Sistema inteligente para estimar a porosidade em sedimentos a partir da análise de sinais GPR

This Thesis presents the elaboration of a methodological propose for the development of an intelligent system, able to automatically achieve the effective porosity, in sedimentary layers, from a data bank built with information from the Ground Penetrating Radar GPR. The intelligent system was built to model the relation between the porosity (response variable) and the electromagnetic attribute from the GPR (explicative variables). Using it, the porosity was estimated using the artificial neural network (Multilayer Perceptron MLP) and the multiple linear regression. The data from the response variable and from the explicative variables were achieved in laboratory and in GPR surveys outlined in controlled sites, on site and in laboratory. The proposed intelligent system has the capacity of estimating the porosity from any available data bank, which has the same variables used in this Thesis. The architecture of the neural network used can be modified according to the existing necessity, adapting to the available data bank. The use of the multiple linear regression model allowed the identification and quantification of the influence (level of effect) from each explicative variable in the estimation of the porosity. The proposed methodology can revolutionize the use of the GPR, not only for the imaging of the sedimentary geometry and faces, but mainly for the automatically achievement of the porosity one of the most important parameters for the characterization of reservoir rocks (from petroleum or water)

Efeitos do alcalóide indólico caulerpina, obtido de alga do gênero caulerpa, em modelo de colite experimental murina

As doenças inflamatórias intestinais são enfermidades onde a tolerância e homeostase da resposta inflamatória estão comprometidas, gerando lesões teciduais e favorecendo o surgimento de neoplasias. Há dois importantes exemplos de doenças inflamatórias intestinais, a colite ulcerativa, foco do modelo desse estudo, e a doença de Crohn. Os medicamentos utilizados no tratamento dessas doenças desencadeiam diversos efeitos adversos; além disso, em alguns pacientes, eles não são eficazes. Os extratos de algas têm demonstrado várias atividades biológicas, entre elas a atividade anti-inflamatória. Os extratos das algas do gênero Caulerpa foram utilizados em vários estudos, onde modelos inflamatórios foram analisados, entre eles o modelo de colite ulcerativa. A utilização do extrato metanólico da C. mexicana como terapêutica nesse modelo atenuou o quadro clinico desenvolvido pelos animais. Sendo assim, o presente estudo teve como objetivo analisar a ação terapêutica da Caulerpina (CLP), extraída da C. racemosa, no modelo murino de colite ulcerativa. Camundongos C57BL/6 machos foram expostos a uma solução de Dextrana Sulfato de Sódio (DSS) a 3% por sete dias. A partir do primeiro dia de exposição ao DSS os animais foram tratados em dias alternados com a CLP nas doses de 4 e 40 mg/kg e com a dexametasona (3 mg/kg) por via oral. O desenvolvimento da doença foi analisado através do índice de atividade da doença (IAD), que leva em consideração a perda de peso corporal, a consistência e a presença de sangue nas fezes. Após a eutanásia, o cólon foi removido e mensurado, e amostras do tecido colônico foram destinadas a análise histológica e à cultura para dosagem de citocinas. Os níveis de citocinas no sobrenadante da cultura do cólon foram mensurados por ELISA. O tratamento com a CLP (4 mg/kg) desencadeou significativa melhora quanto à perda de peso corporal e ao IAD, e atenuou o encurtamento do cólon em resposta ao DSS. Tal dose foi capaz de reduzir os níveis de citocinas pró-inflamatórias analisadas (TNF-, IFN-, IL-6, IL-17), mas não teve efeito significativo nas citocinas anti-inflamatórias IL-10 e TGF-. O tratamento com a CLP (40 mg/kg) não foi eficaz quanto a perda de peso e ao IAD, além de não ter atenuado a redução do cólon em resposta ao DSS. Essa dose conseguiu reduzir os níveis das citocinas pró-inflamatórias, porém não os níveis de IL-6. O tratamento com a dexametasona obteve melhora discreta quanto à perda de peso corporal e ao IAD, porém não atenuou a redução do cólon em resposta ao DSS. Esse tratamento também conseguiu reduzir todas as citocinas pró-inflamatórias testadas. Deste modo a CLP (4 mg/kg) demonstrou ser uma alternativa promissora no tratamento da colite ulcerativa, em razão dos seus efeitos benéficos sobre parâmetros clínicos, morfológicos e moleculares do modelo em estudo

