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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.
1

Semi-biplanes and semi-symmetric designs /

Leonard, Doublas Alan January 1980 (has links)
No description available.
2

Analise de extratos de plantas medicinais pelo metodo de ativacao com neutrons

VAZ, SANDRA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:38:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:47Z (GMT). No. of bitstreams: 1 02753.pdf: 2050243 bytes, checksum: bad09f6ca0af45251626c9a6196f689f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
3

Analise de extratos de plantas medicinais pelo metodo de ativacao com neutrons

VAZ, SANDRA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:38:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:47Z (GMT). No. of bitstreams: 1 02753.pdf: 2050243 bytes, checksum: bad09f6ca0af45251626c9a6196f689f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
4

Resolução de problemas de probabilidade no ensino médio: uma análise de erros em provas da OBMEP no Maranhão / Solving probability problems in high school: one analysis of errors in OBMEP tests in Maranhão

FERREIRA, Thyago Araujo 28 July 2017 (has links)
Submitted by Daniella Santos (daniella.santos@ufma.br) on 2017-11-23T12:47:27Z No. of bitstreams: 1 ThyagoFerreira.pdf: 3641580 bytes, checksum: 3b4d34126632e0ce0039022e1b95aa44 (MD5) / Made available in DSpace on 2017-11-23T12:47:28Z (GMT). No. of bitstreams: 1 ThyagoFerreira.pdf: 3641580 bytes, checksum: 3b4d34126632e0ce0039022e1b95aa44 (MD5) Previous issue date: 2017-07-28 / CAPES / Recognize the problems and central errors completed by High school students in explaining Probability problems is the paper’s main aim. It analyzed errors in OBMEP’s second step - Level 3 between 2015 and 2016 years in Maranh~ao. Therefore, it was elaborated by seven chapters, talking about: a short history and teaching about robability’s studies; The establishing measures of error classification will be analyze in resolution of OBMEP’s mistakes probability tests - Level 3 in 2015 and 2016 years of Maranh~ao and in the most frequent errors types analyzes about probability inquiries. In Cury’s (2008, 2009 and 2010) studies assurances the errors analysis on the students written records, established on the questions analysis of OBMEP’s probability content tests (Public Schools’ Brazilian Mathematics Olympiad) 2015 and 2016 years, from the floating reading steps of all material, union and categorization answers and management results. / O presente trabalho tem por objetivo principal identificar as dificuldades e os principais erros cometidos pelos alunos do Ensino Médio na resolução de problemas de Probabilidade, mediante análise e classificaçãao de erros nas provas da segunda fase da OBMEP { Nível 3 nos anos 2015 e 2016 no estado do Maranhão. Para tanto, está composto de sete capítulos, os quais versar~ao sobre: um breve histórico sobre o desenvolvimento dos estudos acerca da probabilidade, bem como do seu ensino; o estabelecimento dos critérios de classificação de erros a serem analisados nas resoluções dos problemas de probabilidade nas provas da OBMEP { Nivel 3 nos anos 2015 e 2016 no estado do Maranhão e as análises dos tipos de erros mais frequentes nas resoluções de questões de probabilidade. Tendo como principal aporte teórico e metodológico os trabalhos de Cury (2008, 2009 e 2010), os quais garantem a análise de erros sobre os registros escritos dos alunos, a partir da análise de questões que abordaram o conteúdo de probabilidade nas provas da OBMEP (Olimpíada Brasileira de Matemática das Escolas Públicas) dos anos de 2015 e 2016, a partir das etapas de leitura flutuante de todo material, unitarização e categorização das respostas e tratamento dos resultados.
5

Hybrid Solutions for Mechatronics. Applications to modeling and controller design.

