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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.
401

Gramática de formas e o mobiliário modular multifuncional : um estudo de caso

Schreiner, Fernanda Reis January 2009 (has links)
Esta pesquisa relaciona a teoria da Gramática de Formas (STINY;GIPS, 1972) com os princípios de modulação (HUANG, 2000), para subsidiar um método de antecipação das alternativas de composição capaz de prever a intervenção do usuário. O objeto de investigação, o móvel Vertibral, projetado por Joseph Keenan, é um conjunto de quatro módulos, compostos por 12 requadros lineares de madeira articulados permitindo a interpenetração (WONG,1998) para arranjo entre os módulos. A pesquisa baseia-se na recuperação da gênese do projeto Vertibral a partir de um modelo teórico (associação entre Gramática de Formas e modulação), e seguiu as seguintes etapas: análise do vocabulário do objeto da investigação; identificação e quantificação das relações espaciais possíveis entre dois módulos com a organização de matrizes; exercício de geração de regras formais e arranjos a partir das 232 relações espaciais quantificadas, em relação ao solo quantificadas; e, por último, comparação dos arranjos gerados por participantes do experimento de usabilidade, do tipo Co-discovery (KEMP;GELDEREN, 1996 e DUMAS;REDISH,1993), com relações espaciais quantificadas. A determinação de um método baseado nas etapas deste estudo de caso pode prever a multifuncionalidade para a concepção de um objeto, como o mobiliário. / This research associates the Shape Grammar theory (STINY; GIPS, 1972) to modulation principles (Huang, 2000) as to structure a method for predicting the user’s intervention in modular furniture arrays. The research object, the furniture Vertibral, designed by Joseph Keenan, is constituted by a set of four modules, consisting of 12 wood articulated linear frameworks allowing interpenetration (WONG, 1998) for modules arrangement. The research departs from the retrieval of the Vertibral design principles and follows four steps model: a)object’s vocabulary analysis; b)identification and measurement of possible spatial relationships between two modules with matrices organization; c) generation exercise of formal rules and arrays from 232 computed spatial relations with ground plane reference; and d) comparison of produced arrays made for a usability experiment, according to Co-discovery method (KEMP; GELDEREN, 1996 and DUMAS;REDISH, 1993), with spatial relationships computed. The four stages method seems to have lead to a very high degree of success in creating reliable proxys for multi-functional furniture design.
402

