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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.
241

Comportamiento de placas de CuZnAl para disipadores tipo ADAS

Heresi Venegas, Pablo Camilo January 2012 (has links)
Magíster en Ciencias de la Ingeniería, Mención Ingeniería Sísmica / Ingeniero Civil / En esta investigación se estudia experimental y analíticamente el comportamiento de placas tipo ADAS, fabricadas de una aleación en base a cobre, frente a desplazamientos perpendiculares a su plano. Estas placas son usadas en dispositivos de disipación de energía sísmica en estructuras civiles. La composición nominal de la aleación es 75.35%p.Cu - 16.90%p.Zn - 7.71%p.Al y corresponde a una de las llamadas Aleaciones con Memoria de Forma (SMA). Se fundieron dos aleaciones (Aleación A y Aleación B), las cuales se forjaron y mecanizaron dejando probetas para ensayar en tracción y placas tipo ADAS. Ambas aleaciones poseen composiciones sólo cercanas a la nominal, pues es difícil controlar la rápida evaporación del Zinc. El tratamiento térmico óptimo para obtener fase austenita o martensita sin aumento excesivo del tamaño de grano en las placas ADAS consistió en el calentamiento del material a 850°C durante 15 minutos para luego enfriarlo en agua a temperatura ambiente; sin embargo, el mismo tratamiento produjo mayor tamaño de grano en las probetas de tracción. En ambas aleaciones se encontró fase martensita a temperatura ambiente, con temperaturas de transformación Mf y Af de 270 y 400°C, respectivamente. Se realizaron ensayos a tracción y ensayos a flexión. En los ensayos a tracción a las probetas, se impusieron ciclos de deformación en tracción pura (evitando compresión) hasta alrededor del 4.0%. Las curvas tensión-deformación obtenidas son características de materiales SMA en fase martensítica. El Módulo de Young es alrededor de 50 [GPa] para la Aleación A y 55 [GPA] para la Aleación B, mientras que la tensión inicial del proceso de demaclado es alrededor de 190 [MPa] y 265 [MPa], respectivamente. En los ensayos a flexión a las placas ADAS, se usaron desplazamientos cíclicos de amplitud creciente entre 0.5 [mm] y 40 [mm], obteniendo ciclos histeréticos estables. A partir de éstos, se calculó la Fuerza Máxima, la Rigidez Secante, la Energía Disipada y la Razón de Amortiguamiento Viscoso Equivalente. Al aumentar el desplazamiento, la Rigidez Secante disminuye asintóticamente hasta valores de alrededor un 40% del valor inicial. Por otro lado, la Fuerza Máxima, la Energía Disipada y la Razón de Amortiguamiento Equivalente aumentan, llegando esta última a valores entre 10% y 15% en todos los casos. La curvatura a lo largo de cada placa ADAS se midió usando strain gauges en las fibras extremas, en 3 posiciones diferentes, resultando, para pequeñas deformaciones, curvaturas constantes tal como lo predice la teoría elástica. Finalmente se observó, con un microscopio óptico de bajo aumento, el tipo de fractura de probetas y placas ADAS, siendo éste intergranular en ambos casos. A partir de los datos obtenidos de los ensayos a tracción, se ajustó un modelo de ley constitutiva multilineal, que se incorporó a un modelo computacional de elementos finitos y fibras para predecir el comportamiento flexural de placas tipo ADAS. El modelo predice de buena forma tanto la Fuerza Máxima como la Rigidez Secante de los ciclos, con errores menores al 7.1% y 7.3%, respectivamente. La Energía Disipada y la Razón de Amortiguamiento Equivalente son sobreestimadas por el modelo para desplazamientos más allá de la fluencia, debido principalmente a la diferencia de rigidez al descargar el material supuesta por la ley constitutiva respecto del resultado experimental. Finalmente, la Rigidez Elástica y la Fuerza de Fluencia calculadas a partir de los ensayos son correctamente predichas por el modelo con errores máximos del 12.5%$ y 22.7%, respectivamente, mientras que las fórmulas teóricas deducidas para placas ADAS estiman tales parámetros con errores máximos del 13.4% y 27.8%.
242

Minimální reprezentace víceintervalových booleovských funkcí / Minimální reprezentace víceintervalových booleovských funkcí

Bártek, Filip January 2015 (has links)
When we interpret the input vector of a Boolean function as a binary number, we define interval Boolean function fn [a,b] so that fn [a,b](x) = 1 if and only if a ≤ x ≤ b. Disjunctive normal form is a common way of representing Boolean functions. Minimization of DNF representation of an interval Boolean function can be per- formed in linear time. The natural generalization to k-interval functions seems to be significantly harder to tackle. In this thesis, we discuss the difficulties with finding an optimal solution and introduce a 2k-approximation algorithm.
243

Současná česká poezie a její vnímatel / Contemporary Czech Poetry and its Perceiver

