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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.
91

Calibration and Characterization of Low-Cost Fine Particulate Monitors and their Effect on Individual Empowerment

Taylor, Michael D. 01 December 2016 (has links)
Air quality has long been a major health concern for citizens around the world, and increased levels of exposure to fine particulate matter (PM2:5) has been definitively linked to serious health effects such as cardiovascular disease, respiratory illness, and increased mortality. PM2:5 is one of six attainment criteria pollutants used by the EPA, and is similarly regulated by many other governments worldwide. Unfortunately, the high cost and complexity of most current PM2:5 monitors results in a lack of detailed spatial and temporal resolution, which means that concerned individuals have little insight into their personal exposure levels. This is especially true regarding hyper-local variations and short-term pollution events associated with industrial activity, heavy fossil fuel use, or indoor activity such as cooking. Advances in sensor miniaturization, decreased fabrication costs, and rapidly expanding data connectivity have encouraged the development of small, inexpensive devices capable of estimating PM2:5 concentrations. This new class of sensors opens up new possibilities for personal exposure monitoring. It also creates new challenges related to calibrating and characterizing inexpensively manufactured sensors to provide the level of precision and accuracy needed to yield actionable information without significantly increasing device cost. This thesis addresses the following two primary questions: 1. Can an inexpensive air quality monitor based on mass-manufactured dust sensors be calibrated efficiently in order to achieve inter-device agreement in addition to agreement with professional and federally-endorsed particle monitors? 2. Can an inexpensive air quality monitor increase the confidence and capacity of individuals to understand and control their indoor air quality? In the following thesis, we describe the development of the Speck fine particulate monitor. The Speck processes data from a low-cost dust sensor using a Kalman filter with a piecewise sensing model. We have optimized the parameters for the algorithm through short-term co-location tests with professional HHPC-6 particle counters, and verified typical correlations between the Speck and HHPC-6 units of r2 > 0:90. To account for variations in sensitivity, we have developed a calibration procedure whereby fine particles are aerosolized within an open room or closed calibration chamber. This allows us to produce Specks for commercial distribution as well as the experiments presented herein. Drawing from previous pilot studies, we have distributed low-cost monitors through local library systems and community groups. Pre-deployment and post-deployment surveys characterize user perception of personal exposure and the effect of a low-cost fine particulate monitor on empowerment.
92

Hand made houses for ex-Kamaiyas: a pattern language for the production of low-cost self-help housing in western Terai regions of Nepal

Bajracharya, Amit January 1900 (has links)
Master of Science / Department of Architecture / David R. Seamon / Kamaiya is a system of Nepalese agriculture bonded labor. In typical wage labor, one can enter or withdraw from the labor market as an independent agent; in the case of bonded labor, however, a worker cannot control his or her labor power. The Kamaiyas were liberated by the Nepalese government in 2000, and promised land to build houses. Without enough money for construction, however, many of these “ex-Kamaiyas,” as they are now called, are without housing or live in sub-standard units. This thesis examines the housing possibilities for the ex-Kamaiyas and aims at creating basic guidelines for planning and designing low-cost, self-help housing. The thesis is an attempt to design affordable and environmentally responsive housing that draws on Nepalese vernacular traditions but incorporates some modern materials and construction methods. The research and designs are based on interviews with ex-Kamaiyas living in the Nepalese villages of Tesanpur, Janatanagar, and Bhuri Gaun. The thesis serves as a guide for non-profit organizations working to provide housing for the ex-Kamaiyas and consists of guidelines, termed “design patterns,” for laying out ex-Kamaiya neighborhoods and for designing and constructing individual houses. The thesis also provides step-by-step construction guidelines for building the houses. The thesis’s last chapter evaluates the proposed housing system and identifies strengths and weaknesses.
93

création et validation d'un outil low-cost d'analyse de la posture du cavalier 'ADPC' / development and validation of a low-cost rider posture analysis device 'ADPC'