Bertollo, Riccardo 10 March 2023 (has links)
The task of modeling and controlling the evolution of dynamical sys- tems is one of the main objectives in mechatronics engineering. When approaching the problem of controlling physical or digital systems, the dynamical models have been historically divided into continuous-time, described by differential equations, and discrete-time, described by difference equations. In the last decade, a new class of models, known as hybrid dynamical systems, has gained popularity in the control community because of its high versatility. This framework combines continuous-time and discrete- time evolution, thus allowing for both the description of a broader class of systems and the achievement of better-performing controllers, compared to the traditional continuous-time alternatives. After the first rigorous introduction of the framework, several Lyapunov-based results were published in the literature, and numerous application areas were shown to benefit from the introduction of a hybrid dynamics, like systems involving impacts or physical systems connected to digital controllers (cyber-physical systems). In this thesis, we use the hybrid framework to study different mechatronics-inspired control problems. The applications we consider are diverse, so we split the presentation into three parts. In the first part we further analyze a particular hybrid control strategy, known as reset control, providing some new theoretical guarantees, together with an application to adaptive control. In the second part we consider two applications of the hybrid framework to the network dynamics field, specifically we analyze the problems of distributed state estimation and of uniform synchronization of nonlinear oscillators. In the third part, we use a hybrid approach to study two applications where this framework has been rarely employed, or not at all, namely smart agriculture and trajectory tracking for a bipedal walking robot. We study these application-inspired problems from a theoretical point of view, giving robust Lyapunov-based stability guarantees. We complement the theoretical analysis with numerical results, obtained from simulations or from experiments.
6

Two-phase slug flow measurement using ultra-sonic techniques in combination with T-Y junctions

Khalifa, K. M. January 2010 (has links)
The accurate measurement of multiphase flows of oil/water/gas is a critical element of oil exploration and production. Thus, over the last three decades; the development and deployment of in-line multiphase flow metering systems has been a major focus worldwide. Accurate measurement of multiphase flow in the oil and gas industry is difficult because there is a wide range of flow regimes and multiphase meters do not generally perform well under the intermittent slug flow conditions which commonly occur in oil production. This thesis investigates the use of Doppler and cross-correlation ultrasonic measurements made in different high gas void fraction flow, partially separated liquid and gas flows, and homogeneous flow and raw slug flow, to assess the accuracy of measurement in these regimes. This approach has been tested on water/air flows in a 50mm diameter pipe facility. The system employs a partial gas/liquid separation and homogenisation using a T-Y junction configuration. A combination of ultrasonic measurement techniques was used to measure flow velocities and conductivity rings to measure the gas fraction. In the partially separated regime, ultrasonic cross-correlation and conductivity rings are used to measure the liquid flow-rate. In the homogeneous flow, a clamp-on ultrasonic Doppler meter is used to measure the homogeneous velocity and combined with conductivity ring measurements to provide measurement of the liquid and gas flow-rates. The slug flow regime measurements employ the raw Doppler shift data from the ultrasonic Doppler flowmeter, together with the slug flow closure equation and combined with gas fraction obtained by conductivity rings, to determine the liquid and gas flow-rates. Measurements were made with liquid velocities from 1.0m/s to 2.0m/s with gas void fractions up to 60%. Using these techniques the accuracies of the liquid flow-rate measurement in the partially separated, homogeneous and slug regimes were 10%, 10% and 15% respectively. The accuracy of the gas flow-rate in both the homogeneous and raw slug regimes was 10%. The method offers the possibility of further improvement in the accuracy by combining measurement from different regimes.
7

Aplicação da AMT para a redução de perdas de matérias-primas e de custos ergonômicos : o caso de uma empresa de componentes de calçados