Hoření, Vendula January 2011 (has links)
Diploma Thesis Abstract: Contemporary Czech Poetry and its Perceiver Charles University in Prague Faculty of Education Czech Language and Litterature Department Vendula Hoření The introduced diploma thesis deals with the topic of contemporary Czech poetry. Its typical form and content are desired to be found. By "contemporary" is meant the period in which the materials for its realisation were collected, i.e. between spring 2010 and spring of the 2011th. Emphasis is placed on the perceiver and the way in which he can meet with poetry today. The hypothesis that the result of research will be revelation that certain contents and forms are timeless, but others only current, was confirmed. As a new content were found topics as responses to the actual phenomenas of virtuality, ecology and consumer society. Among the new forms of contemporary Czech poetry were classified: the project Poems on the Underground, anthology The Best Czech Poetry, competition in author recitation Poetry Slam and singer-songwriter meeting Open mic as taken from foreign models and Physical poetry of Petr Váša and in a certain sense also poetic improvisation of Jakub Foll as original contemporary Czech poetry.
244

Forma jako prostor pro vyjádření hudební myšlenky / Form as a space for expressing musical ideas

Ulrichová, Zuzana January 2011 (has links)
Forma jako prostor pro vyjádření hudební myšlenky Title of the Diploma Thesis: Form as a space for expressing musical ideas Abstract: The Diploma thesis deals with form as a meaningful space for expressing and developing musical ideas. The theoretical part describes various aspects of musical forms and elaborates the basic principles of musical forming. It also compares several books on the topic of musical forms concerning their use in pedagogical practice. Another part presents research on the topic of musical forms teaching. The chapter on pedagogical applications introduces ideas about presenting forms in music classes with the use of productive activities.
245

Dadaistický a konstruktivistický objekt a jeho dědicové / Dadaistic and constructivistic object and its inheritors

Bouchalová, Barbora January 2013 (has links)
Submitted graduation theses has charakter as a theoretical study, which offers different views of questions of sameness and differences in dadaistic and constructivistic objects and in objects of its inheritors. I have made criterions to observe relation between these objects, criterions are: principle of creation, relation between content, form and matherial.We observe also using movement in object art. We show, that object-art have disturbed the then tradition of plastic art. New approach of matherial, decleration common thing as a part of art open up a lot of questions about function of art. The main aim of these theoretical study was to find out samenesses anddifferences in these objels, show a process of object art.We came to the conslusion that between dadaistic and constructivistic objels are some samenesses (for example discruption of visual art, realiton between system and chance, using movement). Didactical, didactical-visual and visual parts are fasten together with theoretical part. These parts watch on object art in two viewpoint: utilization of common thing as a dadaistic principle, relation between matherial and form as a constructivistic principle
246

Západ slunce. Relativita prostoru. / Sunset. Relativity of Space.

Malý, Břetislav January 2012 (has links)
Topic is processed sunset painting technique oil painting means to Latn and is crowned by a series of "Afterglow". is a continuation of previous work dealing with optical illusions and phenomena occurring in nature. "Glare, however, focuses on logical Only authorized color and shape inspired by the light background storyline. This resulted in a series of closed playing with forms and means in the final painting abstract painting
247

Dlouhodobé testování sportovní formy elitních judistů / Analysis of sports form of elite judo athletes

Turek, Jindřich January 2015 (has links)
Title: Analysis of sports form of elite judo athletes Objectives: The main aim of this thesis is testing purposely selected group of elite judo athletes using a battery of tests, which is intended for seinor men's category and find out whether the of performance tests on results of the world competitions. The next aim is describe a judo training of elite judo athletes. Methods: The thesis has an empirical and theoretical-character, which have been used in date collection methods, examining available information from judo training, analysis of professional literature in the field of general sports training and also the experience of many years of competitive practise of the author. The statistical evaluation was used T-test for paired values dependent selection and Spearmen correlation coefficient. Results: The results of this thesis point out that probands who show a high performance in testing are not more successful at world competitons than probands with lower performance in testing. High performance in testing has no effect on success in world competition. Resulting different values of most selected of probands with distinguished from each test in the range of 0.1 - 0.2 diameter marks. Keywords: judo, training, sports form, testing, judo athletes
248

[en] LIGHTNESS, DESIGN AND FURNITURE IN BRAZIL: VISUAL ASPECTS OF A CONCEPT / [pt] LEVEZA, DESIGN E MOBILIÁRIO NO BRASIL: ASPECTOS VISUAIS DE UMA IDEIA