Modelo matemático para predição do VO2máx em cicloergômetro baseado na análise dos gases expirados

Existem diversas equações para predição do VO2máx a partir de variáveis dentro do teste ergométrico em vários ergômetros, no entanto equação semelhante utilizando os limiares ventilatórios na ergoespirometria em teste sub-máximo no cicloergômetro não está disponível. O objetivo do presente estudo foi avaliar a precisão de modelos de predição do VO2máx com base em indicadores de esforço sub-máximo. Neste sentido foram testados em protocolo incremental máximo no cicloergômetro 7.877 voluntários, sendo 4640 indivíduos do sexo feminino e 3147 do sexo masculino, todos saudáveis não atletas, com idades acima de 20 anos, divididos randomicamente em dois grupos: A de estimação e B de validação. A partir das variáveis independentes massa corporal (MC) em kg, carga de trabalho no limiar 2 (WL2) e freqüência cardíaca no limiar 2 (FCL2) foi possível construir um modelo de regressão linear múltipla para predição do VO2máx. Os resultados demonstram que em indivíduos saudáveis não atletas de ambos os sexos é possível predizer o VO2máx com um erro mínimo (EPE = 1,00%) a partir de indicadores submáximos obtidos em teste incremental. O caráter multidisciplinar do trabalho pôde ser caracterizado pelo emprego de técnicas que envolveram pneumologia, educação física, fisiologia e estatística

Influência da laparoscopia e da laparotomia na gasometria, leucometria diferencial e citocinas em modelo de sepse abdominal em ratos

Laparoscopic surgery is associated with reduced surgical trauma, and less acute phase response, as compared with open surgery. Cytokines are important regulators of the biological response to surgical and anesthetic stress. The aim of this study was to determine if CO2 pneumoperitoneum would change cytokine expression, gas parameters and leukocyte count in septic rats. Methods: Wistar rats were randomly assigned to five groups: control (anesthesia only), laparotomy, CO2 pneumoperitoneum, cecum ligation and puncture by laparotomy, and laparoscopic cecum ligation and puncture. After 30 min of the procedures, arterial blood samples were obtained to determine leukocytes subpopulations by hemocytometer. TNFα, IL-1β, IL-6 were determined in intraperitoneal fluid (by ELISA). Gas parameters were measured on arterial blood, intraperitoneal and subperitoneal exsudates. Results: Peritoneal TNFα, IL-1β and IL-6 concentrations were lower in pneumoperitoneum rats than in all other groups (p<0.05). TNFα, IL-1β and IL-6 expression was lower in the laparoscopic than in laparotomic sepsis (p<0.05). Rats from laparoscopic cecum ligation and puncture group developed significant hypercarbic acidosis in blood and subperitoneal fluid when compared to open procedure group. Total white blood cells and lymphocytes were significantly lower in laparoscopic cecum ligation and puncture rats than in the laparotomic (p<0.01). Nevertheless, the laparotomic cecum ligation rats had a significant increase in blood neutrophils and eosinophils when compared with controls (p<0.05). Conclusions: This study demonstrates that the CO2 pneumoperitoneum reduced the inflammatory and immune response in an animal model of peritonitis with respect to intraperitoneal cytokines, white blood cell count and clinical correlates of sepsis. The pneumoperitoneum produced hypercarbic acidosis in septic animals

Modelo de avaliação de risco : São o crescimento e a estequiometria dos girinos afetados pelo efeito interativo entre a presença do predador e da densidade de coespecíficos?

