A Fruticultura Irrigada de pequenos produtores no Baixo-Açu: Uma análise da eficiência de custo

This work has as an objective analyze the efficiency of producers costs of the irrigation Project Baixo-Açu , and identify the determining factors of this efficiency. To achieve these targets it was estimated, in a first stage, a frontier of costs by the method, non parametric of Data Envelopment Analysis-DEA, and measured the stakes of efficiency producers. On the second stage, it was utilized the Tobit regression pattern, estimating an inefficiency function of costs, and were indentified the associated factors of resources waste. Among the results found it was noticed the existence of a high waste of resources, that represent more than 54% of effective cost. Among the factors with the highest wastes are: energy, herbicides, defensives and chemical fertilizers. In a general way, the producers presented low efficiency level and, only, two, of seventy-five researched, achieved the frontier of costs minimization. These results reveal, in a certain way, that the producers in irrigated fruit growing in the project Baixo-Açu don t seek to minimize the production costs. It was still noticed, that the reduction of resources waste, and this way the inefficiency of costs, is associated with the agriculturalist education, his experience in agriculture, his access to the technical assistance and credit

Concentração da posse da terra e o programa nacional de crédito fundiário - uma análise para o estado do Rio Grande do Norte, 2006 - 2012

O objetivo do trabalho é propor um estudo sobre a relação do Programa Nacional de Crédito Fundiário - PNCF, no estado do Rio Grande do Norte, e sua concentração fundiária. Ou seja, se o PNCF está sendo direcionado, para as microrregiões que apresentam maior índice de concentração, de acordo com o índice de Gini, e se as áreas adquiridas através do crédito fundiário estão emergindo nestas microrregiões. Para isto, o estudo levantou a hipótese de que o PNCF no estado do Rio Grande do Norte não está sendo conduzida, de modo a reduzir a concentração fundiária, dentre as microrregiões do estado. Ou seja, não existe correlação entre o índice de Gini, da concentração fundiária, e as áreas adquiridas através do programa. Além disso, o trabalho buscou realizar uma discussão da literatura sobre os programas de reforma agrária assistida pelo mercado. Apresentando os autores que são exaltadores do modelo e das suas potencialidades, atrelando as causas dos problemas levantados como sendo de ordem técnica e operacional, onde os principais autores desta linha são: Van Zyl, Kirsten & Binswanger, (1996), Deininger & Binswanger, (1999). Têm-se também a apresentação da posição dos autores adeptos as políticas fundiárias pautadas na dinâmica e liberação dos mercados de terras, mas que visam contribuir com estudos que permitam uma redução para o custo elevado e a sua incapacidade de abarcar a esfera social, em decorrência do pagamento á vista e a preço de mercado aos donos das terras, são eles: De Janvry & Sadoulet (2002), Gordillo (2002), Banerjee (1999), Jaramillo (1998) e Burki & Perry (1997). Todavia, apresentou-se a corrente de autores que ressalta a natureza socialmente agressiva da Reforma Agrária Assistida pelo Mercado (RAAM), sendo os seus principais contribuidores: El-Ghonemy (2001); Barros, Schwartzman & Sauer (2003); Borras Jr. (2006, 2003 e 2003a); Garoz et al. (2005); Sauer & Pereira (2006); Pereira (2005, 2006 e 2010); Sauer (2010); Lahiff, Borras Jr. & Kay (2007). Em sequência, o trabalho apresentou a transição e características dos programas de acesso à terra, no Brasil, a partir da década de 1990, bem como, alguns indicadores do PNCF, no Brasil e o estado do Rio Grande do Norte. Apresentou-se também os indicadores da concentração fundiária, no Brasil e no estado. Através dos dados do Censo Agropecuário de 2006 foi possível calcular o índice de Gini da distribuição fundiária nas microrregiões no estado do Rio Grande do Norte. Com os dados fornecidos pela Secretaria de Estado de Assuntos Fundiários e de Apoio à Reforma Agrária - SEARA mostrou-se a distribuição das linhas de crédito do PNCF e as áreas adquiridas, entre os anos de 2006 e 2012. Por fim, o valor do coeficiente de correlação simples (r) igual a (0,2865), que com base no teste bilateral da distribuição de t de Student chegou-se no resultado para T calculado no valor de (1,2333), que ao ser comparado com o valor de T crítico igual a (2,898), com 17 graus de liberdade, a um nível de significância de 1%, pode aceitar a hipótese de partida, ou seja, que o PNCF não estava sendo direcionado para diminuir a concentração fundiária no estado

