• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 624
  • 402
  • 118
  • 86
  • 68
  • 49
  • 47
  • 42
  • 24
  • 13
  • 11
  • 11
  • 9
  • 8
  • 8
  • Tagged with
  • 1679
  • 241
  • 188
  • 184
  • 167
  • 151
  • 130
  • 125
  • 112
  • 112
  • 108
  • 102
  • 102
  • 93
  • 87
  • 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.
231

Impacto dos radares fixos na velocidade e na acidentalidade em trecho da rodovia Washington Luís / Impact of thefFixed radars in thesSpeed and the analysis of accidents in segment of the Washington Luis highway

Mario Guissu Yamada 15 December 2005 (has links)
Neste trabalho é avaliado o impacto do emprego de radares fixos na velocidade e na acidentalidade no trecho compreendido entre o Km 153,350 e o Km 227,800 da Rodovia Washington Luís - SP-310 (extensão de 74,450 km), localizado no interior do estado de São Paulo e cuja concessão pertence à empresa Centrovias. A avaliação do impacto na velocidade e na acidentalidade foi realizada em segmentos curtos situados no entorno dos radares e em toda a extensão do trecho. As medições de velocidade foram realizadas nos pontos onde se localizam os radares fixos, em pontos próximos (cerca de 2km antes e 2km depois) e em pontos distantes. Os resultados mostram que o limite legal de velocidade é mais respeitado no local onde se localizam os radares e um pouco antes dos mesmos. Logo depois dos radares e em pontos distantes, o limite máximo de velocidade é muito menos respeitado. É muito alta a porcentagem de veículos que passam pelos radares com velocidade acima do limite legal mais a tolerância de 7km/h (8,4%), e que, portanto, cometem infração e deveriam ser multados. Claramente, a abrangência espacial dos radares fixos no sentido de reduzir as velocidades é limitada a um pequeno segmento localizado, na sua maior parte, imediatamente antes dos mesmos. A evolução dos índices de acidentes mostra que não houve melhoria na segurança com a colocação dos radares nos segmentos localizados no entorno dos mesmos. Praticamente todos os índices apresentaram crescimento. Isso também acontece quando se analisa a evolução dos índices de acidentes ao longo de toda a extensão do trecho de rodovia estudado, pois todos os índices experimentaram crescimento / In this work the impact of the use of fixed radars in the speed and in the analysis of accidents in the segment between the Km 153,350 and the km 227,800 of the Washington Luís Highway is evaluated - SP-310 (extension of 74,450 km), located in the interior of the state of São Paulo and whose concession belongs to the Centrovias company. The evaluation of the impact in the speed and in the analysis of accidents was carried out in short segments situated around of the radars and in all the extension of the segment. The measurements of speed had been done in the points where the fixed radars were located, in points near (about of 2km before and 2km after) and in distant points. The results show that the legal limit of speed is more respected in the place where the radars are located and just before them. Soon after the radars and in distant points, the maximum limit of speed is much less respected. The percentage of vehicles that pass by the radars with speed above of the legal limit plus the tolerance of 7km/h (8,4%), is very high, resulting in infraction that should be fined. Clearly, the use of the fixed radars intending to reduce the speeds is limited to a small segment located, normally immediately before them. The evolution of the indices of accidents shows that did not have improvement in the security using radars in the segments located near them. Practically all the indices had presented growth. This also happens when it is analyzed the evolution of the indices of accidents in all the extension of the studied segment of highway, because all the indices had growth
232

O contemporâneo: uma leitura através do grafite e da moda / The contemporary: a read through graffiti and fashion.