Robôs modulares baseados em agentes mecatrônicos

Cukla, Anselmo Rafael January 2016 (has links)
Nas linhas de montagens industriais, a fim de atender os requisitos de mercado e de ciclo de vida dos produtos, os requisitos de manufatura e as novas tecnologias presentes nos equipamentos indicam a necessidade de reconfiguração e reprogramação do fluxo de processos de forma cada vez mais frequente. Atualmente, uma das opções para implantar um sistema de manufatura flexível, capaz de reagir às mudanças que ocorrem no processo de fabricação, consiste na utilização de tecnologias que forneçam maior flexibilidade, capacidade de reutilização e menor custo. Neste contexto, os robôs baseados em módulos mecatrônicos podem ser uma alternativa em relação aos manipuladores convencionais, pois apresentam uma estrutura cinemática flexível, podendo se adaptar às mudanças das linhas de produção, nas indústrias de manufatura. O presente trabalho apresenta uma proposta para o desenvolvimento de módulos mecatrônicos para a montagem de robôs manipuladores modulares, baseada em um procedimento sequencial composto das seguintes etapas: (a) elaboração do projeto mecânico modular; (b) projeto dos sistemas eletrônicos e de atuação para cada módulo; (c) definição dos agentes mecatrônicos; e (d) descrição dos modelos matemáticos e os algoritmos de comunicação entre módulos mecatrônicos. Nesta pesquisa apresenta-se um estudo no qual os módulos mecatrônicos utilizam energia de origem pneumática e são constituídos por unidades independentes utilizadas na formação de estruturas robotizadas as quais permitem a montagem de diferentes arquiteturas. Um estudo de caso é apresentado para ilustrar a construção de um robô modular cartesiano. Este robô é construído por meio de acoplamentos de módulos mecatrônicos e gerenciado pela associação dos agentes mecatrônicos presentes no sistema, os quais equacionam a cinemática da estrutura formada, planejam a trajetória a ser executada e disponibilizam informações que podem ser utilizadas para o controle, supervisão e proteção do sistema por exemplo. A arquitetura proposta permite a reconfiguração dos recursos de hardware e software, de forma que todos os módulos do robô podem ser reorganizados e/ou substituídos, dependendo da função, aplicação para as quais se destinam. / In industrial manufacturing lines, in order to meet the market requirements and life cycle of manufactured products, the manufacturing requirements and the present of new technologies in equipment, indicate the need for reconfiguration and reprogramming processes, which are becoming more frequent. Currently, one of the options to deploy a flexible manufacturing system that is capable of reacting to changes in the manufacturing process is the use of technologies that provide greater flexibility, reusability and lower cost. In this context, the robots based on mechatronic modules can be an alternative to conventional manipulators, since they have a flexible kinematic structure, which can adapt to the changes in production lines in manufacturing industries. This paper presents a proposal for the development of mechatronic modules for assembly robots modular manipulators, based on a sequential procedure consists of the following steps: (a) Develop a modular mechanical design; (b) design electronic systems and operations for each module; (c) definition of mechatronic agents; and (d) a description of mathematical models and algorithms of the communication between mechatronic modules. This research presents a study where the mechatronic modules use pneumatic energy and consist of independents units used in the formation of robotic structures, thus allowing the assembly of different architectures. In a case study, the construction of a modular Cartesian robot is presented. This robot is built by mounting the mechatronic modules and is managed by mechatronic agents present in the system (Multi-Agent System). This system obtains the kinematic equations of the formed structure, realize the path planning, and provide information that can be used for the control, like supervision and protection system for example. The proposed architecture allows reconfiguration of hardware and software resources, so that all robot modules can be rearranged and/or replaced, depending on the function or, the final application.
403

Studies in Nuclear Energy: Low Risk and Low Carbon

Ford, Michael J. 01 May 2017 (has links)
The amount of greenhouse gas emissions mitigation required to prevent the most dramatic climate change scenarios postulated in the 2014 IPCC Synthesis Report is substantial. Prior analyses have examined the potential for nuclear energy to play a role in decarbonizing the energy sector, one of the largest contributors to emissions worldwide. However, advanced, non-light water reactors, while often touted as a viable alternative for development, have languished. Large light water development projects have a repeated history of extended construction timelines, re-work delays, and significant capital risk. With few exceptions, large-scale nuclear projects have demonstrated neither affordability nor economic competitiveness, and are not well suited to nations with smaller energy grids, or to replace fossil generation in the industrial process heat sector. If nuclear power is to play a role in decarbonization, new policy and technical solutions will be needed. In this manuscript, we examine key aspects of past performance across the nuclear enterprise and explore the future potential of nuclear energy worldwide, focusing on policy and technical solutions that may be needed to move nuclear power forward as a part of a low-carbon energy future. We do so first at a high level, examining the history of nuclear power research and development in the United States, the nation that historically has led the way in the development of this generating technology. A significant portion of our analysis is focused on new developments in this technology – advanced non-light water reactors and small modular reactors. We find that while there are promising technical solutions available, improved funding and focus in research and new models of deployment may be needed if nuclear is to play a continuing or future role. We also find that in examining potential new markets for the technology, a continuing focus on institutional readiness is critical.
404

Development of MRI-compatible transducer array for focused ultrasound surgery : the use of relaxor-based piezocrystals

