Superconductor-Insulator-Superconductor (SIS) mixers offer the best noise properties of any heterodyne mixing technique at millimetre wavelengths. In astronomy, they are used for sensitive spectroscopy, which is vital for understanding the properties of the cold interstellar medium, including regions of star formation activity. Modern SIS receivers have noise properties that are ∼3 times the quantum limit, and it is now becoming increasingly difficult to lower the noise properties any further. In this thesis, I investigate two techniques that extend the capability of SIS receivers. The first technique is extending the instantaneous bandwidth of the receivers, i.e., the intermediate frequency bandwidth (IFBW). For spectral line sources, wide IFBW expands the survey depth to allow multiple emission lines to be observed simultaneously. Here, I present a new SIS mixer device at 230 GHz. The planar circuit was minimised to reduce any parasitic capacitances that may limit the IFBW. Experimentally, the device provides excellent noise temperatures down to 36 K and an IFBW extending from approximately 0-11 GHz. Simulation software was developed to better understand the performance of this device, and it suggests that the IFBW can be extended to higher frequencies if the IF measurement chain is upgraded. The second technique that I investigate is increasing the number of receivers in the focal plane of the receiver, i.e., adding more pixels. There are many challenges involved in this task including how to fit multiple receivers into a small space, how to properly cool the receiver, and how to deliver the local-oscillator signal. Here, I present a new 1 × 4 focal plane array. This array is acting as a demonstrator for a new array architecture that can be expanded into many more pixels in the future. It uses cascaded waveguide power splitters to divide the local-oscillator signal, and then waveguide directional couplers to combine the LO with the astronomical signals. Finally, I present CO(J=1→0) measurements from 34 galaxies in the 5MUSES survey. These measurements trace the amount of cold molecular gas present in these galaxies. By comparing these measurements to other metrics that trace star formation activity (e.g., infrared luminosity), I was able to form empirical relationships between the observed quantities. I also combined these results with other star formation studies from nearby and high redshift galaxies to form scaling relationships spanning a large fraction of cosmic time.

The performance of a dedicated A/D converter located beneath each pixel is explored in this thesis. Specifically, a voltage to frequency converter coupled with a direct injection amplifier designed for use with an IR focal plane array is analyzed. This versatile implementation of a Readout Integrated Circuit can be found applicable to a wide variety of imaging technologies. Noise performance of the conversion system is theoretically calculated, and is supported by SPICE simulations using valid CMOS SPICE models. It is shown that a 10 transistor sub-pixel voltage to frequency analog to digital converter will produce noise that is less than the input shot noise. Design considerations will be addressed to ensure continued performance as the scale of the imagers increase to large format arrays.

The growing awareness of global warming potential has internationally aroused interest and demand in reducing greenhouse gas emissions produced by human activity. Each year, the UK consumes a significant amount of energy for residential and industrial space heating and domestic hot water production. At present, gas boilers are mostly installed in the domestic water heating which contributes significantly to excessive CO2 emissions and consumption of primary energy resources. However, air-source heat pump system has higher performance efficiency comparing to the traditional gas boiler, which can reduce the carbon dioxide emission and the usage of primary energy resources. The coefficient of efficiency of the heat pump can be range from 2 to 4.5 in various situations. The market shares of heat pump have been predicted to increase in the coming years to meet the requirement of the European Union Commission. There were about 22,000 heat pumps set up in the UK with 18 percent growth comparing to 2016 as reported by BSRIA. A range from 0.6 to 5.7 million heat pumps are estimated by the National Grid to be set up by 2030 to increase the energy efficiency of the UK. Although the energy efficiency of the heat pump is extremely high, there is still a space for improvement in air-source heat pump water heating system. The performance of the heat pump water heating system can be further enhanced if the dissolved gases in its hot water circuit can be efficiently discharged. The undissolved bubbles can stack in a specific position of the radiator, which would cause the cold spot. This could immensely reduce the efficiency of the heat pump water heating system. To avoid this happening, the bubble behaviors in the heat pump water heating system need to be extensively investigated. The better understanding of the bubble behaviors in an air-source heat pump water heating system can contribute to the design of an air evacuation valve and heat pump piping systems. In this thesis, the effects of various heat pump hot water side parameters on gas microbubble diameters and bubble productions were measured and analyzed by varying different experimental conditions. Correspondingly, a summarized conclusion has been presented to predict the gas microbubble's diameter distributions and volumetric void fraction distributions at different operating conditions. These parameters include various system pressures, water flow rates, and saturation ratios. In this thesis, the main results showed that larger average bubble diameter is at the higher water flow rates at heat pump exit. At 2.2 bar condition, when system water flow rate increased from 800 l/h to 1150 l/h, the average bubble diameter increased from 0.086 mm to 0.108 mm. Moreover, the average bubble diameters increase along with the decrease in system pressures. At 1000 l/h condition, when system pressure increased from 2.2 bar to 2.7 bar, the average bubble diameter decreased from 0.100 mm to 0.087 mm. At 850 l/h condition, when system pressure increased from 1.7 bar to 2.5 bar, the average bubble diameter decreased from 0.101 mm to 0.081 mm. In addition, the average bubble diameters slightly increase along with the increase in saturation ratio. Besides, a prediction equation for the bubble diameter distribution in the water pipe was proposed. At SR 1.15 and 2.5 bar condition, when water flow rate increased from 900 l/h to 1100 l/h, volumetric void fraction decreased from 2.25 E-05 to 4.83 E-06. However, at 1000 l/h and SR 1.15 condition, when system pressure increased from 2.2 bar to 2.7 bar, volumetric void fraction decreased from 2.16 E-05 to 3.78 E-06. It is found that the highest city main saturation ratio was achieved at 1.07 at the specific environmental condition.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERO / Bibliography: p. 131-132. / by Louis Howard Knotts. / M.S.

