• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 241
  • 183
  • 45
  • 38
  • 17
  • 17
  • 17
  • 16
  • 15
  • 6
  • 5
  • 5
  • 4
  • 2
  • 2
  • Tagged with
  • 652
  • 146
  • 132
  • 69
  • 68
  • 55
  • 50
  • 45
  • 45
  • 41
  • 37
  • 35
  • 32
  • 31
  • 30
  • 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.
111

Méthode de conception des bobinages des actionneurs électriques adaptés aux nouvelles contraintes de l'avionique / Deisgn method for electrical actuators windings for new aeronautical requirements

Moeneclaey, Julien 23 February 2015 (has links)
Le développement d’avions plus électriques se traduit par une plus grande utilisation d'actionneurs électriques qui remplacent des systèmes hydrauliques et pneumatiques existants ou répondent à de nouveaux besoins. La distribution de l'énergie à bord est basée sur un réseau continu 540V connecté à des convertisseurs électroniques de puissance. Les composants électroniques de puissance à grands gaps (SiC, GaN) améliorent les performances des convertisseurs mais les fronts de tension très raides sont imposés aux bobinages des actionneurs électriques. Chaque front excite un régime transitoire comportant une surtension importante et donc des champs électriques intenses dans l’isolation inter-spires des bobines. Lorsque cette contrainte électrique répétitive dépasse le seuil d'apparition des décharges partielles (PDIV), la durée de vie des couches organiques qui isolent les spires est fortement réduite. L'étude détaillée des décharges partielles (DP) dans l'espace qui sépare les fils émaillés des bobinages permet de situer les zones dans lesquelles les DP se produisent. Elle montre que le thermocollage, avec des surépaisseurs adaptées de thermocolle, permet d'élever le PDIV au-delà des pointes répétitives de tension pour les actionneurs qui fonctionnent dans les parties pressurisées des avions. Des solutions ordonnées de bobinages ont été expérimentées sur des bobines cylindriques imprégnées. Cette analyse montre que l'imprégnation augmente légèrement le PDIV de l'isolation inter-spires dans des proportions qui ne correspondent pas totalement aux caractéristiques intrinsèques du vernis utilisé. Par conséquent, les bobines imprégnées doivent être conçues sur la base des performances de l'isolation primaire du fil émaillé. L’arrangement des spires dans une bobine ordonnée permet de répartir les contraintes et donc de concevoir des bobines qui résistent aux pointes de tension répétitives imposées par l'onduleur aux basses pressions correspondant aux zones non pressurisées d'un avion en vol. Un modèle, basé sur un schéma équivalent HF prenant en considération les deux premières résonances des bobines élémentaires, permet d'analyser la répartition des contraintes entre les bobines connectées en série d'une phase. / The More Electric Aircraft development is reflected by a bigger use of the electrical actuators, which replace the hydraulic or pneumatic system existing or they can also answer to new needs. The energy distribution on board is based on a high voltage continuous bus of 540V connected to electrical power converter. The electric power wide band gap components (SiC, GaN) improve the converters performances but very steep of voltage edge is imposed on the windings of the electric actuators. Each edge excites a transitory regime including an important surge which corresponds to intense electric fields in the inter-turns insulation of coils. When this repetitive electrical constraint exceeds the partial discharges inception voltage (PDIV), the life time of the organic layer between the turns is strongly reduced. The detailed study of the partial discharges (PD) in the area which separate the enamel wire of the windings allows to locate the area where the PD appears. The use of thermo-bonding, with a bonding thickness adapted, allows to raise PDIV beyond the repetitive edge of voltage for the actuators which work in the pressurized parts of the planes. The orderly windings solutions were tested on impregnated cylindrical coils. This analysis shows that the impregnation increases slightly the PDIV from the inter-turns insulation in proportions that do not totally correspond to the intrinsic characteristics of the used varnish. Therefore, the impregnated coils must be conceived on the basis of the primary insulation performance of the enamelled wire. The turn’s arrangement in an orderly coil allows to distribute the constraints and so to conceive the windings which can resist the compulsory repetitive of voltage spikes by the inverter in low pressures corresponding to not pressurized zones in a plane during the flight. A model, based on HF equivalent schema taking in consideration the first two resonances of the elementary coils, allows to analyse the constraints distribution between the coils connected in series of a machine phase.
112

