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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.
611

As alterações contábeis na lei das sociedades anônimas em razão da lei nº 11.638/07

Longo, Jônia Koller Di Francesco January 2011 (has links)
Com as alterações no texto da Lei nº 6.404, através da Lei nº 11.638 no que diz respeito, principalmente, a escrituração e elaboração das demonstrações financeiras das sociedades anônimas, culminando em uma padronização internacional em relação as formas de demonstração contábil e seus lançamentos, através de uma abordagem teórica passando pelos órgãos regulamentadores da matéria dentro e fora do Brasil. O que para Hugo Braga e Marcelo Almeida, em sua obra Mudanças Contábeis na Lei Societária (2009), no futuro, ao permitir essa convergência internacional, irá permitir também o benefício do acesso das companhias brasileiras a capitais externos a um custo e taxa de risco menores. Sendo que esta convergência, segundo o autor, contribui ainda para uma maior transparência das informações das empresas, se expondo mais aos investidores internacionais e também ao mercado de um modo geral. / With the changes in the text of Law No. 6404, by Law No. 11,638 with regard mainly to accounting and financial reporting of corporations, culminating in an international standard for forms of financial statement and its release through a theoretical approach past the regulators of the matter inside and outside Brazil. What to Hugo Almeida Braga and Marcelo, in his book Accounting Changes in Corporate Law (2009), in the future to allow this international convergence will also allow the benefit of access of Brazilian companies to foreign capital at a cost and risk rate minors. Since this convergence, according to the author, also contributes to greater transparency of corporate information, is exposed more to international investors and also to the market in general.
612

Modelagem e implementação no ros de um controlador para manipuladores móveis

Barros, Taiser Tadeu Teixeira January 2014 (has links)
Este trabalho apresenta a modelagem matemática para um manipulador móvel composto por uma base móvel (o robô móvel Twil) e um manipulador (o manipulador WAM da Barrett). Os modelos cinemático e dinâmico para a base móvel, manipulador e manipulador móvel são apresentados. Como o manipulador móvel é um sistema não linear, uma estratégia de controle baseada em linearização por realimentação da dinâmica da plataforma seguida por uma transformação não suave para tratar a não holonomicidade do modelo cinemático é proposta. Então o método de backstepping é utilizado para obter as entradas do modelo dinâmico. Um controlador de torque calculado é proposto para o manipulador, Estas técnicas de controle são utilizadas simultaneamente para controlar o manipulador móvel. A implementação dos controladores propostos, na forma de plugins para o gerenciador de controladores é feita no ROS, assim os controladores são executados em tempo real. A maioria dos controladores existentes no ROS são do tipo SISO baseados em controle PID e independentes para cada junta, sendo que neste trabalho controladores MIMO não lineares são implementados. / This work presents a mathematical modelling for a mobile manipulator composed by a mobile base (the Twil mobile robot) and a manipulator (the Barrett WAM manipulator). The kinematic and dynamic models for the mobile base, the manipulator and the mobile manipulator are presented. As the the mobilie manipulator is a non-linear system, a control strategy based on feedback linearization of the platform dynamics followed by a non-smooth transform to handle the non-holonomicity of its kinematic model is proposed. Then, the backstepping method is used to obtain the inputs for the dynamic model. A computed torque controller is proposed for the manipulador. These control techniques are used simultaneously to control the mobile manipulator. The implementation of the proposed controllers is done in ROS as plugins for the controller manager so that the controllers run in real-time. Most controllers existing in ROS are independent joint SISO controllers based on the PID control law while in this work MIMO non-linear controllers are implemented.
613

Desenvolvimento de um modelo matematico mais rigoroso para polimerização radicalar controlada mediada por radicais nitroxido de estireno / Development of more detailed mathematics model for nitroxide mediated living free radical polymerization (NMRP)