A análise da cinemática articular do joelho apresenta-se como fator fundamental na compreensão da função musculoesquelética e mecânica articular. No âmbito clínico, a avaliação do padrão normal de parâmetros biomecânicos, permite a obtenção de valores de referência para comparações com diferentes grupos de indivíduos lesados ou submetidos à cirurgia. Dessa forma, o presente estudo tem como objetivo mapear a normalidade de parâmetros biomecânicos da articulação do joelho, obtidos no plano sagital, durante a extensão do joelho em cadeia cinética aberta, sem carga, utilizando videofluoroscopia. Especificamente, pretende estimar o comportamento do centro de rotação tibiofemoral e patelofemoral, distância perpendicular do ligamento patelar e efetiva dos extensores de joelho, torque de resistência do segmento perna-pé, força do ligamento patelar, força do músculo quadríceps e força de contato patelofemoral, razão entre a força do ligamento patelar e a força do músculo quadríceps, razão entre a força de contato patelofemoral e a força do músculo quadríceps, pressão patelofemoral e tilt patelar ântero-posterior. Para a determinação dos parâmetros biomecânicos foram obtidas imagens radiográficas dinâmicas, por meio de videofluoroscopia, a partir da análise da articulação do joelho no plano sagital, de vinte e cinco indivíduos, executando três repetições do exercício de extensão de joelho em cadeia cinética aberta, sem carga externa aplicada à tíbia. As imagens obtidas foram reproduzidas e digitalizadas utilizando uma placa de captura da marca Silicon Graphics 320. Foram desenvolvidas rotinas computacionais utilizando o software Matlab para processamento e análise dos dados. Os dados obtidos foram analisados estatisticamente utilizando-se o pacote estatístico SPSS, versão 13.0. Foram plotados os valores obtidos para cada parâmetro em função do ângulo de flexão do joelho, para todos os indivíduos da amostra, e realizada uma análise de regressão entre as variáveis interpoladas, obtendo-se respectivo intervalo de confiança e coeficiente de determinação (r2). A partir dos resultados obtidos, foram verificadas correlações muito forte, forte e regular entre os parâmetros do estudo e o ângulo de flexão do joelho, indicando a possibilidade de mapear a normalidade dos parâmetros cinemáticos e cinéticos da articulação do joelho. / The kinetic and kinematics analysis of the knee joint is considered to be of prime importance in the understanding of the musculoskeletal function and joint mechanics. In the clinical scope, the biomechanics evaluation of the normal standard of biomechanics parameters, allow the attainment of indexes of reference for compare different groups of injured individuals or submitted to surgery. On this way, the present study has as the main goal estimate the normality of biomechanics parameters of the knee joint, gotten in the sagittal plane, during the knee extension in open kinetic chain, without load, by means of videofluoroscopy. Specifically, it intends to estimate how the tibiofemoral and patellofemoral rotation center behave, the patellar ligament moment arm and the effective moment arm of the knee extensors muscle group, the resistance torque of the segment leg-foot, patellar ligament force, quadriceps muscle force and patellofemoral joint contact force, the ratio between the patellar ligament force and quadriceps muscle force, the ratio between patellofemoral joint contact force and quadriceps muscle force, patellofemoral pressure and the anteroposterior patellar tilt. For the determination of these biomechanics parameters, dynamic radiographic images had been gotten, by means of videofluoroscopy. From the analysis of the knee joint in the sagittal plane, from twenty-five individuals, performing three repetitions of the knee extension exercise in open kinetic chain, without applied external load to the tibia. The gotten images had been reproduced and digitalized using a capture plate - Silicon Graphics 320. There been developed specific computational routines using Matlab software for processing and analysis of the data. The gotten data had been analyzed statistically using the statistical package SPSS, version 13.0. The gotten values for each parameter related to the knee angle of flexion had been plotted, for all the individuals of the sample, and carried through an regression analysis between the interpolated variables, getting respective reliable interval and coefficient of determination (r2). In the light of these findings, correlations had been verified to be strong, very strong and also very regular among the parameters of the present study and the angle of knee flexion, indicating the possibility of estimate the normality of the kinematic and kinetic parameters of the knee joint.