Desenpenho aeróbio e controle autonômico cardíaco em idosas praticantes de tai chi chuan e sedentárias

Conselho Nacional de Desenvolvimento Científico e Tecnológico

As ações de controle da tuberculose na atenção primária à saúde: a visão do doente

Tuberculosis is a disease of great impact on the world context today. In Brazil, the disease management was directed to the Primary Health Care, due to the determination of the Ministry of Health to decentralize health actions for primary care. Thus, since the actions of diagnosis, treatment and control of the disease should happen in this context, however, there are still many barriers that may hinder the realization of these determinations. This study aims to analyze the development of tuberculosis control activities conducted in the services of primary health care from the patient's vision. This is a descriptive, cross-sectional and quantitative study. The population consists of 517 tuberculosis patients treated in units of Primary Health Care in the city of Natal-RN; the sample consists of 93 TB patients. The collect instrument is structured, based in The Primary Care Assessment Tool (PCAT), validated in Brazil and adapted to assess attention to TB in Brazil, with modifications. This instrument was divided into blocks: the first one describes the socio-demographic information of patients with TB and the second one describes the health services working in control, diagnosis and treatment of TB, and includes issues related to the dimensions of primary care: access, bond, services, coordination of care, guidance to the community and family focus. For quantitative analysis, were built indicators for each item of the instrument. The response patterns are followed according to the Likert scale, which was assigned a value between one and five meant that the degree of preference relation (or agreement) of the statements. Values between 1 and 3 were considered unsatisfactory for the indicator, between 3 and less than 4, regular, and between 4 and 5, satisfactory. The results indicate that 62.37% of patients are male, 27.96% aged 41 to 50 years old, and 34.41% unemployed, with low education and low family income. It was found that the reference hospital services are the front door to the patient (59.14%), and are also the local diagnosis of the disease (72.04%). On access, the conditions satisfactory found are: the number of times the patients need to pick up the health care issue, the marking and the facility to get a consultancy in the HS, assistance provided without harm to the individual's attendance labor and facilities related to the proximity between the residence and services; were considered unsatisfactory conditions related to travel to the HS, and on hours and days of operation of services. As for the cast of services were satisfactory and regular actions related to the request for examination to become viable in the first HS, the availability of pot to perform smear and medicines for the treatment, as well as consultations control and receiving information about the disease and the treatment performed; it is considered unsatisfactory the performance of the home care for patients with TB by the HS that acts as a front door, for implementation of the Directly Observed Treatment (DOT), home visits during treatment, the provision of transportation allowance to the patient and the existence of groups for TB patients. Regarding the coordination of care, resulted in regular the action of referring the patient to other HS to obtain examinations, and as unsatisfactory referral to obtain medications. The relationship bond between patient and health team were considered satisfactory in the majority or regular. As for the family and community focus, is satisfactory only the indicator relating to questions from professionals to the patient about the existence of respiratory symptoms in the family. It is considered that there is need for greater commitment from government entities to the incentives required to TB control, as well as the availability of necessary inputs and training of human resources working in the PHC in the ongoing quest to strengthen primary care, as a place of broader host needs to contact the user with the actions and health professionals. It is recommended the adoption of management mechanisms possible to expand the capacity of the health PHC, promoting the service delivery to the user and ensuring attention to population health.

Avaliação do uso do DCP em areias para controle da capacidade de carga em fundações diretas e controle de compactação de aterros

This work presents results of field and laboratory tests using a Dynamic Cone Penetrometer, DCP. The tests were performed in order to evaluate the use of the equipment in sand for the control of bearing capacity of shallow foundations and fill compaction. For shallow foundations, the laboratory tests were conducted on sand placed in a metallic mould by the method of sand pluviation. Although the results show the inability to reproduce field conditions in the laboratory it was possible to verify the ability of the DCP to identify less resistant soil layers. The DCP tests for the analysis of compaction control were performed in a strong box with inside dimensions of 1,40 m x 1,40 m and 0,70 m in height. The soil layers were compacted with different densities though the use of a vibrating plate in order to obtain correlations between penetration index, DPI, and soil relative density. Other tests were also conducted to assess the influence of soil moisture on tests results. Among other findings, the results showed the great potential for the use of DCP to control the compaction of sand fills