Murari, Andre Rodriguez 12 August 2018 (has links)
Orientador: Liliane Maria Ferrareso Lona / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T15:03:00Z (GMT). No. of bitstreams: 1 Murari_AndreRodriguez_M.pdf: 5474993 bytes, checksum: f934f6e9ffbfd4a8b75be2db5f8df523 (MD5) Previous issue date: 2007 / Resumo: A polimerização radicalar livre controlada - LFRP ("Living Free-Radical Polimerization") tem sido alvo de muita atenção nos últimos anos, pois permite obter polímeros com uma microestrutura altamente controlada, ou seja, com uma distribuição de pesos moleculares médios estreita e polidispersidade (PDI) perto de uma unidade, e com estruturas moleculares complexas (por exemplo: copolímeros bloco puros), com diversas arquiteturas complexas e com funcionalidades variadas. A polimerização iônica também gera microestruturas controladas, contudo as condições de reação para a polimerização iônica requerem elevadas purezas, o que torna inviável economicamente suas aplicações em alguns processos industriais. A polimerização radicalar livre controlada mediada por radicais nitróxido - NMRP ("Nitroxide-Mediated Living Free-Radical Polymerization") é uma das técnicas da LFRP, sendo que é mais robusta às impurezas comparada com a polimerização iônica. Muitos pesquisadores têm desenvolvido modelos cinéticos para predizer o comportamento da NMRP, sendo que muitos deles não consideram em seus modelos os efeitos difusionais. Entretanto, seu mecanismo ainda não é totalmente conhecido. Acredita-se que existam outras reações paralelas não previstas nos mecanismos apresentados em literatura. Isso explicaria o fato de o modelo predizer conversões máximas de 100 %, enquanto que experimentalmente conversões menores são obtidas no final da reação; de alguns modelos serem insensíveis à razão do controlador/iniciador; dos modelos subestimarem os valores de pesos moleculares médios. Neste trabalho buscou-se uma compreensão maior do mecanismo cinético dos processos NMRP através do uso de um modelo matemático que considera a polimerização controlada do estireno usando TEMPO (2,2,6,6-tetrametil-1-piperidinoxil) como controlador e BPO (peróxido de benzoíla) como iniciador químico. Para isso, o problema foi abordado em três frentes: A primeira abordagem assume que existam efeitos difusionais ocorrendo no processo NMRP. Estes efeitos difusionais são extremamente importantes nas polimerizações radicalares convencionais (FRP - Free-Radical Polimerization), mas não foram considerados nos primeiros modelos da NMRP reportados na literatura. Com o passar dos tempos alguns autores começaram a considerar este efeito. Apesar dos muitos artigos publicados nessa área, ainda há muitas controvérsias sobre a existência ou não de efeitos difusionais nos processos NMRP. A primeira contribuição deste trabalho é elucidar este fato, com a proposta de novas correlações que predigam os efeitos difusionais na NMRP do estireno e que possuam embasamento teórico (teoria do volume livre). Correlações empíricas e semi-empíricas (baseadas na teoria de volume livre) usadas tanto na FRP quanto na LFRP foram testadas para NMRP do estireno em um modelo matemático da literatura. Algumas delas baseadas na teoria de volume livre foram modificadas com parâmetros estimados que melhor se ajustassem no sistema de estudo. A segunda abordagem desenvolvida neste trabalho faz um estudo paramétrico de todas as constantes cinéticas utilizadas no modelo. Foi observado que os parâmetros das constantes cinéticas divergem muito na literatura (algumas vezes apresentam ordens de grandezas diferentes). Esta segunda etapa do trabalho visa não somente um melhor ajuste do modelo, mas também identificar as etapas mais importantes e inferir sobre a possibilidade de existirem etapas não consideradas no mecanismo cinético. A terceira abordagem considera estar presente uma reação irreversível entre o controlador e o iniciador químico, etapa esta, não considerada nos modelos matemáticos apresentados na literatura. Na literatura, é descrita uma reação irreversível no início da polimerização do estireno entre o controlador TEMPO e o iniciador químico BPO. Baseado nesta informação introduziu-se um fator de eficiência o controlador - fc, análogo ao já consolidado fator de eficiência do iniciador - f, e estimou-se fc de modo a melhorar a aderência do modelo aos dados experimentais. Foi possível observar uma melhora significativa no ajuste com a introdução do fator de eficiência do controlador. Desta forma, pôde-se mostrar que reações laterais irreversíveis na etapa de iniciação são significativas. Observou-se também, que as correlações semi-empíricas baseadas na teoria do volume livre não melhoram significativamente o modelo, o que pode ser mais um indício de que os efeitos difusionais em NMRP são muito pouco expressivos, contrariando alguns trabalhos de literatura. / Abstract: Living Free-Radical Polymerization (LFRP) has been target of much attention in the last years, because it allows getting polymers with a highly controlled microstructure, with narrow distribution of the average molecular weights and polydispersity (PDI) close to unit, and with complex molecular structures (e.g. pure block copolymers), with different architectures with complex and varied functionality. Ionic polymerization also generates controlled microstructure, however the reaction conditions for ionic polymerization demand high pureness, what makes economically impracticable its the application in some industrial processes. Nitroxide Mediated Living Free Radical Polymerization (NMRP) is one of alternative techniques of the LFRP, which is more robust for impurities compared to the ionic polymerization. Many researchers have developed kinetic models that predict the behavior of the NMRP. However, its mechanism is not yet fully known. It is believed that there are other parallel reactions not foreseen in the mechanisms presented in literature. This explains the fact that the model predict conversions maximum of 100 %, whereas experimentally lower conversions are obtained at the end reaction; some models are insensitive to the controller/initiator rate; of the models under predict average molecular weights. It was intended a greater kinetic mechanism understanding of NMRP processes through the use of a mathematical model which considers the controlled polymerization of styrene using TEMPO (2,2,6,6 - tetramethyl-1-piperidinoxyl) as controller and BPO (benzoil peroxide) as a chemical initiator. Therefore, the problem has been addressed on three fronts: The first approach assumes that there are diffusional effects occurring in the NMRP process. The diffusional effects are extremely important in Free-Radical Polymerization - FRP, but were not considered in the NMRP first models reported in the literature. After a while, some authors have started to consider them. Despite the many articles published in this area, there are still many controversies over the existence or not of diffusional effects in NMRP; therefore the first contribution of this work is to elucidate this fact, with the proposed new correlations that predict the diffusional effects in NMRP of styrene with theoretical basement (the free volume theory). Empirical correlations and semi-empirical (based on the free volume theory) used both in FRP as in LFRP were tested for NMRP of styrene in a mathematical model of literature. Some of them (based in the free volume theory had been modified with new estimated parameters that better were adjusted in the study system. The second approach developed in this work makes a parametric study of all rate kinetic constants used in the model. It was observed that the kinetic constants parameters differ quite in the literature (sometimes have different magnitude orders). This second work phase aims not only a better model fit, but also identify the steps most important and infer the possibility of any steps not considered in the kinetic mechanism. The third approach considers being present a reaction between the controller and irreversible chemical initiator, this stage, not considered in the mathematical models presented in the literature. In the literature, is described a reaction irreversible in the beginning of styrene polymerization between the controller - TEMPO and chemical initiator - BPO. Based on this information, has been inserted a controller efficiency factor - fc, similar to that already consolidated factor in the initiator efficiency - f, and it was estimated in order to improve the agreement between the model and experimental data. It was possible to observe expressive agreement with experimental data using this factor - fc. In such a way, it could be shown that irreversible side reactions in the stage of initiation are significant, and that the correlations semiempirical based on the free volume theory do not improve the model significantly, which can be more one indication the diffusional effect in NMRP are very little significant, contradicting some works in literature. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
614