Prin, Dominique 10 October 2018 (has links)
Conceptualiser, réaliser, étalonner et valider une plateforme d'étude de la posture du cavalier. mise en place de capteurs de selle et de capteurs d'étriers. Nous utiliserons un cheval mécanique référent pour valider notre matériel. Nous voulons mettre en évidence la notion d'assiette passive et d'assiette active. Après modifications et étalonnage du cheval mécanique grâce à l'accéléromètrie, nous créons une plateforme filaire pour étalonnage. Nous réalisons des expérimentations in situ dans les écuries avec des cavaliers de dressage et de CSO. Nous étudions les deux types d'assiette par une expérimentation finale à la recherche de normes. Nous exporterons notre analyse dans le monde du Handisport et dans le monde de la rééducation. / Conceptualize, implement, calibrate and validate a platform for studying the rider's posture. We will use a referring horse simulator for our device's validation.We want to highlight the concept of passive and active riders seat. After changes and horse simulator's calibration by accelerometry, we create a calibrated wired platform such as embedded system. we perform experiments in the stables with expert's riders, jumping and dressage. we are studying the two types of rider's seat with an ending experiment. We try to determine seated standart positions for rider. we will export our analysis experiment in the world of Para and in the rehabilitation's world.
94

Product Development of Material Supply : Implementation of Karakuri Kaizen

Porteiro Paraponiaris, Yanni, Mateos Rodríguez, Arturo January 2019 (has links)
The industry 4.0 is continuously aiming to produce faster, increasing quality, and strictly using what is necessary to achieve efficiency enhancement. Within the wide list of methods used to reach this target, robot automation is usually used, although is expensive and rigid. Alternatively, a Japanese cheap automation philosophy called "Karakuri", is being introduced by Volvo GTO to manage this goal. This thesis relies on this philosophy, which takes profit of the existing energy, like gravity, to put in motion mechanisms, in order to reduce costs and improve the production efficiency by developing a semi-automated material handling system. The design method followed, the Scrum, divides the thesis in several phases of development, presenting a fully developed solution at the end of each one and iteratively increasing the level of definition along the process, to finally provide a solution suitable to be implemented.
95

Luxlogger - sistema autônomo de medição de iluminação natural de baixo custo / Luxlogger - autonomous system of daylight measurement of low cost

Yamanaka, Marcos Hideki 07 July 2008 (has links)
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.
96

Estudo e implementação de uma arquitetura para terminais de baixo custo / Development and implementation of an architecture for low-cost terminals

Garcia Neto, Alvaro 27 May 1986 (has links)
Neste trabalho projetamos e construímos um terminal de baixo custo para o sistema de automação de laboratórios em desenvolvimento no L.I.E. Para tanto, discutimos as diversas arquiteturas empregadas nos terminais buscando obter subsídios com vistas à escolha da mais adequada as aplicações cientificas que são típicas desse microcomputador. Também é feito um estudo comparativo dos diversos dispositivos empregados como terminais, bem como das funções que desempenham nas disposições convencionais dos centros computacionais. Procurou-se implementar um terminal de custo extremamente reduzido, mas capaz de ser facilmente expandido pela incorporação de módulos adicionais. Também foi objetivo do trabalho prover um projeto sólido para permitir facilmente uma vasta gama de alterações, variando desde a substituição de alguns componentes até a troca de todo o sistema operacional residente. Para tanto houve grande cuidado na documentação dos esquemas e da programação. O dispositivo construído mostrou-se bastante versátil, confiável e baixíssimo custo / In the present work we compare several devices used as terminals, as well as the roles they play on a conventional computing centre. Their various architectural aspects are also investigated, providing the ground basis for a terminal biased towards scientific aplications, which are typical of the microcomputer system developed at L.I.E.. We wanted a very low cost traminal that still retained the capability of beeing expanded by the inclusion of additional modules. A solid Project, able to handle the most severe alterations, ranging from the replacement of some ICs to the replacement of the entire resident operational system was aso wanted. To accomplish these goals a great care was taken on the Project documentation of the software as well as of the hardware. The device that was eventually build proved to be very versatile, reliable and low cost one
97

Projeto e construção de laborátórios de biossegurança NB3 de baixo custo. / Design and constrution of low cost BSL3