Cornelli, Renata January 2010 (has links)
Esta dissertação objetivou a avaliação de perdas de matérias-primas em uma empresa de componentes em TPU do setor calçadista do Rio Grande do Sul mas abordou, também, as condições de trabalho sob a ótica do trabalhador e dos especialistas a fim de melhor entender as perdas da empresa e contribuir para a melhoria de todo o processo. O estudo é apresentado em três artigos: o primeiro teve por objetivo principal, após uma revisão da literatura, estudar como os diferentes modelos de sistemas produtivos consideram as perdas de processo, e selecionar uma ferramenta que possa colaborar na redução de perdas de matérias-primas (que causam perdas econômicas) na empresa estudada e que utiliza o método de produção artesanal mas com características também fordistas. Foi selecionado o método de Análise Macroergonômica do Trabalho (AMT) (Guimarães, 2000) por ter, como característica principal, a participação dos funcionários em todas suas etapas, o que é fundamental para a melhoria do processo, principalmente no caso artesanal, já que ele depende do conhecimento tácito dos trabalhadores. O método permitiu a identificação das perdas no processo e sugestões de melhoria das condições de trabalho, apresentadas no artigo 2. O artigo 3 apresenta as melhorias implementadas e os resultados alcançados que acabaram por diminuir as perdas de matérias-primas de 49,17% para 39% . / This work aimed to evaluate losses of raw materials into a components company in the TPU shoe industry of Rio Grande do Sul, but also raised, the working conditions from the perspective of workers and specialists to better understand the demand the company (the losses) but also contribute to improving the entire process. The study is presented in three papers: the first was aimed at following a review of the literature, studying how the different models of production systems consider the loss process, and select a tool that can assist in reducing losses of raw material (which cause economic losses) in the studied company, which uses the method of craft production but also Fordist characteristics. He was selected the method of Macroergonomic Work Analysis (MA) (Guimarães, 2000), having as main characteristic, the participation of employees in all its stages, which is essential for improving the process, especially for small-scale, since it depends on the tacit knowledge of workers. The method allowed the identification of losses in the process and suggestions for improvement of working conditions, outlined in Article 2. Article 3 sets out the improvements implemented and results achieved which ultimately reduce the losses of raw material of 49.17% to 39%.
8

Aplicação da AMT para a redução de perdas de matérias-primas e de custos ergonômicos : o caso de uma empresa de componentes de calçados

Cornelli, Renata January 2010 (has links)
Esta dissertação objetivou a avaliação de perdas de matérias-primas em uma empresa de componentes em TPU do setor calçadista do Rio Grande do Sul mas abordou, também, as condições de trabalho sob a ótica do trabalhador e dos especialistas a fim de melhor entender as perdas da empresa e contribuir para a melhoria de todo o processo. O estudo é apresentado em três artigos: o primeiro teve por objetivo principal, após uma revisão da literatura, estudar como os diferentes modelos de sistemas produtivos consideram as perdas de processo, e selecionar uma ferramenta que possa colaborar na redução de perdas de matérias-primas (que causam perdas econômicas) na empresa estudada e que utiliza o método de produção artesanal mas com características também fordistas. Foi selecionado o método de Análise Macroergonômica do Trabalho (AMT) (Guimarães, 2000) por ter, como característica principal, a participação dos funcionários em todas suas etapas, o que é fundamental para a melhoria do processo, principalmente no caso artesanal, já que ele depende do conhecimento tácito dos trabalhadores. O método permitiu a identificação das perdas no processo e sugestões de melhoria das condições de trabalho, apresentadas no artigo 2. O artigo 3 apresenta as melhorias implementadas e os resultados alcançados que acabaram por diminuir as perdas de matérias-primas de 49,17% para 39% . / This work aimed to evaluate losses of raw materials into a components company in the TPU shoe industry of Rio Grande do Sul, but also raised, the working conditions from the perspective of workers and specialists to better understand the demand the company (the losses) but also contribute to improving the entire process. The study is presented in three papers: the first was aimed at following a review of the literature, studying how the different models of production systems consider the loss process, and select a tool that can assist in reducing losses of raw material (which cause economic losses) in the studied company, which uses the method of craft production but also Fordist characteristics. He was selected the method of Macroergonomic Work Analysis (MA) (Guimarães, 2000), having as main characteristic, the participation of employees in all its stages, which is essential for improving the process, especially for small-scale, since it depends on the tacit knowledge of workers. The method allowed the identification of losses in the process and suggestions for improvement of working conditions, outlined in Article 2. Article 3 sets out the improvements implemented and results achieved which ultimately reduce the losses of raw material of 49.17% to 39%.
9

Aplicação da AMT para a redução de perdas de matérias-primas e de custos ergonômicos : o caso de uma empresa de componentes de calçados

