A dinâmica do campo organizacional e a adoção de estratégias na carcinicultura do RN

This study aimed to understand the relations inside the organizational Structuring of the shrimp Field - the shrimp agribusiness placed in Rio Grande do Norte State and the strategies adopted by its players. In order to achieve that, semi-structured interviews were conducted with samples of various organizations that act in the field, like cooperatives, associations, enterprises of different links in the chain, universities and state agencies. The interviews built up a large collection of secondary data. As expected, it was found that Field and strategies are related in a recursive way: the configuration of the field, a result from his own biography, has decisively influenced the strategies adopted by its actors, who, as evolved, eventually caused further changes in the Field and outlines the plot of this area of interaction. It was found, for example, that after thirty-five years of its genesis, the Field of shrimp RN still has a low level of institutionalization, which helps to understand the difficulty of its actors in establish strategies based on partnerships and cooperation; Those actions are so necessary to alleviate the effects of the crisis that devastated the industry since 2004. It was noticed, however, that this level of institutionalization is a result, beside other factors, the very strategies that field actors are embracing along its trajectory. Thus, this study hopes to have contributed both to the necessary revival of the agency to institutional phenomenon, cited by Oliver (1991), and to meet the need for more contextualized approaches to organizational strategies (MINTZBERG, 1987; CLEGG, 2004; WHITTINGTON, 2004; 2006; SARAIVA and CARRIERI, 2007). It is an exploratory study that needs further investigation in order to get deep in this research. In this sense, others methodologies and theoretical perspectives need to be used, especially those relating to the seizure of the disputes and discursive aspects of power, as salient in the field investigated. Moreover, in terms of "practical actions", it is suggested that, as soon as possible, the main actors of the field (cooperatives, companies, and state entities in class) can be able of agglutinate efforts to support the shrimp field in RN State and make sustainable actions, which can promote the development of activity in a global view. On the apse of shrimp activities everybody wanted to be the "father of the child," Now, someone has to "stay in the goal."

Coevolução e as práticas isomórficas de gestão: um estudo sobre os processos de mudanças institucionais no Instituto Federal de Educação, Ciência e Tecnologia do RN

The Federal Institution for Education, Science and Technology, in its historical path, has been living different changes. The transformations occurred along the way have been determined by coercive forces from the institutional environment, which has became more and more broad and complex throughout the time, obtaining diverse characteristics and new elements such as non institutional factors1 which started to contribute with the other changes. In this context, this work aims to study the isomorphic practices of the managers in the institutional changes process of the IFRN in 1998 and 2008, as of a theoretical coevolutionary perspective (CHILD; RODRIGUES; LEWIN; CARROL; VOLBERDA, 2003). This theory brings a new point of view for the organization analysis to the organizational studies, since it offers a non deterministic and non linear lection of the evolution process, which means, a coevolution. Thus, the organizations and their institutional and non institutional environment auto evolve, auto organize and auto reproduce. Therefore, the institutional and non institutional factors of the macro environment keep a continuous interdependence relationship with the organizations. For the means of this study, it is important to understand that is impossible to comprehend the object, the isomorphic practices, without considering that the previous institutional changes and its evolutions, its continuations and discontinuations, important in the coevolution process. As such, to call upon the institutional historical track is a fundamental aspect to materialize this study, for the recursive movement is indeed present in the coevolution. Another important point to make this research effective is that it is not possible to abdicate from the hologramatic view2 of this study, which considers the object, the isomorphic practices, part of the whole and this whole is also in the parts, therefore it is impossible to comprehend the object of study outside the context where it belongs. With this, as of the objective previously proposed, it is necessary to describe the characteristics of coevolution of the institutional changes related in 1998 and 2008; analyze the dynamic of the isomorphic mechanisms in its respective institutional change process; and describe the lessons learned which the isomorphic practices left to the IFRN, regarding its benefits and difficulties. All these transformations happened through coercive forces3 of the institutional environment. As of the Nineties, these forces became stronger, the environment became broader and more complex, with the emergency of new environmental factors. This study proposed to study the managing process and its practices, related to the micro environment, although it is required to articulate these actions, the demands and requirements from the macro environment. To make this research effective, semi structured interviews have been conducted with the managers who participated in both institutional change processes. In the results analysis, it has been possible to verify the particularity of each change, the one from 1998 with a strong normative action of the managers against coercive forces from the government for the search of recognition and the institutional legitimation and the one in 2008, which has been characterized by the normative action by managers in agreement with the coercive forces from the government, in favor of the government policy for the technological professional education. However, the results analysis it is possible to notice the evidence of a belonging feeling from the interviewed managers