Hernandes, Francisco José Camilo 08 May 2008 (has links)
Laboratórios de biossegurança são classificados em quatro níveis de risco (1 a 4), sendo constituídos de combinações de práticas e técnicas de laboratório, equipamento de segurança e instalações do laboratório. Cada combinação é especificamente adequada para as operações realizadas, vias de transmissões documentadas ou suspeitas de agentes infecciosos e em monitoramento das atividades de laboratórios. O objetivo deste trabalho foi o de tornar possível a construção de laboratórios de Biossegurança Nível 3 (NB3) com baixo custo, mantendo-se as condições mínimas de biossegurança no aspecto da engenharia. Como resultado seis laboratórios NB3 foram construídos para o projeto da FAPESP, denominado Rede de Diversidade Genética Viral (VGDN), com finalidade de diagnóstico de vírus respiratórios e mais uma laboratório para o Ministério da Agricultura, situado no LANAGRO de Pernambuco na cidade de Recife. / Biosafety laboratories are classified into four levels of risk (1 to 4), and consist of combinations of laboratory practices and techniques, safety equipment and facilities of the laboratory. Each combination is particularly suitable for the operations; routes of transmission documented or suspected infectious agents in tracking the activities of laboratories. The objective of this work was to make possible the construction of laboratories for Biosafety Level 3 (BSL3) with low cost, remaining the minimum conditions of biosecurity in the aspect of engineering. As results were built six laboratories BSL3 of FAPESP for the project, called Viral Genetics Diversity Network (VGDN), with the purpose of diagnosis of respiratory viruses and another laboratory for the Ministério da Agricultura, located in LANAGRO of Pernambuco in the city of Recife.
98

Modelagem e caracterização hidráulica de microtubos com múltiplas saídas / Modeling and hydraulic characterization of microtubes with multiple outlets

