General Aviation (GA) accidents constitute the majority of aviation related accidents. In the United States, there have been over 7,000 GA accidents compared to 190 airline accidents in the last 8 years. Flight data analysis has helped reduce the accident rate in commercial aviation. Similarly, safety analysis based on flight data can help GA be safer. The FAA mandates flight data recorders for multi-engine and turbine powered aircraft, but nearly 80% of General Aviation consists of single engine, of which only a small portion contain any form of data recording device. GA aircraft flight data recorders are costly for operating pilots. Low-cost flight recorders are few and rarely used in GA safety analysis due to lack of accuracy compared to the certified on-board equipment. In this thesis, I investigate the feasibility of using a low-cost Attitude and Heading Reference System (AHRS) to detect hazardous states in GA aircraft. I considered the case of roll angles and found that the low-cost device has significant measurement errors. I developed models to correct the roll angle error as well as methods to improve the detection of hazardous roll angles. I devised a method to evaluate the time accuracy along with the angle accuracy and showed that despite the errors, the low-cost device can provide partial hazardous state detection information.

<div>Recently, with the advancement in drone technology, more and more hobby drones are being manufactured and sold across the world. However, these drones can be repurposed</div><div>for the use in illicit activities such as hostile-load delivery. At the moment there are not many systems readily available for detecting and intercepting those hostile drones. Although there is a prototype of a working drone interceptor system built by the researchers of Purdue University, the system was not ready for the general public due to its nature of proof-of-concept and the high price range of the military-grade RADAR used in the prototype. It is essential to substitute such high-cost elements with low-cost ones, to make such drone interception system affordable enough for large-scale deployment.</div><div><br></div><div><div>This study aims to provide an alternative, affordable way to substitute an expensive, high-precision RADAR system with Convolutional Neural Network based drone detection system, which can be built using multiple low-cost single board computers. The experiment will try to find the feasibility of the proposed system and will evaluate the accuracy of the drone detection in a controlled environment.</div></div>

A irrigação por aspersão em malha está inserida nos conceitos da nova agricultura irrigada, pois se trata de um sistema simples e efetivo, com custo altamente competitivo, de fácil implantação e baixo consumo de energia elétrica, quando comparado a outros sistemas de irrigação. Este sistema foi desenvolvido para irrigar pastagens, no entanto, atualmente, está sendo expandida para outras áreas, tais como café. No Brasil a automação de sistemas de irrigação vem sendo implantada com maior intensidade nos últimos anos, principalmente em função do surgimento de técnicas apropriadas que acompanha a modernização crescente da agricultura e abertura do mercado brasileiro às importações. A automação se faz necessária não somente pela possibilidade de redução dos custos com mão de obra, mas principalmente por necessidades operacionais, tais como irrigação de grandes áreas no período noturno. O trabalho teve por objetivo desenvolver e avaliar um dispositivo hidráulico-mecânico para sequenciamento automático da aspersão em malha, para facilitar o manejo do sistema de irrigação de maneira a reduzir as despesas com mão de obra e energia elétrica. Os protótipos foram feitos e avaliados no Laboratório de Hidráulica e Irrigação do Departamento de Engenharia de Biossistemas, da Escola Superior de Agricultura Luiz de Queiroz (ESALQ), da Universidade do Estado de São Paulo (USP). Planejou-se uma lógica de automação sequenciada de válvulas hidráulicas, controladas por válvulas multivias acionadas por um temporizador volumétrico. Construiu-se uma malha de irrigação, com quatro aspersores e em cada tubo de subida foram instaladas válvulas hidráulicas. Construíram-se protótipos dos sequenciadores para cada aspersor, constituídos de um temporizador volumétrico, uma válvula multivias e um sistema de gatilho, para troca de posição do êmbolo. Realizaram-se testes de avaliação do sistema de sequenciamento, e observou-se que os tempos de irrigação por aspersor foram semelhantes aos tempos calculados para cada temporizador. Com isso o sistema mostrou ser uma alternativa técnica viável para a automação sequenciada de aspersores em um sistema de aspersão em malha. / The net-sprinkler irrigation system is inserted in the new concepts of irrigated agriculture, because it is simple and effective, with high competitive cost, easy deployment and low power consumption when compared to other irrigation systems. This system initially was developed to irrigate pasture however nowadays it is being expanded to other areas, such as coffee. In Brazil, the automation of irrigation systems has been intensitly implemented in recent years, mainly due to the development of appropriate techniques that