Natália Alves de Toledo 24 June 2014 (has links)
O objetivo deste trabalho é verificar como a arte e a moda, representam o cotidiano no contemporâneo, principalmente no que diz respeito à crítica ao sistema vigente, a representação do instante formador do cotidiano e da apropriação da arte pelo consumo. Por necessidade de um recorte metodológico as Artes de Muro também conhecidas como Grafites foram escolhidas como fenômeno de observação por ser uma arte pública e de fácil acesso a maioria dos indivíduos que interagem com o espaço urbano. Observa-se que embora a Arte de Muro seja em sua maioria uma crítica aos moldes impostos pelo sistema, ela acaba por ser aglutinada por ele e transformada em bens de consumo de alto valor. / The objective of this work is to see how art and fashion, represent the everyday in contemporary, especially with regard to the criticism of the current system, the representation of time trainer every day and appropriation of art by consumption. On the need for a methodological approach for the Arts also known as Wall Graffiti were chosen as a phenomenon of observation to be a public and easily accessible to most individuals who interact with the urban space art. It is observed that although the Art Wall is mostly a critique of the molds imposed by the system, it turns out to be bonded by it and transformed into consume high value goods.
233

Linearização suave de pontos fixos hiperbólicos / Smooth linearization of hiperbolic fixed points.

José Humberto Bravo Vidarte 26 March 2010 (has links)
Neste trabalho tem por objetivo a construção de conjugações suaves de pontos fixos hiperbólicos com condições de não ressonância. Por tanto, inicialmente são apresentados alguns conceitos básicos sobre espaços de Banach e alguns resultados de equações diferenciais ordinárias em espaços de Banach e sistemas dinâmicos, apresentamos o teorema de Hartman Grobman como motivação inicial de Linearização. Apresentamos também vários exemplos como motivação para estudar o Teorema de Sternberg para contrações hiperbólicas, o principal resultado estudado nesta dissertação para contrações hiperbólicas / This work has the objetive of building smooth conjugations of hyperbolic fixed points with non-resonance conditions. So, first we present some basics of Banach spaces and some results of ordinary differential equations in Banach spaces and dynamical systems, we present the theorem of Hartman Grobman as original motivation for linearization . We also present several examples as motivation to study the Sternberg theorem for hyperbolic contractions, as main result studied in this dissertation
234

Estudo numérico e experimental do armazenamento de energia por calor latente em um leito fixo / Numerical and experimental study of energy storage for latent heat in a fixed bed

Moraes, Raykleison Igor dos Reis 20 August 2018 (has links)
Orientador: Kamal Abdel Radi Ismail / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T09:32:00Z (GMT). No. of bitstreams: 1 Moraes_RaykleisonIgordosReis_D.pdf: 4245831 bytes, checksum: 07427cc907cc6cf8690c510c3dd14a1c (MD5) Previous issue date: 2012 / Resumo: O presente trabalho consiste na investigação numérica e experimental do carregamento de um leito fixo com material de mudança de fase no interior das cápsulas esféricas. O modelo matemático é baseado na equação da energia e a solução obtida com a técnica numérica em diferenças finitas com o esquema da malha móvel. O acoplamento do fluido de trabalho com as cápsulas foi feita utilizando o balanço de energia com o material de mudança de fase, obtendo a temperatura em função do tempo e da posição no leito. O modelo desenvolvido mostra os efeitos da temperatura de entrada, vazão mássica, diâmetro da cápsula esférica, material das cápsulas, tempo de carregamento e altura do armazenado. A Validação e otimização dos resultados foi feita com base nos resultados experimentais apresentados. As equações empíricas apresentadas podem ser ferramentas úteis como forma alternativa nos projetos de armazenadores com erro médio de ± 11% e a incerteza nos dados experimentais para a temperatura é de ± 0,5oC. Todos os resultados são analisados e discutidos / Abstract: The present work is to investigate numerical and experimental and the charging of fixed bed PCM within the spherical capsules. The mathematical model is based on the energy equation and the solution obtained with the numerical technique of finite difference scheme with mesh mobile. The coupling of the working fluid with the capsules was conducted using the energy balance of the phase change material, obtaining the temperature versus time and bed position. The model shows the effects of the inlet temperature, mass flow rate, diameter of the spherical capsule, the capsule material, charging time and the stored height. Validation and optimization of the results was based on experimental results. The empirical equations presented can be useful tools as an alternative projects in storages with average error of 11% and the uncertainty of the experimental data for temperature is 0.5oC. All results are analyzed and discussed / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica
235