Controle de temperatura de um trocador de calor. / Heat exchanger temperature controller.

Denis Fava Cerchiaro 27 April 2006 (has links)
O objetivo do trabalho é apresentar o desenvolvimento, simulação e resultados práticos de um Sistema de controle de temperatura, para Experimentos Biomédicos que utilizam soluções aquecidas com vazão variável. O Sistema utiliza um Trocador de Calor projetado para aquecer uma solução que entra no dispositivo a uma temperatura inferior ou igual à do ambiente e sai com o valor programado. A solução é aquecida a partir da água de um reservatório com temperatura controlada. O Controlador de temperatura é do tipo proporcional-integral-derivativo digital e utiliza um microcontrolador para implementação do algoritmo de controle, da aquisição do sinal dos sensores de temperatura, do comando de atuadores e da interface com o usuário / The objective of the work is to present the development, simulation and practical results of a temperature control System for Biomedical Experiments that utilize heated solutions with variable outflow. The System uses a Heat Exchanger designed to heat the solution that enters into device with a lower or the same temperature as the environment and leaves with the programmed value. The Biomedical solution is heated using the Heat Exchanger and water of the reservoir where the temperature is controlled. The digital proportional-integral-derivative temperature Controller takes use of a microcontroller for implementation of the control algorithm, data acquisition of the temperature sensors, command of actuators and user interface
615

