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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.
581

Centralizovaná správa aktivních prvků s využitím Software Defined Networking (SDN) a technologie OpenFlow, včetně zobrazení grafické topologie

TŮMA, Jan January 2016 (has links)
The aim of this master thesis is to create a web-based graphical user interface which communicates with a Software Defined Controller and the OpenFlow protocol to provide a basic network management and a topology graph, then to describe main aspects of the OpenFlow technology and to optimalize the chosen SDN Controller for full support in a multi-vendor enviroment.
582

Model-based Testing of supporting testing of PAC based controlling systems in industrial plants - A case study in printing plants

Fu, Jiangbiao, Song, Jiaqi January 2018 (has links)
Context. Testing is a very critical process to evaluate whether a related function is correctly implemented in the control system. There is an upward trend to using PAC based control system in the automation production context. However, currently, most testing of PAC based controlling system is in manual testing, which has low efficiency and high complexity. Furthermore, there has been little research on the systematic testing of PAC in an industry environment. Objectives. Due to this problem, this study is to investigate whether a model-based testing method can overcome the challenge of manual testing and improve the testing effectiveness in PAC based controlling system. Methods. We use three steps to achieve the objective, and the first one is to implement a systematic mapping study to find existing model-based testing method that is using in the industrial area, what the process and the context. The second one is to implement a case study in a printing house, to see what the real challenge of manual testing, the third one is to find if exist MBT method could be used under such context to overcome challenges. Results. Through mapping study and case study, we found there are many testing methods and implement under diverse context, but none of them focus on the PAC based controlling system. And we found there exist MBT that also can be used in PAC based controlling system to mitigate some manual testing challenges. Conclusions. In our thesis, we implement a mapping study from 38 papers to collect data for existing model-based testing methods to have a deep understanding of this area. We found there are five main contexts that MBT are usually being used and we extract implement process and advantages and disadvantages for MBT methods which value to practitioners and researchers. And we conducted a case study in a printing house in Switzerland to observe the challenges of manual testing of PAC based controlling system. We found one exist MBT method that can be used in our context that makes the test case generation step more effective. And we proposed a simulation testing model that hopefully can address all the manual testing challenges by combined with the exist MBT method.
583

Identificação automática de atrito em atuadores pneumáticos utilizando equipamento de baixo custo / Automatic identification of friction in pneumatic actuators using rig of low cost

