Controle preditivo robusto baseado em desigualdades matriciais lineares aplicado a um sistema de tanques acoplados

This work deals with an on-line control strategy based on Robust Model Predictive Control (RMPC) technique applied in a real coupled tanks system. This process consists of two coupled tanks and a pump to feed the liquid to the system. The control objective (regulator problem) is to keep the tanks levels in the considered operation point even in the presence of disturbance. The RMPC is a technique that allows explicit incorporation of the plant uncertainty in the problem formulation. The goal is to design, at each time step, a state-feedback control law that minimizes a 'worst-case' infinite horizon objective function, subject to constraint in the control. The existence of a feedback control law satisfying the input constraints is reduced to a convex optimization over linear matrix inequalities (LMIs) problem. It is shown in this work that for the plant uncertainty described by the polytope, the feasible receding horizon state feedback control design is robustly stabilizing. The software implementation of the RMPC is made using Scilab, and its communication with Coupled Tanks Systems is done through the OLE for Process Control (OPC) industrial protocol

Sistema para detecção e diagnóstico de falhas em motores elétricos de indução utilizando lógica fuzzy

Induction motors are one of the most important equipment of modern industry. However, in many situations, are subject to inadequate conditions as high temperatures and pressures, load variations and constant vibrations, for example. Such conditions, leaving them more susceptible to failures, either external or internal in nature, unwanted in the industrial process. In this context, predictive maintenance plays an important role, where the detection and diagnosis of faults in a timely manner enables the increase of time of the engine and the possibiity of reducing costs, caused mainly by stopping the production and corrective maintenance the motor itself. In this juncture, this work proposes the design of a system that is able to detect and diagnose faults in induction motors, from the collection of electrical line voltage and current, and also the measurement of engine speed. This information will use as input to a fuzzy inference system based on rules that find and classify a failure from the variation of thess quantities

Modelo matemático para otimização dos custos de um sistema híbrido eólico-solar : aplicação no bombeamento de petróleo

This work purposes the application of a methodology to optimize the implantation cost of an wind-solar hybrid system for oil pumping. The developed model is estimated the implantation cost of system through Multiple Linear Regression technique, on the basis of the previous knowledge of variables: necessary capacity of storage, total daily energy demand, wind power, module power and module number. These variables are gotten by means of sizing. The considered model not only can be applied to the oil pumping, but also for any other purposes of electric energy generation for conversion of solar, wind or solar-wind energy, that demand short powers. Parametric statistical T-student tests had been used to detect the significant difference in the average of total cost to being considered the diameter of the wind, F by Snedecor in the variance analysis to test if the coefficients of the considered model are significantly different of zero and test not-parametric statistical by Friedman, toverify if there is difference in the system cost, by being considered the photovoltaic module powers. In decision of hypothesis tests was considered a 5%-significant level. The configurations module powers showed significant differences in total cost of investment by considering an electrical motor of 3 HP. The configurations module powers showed significant differences in total cost of investment by considering an electrical motor of 5 HP only to wind speed of 4m/s and 6 m/s in wind of 3 m, 4m and 5 m of diameter. There was not significant difference in costs to diameters of winds of 3 m and 4m. The mathematical model and the computational program may be used to others applications which require electrical between 2.250 W and 3.750 W. A computational program was developed to assist the study of several configurations that optimizes the implantation cost of an wind-solar system through considered mathematical model

Desenvolvimento de um sistema para análise de integridade estrutural de equipamentos estáticos baseado em cad vps micro cracks e ultrassom

In general, the designs of equipment takes into account the effects and processes of deterioration it will undergo and arrives at an approximate useful life. However, changes in operational processes and parameters, the action of external agents, the kind of maintenance conducted, the means of monitoring, and natural and accidental occurrences completely modify the desired performance of the equipment. The discontinuities that occur in anisotropic materials often and due to different factors evolve from being subcritical to critical acquiring the status of defect and compromising the physical integrity of the equipment. Increasingly sophisticated technological means of detection, monitoring and assessment of these discontinuities are required to respond ever more rapidly to the requirements of industry. This paper therefore presents a VPS (Virtual Pipe System) computational tool which uses the results of ultrasonic tests on equipment, plotting the discontinuities found in models created in the CAD and CAE systems, and then simulates the behavior of these defects in the structure to give an instantaneous view of the final behavior. This paper also presents an alternative method of conventional ultrasonic testing which correlates the integrity of an overlay (carbon steel and stainless steel attached by welding) and the reflection of ultrasonic waves coming from the interface between the two metals, thus making it possible to identify cracks in the casing and a shift of the overlay

