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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Agricultura familiar: validação e sustentabilidade das patrulhas agrícolas / Family farming: validation and sustainability of state farm machinery services

Neves, Lúcio de Araujo 28 November 2011 (has links)
Made available in DSpace on 2014-08-20T14:32:58Z (GMT). No. of bitstreams: 1 Dissertacao_Lucio_Araujo_Neves.pdf: 3077726 bytes, checksum: 1471fcf72af944a4d0d568d3bf6ed9d6 (MD5) Previous issue date: 2011-11-28 / The Family Farming increasingly seeking viable alternatives of mechanization, especially in order to minimize the physical effort that the farmer has to spend in his daily work. In order to contribute to this situation, some municipalities have formed farm machinery services (MSs), which is the name given to the collection of agricultural machinery available to farmers. This study aims to characterize and evaluate the performance of the MSs of the municipalities of Arroio do Padre, Canguçu, Capão Leão, Jaguarão, São Lourenço do Sul and Turuçu, all located in the southern region of Rio Grande do Sul state, Brazil. To this end, an exploratory survey was applied, which dividinged the people involved in internal customers (people directly involved in the management of the MSs, intermediate customers (machine operators) and external customers (farmers who use the services of MSs). For the collection of field data, a semi-structured interviews and questionnaires were used. The data showed that MSs are well structured in terms of machinery, as they have in their compositions a variety of machines in accordance to with the main crops plantedin of the in the regions where they operate. However, there are problems, especially with respect to their sizing and the real needs of family farmers. Also, it was observed that the best management practice in the MSs occurs when this task is transferred to the associations of producers, this lead causes them to organize themselves, create a spirit of cooperation and mutual assistance. This, in turn, is also a way to improve the care of a public asset that belongs to everyone. Another point that stands out refers to the machine operators. It was observed that, in the cities analyzed, this type of activity has improved operating results when operators are outsourced. The investigation allowed concluding that the state farm machinery services have as main characteristic the assistance to farmers, especially those with less means to mechanize their properties. / A Agricultura Familiar cada vez mais busca alternativas viáveis de mecanização, principalmente no sentido de minimizar o esforço físico que o produtor tem de despender no seu dia a dia. Com a finalidade de contribuir com tal situação, alguns municípios criaram as patrulhas agrícolas (PAs), que é o nome dado ao conjunto de máquinas e implementos colocados à disposição dos agricultores familiares. Este estudo tem por objetivo caracterizar e avaliar o funcionamento das PAs dos municípios de Arroio do Padre, Canguçu, Capão do Leão, Jaguarão, São Lourenço do Sul e Turuçu, todos localizados na região sul do Rio Grande do Sul. Para tal, utilizou-se de um estudo exploratório, em que se dividiu os clientes em Internos (pessoas envolvidas diretamente na administração das PAs), Intermediários (operadores das máquinas) e Externos (produtores que utilizam os serviços das PAs). Para a coleta de dados a campo, foram utilizados entrevistas semi-estruturadas e questionários. Os dados mostraram que as PAs estão bem estruturadas em termos de máquinas, uma vez que possuem em suas composições, equipamentos diversificados de acordo com as culturas implantadas nas regiões em que estão inseridas. Contudo, existem problemas, principalmente, com relação ao dimensionamento das mesmas e as reais necessidades das propriedades familiares. Também, observou-se que a melhor prática de administração das PAs se dá no repasse dessa tarefa às associações de produtores, isso faz com que os mesmos se organizem, criem um espírito de cooperação e ajuda mútua. Essa, por sua vez, é também uma forma de aumentar os cuidados com o bem que é público e de todos. Os operadores das máquinas têm melhores resultados operacionais, quando são terceirizados. Verificou-se, ainda que as patrulhas agrícolas têm como principal característica o auxílio aos agricultores familiares, especialmente àqueles com menores condições de mecanizar suas propriedades.
112

Projeto de um dosador de fertilizantes para semeadora / adubadora de grãos graúdos de baixa potência para agricultura familiar