[en] OPTIMAL LOCATION OF SENSORS AND CONTROLLERS IN DISTRIBUTED SYSTEMS / [pt] LOCALIZAÇÃO ÓTIMA DE SENSORES E CONTROLADORES EM SISTEMAS DISTRIBUÍDOS

HELIOS MALEBRANCHE OLBRISCH FRERES FILHO 24 January 2008 (has links)
[pt] Nesta tese é considerada a localização ótima de sensores (LOS) e controladores (LOC) em sistemas dinâmicos de parâmetros distribuídos (SPD) governados por equações diferenciais parciais. Uma discussão dos problemas de Identificação de Sistemas, Estimação de Estado, e Controle Ótimo, para sistemas de dimensão infinita, antecede o desenvolvimento de um exemplo ilustrativo da localização ótima de sensores e controladores num problema de controle ótimo. A contribuição original deste trabalho consiste na elaboração de um survey sobre LOS e LOC para SPD. Uma revisão geral dos diversos métodos discutidos na literatura corrente é apresentada. Esses métodos são então classificados de acordo com suas respectivas particularidades e agrupados segundo a técnica utilizada na LOS e LOC. Uma avaliação crítica da área de pesquisa é então desenvolvida seguindo a classificação proposta neste trabalho. / [en] In this thesis the optimal sensors (OSL)and controllers (OCL) location is considered for dynamical distributed parameter systems (DPS) governed by partial differential equations. The problems of system Identification, State Estimation, and Optimal Control for infinite dimenional systems are discussed; thus following an ilustrative example for the optimal sensors and controllers location applied to an optimal control problem. Te original contribution in this work concerns the presentation of a survey on OSL and OCL for DPS. A general review of the several methods discussed in the current literature is presented. These methods are then classified according to their respective particularities, and they are grouped in accordance with the techniques used in the OSL and OCL problems. A critical evaluation in the fiels is developed in the light of the classification proposed here.
616

Less is More : Experiences of abandoning the budget

Pavlova, Julia, Skogqvist, Fredrika January 2017 (has links)
The budget is widely criticised for consuming time and resources without adding sufficientvalue, however, it is undeniably one of the most important tools for planning andcoordination. This case study examines a company that has abandoned the budget andreplaced it with new planning and forecasting processes to achieve a dynamic process with aforward-looking mentality and less focus on details. The objective of the study is toinvestigate the experiences of the new processes and how the ways of working have beenaffected from a management accounting change perspective, with a focus from thecontroller’s perspective. The changed planning processes are conceptualised as a part of theorganisation’s rules and routines.The findings showed that the purpose of the new processes was unclear in some respects,and although the new rules were accepted, many old routines had not yet changed.Perceived lack of system support combined with a conviction that certain aspects of the oldprocesses were essential to perform qualitative work, are two explanatory factors. The levelof detail had decreased in many aspects, but time has not yet been freed up for thecontrollers in favour of value-adding activities.
617

Optimization Techniques For an Artificial Potential Fields Racing Car Controller

Abdelrasoul, Nader January 2013 (has links)
Context. Building autonomous racing car controllers is a growing field of computer science which has been receiving great attention lately. An approach named Artificial Potential Fields (APF) is used widely as a path finding and obstacle avoidance approach in robotics and vehicle motion controlling systems. The use of APF results in a collision free path, it can also be used to achieve other goals such as overtaking and maneuverability. Objectives. The aim of this thesis is to build an autonomous racing car controller that can achieve good performance in terms of speed, time, and damage level. To fulfill our aim we need to achieve optimality in the controller choices because racing requires the highest possible performance. Also, we need to build the controller using algorithms that does not result in high computational overhead. Methods. We used Particle Swarm Optimization (PSO) in combination with APF to achieve optimal car controlling. The Open Racing Car Simulator (TORCS) was used as a testbed for the proposed controller, we have conducted two experiments with different configuration each time to test the performance of our APF- PSO controller. Results. The obtained results showed that using the APF-PSO controller resulted in good performance compared to top performing controllers. Also, the results showed that the use of PSO proved to enhance the performance compared to using APF only. High performance has been proven in the solo driving and in racing competitions, with the exception of an increased level of damage, however, the level of damage was not very high and did not result in a controller shut down. Conclusions. Based on the obtained results we have concluded that the use of PSO with APF results in high performance while taking low computational cost.
618