Algoritmy pro vybrané geometrické problémy nad zonotopy a jejich aplikace v optimalizaci a v analýze dat / Algorithms for various geometric problems over zonotopes and their applications in optimization and data analysis

Rada, Miroslav January 2009 (has links)
The thesis unifies the most important author's results in the field of algorithms concerning zonotopes and their applications in optimization and statistics. The computational-geometric results consist of a new compact output-sensitive algorithm for enumerating vertices of a zonotope, which outperforms the rival algorithm with the same complexity-theoretic properties both theoretically and empirically, and a polynomial algorithm for arbitrarily precise approximation of a zonotope with the Löwner-John ellipsoid. In the application area, the thesis presents a result, which connects linear regression model with interval outputs with the zonotope matters. The usage of presented geometric algorithms for solving a nonconvex optimisation problem is also discussed.
113

TO TEACH COMBINATORICS, USING SELECTED PROBLEMS

Modan, Laurentiu 07 May 2012 (has links)
In 1972, professor Grigore Moisil, the most famous Romanian academician for Mathematics, said about Combinatorics, that it is “an opportunity of a renewed gladness”, because “each problem in the domain asks for its solving, an expenditure without any economy of the human intelligence”. More, the research methods, used in Combinatorics, are different from a problem to the other! This is the explanation for the existence of my actual paper, in which I propose to teach Combinatorics, using selected problems. MS classification: 05A05, 97D50.
114

Three Spirituals: arranged for Solo Piano

Gärtig, Raphael 25 July 2022 (has links)
With a medium level of technical and interpretive difficulty, these arrangements of “Three Spirituals” are aimed at more advanced pianists. Lasting around 1½ to 2½ minutes each, the three movements are all fairly short and can be performed separately or – as recommended by the composer – in the order given here.:“Go Down, Moses” “Sometimes I Feel Like A Motherless Child” “Nobody Knows The Trouble I’ve Seen” / Die Arrangements der hier vorliegenden Ausgabe von „Three Spirituals“ richten sich mit ihrem in spieltechnischer Hinsicht mittleren Schwierigkeitsgrad und ihren musikalischen Anforderungen an schon etwas fortgeschrittenere Klavierspieler. Mit einer Dauer von circa eineinhalb bis zweieinhalb Minuten haben alle drei Sätze eine überschaubare Länge und können sehr gern einzeln oder – empfehlenswerterweise – in der hier abgedruckten Reihenfolge vorgetragen werden.:“Go Down, Moses” “Sometimes I Feel Like A Motherless Child” “Nobody Knows The Trouble I’ve Seen”
115

Klassikadaptionen in Rock, Pop und Filmmusik: Ihr analytisches Potential für den schulischen Musikunterricht

Reichel, Elke 27 October 2023 (has links)
Die theoretische Auseinandersetzung mit Musik vergangener Epochen löst in Schule und Musikhochschule selten Begeisterung aus. Zu weit scheint sie wegzuführen von den typischen Hörgewohnheiten und der Musizierpraxis junger Menschen. Doch gerade populäre Gegenwartsmusik bietet eine Vielfalt an Möglichkeiten, Schüler*innen und Studierende an Inhalte von Musikwissenschaft und historisch informierter Musiktheorie heranzuführen, denn Rock, Pop und Filmmusik beziehen sich durch Zitate, tradierte Wendungen und Topoi auf Jahrhunderte europäischer Musikgeschichte. Vor dem Hintergrund der nahezu unbegrenzten medialen Verfügbarkeit von Werken verschiedenster Epochen und Stilrichtungen ergeben sich in diesen Genres zahllose Möglichkeiten der Kombination solcher Elemente. Historische Bezüge in aktueller Musik beinhalten die Chance, junge Menschen für musikalische Strukturen und ihre historischen Dimensionen zu sensibilisieren. Darüber hinaus bietet die Verschmelzung kontrastierender stilistischer Merkmale innovatives Potenzial für das Live-Arrangement mit leistungsheterogenen Gruppen. Anhand kurzer Beispiele werden Einsatzmöglichkeiten populärer Titel in der Unterrichtspraxis vorgestellt. / Theoretical study of the music of past epochs rarely triggers great enthusiasm at schools or conservatories. It seems to lead away from the typical listening habits and musical practices of young people. But contemporary popular music provides many opportunities to introduce students into essential fields of musicology and historically informed music theory. Rock, pop and film music relate to centuries of European music history by using citations, inherited idioms, and topoi. Against the background of unlimited availability of compositions of different epochs and styles in the media, countless opportunities to combine such elements can be observed in these genres. Historical references in current musics provide the chance to sensitize young people for musical structures and their historical dimensions. Furthermore, the fusion of contrasting stylistic characteristics bears innovative potential that teachers can use for live arrangement in school classes and groups with heterogeneous capabilities. This article introduces opportunities of integrating popular titles into teaching practice on the basis of short examples.
116