Influencia da altura do remanescente coronario e do tipo de retenção intra-radicular na resistencia e modo de fratura de raizes bovinas restauradas com coroas totais

Resende, Cristina do Amparo 24 January 2005 (has links)
Orientador: Luis Roberto Marcondes Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:54:21Z (GMT). No. of bitstreams: 1 Resende_CristinadoAmparo_M.pdf: 828266 bytes, checksum: 67ff65721ab9a2c7931bd0a2be4a3001 (MD5) Previous issue date: 2005 / Resumo: O objetivo deste estudo foi avaliar a influência da altura do remanescente coronário e de diferentes tipos de retenções intra-radiculares na resistência à fratura de raízes bovinas restauradas com coroas totais confeccionadas em resina composta laboratorial nas seguintes condições: ausência de remanescente coronário ou presença de um ou dois milímetros e cinco métodos de retenção intra-radicular. Cento e cinqüenta dentes bovinos foram selecionados padronizando-se as dimensões das raízes. As coroas foram seccionadas e as raízes remanescentes receberam tratamento endodôntico e foram divididas, aleatoriamente, em quinze experimentais (n=10): G1 - pino de fibra de vidro (FV) e 0 mm; G2 - FV e 1 mm; G3 - FV e 2 mm; G4 - pino pré-fabricado metálico (PM) e 0 mm; G5 - PM e 1 mm; G6 - PM e 2 mm; G7 - pino de fibra de carbono (FC) e 0 mm; G8 - FC e 1 mm; G9 - FC e 2 mm; G10 - núcleo metálico fundido (NMF) e 0 mm; G11 - NMF e 1 mm; G12 - NMF e 2 mm; G13 ¿ preenchimento do canal radicular com resina composta (RC) e 0 mm; G14 - RC e 1 mm; G15 - RC e 2 mm. As coroas totais foram cimentadas com cimento resinoso e as raízes foram fixadas em resina poliestirênica, simulando-se o ligamento periodontal com material de moldagem à base de poliéter. As amostras foram submetidas ao carregamento tangencial de compressão, sob um ângulo de 135o a 0,5 mm/min até ocorrer a fratura. Os resultados (ANOVA / Tukey a=0,05) demonstraram que na ausência de remanescente, o grupo RC apresentou os maiores valores de resistência à fratura, não diferindo estatisticamente dos grupos restaurados com FC, FV e PM; o grupo restaurado com NMF apresentou os menores valores médios de resistência à fratura. Na presença de 1 mm de remanescente o grupo PM apresentou os maiores valores de resistência à fratura, não diferindo estatisticamente dos grupos restaurados com FV, NMF e RC e o grupo FC apresentou os menores valores médios. Na presença de 2 mm de remanescente, os diferentes tipos de retenções não promoveram diferenças entre os valores médios de resistência à fratura. Para os grupos restaurados com FV, FC e NMF, a altura do remanescente não influenciou nos resultados. Para os grupos PM, a altura de 1 mm proporcionou os maiores valores de resistência à fratura e o grupo com 2 mm de remanescente apresentou os menores valores. No grupo RC, a ausência de remanescente dental coronário promoveu os melhores resultados e o grupo com 1 mm de remanescente apresentou os piores resultados. A análise geral dos padrões de fratura demonstrou que 68% das fraturas atingiram os terços apical ou médio. Os grupos restaurados com pinos de fibra de vidro apresentaram os melhores padrões de fratura, enquanto os restaurados apenas com resina composta apresentaram os piores padrões de fratura / Abstract: The purpose of this study was to evaluate the influence of dental coronal structure height and different types of intraradicular retention on the fracture strength of bovine roots restored with total crowns made of laboratory composite resin under the following conditions: absence of dental coronal structure or presence of one or two millimeters, and five methods of intraradicular retention. One hundred fifty bovine teeth were chosen and the canal size was standardized. The crowns were sectioned and the canals were treated endodontically and the specimens distributed randomly into 15 experimental groups: G1 ¿ fiberglass post (FV) and 0 mm; G2 ¿ FV and 1 mm; G3 ¿ FV and 2 mm; G4 ¿ prefabricated metal post (PM) and 0 mm; G5 ¿ (PM) and 1 mm; G6 ¿ (PM) and 2 mm; G7 ¿ carbon fiber post (FC) and 0 mm; G8 ¿ (FC) and 1 mm; G9 ¿ (FC) 1 mm; G15 ¿ RC and 2 mm. Total crowns were luted with resin cement and the roots were fixed in resin blocks and artificial periodontal ligament was simulated with casting material made of polyether. The specimens were submitted to compressive strength test at 135o and 0.5 mm/min until fracture occurred. The results (ANOVA / Tukey a=0.05), showed that in absence of dental coronal structure, the group RC presented the most fracture strength values, not differing statistically from groups restored by FC, FV and PM, and the group restored by NMF presented the lowest mean values. In the presence of 1 mm, Group PM presented the highest fracture strength values, not differing statistically from groups restored by FV, NMF and RC, and the group restored by FC presented the lowest mean values. In the presence of 2 mm, the different types of intraradicular retentions did not cause differences among mean fracture strength values. In the groups restored by FV, FC and NMF, the dental coronal structure height had no influence on the results. In the PM group, the height of 1 mm, showed the highest and the group with 2 mm presented the lowest mean values. In the group RC the absence of dental coronal structure showed the best results and the group with 1 mm presented the worst results. The general fracture pattern analysis showed that 68% of fractures involved the gingival and apical thirds. The groups restored by FV showed the best fracture patterns, and the groups restored by RC, the worst / Mestrado / Dentística / Mestre em Clínica Odontológica
236