Felix, Roger Oliva 27 July 2018 (has links)
Submitted by Roger Oliva Felix (roger.oliva.felix@hotmail.com) on 2018-08-17T18:58:00Z No. of bitstreams: 1 felix_dissertation.pdf: 7309569 bytes, checksum: 90790c5622c5031e74dcc461ccefb15b (MD5) / Rejected by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: 1 - Inserir no corpo do texto a ata de aprovação, pois é um item obrigatório. Agradecemos a compreensão. on 2018-08-21T12:19:26Z (GMT) / Submitted by Roger Oliva Felix (roger.oliva.felix@hotmail.com) on 2018-08-21T12:44:28Z No. of bitstreams: 1 felix_dissertation.pdf: 7309569 bytes, checksum: 90790c5622c5031e74dcc461ccefb15b (MD5) / Approved for entry into archive by Minervina Teixeira Lopes null (vina_lopes@bauru.unesp.br) on 2018-08-21T12:57:04Z (GMT) No. of bitstreams: 1 felix_ro_me_bauru.pdf: 7133378 bytes, checksum: 7876ad942a5467301d81cd82ddae630d (MD5) / Made available in DSpace on 2018-08-21T12:57:04Z (GMT). No. of bitstreams: 1 felix_ro_me_bauru.pdf: 7133378 bytes, checksum: 7876ad942a5467301d81cd82ddae630d (MD5) Previous issue date: 2018-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho aborda o estudo experimental das características não lineares de atrito interno em atuadores pneumáticos. Os atuadores pneumáticos contêm uma tecnologia limpa comparados com os atuadores hidráulicos, ótima relação entre potência e massa suportada, e baixo custo em relação a atuadores elétricos. Também possuem internamente características não lineares que influenciam no controle de um servoposicionador, incluindo principalmente a vedação do êmbolo com o perfil do atuador e a vedação da haste. Portanto, para obter a precisão de posicionamento é necessária uma caracterização do atrito interno. Os métodos utilizados para o desenvolvimento da pesquisa são: investigação do problema de atrito com o modelo LuGre; desenvolvimento do equipamento experimental com um controlador de baixo custo Raspberry Pi; e realização dos experimentos com a identificação automática de atrito em atuadores pneumáticos. Obtendo assim, a visualização gráfica da força de atrito em função da velocidade em regime permanente. A força de atrito em relação aos parâmetros do modelo é calculada em tempo real, possibilitando, dessa forma, a visualização do comportamento da força ao longo do deslocamento do êmbolo do atuador. Os resultados têm a finalidade de verificar as características de atrito do atuador pneumático através dos parâmetros identificados. Desse modo, é possível classificar o atuador pneumático mais adequado para aplicação em sistemas de posicionamento e monitorar o seu desgaste. / This work presents an experimental procedure for determination of the nonlinear characteristics of internal friction of pneumatic actuators. Pneumatic actuators are a clean technology compared to hydraulic actuators, have good relationship between power and supported mass, and low cost compared to electric actuators. They also have nonlinear characteristics which influence the control of the servo positioner, including mainly the piston seal with the intern surface of the pneumatic actuators and rod seal, therefore to get the positioning accuracy it is necessary a good characterization of internal friction. The methods used for the development of the research are: investigation of the friction problem with the LuGre model; development of experimental equipment with a low cost controller Raspberry Pi; and achievement of the experiments with the automatic identification of friction in pneumatic actuators. Thus, it is obtained the graphical visualization of the friction force as a function of the velocity in steady state. The friction force in relation to model parameters is calculated in real time, enabling the visualization of behaviour of pneumatic force along of displacement piston of the actuator. The results have as purpose verify the friction characteristics of the pneumatic actuator using the identified parameters, thus, it is possible to classify the best pneumatic actuator for application in positioning systems and to monitor the your wear.
584

Shedding light on the controller profession : controllers’ value-creation in Swedish organizations

Färm, Josefine, Jönsson, Caroline January 2018 (has links)
Problematization: Financial departments have during the recent years developed due to environmental changes, and so has the controller profession. Controllers are working hard in the shadow of the CFO, together with an unclear definition over their tasks. By shedding light on the controller can their value-creation for the organization be defined. Purpose: The purpose of this research is to examine developments of the controller profession from a Swedish organizational context. Furthermore, this thesis aims to investigate if there is an expansion of the controller professions role, within organizations, that affecting their ability to create value. Methodology: The research has been conducted with a qualitative approach. In this study was 8 interviews performed with controllers in Swedish organizations. This research further examines the controller profession from a general context, in other words, without no specific industry orientation. Findings /conclusions: The findings of this study argue for that there still exist an indistinct definition over the controller profession, thus developments within their role can be confirmed. The traditional view of controllers’ work should therefore be prolonged. Controllers are still just as accountable for financial assignment, the role has however, developed to become involved in most of parts organizations’ businesses and adapted an advisory role. The advancements have made the controller role to a central position with great ability to create value within an organization, yet, to what extend depends on various factors and aspects.
585

Řešení skladového hospodářství na platformě Windows Mobile s integrací do systému SAP

Cyprich, Miroslav January 2015 (has links)
This thesis deals with the creation of an application developed for a real company using Web Dynpro ABAP technology. The application allows devices running on Windows Mobile platform access to SAP warehouse management.
586

Logistický controlling a jeho postavení v řízení podniku / Logistic Controlling And Its Role In Business Management

Šimáně, David January 2016 (has links)
The Master´s thesis focus on evaluation of logistics controlling as a support of logistics process in Škoda Auto a.s. and suggests a solution to company´s logistics controlling case study. Firstly the thesis defines theoretical basics such as enterprise management, controlling and its role in company management, tasks of controller or logistician and specifics of logistics controlling. Then it includes the explanation of Make or Buy method which is used in solving the case study. The practical part analyzes particularities of logistics and its controlling in Škoda Auto. It specifies the main tasks of controlling department of the company especially planning, controlling, analysis of variances, tracking and optimization costs, reporting for the logistics management and other departments. At the end of this section the case study is presented and solved, which is an illustration optimization of logistics costs, which provides logistics controlling. It evaluates practical benefits of logistics controlling within the company´s logistics process and proposes recommendations to increase the efficiency of logistics controlling weaknesses.
587