Many prey organisms change their phenotype to reduce the predation risk. However, such changes are associated with trade-offs, and can have negative effects on prey growth or reproduction. Understand how preys assess the predation risk is essential to evaluate the adaptive value of predator-induced phenotypic and its ecological consequences. In this study, we performed a mesocosm experiment to test: i) if growth and stoichiometry of Lithobates catesbeianus tadpoles is altered in response to giant water bug presence (Belostoma spp.); ii) if these responses depend on tadpoles density in environment. Here, we show that tadpoles growth and stoichiometry are not changed by predator presence, neither in low nor in high densities. Our results suggest that tadpoles exposed to predation risk regulate their physiology to preserve the elemental stoichiometric homeostase of their body and excretion. Further, point out to need for future studies that elucidate under what conditions growth and stoichiometry are changed in response to predation risk

Uma perspectiva de extensão do modelo de aceitação de tecnologia para explicar o uso de linguagens de desenvolvimento WEB: pesquisa com desenvolvedores Pyton e Java

The spread of the Web boosted the dissemination of Information Systems (IS) based on the Web. In order to support the implementation of these systems, several technologies came up or evolved with this purpose, namely the programming languages. The Technology Acceptance Model TAM (Davis, 1986) was conceived aiming to evaluate the acceptance/use of information technologies by their users. A lot of studies and many applications have used the TAM, however, in the literature it was not found a mention of the use of such model related to the use of programming languages. This study aims to investigate which factors influence the use of programming languages on the development of Web systems by their developers, applying an extension of the TAM, proposed in this work. To do so, a research was done with Web developers in two Yahoo groups: java-br and python-brasil, where 26 Java questionnaires and 39 Python questionnaires were fully answered. The questionnaire had general questions and questions which measured intrinsic and extrinsic factors of the programming languages, the perceived usefulness, the perceived ease of use, the attitude toward the using and the programming language use. Most of the respondents were men, graduate, between 20 and 30 years old, working in the southeast and south regions. The research was descriptive in the sense of its objectives. Statistical tools, descriptive statistics, main components and linear regression analysis were used for the data analysis. The foremost research results were: Java and Python have machine independence, extensibility, generality and reliability; Java and Python are more used by corporations and international organizations than supported by the government or educational institutions; there are more Java programmers than Python programmers; the perceived usefulness is influenced by the perceived ease of use; the generality and the extensibility are intrinsic factors of programming languages which influence the perceived ease of use; the perceived ease of use influences the attitude toward the using of the programming language

Melhoria da segurança pública: uma proposta para alocação de unidades policiais utilizando o modelo das p-medianas e do caixeiro viajante

The decrease in crime is one of the core issues that cause concern in society today. This study aims to propose improvements to public safety from the choice of points to the location of police units, ie the points which support the car and the police. For this, three models were developed in order to assist decision making regarding the best placement of these bases. The Model of Police Units Routing has the intention to analyze the current configuration of a given region and develop optimal routes for round preventative. The Model of Allocation and Routing for New Police Units (MARNUP) used the model of facility location called p-median weighted and traveling salesman problem (TSP) combined aiming an ideal setting for regions that do not yet have support points or to assess how far the distribution is present in relation to that found in solution. The Model Redefinition and Routing Unit Police (MRRUP) seek to change the current positioning taking into account the budgetary constraints of the decision maker. To verify the applicability of these models we used data from 602 points to instances of police command that is responsible for the capital city of Natal. The city currently has 31 police units for 36 of these 19 districts and police have some assistance. This reality can lead to higher costs and higher response times for answering emergency calls. The results of the models showed that in an ideal situation it is possible to define a distance of 500 km/round, whereas in this 900 km are covered by approximately round. However, a change from three-point lead reduced to 700 km / round which represents a decrease of 22% in the route. This reduction should help improve response time to emergency care, improving the level of service provided by the increase of solved cases, reducing police shifts and routing preventive patrols

Estabilidade e robustez de um controlador adaptativo indireto por um modelo de referência e estrutura variável