Cornelli, Renata January 2010 (has links)
Esta dissertação objetivou a avaliação de perdas de matérias-primas em uma empresa de componentes em TPU do setor calçadista do Rio Grande do Sul mas abordou, também, as condições de trabalho sob a ótica do trabalhador e dos especialistas a fim de melhor entender as perdas da empresa e contribuir para a melhoria de todo o processo. O estudo é apresentado em três artigos: o primeiro teve por objetivo principal, após uma revisão da literatura, estudar como os diferentes modelos de sistemas produtivos consideram as perdas de processo, e selecionar uma ferramenta que possa colaborar na redução de perdas de matérias-primas (que causam perdas econômicas) na empresa estudada e que utiliza o método de produção artesanal mas com características também fordistas. Foi selecionado o método de Análise Macroergonômica do Trabalho (AMT) (Guimarães, 2000) por ter, como característica principal, a participação dos funcionários em todas suas etapas, o que é fundamental para a melhoria do processo, principalmente no caso artesanal, já que ele depende do conhecimento tácito dos trabalhadores. O método permitiu a identificação das perdas no processo e sugestões de melhoria das condições de trabalho, apresentadas no artigo 2. O artigo 3 apresenta as melhorias implementadas e os resultados alcançados que acabaram por diminuir as perdas de matérias-primas de 49,17% para 39% . / This work aimed to evaluate losses of raw materials into a components company in the TPU shoe industry of Rio Grande do Sul, but also raised, the working conditions from the perspective of workers and specialists to better understand the demand the company (the losses) but also contribute to improving the entire process. The study is presented in three papers: the first was aimed at following a review of the literature, studying how the different models of production systems consider the loss process, and select a tool that can assist in reducing losses of raw material (which cause economic losses) in the studied company, which uses the method of craft production but also Fordist characteristics. He was selected the method of Macroergonomic Work Analysis (MA) (Guimarães, 2000), having as main characteristic, the participation of employees in all its stages, which is essential for improving the process, especially for small-scale, since it depends on the tacit knowledge of workers. The method allowed the identification of losses in the process and suggestions for improvement of working conditions, outlined in Article 2. Article 3 sets out the improvements implemented and results achieved which ultimately reduce the losses of raw material of 49.17% to 39%.
10

Two-phase slug flow measurement using ultrasonic techniques in combination with T-Y junctions

Khalifa, K. M. January 2010 (has links)
The accurate measurement of multiphase flows of oil/water/gas is a critical element of oil exploration and production. Thus, over the last three decades; the development and deployment of in-line multiphase flow metering systems has been a major focus worldwide. Accurate measurement of multiphase flow in the oil and gas industry is difficult because there is a wide range of flow regimes and multiphase meters do not generally perform well under the intermittent slug flow conditions which commonly occur in oil production. This thesis investigates the use of Doppler and cross-correlation ultrasonic measurements made in different high gas void fraction flow, partially separated liquid and gas flows, and homogeneous flow and raw slug flow, to assess the accuracy of measurement in these regimes. This approach has been tested on water/air flows in a 50mm diameter pipe facility. The system employs a partial gas/liquid separation and homogenisation using a T-Y junction configuration. A combination of ultrasonic measurement techniques was used to measure flow velocities and conductivity rings to measure the gas fraction. In the partially separated regime, ultrasonic cross-correlation and conductivity rings are used to measure the liquid flow-rate. In the homogeneous flow, a clamp-on ultrasonic Doppler meter is used to measure the homogeneous velocity and combined with conductivity ring measurements to provide measurement of the liquid and gas flow-rates. The slug flow regime measurements employ the raw Doppler shift data from the ultrasonic Doppler flowmeter, together with the slug flow closure equation and combined with gas fraction obtained by conductivity rings, to determine the liquid and gas flow-rates. Measurements were made with liquid velocities from 1.0m/s to 2.0m/s with gas void fractions up to 60%. Using these techniques the accuracies of the liquid flow-rate measurement in the partially separated, homogeneous and slug regimes were 10%, 10% and 15% respectively. The accuracy of the gas flow-rate in both the homogeneous and raw slug regimes was 10%. The method offers the possibility of further improvement in the accuracy by combining measurement from different regimes.

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