Beta Sigma, the American Wind Symphony, and the College Band Directors National Association. These commissioning projects and many others have contributed hosts of new quality works to the repertoire of the wind band. The West Point Band's 1952 commissioning project celebrating the Sesquicentennial of the United States Military Academy was among the first of these mid-twentieth century commissioning projects to seek out prominent composers of the day and have them write works for wind band. The project contributed several seminal pieces to the wind band's repertoire, including Morton Gould's Symphony for Band: West Point. In 1996, as tribute to both the Academy and to the earlier commissioning project, the West Point Band sought to celebrate the Academy's 2002 bicentennial in a similar fashion by commissioning well-known composers to contribute substantial wind works. These pieces would be premiered and recorded by the West Point Band over a number of years, including a gala Bicentennial Celebration concert at Carnegie Hall in March 2002. The purpose of this study is to create a consolidated written record of the wind music composed for the West Point Band as part of the band's Bicentennial Wind Commissioning Project, and to describe the process and circumstances by which this music was created and premiered. The continuing development of a quality original repertoire is important to the wind band community as a whole, and commissioning composers to write wind band music is the primary means by which new music is acquired. By any account, the twenty-six works produced through the West Point Band's Bicentennial Commissioning Project constitute a significant contribution to this repertoire. As this project and many of these pieces are not well known, it is the author's intent to bring increased attention to this commissioning project and to this music.
366

The Impact of American Conductors on the Development of Japanese Wind Band Repertoire as Evidenced in the Programming of Tokyo Kosei Wind Orchestra, Musashino Academia Musicae, Showa Academia Musicae, Senzoku Gakuen School of Music, and Tokyo University of the Arts

Lo, Albert 12 1900 (has links)
The wind bands in Japan are considered by many scholars and wind band conductors to be among some of the finest ensembles in today's wind ensemble medium. The literature and repertoire of Japanese ensembles have evolved from orchestral transcriptions, patriotic music, and military marches to original compositions by European, American, and Japanese composers. British conductor Timothy Reynish states that Japanese wind band music has looked traditionally towards the United States and occasionally United Kingdom for inspiration and repertoire. This phenomenon can be attributed to the many collegiate American and the few English wind band conductors who traveled to Japan as guest conductors, and in some cases, became residents of Japan. The focus of this study is to closely examine this significant impact of American collegiate wind band conductors, their influence on Japanese programming and how that programming has affected the collegiate repertoire. This study includes surveys of repertoire, concert programs, discographies of recordings, and interviews with prominent American conductors currently conducting in Japan. This research documents the impact that American wind band conductors have had on the programming of Japanese wind bands and how their influence have altered the collegiate repertoire. Evidence of this impact is documented by Toshio Akiyama, who states that "The influence of visiting musicians from abroad must be measured as one of the most influential aspects affecting Japanese band growth. Although the effect of Japanese musicians traveling to the United States or Europe has been beneficial, the overall impact on large numbers of people has been more directly due to the visitors from abroad."
367

High Strain Rate Deformation Behavior of Single-Phase and Multi-Phase High Entropy Alloys

Muskeri, Saideep 05 1900 (has links)
Fundamental understanding of high strain rate deformation behavior of materials is critical in designing new alloys for wide-ranging applications including military, automobile, spacecraft, and industrial applications. High entropy alloys, consisting of multiple elements in (near) equimolar proportions, represent a new paradigm in structural alloy design providing ample opportunity for achieving excellent performance in high strain rate applications by proper selection of constituent elements and/or thermomechanical processing. This dissertation is focused on fundamental understanding of high strain-rate deformation behavior of several high entropy alloy systems with widely varying microstructures. Ballistic impact testing of face centered cubic Al0.1CoCrFeNi high entropy alloy showed failure by ductile hole growth. The deformed microstructure showed extensive micro-banding and micro-twinning at low velocities while adiabatic shear bands and dynamic recrystallization were seen at higher velocities. The Al0.7CoCrFeNi and AlCoCrFeNi2.1 eutectic high entropy alloys, with BCC and FCC phases in lamellar morphology, showed failure by discing. A network of cracks coupled with small and inhomogeneous plastic deformation led to the brittle mode of failure in these eutectic alloys. Phase-specific mechanical behavior using small-scale techniques revealed higher strength and strain rate sensitivity for the B2 phase compared to the L12 phase. The interphase boundary demonstrated good stability without any cracks at high compressive strain rates. The Al0.3CoCrFeNi high entropy alloy with bimodal microstructure demonstrated an excellent combination of strength and ductility. Ballistic impact testing of Al0.3CoCrFeNi alloy showed failure by ductile hole growth and demonstrated superior performance compared to all the other high entropy alloy systems studied. The failure mechanism was dominated by micro-banding, micro-twining, and adiabatic shear localization. Comparison of all the high entropy alloy systems with currently used state-of-the-art rolled homogenous armor (RHA) steel showed a strong dependence of failure modes on microstructural features.
368