In this thesis, it is developed the robustness and stability analysis of a variable structure model reference adaptive controller considering the presence of disturbances and unmodeled dynamics. The controller is applied to uncertain, monovariable, linear time-invariant plants with relative degree one, and its development is based on the indirect adaptive control. In the direct approach, well known in the literature, the switching laws are designed for the controller parameters. In the indirect one, they are designed for the plant parameters and, thus, the selection of the relays upper bounds becomes more intuitive, whereas they are related to physical parameters, which present uncertainties that can be known easier, such as resistances, capacitances, inertia moments and friction coefficients. Two versions for the controller algorithm with the stability analysis are presented. The global asymptotic stability with respect to a compact set is guaranteed for both cases. Simulation results under adverse operation conditions in order to verify the theoretical results and to show the performance and robustness of the proposed controller are showed. Moreover, for practical purposes, some simplifications on the original algorithm are developed

Estimação da demanda de instalações elétricas de edificações com múltiplas unidades de consumo

This work aims to predict the total maximum demand of a transformer that will be used in power systems to attend a Multiple Unit Consumption (MUC) in design. In 1987, COSERN noted that calculation of maximum total demand for a building should be different from that which defines the scaling of the input protection extension in order to not overestimate the power of the transformer. Since then there have been many changes, both in consumption habits of the population, as in electrical appliances, so that this work will endeavor to improve the estimation of peak demand. For the survey, data were collected for identification and electrical projects in different MUCs located in Natal. In some of them, measurements were made of demand for 7 consecutive days and adjusted for an integration interval of 30 minutes. The estimation of the maximum demand was made through mathematical models that calculate the desired response from a set of information previously known of MUCs. The models tested were simple linear regressions, multiple linear regressions and artificial neural networks. The various calculated results over the study were compared, and ultimately, the best answer found was put into comparison with the previously proposed model

Desacoplamento de um gerador síncrono através de um controle adaptativo por modelo de referência baseado em funções de Base radial

An alternative nonlinear technique for decoupling and control is presented. This technique is based on a RBF (Radial Basis Functions) neural network and it is applied to the synchronous generator model. The synchronous generator is a coupled system, in other words, a change at one input variable of the system, changes more than one output. The RBF network will perform the decoupling, separating the control of the following outputs variables: the load angle and flux linkage in the field winding. This technique does not require knowledge of the system parameters and, due the nature of radial basis functions, it shows itself stable to parametric uncertainties, disturbances and simpler when it is applied in control. The RBF decoupler is designed in this work for decouple a nonlinear MIMO system with two inputs and two outputs. The weights between hidden and output layer are modified online, using an adaptive law in real time. The adaptive law is developed by Lyapunov s Method. A decoupling adaptive controller uses the errors between system outputs and model outputs, and filtered outputs of the system to produce control signals. The RBF network forces each outputs of generator to behave like reference model. When the RBF approaches adequately control signals, the system decoupling is achieved. A mathematical proof and analysis are showed. Simulations are presented to show the performance and robustness of the RBF network

Identificação em tempo real de modelo dinâmico de robô móvel com acionamento diferencial e zona morta

Several mobile robots show non-linear behavior, mainly due friction phenomena between the mechanical parts of the robot or between the robot and the ground. Linear models are efficient in some cases, but it is necessary take the robot non-linearity in consideration when precise displacement and positioning are desired. In this work a parametric model identification procedure for a mobile robot with differential drive that considers the dead-zone in the robot actuators is proposed. The method consists in dividing the system into Hammerstein systems and then uses the key-term separation principle to present the input-output relations which shows the parameters from both linear and non-linear blocks. The parameters are then simultaneously estimated through a recursive least squares algorithm. The results shows that is possible to identify the dead-zone thresholds together with the linear parameters

Algoritmos genéricos para otimização de uma arquitetura de controle inteligente híerárquico