accompanies the agricultural modernization and openness of the Brazilian market to imports. Automation is necessary not only tof reduce costs and manpower, but mainly for operational needs such as irrigation of large areas at night. The study aimed to develop and evaluate a hydraulic-mechanical device for automated sequencing of sprinkler system in a grid, to facilitate the management of the irrigation system ,as well, to reduce the cost of manpower and electricity. The prototypes were made and evaluated in the Laboratory of Hydraulics and Irrigation Department of Biosystems Engineering, School of Agriculture \"Luiz de Queiroz\" (ESALQ), University of São Paulo (USP). It was planned a sequential logic automation of hydraulic valves, and it was controlled by multiways valve asset up by volumetric timer. It was installed a network irrigation with four sprinklers and in each sprinkler was installed a hydraulic valve. Sequential device prototypes were built for each rotor, it consist of a volume timer, a multiway valve and a trigger system to change position of the plunger. We conducted tests to evaluate the sequencing system, and noted that the sprinkler irrigation times were similar to the calculated times for each timer. The hydraulic-mechanical system developed proved to be a viable alternative to automation sequenced sprinklers in a netsprinkler irrigation system.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-03-16T14:51:31Z No. of bitstreams: 2 Dissertação - Sémebber Silva Lino - 2018.pdf: 6051816 bytes, checksum: ea335e51b02781bbf65596b8422bac01 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-03-19T11:54:12Z (GMT) No. of bitstreams: 2 Dissertação - Sémebber Silva Lino - 2018.pdf: 6051816 bytes, checksum: ea335e51b02781bbf65596b8422bac01 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-19T11:54:12Z (GMT). No. of bitstreams: 2 Dissertação - Sémebber Silva Lino - 2018.pdf: 6051816 bytes, checksum: ea335e51b02781bbf65596b8422bac01 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-23 / Extension or flexion movements of the body in a healthy individual are routine physical activity in daily life, necessary for its autonomy and independence.Injuries to the spinal cord and brain are the main causes of paraplegia, which makes it impossible for human locomotion with autonomy. The use of a wheelchair will help them into your daily horizontal mobility. But the possibility of using an orthotic device to allow it to increase the amplitude of the movements of extension or flexion will help in maintaining your bone density, improving your blood circulation and enlargement of muscle tone, involving tension in muscles, arteries and other tissues organic well as excessive involuntary reflex. Therefore, this study aims to present a mathematical model to describe the trajectory of nodes corresponding to the movable joints and upper extremity of a low cost orthosestic device, of the exoskeleton type, to be coupled in the wheelchair, using computer simulation to determine the variation of positions and velocities of these joints associated with the articulations of the hip and lower limbs of the paraplegic wheelchair user, when performing extension or flexion movements of the body segments, besides the simulation of a prototype developed in CAD. As for the main results of the research, first, there is the trajectory of the nodes with respect the mobile joints and upper end using the representation of Denavit-Hartenberg, generated graphically by numerical and computer simulation, in order to validate and make feasible the mechanical construction of the device. Then, as the variation of the positions and velocities of motor gasket associated with the user’s knee joint device, has its graphical representation plucked by multistep interactive Runge-Kuta 4th Order, using the Lagrange equations for numerical and computational simulation of the transmission system drive, with the application of a torque on the crank of the robotic mechanism proposed, thus confirming its usability, reliability and security. Finally, the development of a 3D virtual prototype device CAD. Therefore, the preparation and provision of this manual orthotic device developed to assist in the vertical mobility of the paraplegic with spinal cord injury, will improve physical, psychological health, functional independence and daily well-being, and helping them in their autonomy to support on the feet. / Os movimentos de extensão ou flexão corporal em um indivíduo saudável são atividades físicas rotineiras necessárias para sua autonomia e independência. As lesões da medula espinhal e do cérebro são as principais causas da paraplegia, que impossibilitam a locomoção humana com autonomia. O uso de uma cadeira de rodas os auxiliará em sua mobilidade horizontal diária. Mas a possibilidade de uso de um dispositivo ortético que lhe permita aumentar a amplitude dos movimentos de extensão ou flexão, contribuirá na manutenção da sua densidade óssea, melhorando sua circulação sanguínea e ampliação do tônus muscular, envolvendo tensão em músculos, artérias ou outros tecidos orgânicos além de reflexos involuntários excessivos. Por conseguinte, este estudo objetiva apresentar um modelo matemático para descrever a trajetória dos nós correspondentes as juntas