Vasconcelos, Márcia Beatriz Silva 19 December 2011 (has links)
Made available in DSpace on 2014-08-20T14:33:00Z (GMT). No. of bitstreams: 1 Dissertacao_Marcia_Beatriz_Vasconcelos.pdf: 2622303 bytes, checksum: fc997b6c1682e74631f3ca53318515e1 (MD5) Previous issue date: 2011-12-19 / The Family Farm has a great capacity for productive conversion and management, fitting the best possible economic, social and cultural rights, including the market in an effective and dynamic, but facing some problems to absorb new technologies to increase productivity. There is the great importance of developing technologies for family farms, covering their needs and demands of economically and efficiently. Therefore this study aimed to develop a prototype feeder fertilizer that meets the two sowing lines simultaneously, and to verify the functionality of the design principles of the chosen solution. We evaluated the performance of the prototype with four types of fertilizer, three conditions for opening the dispenser system (430, 839 and 1.270mm ²) and three speeds (2.5, 5.0 and 7.5 rpm) of the active organ. The performance of the fertilizer metering mechanism was judged satisfactory for granulated products, but should be improved to avoid disrupting the flow of materials in powder form at low speeds. It was possible to obtain flow rates of fertilizer between 14 and 100 g / s, which meet the needs of family farmers. / A Agricultura Familiar apresenta uma grande capacidade de reconversão produtiva e de gestão, se adequando às melhores possibilidades econômicas, sociais e culturais, inclusive de mercado de maneira eficaz e dinâmica, porém enfrentam alguns problemas para absorver novas tecnologias para o aumento de sua produtividade. Verifica-se a grande importância de desenvolvimento de tecnologias voltadas a agricultura familiar, que contemple suas necessidade e demandas de forma econômica e eficiente. Com isso o presente trabalho objetivou desenvolver um protótipo de dosador de fertilizante que atende a duas linhas de semeadura simultaneamente, bem como verificar a funcionalidade dos princípios de solução da concepção escolhida. Avaliou-se o desempenho do protótipo com quatro tipos de fertilizantes, três condições de abertura no sistema dosador (430, 839 e 1.270mm²) e três rotações (2,5; 5,0 e 7,5 rpm) do órgão ativo. O desempenho do mecanismo dosador de fertilizante foi julgado satisfatório para os produtos granulados, porém deve ser melhorado para evitar a interrupção do fluxo dos materiais na forma de pó em baixas rotações. Foi possível obter vazões de fertilizantes entre 14 e 100 g/s, as quais atendem às necessidades dos agricultores familiares.
113

Analyzing the Effects of Autonomous Navigation on Row Crop Farming

Eric Kong (11150976) 03 August 2021 (has links)
As the global population rises, so does the demand for food, feed, fiber, and fuel. Meeting this demand has become increasingly difficult due to the decline in farm labor and challenges associated with the economic viability of agricultural systems. Autonomous agricultural machinery has the potential to mitigate some of major challenges that crop production systems will face. Widespread adoption of autonomous machinery is dependent on two key factors, the cost and environmental impact. The development and adoption of autonomous vehicles will only occur if it is profitable for equipment manufacturers and farmers. As distillate fuel use for crop production increases, fuel efficient operations that minimize greenhouse gas emissions will mitigate the environmental impact of farming.<br><div><br></div><div>The objective of this research was to develop a model to quantify the cost, energy use, and emissions associated with the use of agricultural machinery used for row crop farming. The model calculates the cost of different sized machinery fleets for planting and harvest. Autonomy facilitates swarm farming, and the model can quantify and compare these to human-operated machinery systems.<br></div><div><br></div><div>For an 800-hectare case study farm in the Midwest, with the acreage split evenly between corn and soybeans, the most cost-effective planting machinery fleet was comprised of two autonomous, 56-kW JD 5075E tractors pulling 4-row planters ($40/ha/yr). The most cost-effective fleet used the most fuel (4,327 liters) and produced the most emissions (219,735 grams). For a similar conventional system to complete planting during the same working window, it would require 4 tractors and cost $75/ha/yr. The $35/ha/yr difference between the similar fleets was the value added by autonomy. Current row crop farming trends have shifted towards fewer operators with larger machines and implements. The most cost-effective, single operator machinery set from the database (Case Magnum 200 with a 16-row planter) costs $43/ha/yr more than overall most cost-effective fleet. Total fuel used to complete the planting operation was minimized by using a single John Deere 8320R pulling a 36-row planter. To plant all 800-hectares, the 8320R used 2,528 liters of diesel fuel and produced a combined 44,002 grams of emissions. The JD 5075E was able to minimize cost, but it used the most fuel and produced the most greenhouse gas.<br></div><div><b><br></b></div>
114