Controlling a jeho postavení v řízení podniku / Controlling and its position in the management of a company

Viezan, Daniel January 2016 (has links)
This diploma thesis deals with a position of controlling such as a modern instrument of management in particular manufacturing company of GZ Media, a.s. The thesis is divided into more parts. The theoretical part is based on available expert literature. The author of thesis introduces to reader a concept of controlling, its kinds and used instruments in this part. The second part is focused on a basic characteristic and a financial ranking of the chosen company. In the analytic part the productivity and effectiveness of gramophone record is analyzed in the part of production of controlling. The attention is focused on cost type of controlling, such as the calculation system and calculation patterns. There are graphs, charts and schemes used for better orientation. In conclusion of thesis there are summarized analyzes and proposed recommendations for more effective management of the company.
588

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.
589

Estudo de alternativas para o ajuste de controladores PID utilizando métodos baseados em dados

Bergel, Marcus Eduardo January 2009 (has links)
Controladores PID são amplamente utilizados no controle de processos industriais. Estes controladores precisam necessariamente ser ajustados adequadamente a fim de garantir a correta operação do processo controlado. A fim de suprir esta necessidade surgiram os chamados métodos de ajuste para controladores PID, inicialmente propostos por John Ziegler e Nathaniel B. Nichols em 1942. Desde então muitos outros métodos de ajuste baseados nas idéias de Ziegler e Nichols foram propostos, surgindo assim uma família de métodos afins. Em vista da simplicidade de implementação e do consequente baixo custo computacional envolvido, estes métodos mostraram-se adequados para serem incorporados ao firmware de controladores PID industriais de baixo custo. Estes métodos acabaram por gerar um legado tal que sua utilização persiste intensamente até os dias de hoje. No entanto, frente à crescente oferta de microcontroladores de baixo custo e alto desempenho, o custo computacional de um método de ajuste vem perdendo relevância. Isso abre margem para explorar outros métodos que proporcionem melhor desempenho e robustez, mas, por ventura, demandem mais recursos computacionais. Dessa forma, este trabalho propõe-se a avaliar métodos alternativos que sejam compatíveis com os recursos computacionais atuais. Métodos com maior custo computacional, como o Virtual Reference Feedback Tuning (VRFT), Iterative Feedback Tuning (IFT) e Iterative Correlation-based Tuning (ICbT), são apresentados como candidatos para serem incorporados ao firmware de controladores PID industriais. Tratam-se de métodos diretos de ajuste baseado em dados onde os parâmetros do controlador são determinados de forma que o comportamento do sistema em malha fechada seja tal que minimize um critério de desempenho definido a priori. Através deste critério de desempenho pode-se definir o comportamento desejado para o sistema em malha fechada. Neste trabalho são analisadas as principais características destes métodos, resultados obtidos e custo computacional. Com base nos resultados desta análise é mostrado que os métodos VRFT, IFT e ICbT podem ser utilizados como alternativa para o ajuste (incorporado ao firmware) de controladores PID industriais. / PID controllers are widely used in industrial process control. These controllers must necessarily be properly tuned to ensure the correct operation of the controlled process. In order to meet this need, the so-called tuning methods for PID controllers have emerged, initially proposed by John Ziegler and Nathaniel B. Nichols in 1942. Since then many other controller design methods based on the ideas of Ziegler and Nichols have been proposed, giving rise to a family of related methods. Given the simplicity of implementation and the low computational effort involved, these methods are suitable to be incorporated into the firmware of low cost industrial PID controllers. These methods have generated such a legacy that its use remains intense until the present day. However, with the growing offer of low cost and high performance microcontrollers, the computational effort of a tuning method is becoming less important. This opens up scope for exploring other methods that provide better performance and robustness, possibly at the cost of demanding more computational resources. This study aims to evaluate alternative methods that are compatible with current computational resources. Methods with higher computational effort, such as Virtual Reference Feedback Tuning (VRFT), Iterative Feedback Tuning (IFT) and Iterative Correlation based Tuning (ICbT) are presented as candidates to be incorporated into the firmware of industrial PID controllers. These are direct data-based methods for the adjustment of controllers where the parameters are determined such that the behavior of the closed-loop system is such as to minimize a performance criterion defined a priori. Through this performance criterion one can specify the desired behavior for the closed-loop system. This work analyzes the main characteristics of these methods, results and computational effort. Based on the results of this analysis it is shown that the methods VRFT, IFT and ICbT can be used as an alternative to the adjustment (build into the firmware) of industrial PID controllers.
590