móveis e extremidade superior de um dispositivo ortético manual de baixo custo, do tipo exoesqueleto, a ser acoplado na cadeira de rodas do paraplégico, usando-se de simulação computacional para determinar a variação das posições e velocidades dessas juntas associadas às articulações do seu quadril e membros inferiores, ao realizar movimentos de extensão ou flexão dos segmentos corporais, além da simulação de um protótipo desenvolvido em CAD. Quanto aos principais resultados decorrentes da pesquisa, primeiramente, obteve-se a trajetória dos nós referentes às juntas móveis e extremidade superior utilizando-se da representação de Denavit-Hartenberg, gerada graficamente por simulação numérico- computacional, no intuito de validar e viabilizar a construção mecânica do dispositivo. Em seguida, a variação das posições e velocidades da junta motora associada à articulação do joelho do usuário do dispositivo, teve sua representação gráfica tangida pelo método interativo multipasso de Runge-Kuta de 4ª ordem, usando-se das equações de Lagrange para simulação numérico-computacional do acionamento do sistema de transmissão, com a aplicação de um torque na manivela do mecanismo robótico proposto, confirmando assim, a sua usabilidade, confiabilidade e segurança. Por último, o desenvolvimento de um protótipo virtual 3D em CAD do dispositivo. Portanto, a confecção e disponibilização desse dispositivo ortético desenvolvido para auxiliar na mobilidade vertical do paraplégico com lesão medular, melhorará sua saúde física, psicológica, independência funcional e bem-estar diário, auxiliando-o na autonomia para apoiar sobre os pés.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-30T09:23:03Z No. of bitstreams: 2 Dissertação - Gustavo de Souza Neves - 2016.pdf: 2403103 bytes, checksum: e89c1c7d2a7ed732e3b4cd3a17b311ce (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-30T09:23:52Z (GMT) No. of bitstreams: 2 Dissertação - Gustavo de Souza Neves - 2016.pdf: 2403103 bytes, checksum: e89c1c7d2a7ed732e3b4cd3a17b311ce (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-30T09:23:52Z (GMT). No. of bitstreams: 2 Dissertação - Gustavo de Souza Neves - 2016.pdf: 2403103 bytes, checksum: e89c1c7d2a7ed732e3b4cd3a17b311ce (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-16 / Conventional means of transportation have a significant impact on people's lives, which depend on the current model to perform their routine activities. Families can expend up to 20% of their income on transport. On the other hand, internal combustion vehicles emit gases that impair nature, have low efficiency reaching a maximum 30% yield. In contrast, the electric vehicle has up to 90% efficiency and does not emit harmful gases directly. These factors contribute to the increase of financial and energy waste. This study aims to contribute to minimizing these impacts through analysis of an electric propulsion system of low cost, powered by photovoltaic source to be installed in a vehicle structure of PVC (Polyvinyl Chloride). The use of this renewable energy source enables the implementation of a photovoltaic power generation system, stored in lead acid batteries used in most of vehicles. After analysis of decision matrix, it was determined the most appropriate model that supports the proposal economically and evaluated electric DC motors found in conventional vehicles. These it was found that the engine of the windshield wipers can be used in vehicle propulsion system. To control the entire electrical system was used PIC micro controller, responsible for driving the motors through H bridge, consisting of MOSFET transistors. The simulation of this control system was held at the Proteus®. / Os meios de transportes convencionais têm impacto relevante na vida das pessoas, as quais dependem do modelo atual para realização de suas atividades rotineiras. Famílias de classe média dispendem até 20% de sua renda com transportes. Por outro lado, veículos de combustão interna emitem gases que contribuem para o efeito estufa, são de baixa eficiência, com no máximo 30% de aproveitamento. Em oposição, o veículo elétrico possui até 90% de eficiência e não emite gases de efeito estufa diretamente. Esses fatores contribuem com o aumento de desperdício financeiro e energético. Este estudo visa colaborar com a minimização destes impactos, por meio da análise de um sistema propulsor elétrico de baixo custo, alimentado por fonte fotovoltaica a ser instalado em um veículo de estrutura em PVC (Policloreto de Vinila). A utilização dessa fonte de energia renovável possibilita a implantação de um sistema de geração de energia fotovoltaica, armazenada em baterias de chumbo-ácido, utilizadas em veículos ã combustão. Após anáslise por matriz de decisão, foi determinado o modelo mais adequado que atende ã proposta de forma econômica e avaliados motores elétricos de corrente contínua, encontrados em veículos convencionais. Destes se verificou que os motores de limpadores de para-brisa podem ser empregados no sistema de propulsão do veículo. Para controlar todo o sistema elétrico foi utilizado o micro controlador PIC, responsável pelo acionamento dos motores através de ponte H, constituídas por transistores MOSFET. Foi realizada a simulaço desse sistema de controle no programa Proteus®.