Nesta pesquisa, que consiste de um estudo de caso, elaboramos uma sequência didática que prevê atividades que devem ser resolvidas de duas maneiras distintas. Uma das maneiras utiliza conceitos de Geometria Plana – como Teorema de Pitágoras e semelhanças – e a outra maneira utiliza conceitos de Geometria Analítica – como equações de reta e cálculos de área via determinantes. Para analisar os dados coletados, com a aplicação desta sequência, a Teoria de Registros de Representação Semiótica foi utilizada. Duval (2009), autor da teoria, trata sobre a importância dos registros em Ensino de Matemática, sobre a conversão de um registro em outro e sobre a necessidade de utilização de mais de um registro como um meio de entender o modo matemático de pensar. Como meio de dar um suporte a nossa pesquisa, em nossa revisão bibliográfica, procuramos produções recentes, nas quais foram utilizadas a mesma teoria sob o aspecto da conversão, e analisamos também se os livros didáticos de Matemática, do terceiro ano do Ensino Médio, contemplam atividades que incentivem a utilização de mais de um registro para resolução de atividades. Esta sequência foi aplicada em uma turma de alunos do terceiro ano, de uma escola de Ensino Médio Técnico integrado e sua estrutura foi inspirada na Investigação Matemática de Ponte (2006). Nesta pesquisa, os registros, majoritariamente utilizados pelos alunos, foram os de Geometria Plana – Figural – e de Geometria Analítica – Gráfico – e verificamos que os alunos conseguiram, quando solicitados, articular a utilização destes dois tipos de registro. / In this case study we elaborate a didactic sequence that predicts activities that should be solved in two different ways. One of them uses the concepts of plane geometry – such as the Pythagorean theorem and similarities – and the other uses the concepts of analytic geometry – such as the equations of a line and area calculations. To analyze the data assembled with the application of this sequence we used The Theory of Registers of Semiotic Representation. Duval (2009), the author of this theory, addresses the importance of registers in Mathematics Teaching, the conversion of one register to another, and the need to use more than one register as a way to understand the mathematical way of thinking. To support our research, we looked in our bibliographical review for recent articles that made use of the same theory under the conversion aspect, and we also analyzed whether third year high school mathematics textbooks offer activities that encourage the use of more than one register in the solution of activities. This sequence was applied in a class of third-year students, from an integrated technical high school and its structure was inspired by Ponte’s Mathematical Investigation (2006). In this research, the registers most used by the students were those of plane geometry – figure – and of analytic geometry – graph – and we verified that the students, on request, achieved to articulate the use of these two types of registers.