Otimização de um sistema de distribuição predial de água fria: estudo de caso

This dissertation presents a methodology to the optimization of a predial system of cold water distribution. It s about a study of a case applied to the Tropical Buzios Residential Condominium, located in the Búzio s Beach, Nísia Floresta city, the east coast of the Rio Grande do Norte state, twenty kilometers far from Natal. The design of cold water distribution networks according to Norm NBR 5626 of the ABNT - Brazilian Association of Techniques Norms, does not guarantee that the joined solution is the optimal solution of less cost. It s necessary the use of an optimization methodology, that supplies us, between all the possible solutions, the minimum cost solution. In the optimization process of the predial system of water distribution of the Tropical Búzios Condominium, is used Method Granados, that is an iterative algorithm of optimization, based on the Dynamic Programming, that supplies the minimum cost s network, in function of the piezometric quota of the reservoir. For the application of this Method in ramifies networks, is used a program of computer in C language. This process is divided in two stages: attainment of the previous solution and reduction of the piezometric quota of headboard. In the attainment of the previous solution, the minors possible diameters are used that guarantee the limit of maximum speed and the requirements of minimum pressures. The piezometric quota of headboard is raised to guarantee these requirements. In the second stage of the Granados Method, an iterative process is used and it objective is to reduce the quota of headboard gradually, considering the substitution of stretches of the network pipes for the subsequent diameters, considering a minimum addition of the network cost. The diameter change is made in the optimal stretch that presents the lesser Exchange Gradient. The process is locked up when the headboard quota of desired is reached. The optimized network s material costs are calculated, and is made the analysis of the same ones, through the comparison with the conventional network s costs

Aprendendo e ensinando o sistema de numeração decimal: uma contribuição à prática pedagógica do professor

The central question of the present study is to identify the epistemological knowledge that the teachers-trainees possess regarding the characteristics (properties) of the decimal numbering system; its purpose is to offer a contribution to the pedagogic practice of the teachers who work within the Basic Literacy Cycle, in terms of what concerns both the acquisition of contents and the development of the knowledge that helps them in the elaboration of adequate strategies to working with the Decimal Numbering System in the classroom. The study is based on the constructivist sociointeractionist approach to teaching Mathematics and it constitutes, in itself, a methodological intervention with the teachers-trainees engaged in the Professional Qualification Program in Basic Education of the Federal University of Rio Grande do Norte. The foundations of the study were found in investigations of researchers who had carried out studies on the construction of numerical writing, showing, for instance, that the construction process of ideas and procedures involved in groupings and changes to base 10 take a lot longer to be accomplished than one can imagine. A set of activities was then elaborated which could not only contribute to the acquisition of contents but that could also make the teachers-trainees reflect upon their teaching practices in the classroom so that in this way they will be able to elaborate more consistent didactic approaches, taking into consideration the previous knowledge of the students and also some obstacles that often appear along the way. Even when teachers have access to the most appropriate dicactic resources, the lack of knowledge of the content and of the real meaning of that content make the Decimal Numbering System, a subject of fundamental importance, be taught most times in a mechanical way. The analisys of the discussions and behaviours of the teachers-trainees during the activities reavealed that they made them reflect upon their current practices in the classroom and that, as a whole, the aims of each of the activities carried out with the teachers-trainers were reached

Custos e benefícios de um programa de exercício aeróbios na doença pulmonar obstrutica crônica: ensaio cliníco aleatório controlado

Pulmonary Rehabilitation, especially due to aerobic exercise, positive impact in reducing morbidity/mortality of patients with COPD, however the economic impact with costs of implementing simple programs of aerobic exercise are scarce. This is a blind randomized clinical trials, which aimed to evaluate the costs and benefits of a simple program of aerobic exercise in individuals with COPD, considering the financial costs of the Public Health System and its secondary endpoints. We evaluated lung function, the distance walked during six minutes of walking, the respiratory and peripheral muscle strength, quality of life related to health (QLRH), body composition and level of activity of daily living (ADL) before and after eight weeks of an aerobic exercise program consisting of educational guidance for both groups, control and intervention and supervised walks to the intervention group. The health costs generated in both groups were calculated following table Brazilian Public Health System. The sample consisted of forty patients, two being excluded in the initial phase of desaturation during the walk test six minutes. Were randomized into control and intervention group thirty-eight patients, three were excluded from the control group and one was excluded from the intervention group. At the end, thirty-four COPD comprised the sample, 16 in the control group and 18 in the intervention group (FEV1: 50.9 ± 14% pred and FEV1: 56 ± 0.5% pred, respectively). After for intervention, the intervention group showed improvement in meters walked, the sensation of dyspnea and fatigue at work, BODE index (p <0.01) in QLRH, ADL level (p <0.001) as well as increased strength lower limbs (p <0.05). The final cost of the program for the intervention group was R $ 148.75, including: assessments, hiking supervised by a physiotherapist and reassessments. No patient had exacerbation of IG, while 2 patients in the CG exacerbated, generating an average individual cost of R $ 689.15. The aerobic exercises in the form of walking showed significant clinical benefits and economic feasibility of its implementation, due to low cost and easy accessibility for patients, allowing them to add their daily practice of aerobic exercises