A questão ambiental atualmente tem gerado grandes discussões sobre energias renováveis sendo que uma das grandes fontes é o sol. Porém, o aproveitamento da sua energia luminosa ainda não tem sido feito em larga escala em países que possuem essa disponibilidade, como é o caso do Brasil. Um dos motivos pode ser a falta de uma maior compreensão de como fazer o dimensionamento da iluminação natural. Este trabalho propõe o desenvolvimento de um sistema de medição desta iluminação natural, através de sensores de baixo custo adaptados para a função de medição, além de um equipamento de medidas e armazenagem de dados, bem um programa computacional que permita a descarga, gravação e interpretação desses dados em um computador. Através deste sistema poderá ser analisada a disponibilidade de luz natural externa, assim como a sua distribuição em espaços construídos simultaneamente. / The environmental issue has now created major discussions on renewable energy, being one of the major sources is the sun. However, the exploitation of its energy light has not yet been done on a large scale in countries that have such availability, such as Brazil. One reason may be the lack of a better understanding of how to make scaling of natural light. This paper proposes the development of a system of measurement of daylight, through low-cost sensors adapted for the task of measuring, and an equipment measures and storage of data, and a software that allows the discharge, recording and interpretation such data in a computer. Through this system could be considered the availability of external daylight, as well as their distribution in space constructed simultaneously.

Nas últimas décadas, o interesse na eletrônica flexível tem aumentado. Sistemas que apresentam benefícios, tais como: baixo custo, melhor desempenho, transparência, confiabilidade e melhores credenciais ecológicas, estão sendo extensivamente pesquisados por vários grupos. Os transistores de filmes-finos possuem potencial para alcançarem essas características. Dispositivos baseados em óxido de zinco (ZnO) tem atraído pesquisadores devido as suas propriedades elétricas, sensoriais e ópticas. Neste trabalho, nanopartículas de ZnO foram utilizadas como semicondutor ativo e cross-linked PVP (polivinilfenol) e PECVD-SiO2 (plasma enhanced chemical vapor deposition silicon dioxide) como dielétricos de porta para integrar transistores de filmes-finos. Este processo de integração tem por objetivo os pré-requisitos de baixo custo e baixa temperatura (<200°C). Por esta razão, a utilização de técnicas de integração simples, como o spin-coating ou a técnica de sidewall-etchback, foram utilizadas. Infelizmente, existem problemas relacionados à confiabilidade em dispositivos baseados em ZnO, entre eles a degradação no tempo ou a histerese. Após uma investigação experimental da histerese na característica de transferência, um modelo qualitativo para o comportamento observado é proposto. Observou-se que a direção da histerese é afetada pela variação da temperatura quando o dielétrico polimérico é usado. Baseando-se na caracterização dos transistores, a polarização do PVP, as armadilhas na superfície das nanopartículas e na interface com o dielétrico, bem como a liberação de moléculas de oxigênio da superfície das nanopartículas foram atribuídas como as principais causas da histerese. Além disso, uma flutuação discreta da corrente é observada em testes de estresse devido à captura e liberação de portadores em determinados caminhos de corrente no transistor, semelhante a random telegraph signal (RTS), relatado em MOSFET nanométricos. Este resultado suporta o hipotético mecanismo de transporte de elétrons (caminhos de percolação) em filmes compostos por ZnO nanoparticulado. / During the last decades, the interest in flexible electronics has arisen. Systems that present benefits such as low cost, improved performance, transparency, reliability and better environmental credential are being extensively researched by several groups. Thin-film transistors (TFT) have good potential concerning these technologies. Therefore, zinc oxide (ZnO) based devices have been attracting researchers for its electrical, sensory and optical properties. In this work, ZnO nanoparticles were used to integrate thin-film transistors, in which cross-linked PVP (Poly(4-vinylphenol)) and PECVD-SiO2 (plasma enhanced chemical vapor deposition silicon dioxide) were used as gate dielectric layer. The complete integration process targets low cost and low temperature requirements (< 200°C). For this reason, simple process techniques as spin-coating or sidewall-etchback were used. Unfortunately, there are different reliability concerns in ZnO devices, among them aging or hysteresis. An experimental investigation of the hysteresis in the transfer characteristic is performed, and a qualitative model for the observed behavior is proposed. It was observed that the hysteresis direction is affected by temperature variation when the polymeric dielectric is used. The PVP bulk polarization, the traps in nanoparticles and at the polymeric dielectric interface, as well as the desorption of oxygen molecules in the surface of the nanoparticles, were attributed as the main cause of the hysteretic behavior. Moreover, capture and release of charge carriers by traps at determined current paths in the transistor lead to discrete current fluctuations in stress tests, similar to random telegraph signal (RTS) reported in nanoscale MOSFET. This result supports the hypothesis of charge transport mechanism (percolation paths) in nanoparticulate ZnO.