Qiu, Zhen January 2014 (has links)
Focused ultrasound surgery (FUS) is considered as a promising approach for treating cancer and other conditions and is gaining increasing interest. However, the limited availability of experimental ultrasound array sources and multichannel electronics able to drive them hinder the research into FUS system configurations for patient conditions such as breast cancer. The work in this dissertation explored the development of ultrasound arrays for MRI guided FUS, from the point of view of the potential piezoelectric material of choice. Two materials are of particular interests in this work: Binary (x)Pb(Mg1/3Nb2/3) O3 - (1-x)PbTiO3 (PMN-PT) piezocrystal, and newly specialized FUS material, PZ54 ceramic. A characterization methodology was developed to fully characterize the materials of choice, under ambient and extreme conditions relevant to FUS applications. Practicalities of adopting these materials into FUS were studied by using the characterized materials in designing and fabricating FUS arrays. A spherical, faceted array geometry inspired by the geodesic dome structure was proposed and implemented for the first time. Four bespoke devices, each with 96 individual elements, were implemented using PZ26 ceramic, PZ26 composite, PZ54 composite and PMN-PT composite materials, respectively for comparison. The arrays were connected to commercial electronics afterwards, to explore a prototyping route for connecting FUS devices and modular driving systems. It is concluded that PMN-PT piezocrystal and PZ54 ceramic material can offer excellent performance over conventional piezoelectric ceramics, although PMN-PT piezocrystal is sensitive to extreme conditions. The usable range of PMN-PT is suggested to be limited to 60°C in temperature and 10 MPa in pressure. However, PMN-PT piezocrystal could still be a potential alternative to conventional ceramics in FUS application if assisted with sufficient cooling circulation and bias field. The geodesic array geometry is also concluded to be able to achieve good focusing of ultrasound beam. With optimized phase control through multi-channel electronics, the focusing was improved with focusing gain up to about 30; the steering range of focus was explored within a volume of 5 x 5 x 10 mm3 beyond the array’s geometric focus, side lobes were limited to below the level of -9 dB in acoustic intensity. Larger numbers of individual controllable elements and alternative array designs will be explored in future to investigate application such as breast cancer treatment and potential pre-clinical trials.
405

Pásový podvozek lesního vyvážecího stroje / Tracked chassis of a forwarder

Svoboda, Jan January 2016 (has links)
The thesis describes the design of a modular track undercarriage system for a forest utility vehicle called the forest forwarder. In the introduction there is a research study which reviews a variety of design options. The main part of the thesis describes the 3D model created in the Catia V5 programme. The model was subjected to an analysis of dynamic effects by simulated use of the track undercarriage system in the MSC Adams programme. A selected part of the undercarriage was analyzed by the finite element method in the Ansys Workbench programme. Drawing documentation of some of the components is included at the end of the thesis.
406

The Arithmetic of Modular Grids

Molnar, Grant Steven 01 July 2018 (has links)
Let Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic weight modular forms with poles only at the cusp (∞), and let widehat Mk(∞) (Gamma, nu) subseteq Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic modular forms in Mk(∞) (Gamma, nu) which vanish at every cusp other than (∞). We construct canonical bases for these spaces in terms of Maass--Poincaré series, and show that the coefficients of these bases satisfy Zagier duality.
407

Caractetrização de operadores modulares implementados em FPGA

Fernandes, Armando Filipe Carvalhido January 2010 (has links)
Tese de mestrado integrado. Engenharia Electrotécnica e de computadores. Faculdade de Engenharia. Universidade do Porto. 2010
408

Designing an Autonomous Helicopter Testbed: From Conception Through Implementation