Grid Representations and the Chromatic Number Martin Balko August 2, 2012 Department: Department of Applied Mathematics Supervisor: doc. RNDr. Pavel Valtr Dr. Supervisor's email address: valtr@kam.mff.cuni.cz Abstract In the thesis we study grid drawings of graphs and their connections with graph colorings. A grid drawing of a graph maps vertices to distinct points of the grid Zd and edges to line segments that avoid grid points representing other vertices. We show that a graph G is qd -colorable, d, q ≥ 2, if and only if there is a grid drawing of G in Zd in which no line segment intersects more than q grid points. Second, we study grid drawings with bounded number of columns, introducing some new NP- complete problems. We also show a sharp lower bound on the area of plane grid drawings of balanced complete k-partite graphs, proving a conjecture of David R. Wood. Finally, we show that any planar graph has a planar grid drawing where every line segment contains exactly two grid points. This result proves conjectures of D. Flores Pe˝naloza and F. J. Zaragoza Martinez. Keywords: graph representations, grid, chromatic number, plane

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-04-05T16:13:58Z No. of bitstreams: 1 PDF - André Ferreira de Lima.pdf: 3565371 bytes, checksum: 0a8efcec0e9cf60bc3a6802450c7ea9b (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-04-12T17:35:38Z (GMT) No. of bitstreams: 1 PDF - André Ferreira de Lima.pdf: 3565371 bytes, checksum: 0a8efcec0e9cf60bc3a6802450c7ea9b (MD5) / Made available in DSpace on 2016-04-12T17:36:11Z (GMT). No. of bitstreams: 1 PDF - André Ferreira de Lima.pdf: 3565371 bytes, checksum: 0a8efcec0e9cf60bc3a6802450c7ea9b (MD5) Previous issue date: 2015-09-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / My interest for, and my first ideas related to, this research area began during my initial teacher training. Today, I can verify some results from the reflections along this journey. They make us infer that if geometry is approached since the first years in school, initially through empiric ideas, and later on through the exploration of concepts of plane geometry, that would be a more coherent way for school children to develop geometrical concepts. However, the recognition of geometry was relegated by almost everyone for many years, which has damaged its teaching quality in the schools. Fortunately, during the last three decades, there is a tendency to recuperate and show the potential of geometrical knowledge for the development of a human being. In this context, we are searching for possible explications that lead us to the answer to our guiding questions: What effects are produced by a series of planned activities that favor the exploration of a concrete/sensitive geometry in order to approach notions of plane geometry with fifth-graders? To what extent does this classroom intervention, guided by the recommendations for geometry teaching to fifth-graders, contribute to the development of concepts of plane geometry based on the exploration of activities that involve the composition and decomposition of some representations of geometric solids? In order to discuss these questions, this study aims to investigate the effects produced by a series of planned activities that favors the exploration of a concrete/sensitive geometry in order to approach notions of plane geometry with fifth-graders, through situations that involve the composition and decomposition of some representations of geometric solids. We carried out a qualitative field study with an interpretative and naturalistic aspect, involving 25 pupils from a fifth-grade-class at a State school in the town of Monteiro, State of Paraíba, Brazil. The research structure was based on a set of eight activities related to geography that were denominated along the episodes of the text. These activities were thought in the light of a geometry that initially favors the concrete, sensitive character as a possibility to develop some tri-dimensional geometric concepts and, later on, approach elements of plane geometry in a constant dialogue between plane and spatial geometry. The data was gathered between the months of February and March of 2015. Various instruments were used in this task, among them the activity notebooks that were handed out to every work group during every episode, the film recording, the facial, corporal and gestural expressions along the process of achieving information, and commentaries said before or after the moments of construction of geometric knowledge. As part of the results, it can be highlighted that the activities developed in groups favored an interpersonal communication where the more skillful participants contributed to the learning of those that presented more difficulties. / O interesse pelo tema dessa pesquisa tem origem na Licenciatura em Matemática do professorpesquisador. Momento esse em que surgiram as primeiras ideias. Hoje, verificam-se alguns resultados das reflexões durante essa caminhada. Defende-se que há um caminho mais coerente para que as crianças possam construir conceitos geométricos, desde que o ensino de geometria seja desenvolvido, inicialmente em ideias empíricas para em seguida explorar conceitos da geometria plana e que seja abordado desde os anos iniciais do Ensino Fundamental. Porém, o reconhecimento do ensino de geometria foi relegado por quase todos durante muitos anos e acabou prejudicando a qualidade dele nas escolas. Uma das causas desse abandono foi o Movimento de Matemática Moderna (MMM). Felizmente, nas últimas três décadas, procuram-se resgatar e mostrar a potencialidade do conhecimento geométrico para a formação do indivíduo. Diante disso, trilhou-se na busca de possíveis explicações que possibilitassem responder a seguinte questão norteadora: Quais são os efeitos produzidos por uma série de atividades