Analytical and empirical models of online auctions

Ødegaard, Fredrik 11 1900 (has links)
This thesis provides a discussion on some analytical and empirical models of online auctions. The objective is to provide an alternative framework for analyzing online auctions, and to characterize the distribution of intermediate prices. Chapter 1 provides a mathematical formulation of the eBay auction format and background to the data used in the empirical analysis. Chapter 2 analyzes policies for optimally disposing inventory using online auctions. It is assumed a seller has a fixed number of items to sell using a sequence of, possibly overlapping, single-item auctions. The decision the seller must make is when to start each auction. The decision involves a trade-off between a holding cost for each period an item remains unsold, and a cannibalization effect among competing auctions. Consequently the seller must trade-off the expected marginal gain for the ongoing auctions with the expected marginal cost of the unreleased items by further deferring their release. The problem is formulated as a discrete time Markov Decision Problem. Conditions are derived to ensure that the optimal release policy is a control limit policy in the current price of the ongoing auctions. Chapter 2 focuses on the two item case which has sufficient complexity to raise challenging questions. An underlying assumption in Chapter 2 is that the auction dynamics can be captured by a set of transition probabilities. Chapter 3 shows with two fixed bidding strategies how the transition probabilities can be derived for a given auction format and bidder arrival process. The two specific bidding strategies analyzed are when bidders bid: 1) a minimal increment, and 2) their true valuation. Chapters 4 and 5 provides empirical analyzes of 4,000 eBay auctions conducted by Dell. Chapter 4 provides a statistical model where over discrete time periods, prices of online auctions follow a zero-inflated gamma distribution. Chapter 5 provides an analysis of the 44,000 bids placed in the auctions, based on bids following a gamma distribution. Both models presented in Chapters 4 and 5 are based on conditional probabilities given the price and elapsed time of an auction, and certain parameters of the competing auctions. Chapter 6 concludes the thesis with a discussion of the main results and possible extensions. / Business, Sauder School of / Graduate
237