MARINA KOSOVSKI MALUF 23 September 2013 (has links)
[pt] O estudo de aspectos formais e visuais remete ao ensino de design do começo do século XX, e ainda tem demonstrado ser tema de interesse inesgotável diante das constantes atualizações no campo da prática e do ensino de design. No âmbito do design de mobiliário no Brasil, bastante atenção foi dedicada às biografias ou aos contextos históricos de alguns ícones, mas não tanta ao exercício de apreender aspectos de sua própria materialidade. Tomando a forma e a visualidade da ideia de leveza como eixo condutor, este trabalho propõe uma reaproximação a um tipo consagrado de mobiliário para casa produzido no Brasil, a partir dos anos 50, através da tensão entre certas referências culturais, sociais e técnicas em imagens da leveza na modernidade, e um exercício de análise de seus aspectos formais e visuais em oito assentos selecionados. O objetivo principal do trabalho é destacar um repertório formal e visual corporificado na tipologia de design do mobiliário estudado, investindo também na sistematização e síntese de aspectos formais e visuais nas especificidades do mobiliário em geral, e do espaço tridimensional, que podem servir tanto à prática quanto ao ensino de design. / [en] The investigation of formal and visual aspects recalls to the teaching of design back to the beginning of the XX century and it still proves to be a subject of endless interest before the constant updating in the field of practice and teaching of design. Within the scope of furniture design in Brazil, a great deal of attention was drawn to biographies or to the historical context of some icons. It is not possible to say the same when it comes to the exercise of learning the aspects of materiality itself. Taking into account the underlying concepts of lightness such as shape and visuality, the present work aims at reapproaching a renowned kind of home furniture manufactured in Brazil from the 50s on, through the tension amongst certain cultural, social and technical references, as well as techniques on images of lightness in the modernity and an exercise of analysis of its formal and visual aspects in eight pre-selected samples. The general goal of this work is to highlight a formal and visual repertory, which has been incorporated in the typology of design of the pieces of furniture approached hereby. Other aspects here approached are the systematization and synthesis of the formal and visual aspects within the peculiarities of furniture on a whole, as well as the tridimensional space, which can be either used in the practical field and for the teaching of design.
249

[en] RECONSTRUTION OF GEOMETRY BASED IN CONNECTIVITY AND MESH SAMPLES / [pt] RECONSTRUÇÃO DE GEOMETRIA A PARTIR DA CONECTIVIDADE DA MALHA E DE PONTOS DE CONTROLE

CATIUSCIA ALBUQUERQUE BENEVENTE BORGES 31 August 2007 (has links)
[pt] Este trabalho busca reconstruir a geometria de uma malha partindo de sua conectividade e de um conjunto esparso de pontos com geometria conhecida, denominados pontos de controle. O problema é formulado como a maximização da suavidade da superfície fixando a posição dos pontos de controle. Nessa formulação, o método consiste em resolver um sistema linear esparso aplicando-se mínimos quadrados. Diferentes propostas para a seleção de pontos de controle, o método de minimização e a construção do sistema linear são apresentadas e comparadas. / [en] This work aims at reconstructing the geometry of a mesh from its connectivity and a small set of control points, whose geometry is known.The problem is formulated as a maximization of the surface smoothness restricting the position of the control points. With this formulation, the method reduces to solving a sparse linear system using least squares minimization. Several proposals for the selection of the control points, the minimization method and the linear system construction are presented and compared .
250

Os direitos autorais no mercado da música / Copyright and the new music economy

Losso, Fabio Malina 05 May 2008 (has links)
A presente tese parte da constatação de que diversas crises nos direitos autorais impactaram o mercado da música, todas coincidentes com a introdução de novas tecnologias. Com o advento das tecnologias digitais de fixação de obras musicais e da internet, passou-se a questionar se o momento atual permite identificar uma autêntica crise no direito do autor e, a partir disso, como se pode refletir sobre as questões decorrentes das novas tecnologias que, fatalmente, são pensadas com as velhas normas e teorias. São linhas essenciais do trabalho: a) a criatividade musical e o impacto de diferentes tecnologias para sua fixação e distribuição; b) a criatividade musical e o reconhecimento e a proteção de direitos do criador; c) a inflexão entre os interesses do criador e os outros diversos sujeitos envolvidos na fixação e distribuição da obra artística musical ao lado do interesse dos destinatários; d) a pluralidade de soluções para definir os moldes dessa inflexão e as direções tomadas pelo direito brasileiro. Verifica-se, no decorrer do presente estudo, a existência de conflito de interesses entre o investidor cultural, o compositor e o consumidor, que se projeta no conflito entre os direitos autorais e o direito de acesso aos bens culturais. A conformação de ambos constitui um relevante desafio trazido pelos novos tempos da chamada \"sociedade da informação\", na qual a música digital está inserida. / The present thesis parts from the affirmative that many crises in copyright impacted the music market, all coincident with the introduction of new technologies. With the advent of digital technologies for the fixation of musical works and of the intemet, it was questioned whether the present moment permits identification of an authentic crisis in copyright, and, from that, how is it possible to reflect about the issues due to the new technologies that, fatally, are thought according to old laws and theories. The essential guidelines of the thesis are: a) musical creativity and the impact of different technologies for its fixation and distribution; b) musical creativity and the acknowledgement and copyrights protection; c) the inflexion between the author\'s and other people\'s, who are involved in the fixation and distribution of artistic musical works, interests contrasted with the interests of the addressees; d) the plurality of solutions to define the molds of this inflexion and the directions taken by Brazilian law. It is verified, throughout the present study, the existence of a conflict of interests between the cultural investor, the composer and the consumer, that projects itself on the conflict between copyrights and the right to access cultural assets. The conformation of both constitutes a relevant challenge brought by the new times of what is called \"information society\", in which digital music is inserted.

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