Garcia, Richard D 22 January 2008 (has links)
Miniature Unmanned Aerial Vehicles (UAVs) are currently being researched for a wide range of tasks, including search and rescue, surveillance, reconnaissance, traffic monitoring, fire detection, pipe and electrical line inspection, and border patrol to name only a few of the application domains. Although small / miniature UAVs, including both Vertical Takeoff and Landing (VTOL) vehicles and small helicopters, have shown great potential in both civilian and military domains, including research and development, integration, prototyping, and field testing, these unmanned systems / vehicles are limited to only a handful of university labs. For VTOL type aircraft the number is less than fifteen worldwide! This lack of development is due to both the extensive time and cost required to design, integrate and test a fully operational prototype as well as the shortcomings of published materials to fully describe how to design and build a "complete" and "operational" prototype system. This dissertation overcomes existing barriers and limitations by describing and presenting in great detail every technical aspect of designing and integrating a small UAV helicopter including the on-board navigation controller, capable of fully autonomous takeoff, waypoint navigation, and landing. The presented research goes beyond previous works by designing the system as a testbed vehicle. This design aims to provide a general framework that will not only allow researchers the ability to supplement the system with new technologies but will also allow researchers to add innovation to the vehicle itself. Examples include modification or replacement of controllers, updated filtering and fusion techniques, addition or replacement of sensors, vision algorithms, Operating Systems (OS) changes or replacements, and platform modification or replacement. This is supported by the testbed's design to not only adhere to the technology it currently utilizes but to be general enough to adhere to a multitude of technology that have yet to be tested. This research will allow labs without the proper expertise to build a safe and reliable vehicle that can provide them access to real world data thus increasing the effectiveness and validity of their research. It will also allow researchers working in simulation to quickly enter into UAV development without utilizing thousands of man hours to create an unmanned vehicle. The presented research is designed to benefit the entire UAV researching community by allowing in depth access to an area of research that has been typically classified as too expensive and too time consuming to enter.
409

USING MODULAR ARCHITECTURES TO PREDICT CHANGE OF BELIEFS IN ONLINE DEBATES

Aldo Fabrizio Porco (7460849) 17 October 2019 (has links)
<div> <div> <div> <p>Researchers studying persuasion have mostly focused on modeling arguments to understand how people’s beliefs can change. However, in order to convince an audience the speakers usually adapt their speech. This can be seen often in political campaigns when ideas are phrased - framed - in different ways according to the geo-graphical region the candidate is in. This practice suggests that, in order to change people’s beliefs, it is important to take into account their previous perspectives and topics of interest. </p><p><br></p> <p>In this work we propose ChangeMyStance, a novel task to predict if a user would change their mind after being exposed to opposing views on a particular subject. This setting takes into account users’ beliefs before a debate, thus modeling their preconceived notions about the topic. Moreover, we explore a new approach to solve the problem, where the task is decomposed into ”simpler” problems. Breaking the main objective into several tasks allows to build expert modules that combined produce better results. This strategy significantly outperforms a BERT end-to-end model over the same inputs. </p> </div> </div> </div>
410

Sustainable Neighbourhood Design in Jakobsgårdarna, Borlänge

Turk, Suheyla January 2019 (has links)
Energy efficient houses benefit communities not only to provide renewable energy shares and generating surplus electricity supporting local economic development. Also, residents in energy efficient houses have less energy usage that reduces household budget expenses. However, one of the obstacles of energy efficient technology installment of residential buildings is high investment cost, which can be solved with the usage of modular housing. In Europe, housing costs have a large share, especially for Sweden, housing expenses is a burden mostly for people who are at the risk of poverty. Also, high investment costs of energy efficient housing are combined with high construction prices leading a large share of budgets and effort to make houses affordable for low income groups. This study develops a scenario to find solutions for affordable housing problem in Sweden with a design proposal. The aim of this study is to investigate if there are ways of achieving socio-economic mix by the production of energy efficient affordable housing and urban gardening to develop a strategy for resource efficiency in Jakobsgårdarna. To achieve the aim, energy efficient affordable housing designed as modular units to achieve a local economic development. This study uses a design-based research method consisting of learning from background cases to transfer lesson learned in design phase of the sustainable neighborhood consisting of energy efficient technologies. Background cases were analyzed with literature review to define sustainable neighborhood, which was then used to develop a hypothesis. Findings of this thesis generates definition of sustainability tools consisting of a collaborative ownership; designing common kitchens; producing electricity and biogas from renewable energy sources; practicing urban agriculture; managing waste and storm and methods to cross subsidize energy efficient affordable housing production. The outcome of this research provides a sustainable neighborhood design proposal for Jacobsgårdarna, Borlänge.

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