Anaerobic Digestion of Corn Ethanol Thin Stillage for Biogas Production in Batch and By Downflow Fixed Film Reactor

Wilkinson, Andrea January 2011 (has links)
Anaerobic digestion (AD) of corn thin stillage (CTS) offers the potential to reduce corn grain ethanol production energy consumption. This thesis focuses on results collected from AD of CTS at mesophilic temperatures in batch and by down-flow fixed film reactor. Experiments conducted include a series of biochemical methane potential (BMP) assays that investigated the digestion of CTS as the sole carbon source at a variety of food-to- microorganism ratios with and without acclimated biomass, under co-digestion conditions and also with the addition of supplemental nutrients. Additional BMP assays were conducted which investigated the potential to reduce fresh water consumption by using of digested effluent for substrate dilution. Continuous studies employed two 28L down-flow stationary fixed film reactors to examine. Chemical oxygen demand and volatile solids removal efficiencies greater than 85% were achieved up to an organic loading rate of 7.4 g TCOD/L/d and hydraulic retention time of 5 days.
238

Přechod společnosti z IFRS na české účetní předpisy / Transition od company from IFRS compliant reporting to the reporting based on the Czech GAAP

Peřinková, Kateřina January 2015 (has links)
The thesis deals with the topic of the transition from IFRS compliant reporting to the reporting based on the Czech GAAP, which is not sufficiently covered by Czech accounting legislation. Many companies may face these problems in the future, some companies has even had to deal with it, and therefore it is necessary to create rules covering the transition, which the companies would have to follow. The theoretical part focuses on the creation of the rules for the transition of the reporting. The practical part illustrates the transition on selected items of the fixed assets from the financial statements of the company České Dráhy, a. s. Namely the area of tangible fixed assets, e. i. property, plant and equipment, investment property, assets held for sale and assets leased under finance leases and the area of investments in subsidiaries, associates and joint ventures. The last part of the thesis describes the impact of the transition from IFRS compliant reporting to the reporting based on the Czech GAAP on deferred tax.
239

Inte en kvinna till : En empirisk studie gällande korrelationen mellan arbetslöshet och grov kvinnofridskränkning i svenska kommuner.

Stålhane, Agnes, Delilovic, Ines January 2021 (has links)
Uppsatsen undersöker en eventuell korrelation mellan arbetslöshet och antal anmälda fall av grov kvinnofridskränkning i samtliga svenska kommuner. Frågeställningar som ska besvaras är “Finns det en korrelation mellan arbetslöshet och antal anmälda fall av grov kvinnofridskränkning?” samt “Vad kan ett eventuellt samband bero på, för kvinnlig respektive manlig arbetslöshet?”. Arbetets beroende variabel är antal anmälda fall av grov kvinnofridskränkning per 100 000 invånare och oberoende variabel arbetslöshet, vilken kommer att uppdelas mellan kön. Ett antal kontrollvariabler, såsom medianinkomst och eftergymnasial utbildning, kommer även att användas. Tidigare forskning, vilken kommer att behandlas i framställningen, har visat samband mellan arbetslöshet och brottslighet; däremot finns det få studier som är inriktade på just grov kvinnofridskränkning. Resultat från vår studie tyder på att det föreligger en positiv korrelation mellan mäns arbetslöshet och antal anmälda fall av grov kvinnofridskränkning, samt en negativ korrelation mellan kvinnors arbetslöshet och antal anmälda fall av grov kvinnofridskränkning.
240

Effect of Cloud Cover on Optimum Orientations of Fixed Solar Panels for Maximum Yearly Energy Collection

Prasad, Prethew 02 June 2021 (has links)
No description available.

Page generated in 0.0784 seconds