'n Orkestrasie van Arnold van Wyk se Nagmusiek

Claassen, Hanrich 03 1900 (has links)
Thesis (M.Mus.)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Arnold van Wyk's monumental Night Music is regarded as one of the most important and original South African piano compositions. Night Music offers a legion of untapped timbre possibilities and certainly lends itself to the embodiment of the more expressive and versatile medium of the symphony orchestra. The orchestration of Night Music is an attempt to establish a version which, through utilizing a different medium of presentation, will elucidate Van Wyk's masterpiece and make it more accessible; not as a replacement of the original, but as an enhancement. / AFRIKAANSE OPSOMMING: Arnold van Wyk se monumentale Nagmusiek word as een van die belangrikste en oorspronklikste Suid-Afrikaanse klavierkomposisies beskou. Nagmusiek bied 'n legio onontginde timbremoontlikhede en leen hom dus beslis tot die vergestalting daarvan in die meer uitdrukkingsvolle en veelsydige medium van die simfonie-orkes. Die orkestrasie van Nagmusiek is 'n poging om 'n weergawe daar te stel wat by wyse van 'n ander uitbeeldingsmedium Van Wyk se meesterstuk toelig en meer toeganklik maak, nie as plaasvervanger van die oorspronklike nie, maar as verlengstuk daarvan.
117

個人檔案編排與描述之研究--以國內兩大典藏機構為例 / A Study on Arrangement and Description of Personal Archives in Taiwan: Based on the Cases of Two Major Archival Repositories

廖淑媚, Liao, Shu-Mei Unknown Date (has links)
個人檔案不僅是一個人一生的總合紀錄,更重要地,可以補充國家歷史記憶,對研究社會歷史、風俗民情具有重要的參考價值。但基於個人檔案之特殊產生方式及不具固定書寫格式等性質,檔案典藏單位在個人檔案的整理實務上,如何進行最佳的編排與描述,以提升檔案資訊的有效利用,亦成為重要的研究課題。 本研究採用「文獻分析法」、「深度訪談法」及「比較法」進行研究。以具代表性的兩大典藏機構(國史館、中央研究院)為研究對象,中央研究院內以近史所檔案館、近史所胡適紀念館、史語所傅斯年圖書館、台史所古文書室等四個單位為代表。首先藉由文獻分析及深度訪談探究個人檔案典藏單位對於個人檔案編排與描述之現況,然後加以比較分析。 根據研究結果,對於國內個人檔案典藏單位編排與描述實務,提出結論如下:一、編排實務現況:(一)多數檔案典藏單位無法遵守原始順序原則,(二)檔案典藏單位缺乏一致性的編排原則;二、描述實務現況:(一)檔案典藏單位缺乏一致性的內容描述標準,(二)多數檔案典藏單位缺乏全宗及系列層級的描述,(三)「題名、摘要、日期、實體描述、備註、使用限制」是各單位共同描述的項目,(四)大部分檔案典藏單位未進行權威控制工作;三、相較於一般檔案,個人檔案的編排與描述面臨更多的問題與挑戰。 最後就前述研究結論,提出建議:一、擬定一致性的編排原則與描述標準;二、將個人檔案納入全國性檔案聯合目錄之中;三、強化檔案產生者的描述;四、加強全宗及系列層級的描述;五、建置個人檔案人名權威檔;六、加強個人檔案整編人員的專業訓練;七、成立個人檔案特殊興趣團體。 / Personal archives are not just the records of one's life. More importantly, they are contributing to a nation's history and are valuable in research on social history and cultural habits. However, because of the special way that personal archives are produced and their lack of unified formats, how the arrangement and descriptions of these archives are managed by repositories to elevate their value as resources becomes an important question to be discussed. This study used "literary analysis," "in-depth interviews" and "comparisons" on our subjects and it used two representative archives: the Academia Historica and Academia Sinica of Taiwan. Within the Academia Sinica, we chose the Archives and Hu Shih Memorial Hall of the Institute of Modern History, the Library of the Institute of History and Philology, and the Paleography Archives of the Institute of Taiwan History for our study. First, we explored the situations of the arrangements and descriptions of personal archives in these institutions through literary analysis and in-depth interviews; then we ran the results through comparative analysis. According to our findings, we reached the following conclusions on the current arrangements and descriptions of personal archive repositories in Taiwan: First, on arrangement: 1) most repositories do not follow the original order, and 2) repositories often lack unified formatting principles. Second, on descriptions: 1) repositories lack unified content description guidelines, 2) most repositories lack descriptions for fonds and series, 3) common elements shared by various repositories are: title of unit, abstract, date of unit, physical description, notes and restrictions on use, 4) most repositoires are not under authority control. Third, compared to public records, the arrangements and descriptions of personal archives are more problematic and challenging. Finally, based on the aforementioned conclusions, we suggest: 1) a set of unified arrangement principles and description guidelines be set, 2) personal archives be added into the contents of national archives, 3) more emphasis be placed on the descriptions of creators, 4) more emphasis be placed on the descriptions of fonds and series, 5) name authority files be established, 6) professional training for personal archivers be provided, and 7) interest groups for personal archives be established.
118