Terceirização em tecnologia da informação sob os aspectos de estratégia, tomada de decisão e análise de investimentos :estudo de múltiplos casos em três organizações franqueadas da Coca-Cola do Brasil

Desde a criação da tecnologia e do seu uso pelas empresas, a relação custo e benefício nem sempre foi bem elucidada tanto para os responsáveis pela área de tecnologia quanto para a alta direção. Mas, apesar disto, cada vez mais as organizações investem maciçamente em tecnologia, esperando que esta seja a solução para diversos problemas. Por isto, esta questão tem se tornado crucial para o processo de tomada de decisões, visto que investimentos nesta área costumam ser dispendiosos e, na atual conjuntura, estas análises precisam ser extremamente criteriosas para que se miniminizem as possibilidades de insucesso dos projetos, principalmente numa economia estabilizada e de concorrência acirrada. Uma das alternativas que as empresas têm buscado para atingir o sucesso e correr menos riscos é a terceirização da área de TI. Partindo desta visão, a presente dissertação tem por objetivo realizar uma investigação sobre a terceirização dos serviços de TI em todos os seus aspectos, isto é, desde a sua motivação, serviços efetivamente terceirizados, vantagens, desvantagens e possíveis obstáculos, a visão do alinhamento estratégico da TI, os processos de gestão de contratos e formas de controle e, por fim, tendências futuras. Trata-se de uma pesquisa de múltiplos casos, envolvendo franquias do Sistema Coca-Cola no Brasil. O estudo apresenta uma pesquisa bibliográfica sobre o processo de tomada de decisão empresarial, a análise de investimentos, a gestão e a terceirização da TI, o que permitem definir as dimensões de análise da pesquisa. Na pesquisa de campo foram entrevistados os gerentes da área de TI, nas cidades de Brasília-DF, Goiânia-GO e Ribeirão Preto-SP. A pesquisa de campo permitiu identificar como as mesmas avaliam seus investimentos em TI, como esta área é gerenciada, o que as levou a optar pela terceirização e como os processos terceirizados afetam a organização. Por se tratar de uma pesquisa qualitativa, optou-se por analisar comparativamente as três organizações. Com a realização deste estudo, obtiveram-se, como principais resultados, que as organizações estão utilizando a terceirização em TI para focar no negócio principal e, mesmo encontrando diversas desvantagens, inclusive com relação a custos, acreditam que os benefícios justificam. Ainda identificaram-se alguns obstáculos internos para a terceirização, principalmente quanto ao receio de se perder a inteligência do negócio. O acompanhamento dessas atividades terceirizadas é realizado pela equipe interna e por critérios estruturados, onde se verificam os níveis de serviço

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developping the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. Its important to point out that, in spite of the loads being normally connected to the transformers secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Contribuições à análise de robustez de sistemas de controle usando redes neurais

This work develops a robustness analysis with respect to the modeling errors, being applied to the strategies of indirect control using Artificial Neural Networks - ANN s, belong to the multilayer feedforward perceptron class with on-line training based on gradient method (backpropagation). The presented schemes are called Indirect Hybrid Control and Indirect Neural Control. They are presented two Robustness Theorems, being one for each proposed indirect control scheme, which allow the computation of the maximum steady-state control error that will occur due to the modeling error what is caused by the neural identifier, either for the closed loop configuration having a conventional controller - Indirect Hybrid Control, or for the closed loop configuration having a neural controller - Indirect Neural Control. Considering that the robustness analysis is restrict only to the steady-state plant behavior, this work also includes a stability analysis transcription that is suitable for multilayer perceptron class of ANN s trained with backpropagation algorithm, to assure the convergence and stability of the used neural systems. By other side, the boundness of the initial transient behavior is assured by the assumption that the plant is BIBO (Bounded Input, Bounded Output) stable. The Robustness Theorems were tested on the proposed indirect control strategies, while applied to regulation control of simulated examples using nonlinear plants, and its results are presented