Human vulnerability can be characterized as people living with uncertain livelihood options, precariously settled in structurally unsafe buildings. A striking aspect of this vulnerability is the large number of people living in earthen structures within seismically active zones. This reality is exemplified by the earthquake which occurred this past summer around Pisco, Peru. The earthquake caused enormous damage to more than 80% of the adobe buildings. Although confined masonry is the preferred construction technique for families who can afford it, adobe is still the only economically viable alternative for most. Presently reconstruction efforts are focused on encouraging residents to build with reinforced masonry, but the reality is that once these volunteers leave, or their funding runs out, people living in these areas will not be able to afford to continue with these enhanced types of construction. The goal then, is to come up with a hybrid of earthen construction found in the area that incorporates what is known of structural reinforcement with found or recycled objects that can contribute to improved tensile strength. This hybrid will allow for the rebuilding of Pisco at an affordable, yet highly stable level. This thesis will begin by visiting Pisco to conduct forensic studies of structural failures with documentation of physical observations and discussions with local institutions that have researched the crisis. Interviews with residents will also give insight into the events and building failures due to earthquakes as well as local construction methods. Readily available resources will be incorporated into the project in a way that should improve seismic resistance. Throughout this process research will be done on current seismic engineering discoveries in conjunction with indigenous approaches to earthen construction in comparable areas around the world. The possible construction approaches will be tested in collaboration with local Universities’ Seismic testing facilities. Once established, this hybrid earthen construction technique will be applied to one of several different building typologies (housing, schools, churches, etc). The end result will be the creation of a building design that establishes an appropriate reconstruction method at an economic level that will reduce the inhabitants’ susceptibility to future seismic disasters.

Representatives of the U.S. Department of Transportation's Bureau of Transportation Statistics reported that passenger complaints filed for the first quarter of 2015 were up 14.4% over the same period of the previous year. The purpose of this single case study was to explore strategies for mitigating low-cost airlines' passenger complaints. Porter's generic strategies provided the conceptual framework for this research study. Data were collected from 3 ground service managers employed by a low-cost airline in Florida using semistructured interview questions, direct observation, field notes, and review of the airline's website and public documents filed with the U.S. Securities and Exchange Commission. Member checking and methodological triangulation were used to ensure data saturation. Inductive line-by-line analysis of participant interviews and review of documents and website to identify similar words and phrases resulted in the emergence of 5 themes: complaints, training, customer retention, policies and procedures, and low-cost strategies. The implication for social change exists because airline managers can apply insights gained from this study to mitigate passenger complaints, thereby increasing the number of customers, lowering fares, and maintaining profitability. In this way, the study may support the creation of additional jobs for airlines as well as other industries providing services to an expanded workforce necessary to accommodate more passengers. Further, in supporting better performance for low-cost carriers, this study may help these businesses to offer low fares to customers previously unable to afford travel, enabling them to visit new places and gain a better understanding of other cultures.

Thesis (M.A. (Dev. Studies)) --University of Limpopo, 2007 / This study analyzes challenges facing housing programmes, predominantly low cost housing projects. An assessment of the Nobody Mothapo low cost housing project in the Polokwane Municipality was done. The officials of the Department of Local Government and Housing, Polokwane Municipality, and beneficiaries of the Nobody Mothapo project participated in the study. The sample consisted of 43 participants with different characteristics. Group discussions were conducted during the data collection process. The findings of this study are that government is attempting to fulfill its obligations by providing shelter to the needy people although there are negative effects hampering the implementation process. The slow housing delivery process and poor quality houses are negatively affecting homeless people. Human settlements are still established without the necessary infrastructure such as electricity, roads and other social amenities. In this study the challenges facing this housing delivery process are discussed. Recommendations are made regarding the role of government. Consumer education is emphasized to enhance community participation in their development and adherence to project management principles in the planning and implementation of low cost housing projects. / Not listed