MEDBORGARFÖRSLAGETS UPPGÅNG OCH FALL -En studie om medborgarförslag utifrån participatory governance arrangement och politisk nätverksteori

Lagefjäll, Emma, Larsson, Moa January 2019 (has links)
Citizen proposal is one of many participation governance arrangements introduced the last few decades in Sweden in order to improve communication between local government institutions and citizens. In 2002 citizen proposal was introduced by the state, thus making it possible for the municipalities to allow citizens and other inhabitants to come up with proposals to the elected. In 2007 the law was revised and now gave the municipalities opportunity to delegate decision-making related to citizen proposals to the committees [nämnder/styrelser]. This study examines the implementation of citizen proposals in Kumla municipality 2002-2019. First analysing the arguments raised by the municipality to implement citizen proposal in Kumla, it then proceeds to show how it was implemented before and after the revision of the law that gave opportunity to delegate decision-making to the committees and what consequences it had on the content of the decisions. The study ends by showing how and why Kumla municipality decided to repeal the citizen proposal in favour of another kind of citizen participation.
119

Arranjos institucionais e capacidades estatais para implantação de infraestrutura metroviária: nos trilhos do metrô de Salvador / Institutional arrangements and state capacities for the implementation of urban rail infrastructure: on the rails of Salvador\'s subway

Lima, Victor Bastos 16 April 2019 (has links)
A presente pesquisa teve como objeto de estudo o processo de implantação do Sistema Metroviário de Salvador e Lauro de Freitas, buscando investigar as condicionantes da ação estatal para construir esta infraestrutura metroviária. Este trabalho parte do ambiente institucional instaurado a partir da redemocratização do Brasil em 1988 para a produção de políticas públicas, tomando como premissas o presidencialismo de coalizões, o novo regime federativo, o fortalecimento dos órgãos de controle da administração pública e a necessidade de participação social nos processos decisórios. Olhando para as estruturas criadas para a produção desta política de infraestrutura urbana, este trabalho teve a pretensão de explicar como os arranjos institucionais de políticas públicas dotam o Estado de poder para agir, isto é, como eles favorecem ou dificultam a formação de capacidades estatais para implantação de infraestrutura metroviária. Para tanto, considerou-se o período de construção do Sistema Metroviário de Salvador e Lauro de Freitas até o momento de sua inauguração (1997-2014), dividindo este objeto em três fases. O primeiro período (1997-2005) inaugura um modelo de cogestão entre a administração do Município de Salvador e a administração federal com vistas ao gerenciamento das obras para a implantação do metrô. De outro modo, a segunda etapa (2005-2011) é caracterizada pelo protagonismo quase que exclusivo desta administração municipal na condução desta política. Por fim, a terceira fase (2011-2014) é marcada pela transferência do projeto do metrô ao Estado da Bahia, contexto no qual esta política passa a ter escala metropolitana e a ser implementada por meio de uma parceria público-privada. Com base em fontes documentais, especialmente informações produzidas por instituições envolvidas nesta política, e na realização de entrevistas semiestruturadas, esta pesquisa analisou como atributos de política pública foram mobilizados em cada uma destas fases no sentido de produzir ação para o desenvolvimento desta infraestrutura. A análise qualitativa dos dados sugere que o desenho do arranjo institucional e as suas alterações influenciam a disponibilidade e a mobilização de recursos, competências e instrumentos de políticas públicas para a produção de eficácia e legitimidade, isto é, para criar autonomia e inserção da ação estatal / This research aims to study the construction process of the metro system in the Brazilian cities of Salvador and Lauro de Freitas, investigating the constraints of state agency to build this metro infrastructure. This work starts from the institutional environment to develop public policies, established by the democratization of Brazil in 1988, based on the presidential system of coalitions, the new federative regime, the strengthening control agencies and the relevance of social participation in the decision-making processes. Looking at the structures created to produce this urban infrastructure policy, this research tried to explain how institutional arrangements of public policies condition state agency, in other words, how they enhance or undermine the formation of policy capacities to deliver metro infrastructure. For this purpose, the period of construction of Salvador and Lauro de Freitas Metro System was considered until its inauguration (1997-2014), dividing this object into three phases. The first period (1997- 2005) inaugurates a model of co-management between the administration of the municipality of Salvador and the federal administration in order to manage the works. Otherwise, the second stage (2005-2011) is characterized by the predominant role of the municipal administration in the steering of this policy. Finally, the third phase (2011-2014) is marked by the transfer of this project to the state of Bahia, a context in which this policy adopted a metropolitan scale and an implementation through a public-private partnership. Based on document sources, especially qualitative data produced by organizations involved in this policy, and semi-structured interviews, this research analysed how policy attributes were mobilized in each of these three phases in order to generate state agency to build this urban infrastructure. The qualitative analysis of the data suggests that the design of institutional arrangements and its changes influence the availability and mobilization of resources, competences and policy instruments to the promotion of efficacy and legitimacy in this policy, in other words, to increase autonomy and embeddedness of state action
120