Plataforma Robótica de Baixíssimo Custo para Robótica Educacional

Robots are present each time more on several areas of our society, however they are still considered expensive equipments that are restricted to few people. This work con- sists on the development of control techniques and architectures that make possible the construction and programming of low cost robots with low programming and building complexity. One key aspect of the proposed architecture is the use of audio interfaces to control actuators and read sensors, thus allowing the usage of any device that can produce sounds as a control unit of a robot. The work also includes the development of web ba- sed programming environments that allow the usage of computers or mobile phones as control units of the robot, which can be remotely programmed and controlled. The work also includes possible applications of such low cost robotic platform, including mainly its educational usage, which was experimentally validated by teachers and students of seve- ral graduation courses. We also present an analysis of data obtained from interviews done with the students before and after the use of our platform, which confirms its acceptance as a teaching support tool

Análise e projeto de superfícies seletivas de frequência com elementos pré-fractais para aplicações em comunicações indoor

In this thesis, a frequency selective surface (FSS) consists of a two-dimensional periodic structure mounted on a dielectric substrate, which is capable of selecting signals in one or more frequency bands of interest. In search of better performance, more compact dimensions, low cost manufacturing, among other characteristics, these periodic structures have been continually optimized over time. Due to its spectral characteristics, which are similar to band-stop or band-pass filters, the FSSs have been studied and used in several applications for more than four decades. The design of an FSS with a periodic structure composed by pre-fractal elements facilitates the tuning of these spatial filters and the adjustment of its electromagnetic parameters, enabling a compact design which generally has a stable frequency response and superior performance relative to its euclidean counterpart. The unique properties of geometric fractals have shown to be useful, mainly in the production of antennas and frequency selective surfaces, enabling innovative solutions and commercial applications in microwave range. In recent applications, the FSSs modify the indoor propagation environments (emerging concept called wireless building ). In this context, the use of pre-fractal elements has also shown promising results, allowing a more effective filtering of more than one frequency band with a single-layer structure. This thesis approaches the design of FSSs using pre-fractal elements based on Vicsek, Peano and teragons geometries, which act as band-stop spatial filters. The transmission properties of the periodic surfaces are analyzed to design compact and efficient devices with stable frequency responses, applicable to microwave frequency range and suitable for use in indoor communications. The results are discussed in terms of the electromagnetic effect resulting from the variation of parameters such as: fractal iteration number (or fractal level), scale factor, fractal dimension and periodicity of FSS, according the pre-fractal element applied on the surface. The analysis of the fractal dimension s influence on the resonant properties of a FSS is a new contribution in relation to researches about microwave devices that use fractal geometry. Due to its own characteristics and the geometric shape of the Peano pre-fractal elements, the reconfiguration possibility of these structures is also investigated and discussed. This thesis also approaches, the construction of efficient selective filters with new configurations of teragons pre-fractal patches, proposed to control the WLAN coverage in indoor environments by rejecting the signals in the bands of 2.4~2.5 GHz (IEEE 802.11 b) and 5.0~6.0 GHz (IEEE 802.11a). The FSSs are initially analyzed through simulations performed by commercial software s: Ansoft DesignerTM and HFSSTM. The fractal design methodology is validated by experimental characterization of the built prototypes, using alternatively, different measurement setups, with commercial horn antennas and microstrip monopoles fabricated for low cost measurements

Modelagem e controle de um microveículo aéreo: uma aplicação de estabilidade robusta com a técnica backstepping em uma estrutura hexarrotor

In this Thesis, the development of the dynamic model of multirotor unmanned aerial vehicle with vertical takeoff and landing characteristics, considering input nonlinearities and a full state robust backstepping controller are presented. The dynamic model is expressed using the Newton-Euler laws, aiming to obtain a better mathematical representation of the mechanical system for system analysis and control design, not only when it is hovering, but also when it is taking-off, or landing, or flying to perform a task. The input nonlinearities are the deadzone and saturation, where the gravitational effect and the inherent physical constrains of the rotors are related and addressed. The experimental multirotor aerial vehicle is equipped with an inertial measurement unit and a sonar sensor, which appropriately provides measurements of attitude and altitude. A real-time attitude estimation scheme based on the extended Kalman filter using quaternions was developed. Then, for robustness analysis, sensors were modeled as the ideal value with addition of an unknown bias and unknown white noise. The bounded robust attitude/altitude controller were derived based on globally uniformly practically asymptotically stable for real systems, that remains globally uniformly asymptotically stable if and only if their solutions are globally uniformly bounded, dealing with convergence and stability into a ball of the state space with non-null radius, under some assumptions. The Lyapunov analysis technique was used to prove the stability of the closed-loop system, compute bounds on control gains and guaranteeing desired bounds on attitude dynamics tracking errors in the presence of measurement disturbances. The controller laws were tested in numerical simulations and in an experimental hexarotor, developed at the UFRN Robotics Laboratory