Bioética e biodireito: interfaces e confluências

This thesis addresses the development of technoscience in times of transnational globalization and highlights the vulnerability of the discourse of social progress, which may be replaced by evidence of social risk before the artificiality of nature and humanity. That demands an ethical and legal responses to events that impose the necessity of an ethical control in biotechnology research involving human beings contributing to the rise of Bioethics and Biolaw as fields of knowledge. This theme is studied from a multidisciplinary perspective seeking a dynamic dimension in the interpretation of research data reconnecting Social Sciences to Legal Sciences (Biolaw) and to Philosophy (Bioethics), in order to obtain answers to the problems posed. The objective delimited is to examine the interfaces between Biolaw and Bioethics, in order to observe the confluence of these areas of knowledge. Biolaw is considered as a new legal branch derived from the paradigmatic transition of Law and wonders how it will stand before questions resulting of social transformations caused by biotechnological development that endangers humans and society. It is concluded that the relationship between Bioethics and Biolaw is recursive and inseparable and it contributed to the "unthink" of traditional legal model of linear view/reductionist allowing that the "certainties" will be replaced by "possibilities", which comes to enable Biolaw to confront the issues caused by the development of biotechnology that violates physically and morally the human person. It is perceived, therefore, that Biolaw is driven and aided by bioethical reflections and it positions itself before the dilemmas caused by biotechnology in creating, interpreting and applying coercive rules which aims to protect the human being, his offspring and society

Vida, experiência, conhecimento : a reforma do sujeito cognoscente em Tsunessaburo Makiguchi

Utilizing a great part of the works by Japanese educator Tsunesaburo Makiguchi and the register of fragments of his life, this thesis affirms that knowledge emerges from peoples` experience as they go about their daily lives. Facts, events, genetic inheritance, cultural patrimony, family history, the place where one was born and lived, and psychological predispositions nurture and form a vision of the world and of life in general. In Makiguchi s case, this multi-causal constellation led him to conceive the system of the value-creating pedagogy of good, gain and beauty; discussing the importance of cognition and evaluation in the experience of the human being. His life is exemplary in demonstrating that these aspects are inter-connected and, in a recursive movement between knowledge and self-knowledge, they can generate creative systems for understanding the world and introducing, essentially, the author into the epistemological problematic of complexity. The Makiguchian system and Edgar Morin s complexity approach suggest a pragmatic, paradigmatic reform of education and a thought reformation in the direction of the complex pedagogy, and that it creates a web that connects master-disciple, subject-object, human-world, local-global and singular-universal

Um sistema para estimação da vazão de gás de poços produzindo por Plunger Lift para vaso separador de teste em plataformas de petróleo

This work intends to analyze the behavior of the gas flow of plunger lift wells producing to well testing separators in offshore production platforms to aim a technical procedure to estimate the gas flow during the slug production period. The motivation for this work appeared from the expectation of some wells equipped with plunger lift method by PETROBRAS in Ubarana sea field located at Rio Grande do Norte State coast where the produced fluids measurement is made in well testing separators at the platform. The oil artificial lift method called plunger lift is used when the available energy of the reservoir is not high enough to overcome all the necessary load losses to lift the oil from the bottom of the well to the surface continuously. This method consists, basically, in one free piston acting as a mechanical interface between the formation gas and the produced liquids, greatly increasing the well s lifting efficiency. A pneumatic control valve is mounted at the flow line to control the cycles. When this valve opens, the plunger starts to move from the bottom to the surface of the well lifting all the oil and gas that are above it until to reach the well test separator where the fluids are measured. The well test separator is used to measure all the volumes produced by the well during a certain period of time called production test. In most cases, the separators are designed to measure stabilized flow, in other words, reasonably constant flow by the use of level and pressure electronic controllers (PLC) and by assumption of a steady pressure inside the separator. With plunger lift wells the liquid and gas flow at the surface are cyclical and unstable what causes the appearance of slugs inside the separator, mainly in the gas phase, because introduce significant errors in the measurement system (e.g.: overrange error). The flow gas analysis proposed in this work is based on two mathematical models used together: i) a plunger lift well model proposed by Baruzzi [1] with later modifications made by Bolonhini [2] to built a plunger lift simulator; ii) a two-phase separator model (gas + liquid) based from a three-phase separator model (gas + oil + water) proposed by Nunes [3]. Based on the models above and with field data collected from the well test separator of PUB-02 platform (Ubarana sea field) it was possible to demonstrate that the output gas flow of the separator can be estimate, with a reasonable precision, from the control signal of the Pressure Control Valve (PCV). Several models of the System Identification Toolbox from MATLAB® were analyzed to evaluate which one better fit to the data collected from the field. For validation of the models, it was used the AIC criterion, as well as a variant of the cross validation criterion. The ARX model performance was the best one to fit to the data and, this way, we decided to evaluate a recursive algorithm (RARX) also with real time data. The results were quite promising that indicating the viability to estimate the output gas flow rate from a plunger lift well producing to a well test separator, with the built-in information of the control signal to the PCV