VOLUME MEASUREMENT OF BIOLOGICAL MATERIALS IN LIVESTOCK OR VEHICULAR SETTINGS USING COMPUTER VISION

Matthew B Rogers (13171323) 28 July 2022 (has links)
<p>A Velodyne Puck VLP-16 LiDAR and a Carnegie Robotics Multisense S21 stereo camera were placed in an environmental testing chamber to investigate dust and lighting effects on depth returns. The environmental testing chamber was designed and built with varied lighting conditions with corn dust plumes forming the atmosphere. Specific software employing ROS, Python, and OpenCV were written for point cloud streaming and publishing. Dust chamber results showed while dust effects were present in point clouds produced by both instruments, the stereo camera was able to “see” the far wall of the chamber and did not image the dust plume, unlike the LiDAR sensor. The stereo camera was also set up to measure the volume of total mixed ration (TMR) and shelled grain in various volume scenarios with mixed surface terrains. Calculations for finding actual pixel area based on depth were utilized along with a volume formula exploiting the depth capability of the stereo camera for the results. Resulting accuracy was good for a target of 8 liters of shelled corn with final values between 6.8 and 8.3 liters from three varied surface scenarios. Lessons learned from the chamber and volume measurements were applied to loading large grain vessels being filled from a 750-bushel grain cart in the form of calculating the volume of corn grain and tracking the location of the vessel in near real time. Segmentation, masking, and template matching were the primary software tools used within ROS, OpenCV, and Python. The S21 was the center hardware piece. Resulting video and images show some lag between depth and color images, dust blocking depth pixels, and template matching misses. However, results were sufficient to show proof of concept of tracking and volume estimation. </p>
115

Determining the content of a farm power and machinery course for vocational agriculture high schools in Virginia

Thompson, Evans Guy January 1952 (has links)
1. This is a study of 60 white teachers of vocational agriculture in Virginia to determine the desirable content of a farm power and machinery course for vocational agriculture in the high schools of Virginia. The purposes of the study were: a. To determine the nature and content of farm power and machinery units being taught by teachers of vocational agriculture in the high schools of Virginia. b. To determine the teaching units in farm power and machinery that should be included in the high school vocational agriculture course. Based on the teaching experience of the teachers included in this study, it is concluded that the practices being used and recommended by a majority of these teachers should be considered as acceptable guides for all teachers to follow in organizing and conducting their instructional program in farm power and machinery. The recommended teaching units include a study of: determining the place of power and machinery on the farm, preventing accidents on the farm, tractors, transportation equipment, tillage implements, seeding equipment, lime, manure, fertilizer distributors, harvesting equipment, crop processing equipment, clean, grading equipment, spraying, dusting equipment, pumps, rams, miscellaneous farm equipment, and storing equipment. / M.S.
116

Bearing failure detection in farm machinery using low-cost acoustic techniques

Worley, Stacy K. 30 June 2009 (has links)
Unexpected bearing failures in agricultural equipment can result in considerable inconvenience, potential hazard, and monetary loss. Continuous bearing condition monitoring using vibration and audio spectrum analysis can detect imminent bearing failures before dangerous situations develop. Current application of bearing condition monitoring using vibration signature analysis has focused on fixed industrial applications involving high cost equipment and high shaft speeds. The feasible application of current technology on mobile agricultural equipment requires a lower-cost method of signal sensing and processing. Lower shaft speeds and the use of neural-net based pattern recognition techniques can allow the use of lower-cost transducers necessary for practical adoption on mobile equipment. A test apparatus was developed and constructed to test the feasibility of using a electret microphone as a sensor for monitoring bearing condition through vibration signature analysis. Laboratory experiments designed to evaluate the sensors with test bearings at both an advanced and an early stage of wear were developed. A field-worn bearing that had been removed from a unit of farm machinery was obtained and examined. Twelve new bearings identical in type to the field worn bearing were also examined, altered to simulate an early stage of wear, and re-examined. Identical experiments were conducted on both the field-worn and altered bearings. The signal acquired from a field-worn bearing was compared with the signal acquired from a new bearing using a two-sample, paired t-test for means at an alpha level of 0.05 and a graphical defect frequency analysis. The signals acquired from the altered bearings were compared with the signals acquired from the new bearings using the same statistical and graphical test performed on the field-worn bearings. The goal of the analysis was to evaluate the performance of the microphone by attempting to identify significant frequency patterns that could be used to determine the condition of the test bearing while in operation. Duplicate experiments conducted using the accelerometer provided a comparison of sensor performance. The microphone performed well for bearings at an advanced stage of wear. The sensitivity of the accelerometer resulted in better performance when used with bearings at an early stage of wear. / Master of Science
117