Alves, Dinara Grasiela 30 June 2014 (has links)
A busca por estratégias para otimizar a eficiência de aplicação de água tem sido objeto de estudo de vários pesquisadores. Neste sentido, destaca-se a utilização de sistemas de microirrigação com microtubos devido ao seu baixo custo e elevada uniformidade de aplicação de água, sendo uma boa alternativa para pequenos agricultores. O emissor utilizado neste trabalho foi denominado \"microtubo com múltiplas saídas\" (MMS) o qual, por se tratar de uma configuração inovadora, é um tipo de gotejador inexistente no mercado. Este sistema é caracterizado por possuir menor custo em comparação com os sistemas atuais, que utilizam microtubos, tendo em vista a menor quantidade de material necessário à sua implantação. O objetivo deste trabalho foi modelar, determinar as características hidráulicas do microtubo com múltiplas saídas e sua sensibilidade à obstrução por agentes físicos. A condução desta pesquisa dividiu-se em duas etapas. A primeira consistiu na determinação do diâmetro interno dos microtubos, em ensaios preliminares de verificação do modelo de dimensionamento dos MMS e na determinação do coeficiente de variação de fabricação, os quais foram realizados no Laboratório de Hidráulica do Departamento de Engenharia de Biossistemas da Escola Superior de Agricultura \"Luiz de Queiroz\"/USP, em Piracicaba - SP. A segunda consistiu na determinação das características hidráulicas, na modelagem do escoamento d\'água no interior do microtubo com múltiplas saídas e na avaliação da sensibilidade dos microtubos à obstrução por agentes físicos, as quais foram realizadas no Laboratoire d\'essais et de recherche des matériels d\'irrigation pertencente ao Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture (LERMI/IRSTEA, Aix en Provence, Montpellier, França). A configuração do emissor proposto consiste em um microtubo regulador de pressão (MRP) ligado a um conector com disposição radial de onde derivam seis microtubos emissores (ME). Realizou-se simulações hidráulicas do escoamento nos MMS, utilizando o programa computacional ANSYS Fluent. Determinou-se a sensibilidade à obstrução do MMS e dos microtubos com diâmetro interno de 0,888 e 1,074 mm. O microtubo com múltiplas saídas foi menos sensível à obstrução que os outros microtubos testados, entretanto, o mesmo apresenta áreas críticas quanto à ocorrência de obstrução no interior do conector, principalmente em áreas onde a velocidade da água é próxima ou igual à zero. As diferenças máxima e mínima entre a pressão simulada e a pressão observada experimentalmente foram 13% e 0,2% respectivamente. Desse modo, a simulação não apresentou resultados totalmente satisfatórios em termos de previsão da perda de carga, entretanto, é uma importante ferramenta para identificação de pontos críticos quanto à dissipação da perda de carga e que favorecem a ocorrência de obstrução. Para microtubos, as equações utilizadas no cálculo do fator de atrito da equação de Darcy-Weisbach não apresentaram resultados satisfatórios, contradizendo às recomendações da literatura para tubos convencionais. Uma possível causa dessa discordância é que a definição da faixa do regime de escoamento para microtubos seja diferente dos tubos convencionais, sendo necessária a realização de estudos complementares para se obter resultados mais conclusivos. / The search for strategies to optimize the efficiency of water application has been studied by several researchers. In this sense, we highlight the use of microirrigation systems with microtubes due to its low cost and high uniformity of water application, being a good alternative for small farmers. The emitter used in this work was named \"microtube with multiple outlets\" (MMO) which is a kind of dripper non-existent in the market, because it is an innovative configuration. This system is characterized by having lower cost compared to existing systems that use microtubes, in view of the smaller amount of material required for its implementation. The objective of this work was to model, to determine the hydraulic characteristics of the microtube with multiple outlets and their sensitivity to clogging due physical agents. This research was divided into two stages. The first stage was determining the internal diameter of the microtubes, the lengths of the microtubes and the manufacturing coefficient of variation was conducted in the Hydraulics Laboratory, Department of Biosystems Engineering, School of Agriculture \"Luiz de Queiroz\" (ESALQ/USP) in Piracicaba - SP. The second stage was determining the hydraulic characteristics of the microtubes with multiple outlets, to model the flow of water within the microtube with multiple outlets and to evaluate a susceptibility of microtubes to physical agents. This tests were performed at the Laboratoire d\'essais et de recherche des matériels d\'irrigation belonging to the Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture (LERMI/IRSTEA, Aix en Provence, Montpellier, France). The configuration of the proposed system consists of a supply microtube (SM) and six emitter microtubes (EM) that are connected to the supply microtube through a connector. The hydraulic simulations of flow in microtubes with multiple outlets was carried out using the software ANSYS Fluent. It was determined the MMO sensitivity to clogging and of microtubes with internal diameter of 0.888 and 1.074 mm. The microtube with multiple outlets was less sensitive to clogging than other tested microtubes, however, the MMO presents critical areas to occurrence of clogging within the connector, especially in areas where the water velocity is close or equal to zero. The maximum and minimum difference between the simulated pressure and experimentally observed pressure was 13% and 0.2 % respectively. The simulation did not provide fully satisfactory results in terms of predicting the head loss, however, it is an important tool to identify critical points of head loss and of critical points that favors the occurrence of clogging. For microtubes, the equations used to calculate the Darcy- Weisbach equation friction factor showed no satisfactory results, contradicting the recommendations from the literature for conventional tubes. One possible cause of this discrepancy is that the definition of the flow regime for microtubes is different from conventional tubes. More studies must be conducted to obtain more conclusive results are required.
99

Investigation of novel multi-layer spoke-type ferrite interior permanent magnet machines