Étude de la plasticité du monocristal de phase MAX par déformation aux petites échelles / Study of the single crystal plasticity of MAX phase by deformation at small scales

Sylvain, Wilgens 06 December 2016 (has links)
L'objectif de cette thèse est l'étude de la déformation, à l'échelle microscopique, de la phase MAX Ti2AlN, synthétisée par métallurgie des poudres. Ce travail se divise en trois parties : une première dans laquelle l'accent a été mis sur l'hystérèse mécanique des phases MAX via des essais cyclés, en nanoindentation sphérique et compression ex-situ de micro-piliers, sur des grains d'orientations différentes déterminées par l'EBSD. Dans la deuxième nous nous sommes intéressés à la déformation de micropiliers via des essais de compression cyclés in-situ couplés à la micro-diffraction Laue. L'objectif a été d'analyser les taches diffraction au cours de la déformation du pilier afin de mettre en évidence les mécanismes de déformation élémentaires mis en jeu et d'observer les structures finales via des images MEB post-mortem des piliers. Enfin, une dernière dans laquelle l'objectif a été l'étude des mécanismes de déformation en température à l'échelle microscopique via des essais de nano-indentation allant jusqu'à 800°C. La caractérisation des lignes de glissement en surface et des configurations microstructurales sous l'empreinte a été réalisée par AFM et MET respectivement. Toutes les données recueillies par ces divers essais aux petites échelles, ont permis d'affiner notre compréhension des mécanismes de déformation du monocristal de phase MAX, notamment vis à vis des modèles usuellement proposés dans la littérature. / The thesis's goal is to study the deformation, at microscopic scale, of the MAX phase Ti2AlN synthesized by powder metallurgy. This work is divided into three parts: in the first part, the interest has been put on the hysteretic behavior of the MAX phases via cyclic mechanical solicitations, during spherical indentation tests and ex-situ compression of micro-pillars, on differently orientated grains beforehand determined by EBSD. In the second part, we were interested into the micro-pillar's deformation via insitu cyclic compression tests coupled with Laue micro-diffraction. The goal was to analyse the evolution diffraction lines during the pillar's deformation in order to highlight the elementary deformation mechanisms and to observe the finale structures via the post-mortem SEM imaging of the pillars. Finally, a last part was devoted to study the deformation mechanisms in temperature at microscopic scale via nano-indentation tests up to 800°C. The characterization of the slip lines on the surface has been revealed by AFM and that of t he microstructural configurations (dislocations) under the indent has been done by TEM. All data collected by these various tests at the small scales have refined our understanding of the deformation mechanisms of crystal MAX phase, particularly with respect to the models usually proposed in the literature.
369

Анализа мел-фреквенцијских кепстралних коефицијената као обележја коришћених при аутоматском препознавању говорника / Analiza mel-frekvencijskih kepstralnih koeficijenata kao obeležja korišćenih pri automatskom prepoznavanju govornika / Analysis of mel-frequency cepstral coefficients as features used for automatic speaker recognition

Jokić Ivan 24 October 2014 (has links)
<p>Рад је окренут ка анализи мел-фреквенцијских кепстралних коефицијената као обележја говорника која се користе при аутоматском препознавању говорника. Испитан је утицај промене облика чујних критичних опсега као и модификације енергије у њима на тачност препознавања говорника. Такође испитане су и неке трансформације ради умањења временске променљивости модела истих говорника.</p> / <p>Rad je okrenut ka analizi mel-frekvencijskih kepstralnih koeficijenata kao obeležja govornika koja se koriste pri automatskom prepoznavanju govornika. Ispitan je uticaj promene oblika čujnih kritičnih opsega kao i modifikacije energije u njima na tačnost prepoznavanja govornika. Takođe ispitane su i neke transformacije radi umanjenja vremenske promenljivosti modela istih govornika.</p> / <p>The work is oriented towards the analysis of mel-frequency cepstral<br />coefficients as speaker features used in automatic speaker recognition. The<br />influence of the shape of auditory critical bands as well as the proposed<br />energy modification inside them is tested. Also, some transformations for<br />reducing of time variability of models of the same speakers are proposed.</p>
370

Estudo comparativo de métodos geoestatísticos de estimativas e simulações estocásticas condicionais / Comparative study of geostatistical estimation methods and conditional stochastic simulations