The construction of job sheets in farm forge shop

Myers, Paul Franklin January 1940 (has links)
Master of Science
118

Finite element analysis of multipass effects of vehicles on soil compaction

Pollock, David Garnet January 1984 (has links)
A computer program based on the finite element procedure was modified to analyze the multipass effect of rubber-tired vehicles on soil compaction. The wheel-soil interaction was modeled as an axisymmetric problem by approximating the elliptical wheelsoil contact area with an equivalent circular area. A hyperbolic stress-strain relationship was used to model the nonlinear material characteristics of the soil. The boundary load conditions were based on contact area and contact pressure data for a standard tire. The finite element program developed was verified by conducting a linear elastic analysis of a circular flexible footing problem and comparing the results with closed form solution. The results of the finite element analysis agreed well with the closed form solution. The effects of soil type, wheel-soil contact area, and multiple wheel loading on soil compaction were analyzed. The results of the analyses provided information on soil displacement, stress distribution, and volumetric strain. Residual volumetric strain contours, developed after each loading and unloading cycle (simulating the passage of a wheel), showed zones of maximum compaction and the propagation of compaction zones as a function of the number of wheel loadings. A major portion (80% - 90%) of the total residual volumetric strain was found to occur during the first wheel pass. The rate of increase in volumetric strain dropped noticeably as the number of passes increased. As expected, results of the analysis show that for a given vehicle weight, the use of large tires minimizes the degree of compaction. / Master of Science
119

Robô agrícola móvel (RAM): uma arquitetura baseada em comportamentos hierárquicos e difusos para sistemas autônomos de guiagem e navegação / Agricultural mobile robot (MAR): an architecture based on hierarchical and fuzzy behaviors for autonomous systems of guidance and navigation

Sousa, Rafael Vieira de 10 August 2007 (has links)
Avanços positivos nas pesquisas em veículos agrícolas autônomos (VAA\'s) e de robôs agrícolas móveis (RAM\'s) têm sido conquistados nos últimos anos. Entretanto, um número limitado de trabalhos tem proposto sistemas robustos baseados em arquiteturas robóticas capazes de realizar operações múltiplas e idependentes, bem como adaptar-se às mudanças ambientais no campo. Por outro lado, em outras áreas de pesquisa, um número representativo de arquiteturas baseadas em comportamentos tem sido proposto para guiagem e para navegação autônomas de robôs móveis em ambientes não estruturados e/ou não explorados. No presente trabalho, uma arquitetura robótica baseada em comportamentos é desenvolvida para guiagem e navegação de RAM\'s e VAA\'s. Regras difusas são utilizadas para compor e coordenar comportamentos primitivos e comportamentos complexos. O desenvolvimento inclui: a implementação e a simulação da arquitetura em um mini-robô; a avaliação e a caracterização de sensores para o módulo perceptivo da arquitetura; e a aplicação de um método de análise baseado em um modelo matemático para auxiliar a composição de uma rede de comunicação digital baseada no protocolo CAN para sistemas de controle robóticos. Experimentos foram realizados para avaliar os comportamentos implementados e para avaliar a capacidade de operação da plataforma robótica em um ambiente agrícola simulado. Os resultados mostraram a viabilidade da abordagem proposta. A modularidade da arquitetura com a utilização de controladores difusos descentralizados simplificou a implementação da arquitetura. O processo de arbitragem difuso mostrou-se um método simples e viável para implementar a coordenação de comportamentos e para compor comportamentos complexos. A avaliação e caracterização de sensores, em especial de um sensor ultrassônico, permitiram a determinação de condições operacionais para a utilização desses sensores em VAA\'s ou em RAM\'s. A aplicação do modelo matemático para a rede permitiu a análise de desempenho da rede CAN para diferentes equipamentos e sob diferentes parâmetros de configuração para aplicação em um RAM. / Positive advances on AVV (Agricultural Autonomous Vehicle) and MAR (Mobile Agricultural Robot) research are noticed in recent years. However, a limited number of works have proposed reliable systems based on a robotic architectures that are able to perform multiple and independent operations, as well as to self-adapt under changing environmental conditions in the field. In other hand, in other research areas a considerable number of behavior-based architectures have been proposed for mobile robot for autonomous guidance and navigation in unstructured and/or in unexplored environments. At this work, a robotic behavior-based architecture is developed for guidance and navigation of AAV and MAR. Fuzzy rules are used to compose and coordinate the primitive and the complex behaviors. The development includes: the implementation and the simulation of the proposed architecture on a mini-robot; the evaluation and characterization of sensors for the perceptive module of the architecture; and the application of an analysis method based on a mathematical model to assist the composition of a digital communication networks based on the CAN protocol for robot control systems. Experiments have been performed to evaluate the implemented behaviors and to evaluate the operation ability of the robotic platform on a simulated agricultural environment. The results show the feasibility of the proposed approach. The modularity of the architecture by using decentralized fuzzy controllers simplifies the implementation of the robotic architecture. The fuzzy arbitration process is an easy and a feasible method to implement the behavior coordination and to compose complex behaviors. The sensors evaluation and characterization, in particular of an ultrasonic sensor, have allowed establishing operational conditions for using them in AAV or in a MAR. The application of the network mathematical model has allowed the performance analysis of the CAN-based networks under differentiated equipment and configuration parameters for applications in a MAR.
120