Ssitema integrado de gestão pública: proposta de implantação de um sistema integrado de gestão, autuação e distribuição de termos circunstanciados e inquéritos policiais entre os juizados especiais criminais e delegacias de Natal

Universidade Federal do Rio Grande do Norte

Sistema de tração elétrica flexível baseado em veículos trólebus para alimentação com redes CC e ou CA

Este artigo apresenta os principais resultados e o detalhamento da metodologia e equações de controle de um retificador monofásico pré-regulador de 150kW para sistema trólebus. A estrutura proposta possibilita a Correção ativa do Fator de Potência (CFP) com baixos níveis de Distorção Harmônica Total (DHT) na corrente, em conformidade com a norma internacional IEC 61000-3-4. Fruto de um projeto de Pesquisa, Desenvolvimento e Inovação (P) junto à empresa AES Eletropaulo Metropolitana de São Paulo, em parceria com a empresa de transporte Himalaia S.A., o projeto possui como principais objetivos estimular o interesse para a expansão das linhas de trólebus a partir de uma plataforma de alimentação de menor custo de instalação e manutenção, sem a necessidade de subestações retificadoras, e, com vistas a promover a melhoria da qualidade de vida nos grandes centros urbanos. Nessa nova modalidade proposta para o sistema de alimentação, o trólebus pode ser alimentado tanto pelas redes convencionais em corrente contínua (CC) quanto pelas redes de distribuição em corrente alternada (CA), mantendo-se a disposição a dois fios dos sistemas CC, sendo as mudanças de rede de alimentação (CC ou CA) monitoradas e controladas digitalmente. Todo o sistema de gerenciamento e controle do conversor é realizado digitalmente por FPGA XC3S200. Na evolução do sistema proposto, os autores pretendem inclusive eliminar as linhas aéreas de alimentação, através da utilização de postos de alimentação em CA, especialmente desenvolvidos para os pontos de embarque/desembarque de passageiros para este veículo de transporte coletivo, eliminando-se os aspectos visuais negativos das redes de alimentação deste modal, e, reduzindo-se as falhas de operação do sistema.

Uma linguagem de modelagem da interação para auxiliar a comunicação designer-usuário

The development of interactive systems involves several professionals and the integration between them normally uses common artifacts, such as models, that drive the development process. In the model-driven development approach, the interaction model is an artifact that includes the most of the aspects related to what and how the user can do while he/she interacting with the system. Furthermore, the interactive model may be used to identify usability problems at design time. Therefore, the central problematic addressed by this thesis is twofold. In the first place, the interaction modeling, in a perspective that helps the designer to explicit to developer, who will implement the interface, the aspcts related to the interaction process. In the second place, the anticipated identification of usability problems, that aims to reduce the application final costs. To achieve these goals, this work presents (i) the ALaDIM language, that aims to help the designer on the conception, representation and validation of his interactive message models; (ii) the ALaDIM editor, which was built using the EMF (Eclipse Modeling Framework) and its standardized technologies by OMG (Object Management Group); and (iii) the ALaDIM inspection method, which allows the anticipated identification of usability problems using ALaDIM models. ALaDIM language and editor were respectively specified and implemented using the OMG standards and they can be used in MDA (Model Driven Architecture) activities. Beyond that, we evaluated both ALaDIM language and editor using a CDN (Cognitive Dimensions of Notations) analysis. Finally, this work reports an experiment that validated the ALaDIM inspection method

MoSAC: um módulo para seleção de configurações arquiteturais baseado em critérios de QoS no contexto de sistema distribuídos autoadaptativos