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

Metodologia para re-sintonia de controladores PID industriais

The present work has as objective to present a method of project and implementation of controllers PID, based on industrial instrumentation. An automatic system of auto-tunning of controllers PID will be presented, for systems of first and second order. The software presented in this work is applied in controlled plants by PID controllers implemented in a CLP. Software is applied to make the auto-tunning of the parameters of controller PID of plants that need this tunning. Software presents two stages, the first one is the stage of identification of the system using the least square recursive algorithm and the second is the stage of project of the parameters of controller PID using the root locus algorithm. An important fact of this work is the use of industrial instrumentation for the accomplishment of the experiments. The experiments had been carried through in controlled real plants for controllers PID implemented in the CLP. Thus has not only one resulted obtained with theoreticians experiments made with computational programs, and yes resulted obtained of real systems. The experiments had shown good results gotten with developed software

Modelagem linear e identificação do modelo dinâmico de um robô móvel com acionamento diferencial

This work presents a modelling and identification method for a wheeled mobile robot, including the actuator dynamics. Instead of the classic modelling approach, where the robot position coordinates (x,y) are utilized as state variables (resulting in a non linear model), the proposed discrete model is based on the travelled distance increment Delta_l. Thus, the resulting model is linear and time invariant and it can be identified through classical methods such as Recursive Least Mean Squares. This approach has a problem: Delta_l can not be directly measured. In this paper, this problem is solved using an estimate of Delta_l based on a second order polynomial approximation. Experimental data were colected and the proposed method was used to identify the model of a real robot

Modelagem e controle adaptativo de uma planta didática de nível com instrumentação industrial

The control, automation and optimization areas help to improve the processes used by industry. They contribute to a fast production line, improving the products quality and reducing the manufacturing costs. Didatic plants are good tools for research in these areas, providing a direct contact with some industrial equipaments. Given these capabilities, the main goal of this work is to model and control a didactic plant, which is a level and flow process control system with an industrial instrumentation. With a model it is possible to build a simulator for the plant that allows studies about its behaviour, without any of the real processes operational costs, like experiments with controllers. They can be tested several times before its application in a real process. Among the several types of controllers, it was used adaptive controllers, mainly the Direct Self-Tuning Regulators (DSTR) with Integral Action and the Gain Scheduling (GS). The DSTR was based on Pole-Placement design and use the Recursive Least Square to calculate the controller parameters. The characteristics of an adaptive system was very worth to guarantee a good performance when the controller was applied to the plant

Estimação de Fasores para Proteção de Sistemas Elétricos Baseada em Mínimos Quadrados e Morfologia Matemática

This work proposes a new technique for phasor estimation applied in microprocessor numerical relays for distance protection of transmission lines, based on the recursive least squares method and called least squares modified random walking. The phasor estimation methods have compromised their performance, mainly due to the DC exponential decaying component present in fault currents. In order to reduce the influence of the DC component, a Morphological Filter (FM) was added to the method of least squares and previously applied to the process of phasor estimation. The presented method is implemented in MATLABr and its performance is compared to one-cycle Fourier technique and conventional phasor estimation, which was also based on least squares algorithm. The methods based on least squares technique used for comparison with the proposed method were: forgetting factor recursive, covariance resetting and random walking. The techniques performance analysis were carried out by means of signals synthetic and signals provided of simulations on the Alternative Transient Program (ATP). When compared to other phasor estimation methods, the proposed method showed satisfactory results, when it comes to the estimation speed, the steady state oscillation and the overshoot. Then, the presented method performance was analyzed by means of variations in the fault parameters (resistance, distance, angle of incidence and type of fault). Through this study, the results did not showed significant variations in method performance. Besides, the apparent impedance trajectory and estimated distance of the fault were analysed, and the presented method showed better results in comparison to one-cycle Fourier algorithm