Um bocadinho de cada coisa: trajetória e obra de Pixinguinha. História e música popular no Brasil dos anos 20 e 30 / Um bocadinho de cada coisa: Pixinguinha\'s work and life. History and popular music in Brazil during the decades of the 1920s and 1930s

Bessa, Virginia de Almeida 07 March 2006 (has links)
O trabalho aborda diversos aspectos do universo do entretenimento no Rio de Janeiro das décadas de 1920 e 1930 em sua articulação com a música e com os músicos populares. Seu fio condutor é a trajetória do compositor, instrumentista, arranjador e maestro Alfredo Vianna da Rocha Filho, o Pixinguinha, que atuou e colaborou nos diversos meios do entretenimento do Rio de Janeiro . O percurso é longo: dos cafés-concertos ao rádio, com uma longa pausa na indústria fonográfica. Parte-se do pressuposto que a música popular desempenhou papel mais que relevante naquele contexto. Das rodas de choro ao Palácio do Catete, do morro aos estúdios de gravação, ela esteve presente nos diversos espaços da cidade, revelando vários dos dilemas existentes no país naquele momento: moderna ou típica? negra ou branca? folclórica ou popular? Privilegiamos, como objeto de análise, a escuta do compositor, revelada em suas composições, interpretações e, sobretudo, em seus arranjos, os quais nos permitem escutar sua escuta, e desvendar os modos de inserção e barreiras encontrados pelo músico nesse universo em constante transformação. / This work approaches many aspects of the entertainment universe in Rio de Janeiro during the decades of the 1920s and 1930s, considering its articulation not only with the music but also with the popular musicians. The thread of this study is the personal trajectory of the composer, instrumentalist, arranger and conductor Alfredo Vianna da Rocha Filho ? Pixinguinha ?, who has taken part in many activities of the entertainment universe in Rio de Janeiro. The path is long: from the ?cafés-concerto? to the radio, with a long pause in the phonographic industry. As a point of departure, our study presupposes that the popular music has taken more than a relevant part in this context. From the ?rodas de choro? to the Catete?s Palace, from the ?morro? to the recording studios, popular music was noticed in many places of the town, revealing some of the dilemmas faced by the country in that period: modern or typical? black or white? folk or popular? The listening of the composer is here highlighted as our object of analysis, which can be revealed through Pixinguinha?s compositions, interpretations and above all through his arrangements, which allow us to listen to his listening, and to figure out the ways of insertion as well as the obstacles that the musician had to face up to in this universe subjected to constant transformations.

Page generated in 0.0928 seconds