Construção, calibração e análise de desempenho de um piranômetro de baixo custo, baseado no modelo Kimball-Hobbs

In this work a pyrometer using the classic model of Kimball-Hobbs was developed, tested and calibrated. The solar radiation is verified through the temperature difference between the sensible elements covered by absorbing (black) and reflecting (white) pigmentations of the incoming radiation. The photoacoustic technique was used to optimize the choice of the pigments. Methodologies associated with linearity, thermo-variation, sensibility, response time and distance are also presented. To correctly classify the results, the international standard ISO 9060 as well as indicative parameters of World Meteorological Organization (WMO) are used. In addition a system of data acquisition of two channels with 12 bits, constructed during the this time, was used to measure the global solar radiation on the ground by the pyrometer and also by another pyrometer certified in the case of Keep & zonen. The results statistically show, through the hypothesis test presented here, that both equipments find population average with 95% of correctness

Projeto, construção e análise de desempenho de um forno solar alternativo tipo caixa a baixo custo

An alternative box-type solar oven constructed from the scrap iron of a gas conventional cook is presented, which functions principles are the effect greenhouse and the concentration. The oven of the conventional cook is the baking enclosure where the absorber (pot) of the solar oven is located, being re-covered for a glass blade for the generation of the greenhouse effect isolated lateral and having deep its and for a composite the plaster base and EPS. Segments of plain mirrors had been placed in the laterals of the oven for the concentration of the radiation and a reflecting parabola was introduced in the baking enclosure for the exploitation of the incident reflected radiation in the interior of the oven. The oven is mobile to allow one better aiming of exactly in relation to the apparent movement of the sun. The thermal economic and of materials viabilities of the stove in study will be demonstrate The average internal temperature of the absorber was around 150°C and the internal temperature around 120°C. Will demonstrate that its low cost and good thermal performance represents basic characteristics for the viability of large use of such archetype, mainly for cooking the decreases and averages temperatures. One will reveal that the archetype in study is competitive with the box-type solar cooker conceived in the whole world

Análise do desempenho térmico de um sistema de aquecimento solar de baixo custo

It presents a solar collector to be used in a system for heating water for bathing, whose main characteristics are low cost and easy manufacturing and assembly. The system operates under natural convection or thermosiphon. The absorbing surface of the collector is formed by twelve PVC pipes of 25 mm outside diameter connected in parallel via connections in T of the same material. The tubes were covered with absorbing fins made with recycled aluminum cans. We studied eight settings between absorber plate, thermal insulating EPS boards and thermal reservoirs 150 and 200 liters. It was determined the most efficient configuration for the correct purpose. We evaluated thermal parameters that proved the viability of the heating system studied

Análise da eficiência de aquecedor solar espiral com e sem efeito estufa para piscinas

The technical and economic viability of solar heating for swimming pools is unquestionable, besides there it replaces the high costs and environmental impacts of conventional supply of energy, and it improves an optimization in the pool heating uses. This work applies the principles of the greenhouse effect: advanced thermodynamics, heat retention and equalization of temperature, to optimize the solar heating equipment, reducing the area required by collectors as much as 40% (still estimated value) for commercial collectors, with minor architectural and aesthetic impacts on the environment. It features a solar heating alternative in pools, whose main characteristics: low cost, simplicity in manufacturing and assembly and a faster heating. The system consists of two collectors spiral hoses made of polyethylene with a hundred meters each, and working on a forced flow, with only one pass of the working fluid inside the coils, and is used to pump itself treatment of pool water to obtain the desired flow. One of the collectors will be exposed to direct solar radiation, and the other will be covered by a glass slide and closed laterally, so providing the greenhouse effect. The equipment will be installed in parallel and simultaneously exposed to the sun in order to obtain comparative data on their effectiveness. Will be presented results of thermal tests for this the two cases, with and without transparent cover. Will be demonstrated, by comparison, the thermal, economic and material feasibility of these systems for heating swimming pools.