Xia, Bing January 2017 (has links)
The permanent magnet synchronous machines have been attracting more and more attention due to the advantages of high torque density, outstanding efficiency and maturing technologies. Under the urges of mandatory energy efficiency requirements, they are considered as the most potential candidates to replace the comparatively low-efficient induction machines which dominate the industrial market. However, most of the high performance permanent magnet machines are based on high cost rare-earth materials. Thus, there will be huge demands for low-cost high-performance permanent magnet machines. Ferrite magnet is inexpensive and abundant in supply, and is considered as the most promising alternative to achieve the goal of low cost and high performance. In consideration of the low magnetic energy, this thesis explored the recent developments and possible ideas of ferrite machines, and proposed a novel multi-layer spoke-type interior permanent magnet configuration combining the advantages of flux focusing technique and multi-layer structure. With comparable material cost to induction machines, the proposed ferrite magnet design could deliver 27% higher power with 2-4% higher efficiency with exactly the same frame size. Based on the data base of International Energy Agency (IEA), electricity consumed by electric machines reached 7.1PWh in 2006 [1]. Considering that induction machines take up 90% of the overall industrial installation, the potential energy savings is enormous. This thesis contributes in five key aspects towards the investigation and design of low-cost high-performance ferrite permanent magnet machines. Firstly, accurate analytical models for the multi-layer configurations were developed with the consideration of spatial harmonics, and provided effective yet simple way for preliminary design. Secondly, the influence of key design parameters on performance of the multi-layer ferrite machines were comprehensively investigated, and optimal design could be carried out based on the insightful knowledge revealed. Thirdly, systematic investigation of the demagnetization mechanism was carried out, focusing on the three key factors: armature MMF, intrinsic coercivity and working temperature. Anti-demagnetization designs were presented accordingly to reduce the risk of performance degradation and guarantee the safe operation under various loading conditions. Then, comparative study was carried out with a commercial induction machine for verification of the superior performance of the proposed ferrite machine. Without loss of generality, the two machines had identical stator cores, same rotor diameter and stacking length. Under the operating condition of same stator copper loss, the results confirmed the superior performance of the ferrite machine in terms of torque density, power factor and efficiency. Lastly, mechanical design was discussed to reduce the cost of mass production, and the experimental effort on the prototype machine validates the advantageous performance as well as the analytical and FEA predictions.
100

Investigating passenger satisfaction : a model for measuring service quality of low cost carriers

D'Silva, J. January 2015 (has links)
Service quality is an integral part of the product/service offering provided to a customer. Along with continuously identifying customer expectations and perceptions about service quality, it is imperative for service providers to also investigate whether the service quality increases customer satisfaction and their behavioural intentions. This PhD study theoretically contributes by evaluating one comprehensive service quality model, SERVQUAL designed by Parasuraman et al. (1988), for its potential applicability. The study further contributes by identifying a gap in the literature that the original SERVQUAL model does not entirely represent LCC service quality therefore, LCCSQUAL is proposed: a revised conceptual model with twenty-five variables that reflect the industry-specific attributes of LCC services in the Middle East. LCCs became a common feature in the West after the appearance of Southwest airline in 1971, however in the Middle East; LCCs are a relatively new phenomenon. LCCs are growing rapidly due to the current development of the aviation industry, deregulation and open skies policies in many parts of the Middle East. Most research to date has focused on LCCs in Western or Asian culture, whereas limited research has been conducted in the Middle East region, hence, this study will focus on highlighting the historical development of the Middle East’s aviation industry and the phenomenal growth of the region’s LCCs. This research is first of its kind in the Middle East to be conducted on the LCC service quality as well as in a new cultural background and therefore, it is important to consider that passengers’ are influenced by their culture while making decisions, however; the original SERVQUAL model developed by Parasuraman et al. in (1985) does not include culture as one of the influences in consumer. This PhD study, therefore, bridges another gap in the knowledge by testing the LCCSQUAL in Middle Eastern culture. This PhD followed a multi methodology using both inductive and deductive approaches consisting of qualitative (interviews and a focus group discussion) and quantitative (a self-administered survey questionnaire) methods at Dubai International airport, which has a dedicated LCC terminal. A total of 540 questionnaires was distributed; however, only 516 were finally employed for quantitative analysis. For qualitative analysis, nine in-depth interviews with senior executives of LCC airlines and seven LCC passenger interviews was conducted along with one focus group interview with seven Emirati ladies, first time LCC travellers. Content analysis and NVivo 10 were utilised for qualitative findings and descriptive analysis, Spearman’s rank correlation, factor analysis and cross tabulation were employed to examine the quantitative results. Comparing the results of both methodologies indicated that, passengers experienced wider gaps in the tangibility, reliability and responsiveness dimensions of LCC service quality in the Middle East. The findings of the study concluded that LCC passengers have higher expectations of the LCC services due to receiving luxury services for a long time in the Middle East region. The revised model; LCCSQUAL was tested in the Middle Eastern culture with additional variables and is recommended to be further developed to be culture and country specific. Factor analysis results also highlighted that there are gaps between the expectations and perceptions of the passengers travelling with LCC. This study concludes with several recommendations to LCC management, such as, on-time performance, well-trained staff and crew members, providing clear information to the passengers and providing quality services with low fares.

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