Localização de canais afetando o desempenho de controladores preditivos baseados em modelos

Claro, Érica Rejane Pereira January 2016 (has links)
O escopo desta dissertação é o desenvolvimento de um método para detectar os modelos da matriz dinâmica que estejam degradando o desempenho de controladores preditivos baseados em modelos. O método proposto se baseia na análise de correlação cruzada entre o erro nominal do controlador em malha fechada e a uma estimativa da contribuição de cada canal para o cálculo da saída, filtrada pela função de sensibilidade do controlador. Esse método pode ser empregado na auditoria de controladores com variáveis controladas em setpoints e/ou com variáveis que operem entre faixas, como é usual de se encontrar na indústria. Esta dissertação apresenta os resultados da aplicação bem sucedida do método no sistema de quatro tanques (JOHANSSON, 2000), para o qual três cenários foram avaliados. No primeiro cenário, o método localizou corretamente discrepâncias de ganho e de dinâmica de modelos de um controlador preditivo baseado em modelos (Model-based Predictive Controller, ou controlador MPC). No segundo, o método foi utilizado para avaliar a influência de uma variável externa para melhorar o desempenho de um controlador afetado por distúrbios não medidos. No terceiro cenário, o método localizou canais com modelos nulos que deveriam ser incluídos na matriz de controle de um controlador MPC de estrutura descentralizada. Os resultados deste estudo de caso foram comparados com aqueles obtidos pelo método proposto por BADWE, GUDI e PATWARDHAN (2009), constatando-se que o método proposto é mais robusto que o método usado na comparação, não demandando ajustes de parâmetros por parte do usuário para fornecer bons resultados. A dissertação inclui também um estudo de caso da aplicação industrial do método na auditoria de desempenho de um controlador preditivo linear de estrutura descentralizada, com doze variáveis controladas, oito manipuladas e quatro distúrbios não medidos, aplicado a um sistema de fracionamento de propeno e propano em uma indústria petroquímica. A auditoria permitiu reduzir o escopo de revisão do controlador a dezenove canais da matriz, sendo que quatorze destes correspondiam a canais com modelos nulos que deveriam ser incluídos na matriz. A eficácia do método foi comprovada repetindo-se a avaliação da qualidade de modelo para todas as variáveis controladas. / The scope of this dissertation is the development of a method to detect the models of the dynamic matrix that are affecting the performance of model-based predictive controllers. The proposed method is based on the cross correlation analysis between the nominal controller error and an estimate of the contribution of each channel to the controller output, filtered by the controller nominal sensitivity function. The method can be used in the performance assessment of controllers employing variables controlled at the setpoint and/or those controlled within ranges. This dissertation presents the results of the successful application of the method to the quadruple-tank process (JOHANSSON, 2000), for which three scenarios were evaluated. In the first scenario, the method correctly located gain and dynamic mismatches on a model-based predictive controller (MPC controller). In the second one, the method was used to evaluate the influence of an external variable to improve the performance of a controller affected by unmeasured disturbances. In the third scenario, the method located null models that should be included in the dynamic matrix of a decentralized MPC controller. The results of the three scenarios were compared with the ones obtained through the method proposed by BADWE, GUDI e PATWARDHAN (2009). The proposed method was considered more robust than the reference one for not requiring parameters estimation performed by the user to provide good results. This dissertation also includes a case study about the application of the method on the performance assessment of an industrial linear predictive controller of decentralized structure. The controller has twelve controlled variables, eight manipulated variables, and four unmeasured disturbances and is applied to a propylene-propane fractionation system of a petrochemical industry. The performance assessment allowed reducing the scope of the controller revision to nineteen channels of the models matrix, fourteen of which were null models that should be included in the controller. The efficacy of the proposed method was confirmed by repeating the model quality evaluation for all the controlled variables.

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