A hierarchical fuzzy control scheme is applied to improve vibration suppression by using an electro-mechanical system based on the lever principle. The hierarchical intelligent controller consists of a hierarchical fuzzy supervisor, one fuzzy controller and one robust controller. The supervisor combines controllers output signal to generate the control signal that will be applied on the plant. The objective is to improve the performance of the electromechanical system, considering that the supervisor could take advantage of the different techniques based controllers. The robust controller design is based on a linear mathematical model. Genetic algorithms are used on the fuzzy controller and the supervisor tuning, which are based on non-linear mathematical model. In order to attest the efficiency of the hierarchical fuzzy control scheme, digital simulations were employed. Some comparisons involving the optimized hierarchical controller and the non-optimized hierarchical controller will be made to prove the efficiency of the genetic algorithms and the advantages of its use

Controlador preditivo não linear aplicado ao controle de golfadas em processos de produção de petróleo

Slugging is a well-known slugging phenomenon in multiphase flow, which may cause problems such as vibration in pipeline and high liquid level in the separator. It can be classified according to the place of its occurrence. The most severe, known as slugging in the riser, occurs in the vertical pipe which feeds the platform. Also known as severe slugging, it is capable of causing severe pressure fluctuations in the flow of the process, excessive vibration, flooding in separator tanks, limited production, nonscheduled stop of production, among other negative aspects that motivated the production of this work . A feasible solution to deal with this problem would be to design an effective method for the removal or reduction of the system, a controller. According to the literature, a conventional PID controller did not produce good results due to the high degree of nonlinearity of the process, fueling the development of advanced control techniques. Among these, the model predictive controller (MPC), where the control action results from the solution of an optimization problem, it is robust, can incorporate physical and /or security constraints. The objective of this work is to apply a non-conventional non-linear model predictive control technique to severe slugging, where the amount of liquid mass in the riser is controlled by the production valve and, indirectly, the oscillation of flow and pressure is suppressed, while looking for environmental and economic benefits. The proposed strategy is based on the use of the model linear approximations and repeatedly solving of a quadratic optimization problem, providing solutions that improve at each iteration. In the event where the convergence of this algorithm is satisfied, the predicted values of the process variables are the same as to those obtained by the original nonlinear model, ensuring that the constraints are satisfied for them along the prediction horizon. A mathematical model recently published in the literature, capable of representing characteristics of severe slugging in a real oil well, is used both for simulation and for the project of the proposed controller, whose performance is compared to a linear MPC

Um modelo de unidade de medida inercial utilizando três acelerômetros triaxiais

No espaço tridimensional, um corpo rígido qualquer pode efetuar translações e ou rotações em relação a cada um de seus eixos. Identificar com precisão o deslocamento realizado por um corpo é fundamental para alguns tipos de sistemas em engenharia. Em sistemas de navegação inercial tradicionais, utilizam-se acelerômetros para reconhecer a aceleração linear e giroscópios para reconhecer a velocidade angular registrada durante o deslocamento. O giroscópio, entretanto, é um dispositivo de custo mais elevado e com alto consumo de energia quando comparado a um acelerômetro. Essa desvantagem deu origem a pesquisas a respeito de sistemas e unidades de medidas inerciais que não utilizam giroscópios. A ideia de utilizar apenas acelerômetros para calcular o movimento linear e angular surgiu no início da década de 60 e vem se desenvolvendo através de modelos que variam no número de sensores, na maneira como estes são organizados e no modelo matemático que é utilizado para derivar o movimento do corpo. Esse trabalho propõe um esquema de configuração para construção de uma unidade de medida inercial que utiliza três acelerômetros triaxiais. Para identificar o deslocamento de um corpo rígido a partir deste esquema, foi utilizado um modelo matemático que utiliza apenas os nove sinais de aceleração extraídos dos três sensores. A proposta sugere que os sensores sejam montados e distribuídos em formato de L . Essa disposição permite a utilização de um único plano do sistema de coordenadas, facilitando assim a instalação e configuração destes dispositivos e possibilitando a implantação dos sensores em uma única placa de circuito integrado. Os resultados encontrados a partir das simulações iniciais demonstram a viabilidade da utilização do esquema de configuração proposto

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