Furuie, Rafael de Aguiar 05 October 2009 (has links)
Diferentes métodos geoestatísticos são apresentados como a melhor solução para diferentes contextos de acordo com a natureza dos dados a serem analisados. Alguns dos métodos de estimativa mais populares incluem a krigagem ordinária e a krigagem ordinária lognormal, esta ultima requerendo a transformação dos dados originais para uma distribuição gaussiana. No entanto, esses métodos apresentam limitações, sendo uma das mais discutidas o efeito de suavização apresentado pelas estimativas obtidas. Alguns algoritmos recentes foram propostos como meios de se corrigir este efeito, e são avaliados neste trabalho para a sua eficiência, assim como alguns algoritmos para a transformada reversa dos valores convertidos na krigagem ordinária lognormal. Outra abordagem para o problema é por meio do grupo de métodos denominado de simulação estocástica, alguns dos mais populares sendo a simulação gaussiana seqüencial e a simulação por bandas rotativas, que apesar de não apresentar o efeito de suavização da krigagem, não possuem a precisão local característica dos métodos de estimativa. Este trabalho busca avaliar a eficiência dos diferentes métodos de estimativa (krigagem ordinária, krigagem ordinária lognormal, assim como suas estimativas corrigidas) e simulação (simulação seqüencial gaussiana e simulação por bandas rotativas) para diferentes cenários de dados. Vinte e sete conjuntos de dados exaustivos (em grid 50x50) foram amostrados em 90 pontos por meio da amostragem aleatória simples. Estes conjuntos de dados partiam de uma distribuição gaussiana (Log1) e tinham seus coeficientes de variação progressivamente aumentados até se chegar a uma distribuição altamente assimétrica (Log27). Semivariogramas amostrais foram computados e modelados para os processos geoestatísticos de estimativa e simulação. As estimativas ou realizações resultantes foram então comparadas com os dados exaustivos originais de maneira a se avaliar quão bem esses dados originais eram reproduzidos. Isto foi feito pela comparação de parâmetros estatísticos dos dados originais com os dos dados reconstruídos, assim como por meio de análise gráfica. Resultados demonstraram que o método que apresentou melhores resultados foi a krigagem ordinária lognormal, estes ainda melhores quando aplicada a transformação reversa de Yamamoto, com grande melhora principalmente nos resultados para os dados altamente assimétricos. A krigagem ordinária apresentou sérias limitações na reprodução da cauda inferior dos conjuntos de dados mais assimétricos, apresentando para estes resultados piores que as estimativas não corrigidas. Ambos os métodos de simulação utilizados apresentaram uma baixa correlação como os dados exaustivos, seus resultados também cada vez menos representativos de acordo com o aumento do coeficiente de variação, apesar de apresentar a vantagem de fornecer diferentes cenários para tomada de decisões. / Different geostatistical methods present themselves as the optimal solution to different realities according to the characteristics displayed by the data in analysis. Some of the most popular estimation methods include ordinary kriging and lognormal ordinary kriging, this last one involving the transformation of data from their original space to a Gaussian distribution. However, these methods present some limitations, one of the most prominent ones being the smoothing effect observed in the resulting estimates. Some recent algorithms have been proposed as a way to correct this effect, and are tested in this work for their effectiveness, as well as some methods for the backtransformation of the lognormal converted values. Another approach to the problem is by means of the group of methods known as stochastic simulation, some of the most popular ones being the sequential Gaussian simulation and turning bands simulation, which although do not present the smoothing effect, lack the local accuracy characteristic of the estimation methods. This work seeks to assess the effectiveness of the different estimation (ordinary kriging, lognormal ordinary kriging, and their corrected estimates) and simulation (sequential Gaussian simulation and turning bands simulation) methods for different scenarios. Twenty seven exhaustive data sets (in a 50x50 grid) have been sampled at 90 points based on simple random sampling. These data sets started from a Gaussian distribution (Log1) and had their variation coefficients increased progressively, up to a highly asymmetrical distribution (Log27). Experimental semivariograms have been computed and modeled for geostatistical estimation and simulation processes. The resulting estimates or realizations were then compared to the original exhaustive data in order to assess how well these reproduced the original data. This was done by comparing statistical parameters of the original data and the ones of the reconstructed data, as well as graphically. Results showed that the method that presented the best correlation with the exhaustive data was lognormal ordinary kriging, even better when the backtransformation technique by Yamamoto is applied, which much improved the results for the more asymmetrical data sets. Ordinary kriging and its correction had some severe limitations in reproducing the lower tail of the more asymmetrical data sets, with worst results than those for the uncorrected estimates. Both simulation methods used presented a very small degree of correlation to the exhaustive data, their results also progressively less representative as the variation coefficient grew, even though it has the advantage of presenting several scenarios for decision making.

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