A indústria de máquinas agrícolas: formação de um oligopólio, internacionalização e poder de mercado / The agricultural machinery industry: the emergence of an oligopoly, internationalization and market power

Silva, Rodrigo Peixoto da 05 February 2015 (has links)
O objetivo desta dissertação é realizar um estudo sobre a evolução das estruturas de mercado da indústria de máquinas agrícolas em âmbito mundial, destacando os países e o contexto de sua origem, bem como as características de sua expansão internacional. As estratégias de fusão e aquisição, adotadas como forma predominante de entrada em novos mercados, são enfatizadas, assim como o seu papel sobre o aumento do poder de mercado na indústria brasileira de tratores agrícolas. Para isso o trabalho foi dividido em três capítulos. O primeiro capítulo traz o embasamento teórico sobre as estruturas de mercado em oligopólio e suas formas de concorrência, além de um levantamento histórico da indústria de forma a relacioná-los, destacando suas principais características e marcos de sua evolução. O segundo capítulo traz um panorama geral da indústria e do mercado de máquinas agrícolas mundial na última década, definindo os principais players, suas características e vantagens que proporcionaram o desenvolvimento desta indústria, além de uma caracterização dos padrões de comércio internacional predominantes. Por fim, o último capítulo tem seu foco no caso brasileiro e analisa os impactos da concentração de mercado sobre desempenho da indústria em termos de poder de mercado, realizando, para isto, a estimação dos parâmetros de uma função demanda por tratores agrícolas (elasticidade preço da demanda) e de um indicador de poder de mercado (índice de Lerner). Os resultados desta pesquisa permitem demonstrar que esta indústria tornou-se concentrada com o advento da Revolução Industrial, formando um grande oligopólio, primeiramente em nível nacional e, posteriormente, internacional. A concentração e a internacionalização deram-se principalmente por meio de fusões e aquisições, tendo impactos sobre os níveis e as formas de concorrência predominantes. Os países emergentes exercem papel cada vez mais importante como produtores e demandantes de tratores e colheitadeiras, embora os Estados Unidos e a Europa sejam ainda os principais mercados para esta indústria. No mercado brasileiro, ainda que não tenham ocorrido mudanças significativas na elasticidade preço da demanda, a fusão de duas grandes multinacionais elevou significativamente os índices de poder de mercado por meio do aumento da concentração de mercado. / The aim of this study is to conduct an analysis about the evolution of market structures of agricultural machinery worldwide industry, highlighting the countries and the context of its origin, as well as the characteristics of its international expansion. Merger and acquisition strategies, adopted as predominant form of entry into new markets, are emphasized, as well as its role on the increase of market power in the Brazilian industry of agricultural tractors. The work was divided into three chapters. The first chapter provides the theoretical basis on oligopoly market structures and its forms of competition, in addition to a historical survey of the industry in order to relate them, highlighting its main features and landmarks of its evolution. The second chapter provides an overview of the industry and world agricultural machinery market in the last decade, defining the major players, their characteristics and advantages that afforded the development of this industry, in addition to a characterization of predominant international trade patterns. Finally, the last chapter has its focus on the Brazilian case and analyzes the impacts of market concentration on the industry\'s performance in terms of market power, performing, for this, the estimation of the parameters of a demand function for agricultural tractors (price elasticity of demand) and an indicator of market power (Lerner index). The results allow demonstrating that this industry became concentrated with the advent of the Industrial Revolution, forming a large oligopoly, first at national level and, subsequently, international. The concentration and internationalization came mainly through mergers and acquisitions, having impacts on the levels and forms of competition prevalent. Emerging countries has increased their importance as producers and plaintiffs of tractors and combines, though the United States and Europe are the main markets for this industry. In the Brazilian market, although there have been no significant changes in the price elasticity of demand, the merger of two large multinationals has raised significantly the market power by increasing market concentration.

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