Identificação e comparação entre controle preditivo com modelo não linear e PI sintonizados com PSO em sistema de separação gravitacional de águia-óleo

The separation methods are reduced applications as a result of the operational costs, the low output and the long time to separate the uids. But, these treatment methods are important because of the need for extraction of unwanted contaminants in the oil production. The water and the concentration of oil in water should be minimal (around 40 to 20 ppm) in order to take it to the sea. Because of the need of primary treatment, the objective of this project is to study and implement algorithms for identification of polynomial NARX (Nonlinear Auto-Regressive with Exogenous Input) models in closed loop, implement a structural identification, and compare strategies using PI control and updated on-line NARX predictive models on a combination of three-phase separator in series with three hydro cyclones batteries. The main goal of this project is to: obtain an optimized process of phase separation that will regulate the system, even in the presence of oil gushes; Show that it is possible to get optimized tunings for controllers analyzing the mesh as a whole, and evaluate and compare the strategies of PI and predictive control applied to the process. To accomplish these goals a simulator was used to represent the three phase separator and hydro cyclones. Algorithms were developed for system identification (NARX) using RLS(Recursive Least Square), along with methods for structure models detection. Predictive Control Algorithms were also implemented with NARX model updated on-line, and optimization algorithms using PSO (Particle Swarm Optimization). This project ends with a comparison of results obtained from the use of PI and predictive controllers (both with optimal state through the algorithm of cloud particles) in the simulated system. Thus, concluding that the performed optimizations make the system less sensitive to external perturbations and when optimized, the two controllers show similar results with the assessment of predictive control somewhat less sensitive to disturbances

Métodos estatísticos recursivos aplicados ao problema de estimação de vazão de gás em plantas de Plunger-lift

This work has as main objective to find mathematical models based on linear parametric estimation techniques applied to the problem of calculating the grow of gas in oil wells. In particular we focus on achieving grow models applied to the case of wells that produce by plunger-lift technique on oil rigs, in which case, there are high peaks in the grow values that hinder their direct measurement by instruments. For this, we have developed estimators based on recursive least squares and make an analysis of statistical measures such as autocorrelation, cross-correlation, variogram and the cumulative periodogram, which are calculated recursively as data are obtained in real time from the plant in operation; the values obtained for these measures tell us how accurate the used model is and how it can be changed to better fit the measured values. The models have been tested in a pilot plant which emulates the process gas production in oil wells

Detecção e diagnóstico de falhas não-supervisionados baseados em estimativa de densidade recursiva e classificador fuzzy auto-evolutivo

In this work, we propose a two-stage algorithm for real-time fault detection and identification of industrial plants. Our proposal is based on the analysis of selected features using recursive density estimation and a new evolving classifier algorithm. More specifically, the proposed approach for the detection stage is based on the concept of density in the data space, which is not the same as probability density function, but is a very useful measure for abnormality/outliers detection. This density can be expressed by a Cauchy function and can be calculated recursively, which makes it memory and computational power efficient and, therefore, suitable for on-line applications. The identification/diagnosis stage is based on a self-developing (evolving) fuzzy rule-based classifier system proposed in this work, called AutoClass. An important property of AutoClass is that it can start learning from scratch". Not only do the fuzzy rules not need to be prespecified, but neither do the number of classes for AutoClass (the number may grow, with new class labels being added by the on-line learning process), in a fully unsupervised manner. In the event that an initial rule base exists, AutoClass can evolve/develop it further based on the newly arrived faulty state data. In order to validate our proposal, we present experimental results from a level control didactic process, where control and error signals are used as features for the fault detection and identification systems, but the approach is generic and the number of features can be significant due to the computationally lean methodology, since covariance or more complex calculations, as well as storage of old data, are not required. The obtained results are significantly better than the traditional approaches used for comparison

A teoria da ruína aplicada em um modelo de empresa financeira com risco de crédito

In this work we study a new risk model for a firm which is sensitive to its credit quality, proposed by Yang(2003): Are obtained recursive equations for finite time ruin probability and distribution of ruin time and Volterra type integral equation systems for ultimate ruin probability, severity of ruin and distribution of surplus before and after ruin

Teoria da Ruína em um Modelo de Markov com dois Estados

In this work, we present a risk theory application in the following scenario: In each period of time we have a change in the capital of the ensurance company and the outcome of a two-state Markov chain stabilishs if the company pays a benece it heat to one of its policyholders or it receives a Hightimes c > 0 paid by someone buying a new policy. At the end we will determine once again by the recursive equation for expectation the time ruin for this company