The process for choosing the best components to build systems has become increasingly complex. It becomes more critical if it was need to consider many combinations of components in the context of an architectural configuration. These circumstances occur, mainly, when we have to deal with systems involving critical requirements, such as the timing constraints in distributed multimedia systems, the network bandwidth in mobile applications or even the reliability in real-time systems. This work proposes a process of dynamic selection of architectural configurations based on non-functional requirements criteria of the system, which can be used during a dynamic adaptation. This proposal uses the MAUT theory (Multi-Attribute Utility Theory) for decision making from a finite set of possibilities, which involve multiple criteria to be analyzed. Additionally, it was proposed a metamodel which can be used to describe the application s requirements in terms of the non-functional requirements criteria and their expected values, to express them in order to make the selection of the desired configuration. As a proof of concept, it was implemented a module that performs the dynamic choice of configurations, the MoSAC. This module was implemented using a component-based development approach (CBD), performing a selection of architectural configurations based on the proposed selection process involving multiple criteria. This work also presents a case study where an application was developed in the context of Digital TV to evaluate the time spent on the module to return a valid configuration to be used in a middleware with autoadaptative features, the middleware AdaptTV

STREAM-AP: um processo para sistematizar a escolha de padrões arquiteturais baseado em requisitos não-funcionais

The importance of non-functional requirements for computer systems is increasing. Satisfying these requirements requires special attention to the software architecture, since an unsuitable architecture introduces greater complexity in addition to the intrinsic complexity of the system. Some studies have shown that, despite requirements engineering and software architecture activities act on different aspects of development, they must be performed iteratively and intertwined to produce satisfactory software systems. The STREAM process presents a systematic approach to reduce the gap between requirements and architecture development, emphasizing the functional requirements, but using the non-functional requirements in an ad hoc way. However, non-functional requirements typically influence the system as a whole. Thus, the STREAM uses Architectural Patterns to refine the software architecture. These patterns are chosen by using non-functional requirements in an ad hoc way. This master thesis presents a process to improve STREAM in making the choice of architectural patterns systematic by using non-functional requirements, in order to guide the refinement of a software architecture

Aplicação de sensoriamento remoto e sistema de informação geográfica na determinação da vulnerabilidade natural e ambeintal do Município de Guamaré(RN): simulação de risco às atividades da indústria petrolífera

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Comparação dos tempos de geração e digitação de laudos radiológicos entre um sistema eletrônico baseado em voz sobre IP (VoIP) e um sistema tradicional baseado em papel

OBJETIVO: Comparar os tempos de geração e digitação de laudos radiológicos entre um sistema eletrônico baseado na tecnologia de voz sobre o protocolo de internet (VoIP) e o sistema tradicional, em que o radiologista escreve o laudo à mão. MATERIAIS E MÉTODOS: Foi necessário modelar, construir e implantar o sistema eletrônico proposto, capaz de gravar o laudo em formato de áudio digital, e compará-lo com o tradicional já existente. Por meio de formulários, radiologistas e digitadores anotaram os tempos de geração e digitação dos laudos nos dois sistemas. RESULTADOS: Comparadas as médias dos tempos entre os sistemas, o eletrônico apresentou redução de 20% (p = 0,0410) do tempo médio de geração do laudo em comparação com o sistema tradicional. O tradicional foi mais eficiente em relação ao tempo de digitação, uma vez que a média de tempo do eletrônico foi três vezes maior (p < 0,0001). CONCLUSÃO: Os resultados mostraram diferença estatisticamente significante entre os sistemas comparados, sendo que o eletrônico foi mais eficiente do que o tradicional em relação ao tempo de geração dos laudos, porém, em relação ao tempo de digitação, o tradicional apresentou melhores resultados.

Custos da irrigação e receita líquida do feijoeiro em um sistema pivô central sob variação do comprimento da tubulação de recalque e desnível topográfico

Neste trabalho, foi simulado o custo da irrigação de um sistema tipo pivô central com diferentes comprimentos da tubulação de recalque e desníveis topográficos na produção do feijoeiro comum, na região de Ilha Solteira -SP, bem como sua receita líquida. Considerou-se uma área irrigada pelo equipamento de 103,58 ha, sendo sua configuração a mais econômica possível para as variáveis consideradas. A participação da irrigação no custo de produção do feijoeiro variou de 14,8 a 21,5% entre as condições extremas, ou seja, do menor desnível topográfico (40 m) e comprimento da tubulação de recalque (2.000 m) ao maior desnível (80 m) e comprimento (3.000 m). em todas as configurações do sistema de irrigação e com os preços praticados em agosto de 2008 ou com o preço histórico médio, seria viável a cultura do feijoeiro, proporcionando rendas líquidas de até R$ 3.959,64 ha-1 e até R$ 1.203,14 ha-1, respectivamente.