Towards Pattern Based Architectural Conformance Checking

Olsson, Tobias January 2016 (has links)
Patterns are a source of knowledge when architecting software systems. They provide abstract and time-tested solutions that show how a system should be structured to achieve needed qualities. However, when developing software there is a chance that small mistakes are introduced in the source code. Over time, these mistakes can accumulate and break the structure of the pattern and its qualities are lost. There are methods that can help find such errors, but none of these provide a pattern abstraction. In this work, we describe a method that raises the level of abstraction from checking individual dependencies to checking key dependencies in the pattern. We implement our method, apply it to check the Model-View-Controller pattern. We show that the method can find architectural problems in real source code and examine how removal of detected erosions affects the source code. We conducted an experiment in a software project setting to determine if using the method affects the number of architectural problems. Some project teams were randomly assigned to use a software service that automated our method. It checked how well their implementation conformed to Model-View-Controller every time they updated the source code. The experiment showed that developers that used the tool had significantly fewer detected architectural problems during the course of the project. Our method makes conformance checking easier to use. This might help increase the adoption of conformance checking in industry.
619

Kravanalys och arkitekturell design av en budgetplaneringsapplikation / Requirements Analysis and Architectural Design of a Budget Planning Application

Edlund, Henrik January 2004 (has links)
This thesis presents the theory behind prototyping and user interviews as parts of requirements analysis. It further discusses how these were used in the development of a budget planning application. The implemented Web-based solution uses a new component-based design rooted in a Model-View-Controller architecture. The application is used today with complete success at the Department of Computer and Information Science at Linköping University.
620

Styrning av grafisk färgdisplay / Control of graphical colour - LCD

Marcus, Lina, Sotiriadis, Epaminondas January 2005 (has links)
This master thesis is a result of the work carried out for Research Electronics at Siljansnäs. The company develops customized electronical systems. Because of the rapidly increasing interest in colour displays there has been a desire within the company to represent information from sensors and electrical systems in a more advanced way. Due to the mentioned reason above we were given the assignment to solve how a colour display using the STN technique works. The technique is used by small displays, the size of QVGA. Our ambition of this diploma work is to develop a fully functionally test prototype to evaluate the LCD (Liquid Crystal Display) and the LCD controller. The most important results from this study is the documentation of how a LCD controller works and how the pixels are addressed. We succeded in showing all the pixels we were able to address at the right place on the LCD wich indicates that there is a compatibility between the LCD and the LCD controller . A replacement of the LCD is recommended because of the difficulties working with it. Precisely wich LCD it should be replaced with is not mentioned in this report because of the extent of the work. One of the aims was to evaluate the function of the LCD, not to find an alternative LCD.When studiyng the LPC2129 and MC68K it emerged that both suits well as controlling units for this application, but an implemention with LPC2129 involves greater diffculties because of the absence of external system bus. Our aim is that this work will function as a starting point to further development leading to a controlling unit in working order, and that it will be implemented in other products the company develops. / Föreliggande rapport behandlar vårt magisterarbete på 20 poäng. Arbetet är gjort åt Research Electronics i Siljansnäs som utvecklar skräddarsydda elektroniksystem. På grund av den ökade efterfrågan av färgdisplayer från marknaden har det länge funnits ett behov av att presentera information från givare och mätinstrument på ett mer avancerat sätt. Av ovan nämnda skäl fick vi i uppdrag att undersöka hur en färgdisplay av typen STN (Super Twist Nematic) fungerar. Det är oftast små displayer som använder den här tekniken. Målet från början var att utveckla en fungerande testprototyp för att testa grafikcontrollern och displayen. De viktigaste resultat som framkommit efter arbetet är en dokumentation på hur en grafikcontroller fungerar och hur adressering av pixlar sker. Vi har visat att det är möjligt att använda den givna grafikcontrollern tillsammans med den display som köpts in då alla pixlar som gick att adressera visats på önskad plats på skärmen. Det finns också en rekommendation av byte till en annan display som är enklare att arbeta med. Exakt vilken anges inte i rapporten eftersom det inte har ingått i arbetet att ta hitta en alternativ display utan att undersöka den befintliga. Studien av mikrocontrollern LPC2129 från Philips och processorn MC68K från Freescale visar att båda är bra för applikationen. LPC2129 blir svårare att arbeta med till följd av att det saknas extern systembuss. Våra förhoppningar är att examensarbetet ska bli en god grund för fortsatt arbete som leder till en färdig produkt, och att den används i övriga tillämpningar i företaget.

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