planejadas que privilegiam a exploração de uma geometria sensível para, em seguida, abordar noções da geometria plana com alunos do quinto ano do Ensino Fundamental? Em que medida essa intervenção em sala de aula, guiada pelas recomendações no tocante ao ensino de geometria para o segundo ciclo do Ensino Fundamental, contribuirá para a construção de conceitos da geometria plana a partir da exploração de atividades que envolvam a composição e decomposição de algumas representações de sólidos geométricos? Essa problemática foi discutida a partir do seguinte propósito: investigar quais são os efeitos produzidos por uma série de atividades planejadas que privilegiam a exploração de uma geometria sensível para, em seguida, abordar noções da geometria plana com alunos do quinto ano do Ensino Fundamental através de situações que envolvam a composição e decomposição de algumas representações de sólidos geométricos. Realizou-se uma pesquisa qualitativa sob um aspecto interpretativo e naturalístico em uma escola da Rede Estadual de Ensino da cidade de Monteiro no estado da Paraíba, envolvendo vinte e cinco alunos de uma turma de quinto ano do Ensino Fundamental. A pesquisa estruturou-se através de um conjunto de oito atividades relacionadas à geometria que foram denominadas no decorrer do texto de episódios. Eles foram pensados à luz de uma geometria que privilegie inicialmente o caráter sensível e empírico como uma possibilidade de se construir alguns conceitos geométricos envolvendo três dimensões para, em seguida, abordar elementos da geometria plana fazendo um diálogo constante entre as geometrias plana e espacial. Coletou-se os dados entre os meses de Fevereiro a Maio de 2015. Utilizou-se diversos instrumentos de coleta, destaca-se os cadernos de atividades entregues às equipes em cada episódio e as filmagens. Como resultados, evidencia-se que as atividades desenvolvidas em equipe favoreceram uma comunicação interpessoal em que participantes mais habilidosos contribuíram com os que apresentaram mais dificuldades, fato investigado pela zona de desenvolvimento proximal de Vygotsky. Verificamos também que os discentes deixaram de denominar um sólido geométrico a partir do formato de suas faces à medida que as atividades transcorreram. Por fim, registra-se grande crescimento nas faces da construção do conhecimento geométrico.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-03-08T12:13:27Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Stanley Borges de Oliveira.pdf: 3340773 bytes, checksum: de816c79a26915787dd60d54ce472134 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-06-13T20:37:16Z (GMT) No. of bitstreams: 2 PDF - Stanley Borges de Oliveira.pdf: 3340773 bytes, checksum: de816c79a26915787dd60d54ce472134 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-07-21T20:49:44Z (GMT). No. of bitstreams: 2 PDF - Stanley Borges de Oliveira.pdf: 3340773 bytes, checksum: de816c79a26915787dd60d54ce472134 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-25 / In the presentdissertation we study complex numbers with a special attention to the geometric aspect. Many geometric problems can be answered using the algebraic notation of complex numbers with their rich geometric interpretations with relative ease. The geometric aspects of the complex numbers are often not taught in high school, not even the trigonometric form (or polar form). Therefore, students do not apply the knowledge of complex numbers to solve geometric problems. In this paper we will approach the complex numbers applied to solve both geometric as algebraic problems, making relate geometric concepts with algebraic concepts of complex numbers, and launched as a proposal to develop the ability of students to relate mathematical content offering opportunity of even better fix the concepts of complex numbers. / No presente trabalho de conclusão de curso trataremos sobre os números complexos com uma atenção especial ao seu aspecto geométrico. Alguns problemas geométricos podem ser solucionados usando a notação algébrica dos números complexos com ajuda das suas ricas interpretações geométricas com certa facilidade. O aspecto geométrico dos números complexos muitas vezes não é ensinado no ensino médio, nem sequer a forma trigonométrica (ou polar). Por essa razão, os alunos não aplicam os conhecimentos de números complexos para resolver problemas geométricos. Em muitos casos, essa abordagem vem a facilitar a resolução das soluções. Neste trabalho faremos uma abordagem dos números complexos aplicados para resolver problemas, ora geométricos, ora algébricos, fazendo relacionar os conceitos geométricos com os conceitos algébricos dos números complexos e vice versa, e lançamos como proposta para desenvolver a habilidade dos alunos em relacionar os conteúdos matemáticos oferecendo oportunidade dos mesmo fixarem melhor conceitos dos números complexos.

Detecção automática de regiões planares em nuvens de pontos é um importante passo para muitas aplicações gráficas, de processamento de imagens e de visão computacional. Enquanto a disponibilidade de digitalizadores a laser e a fotografia digital tem nos permitido capturar nuvens de pontos cada vez maiores, técnicas anteriores para detecção de planos são computacionalmente caras, sendo incapazes de alcançar desempenho em tempo real para conjunto de dados contendo dezenas de milhares de pontos, mesmo quando a detecção é feita de um modo não determinístico. Apresentamos uma abordagem determinística para detecção de planos em nuvens de pontos não estruturadas que apresenta complexidade computacional O(n log n) no número de amostras de entrada. Ela é baseada em um método eficiente de votação para a transformada de Hough. Nossa estratégia agrupa conjuntos de pontos aproximadamente coplanares e deposita votos para estes conjuntos em um acumulador esférico, utilizando núcleos Gaussianos trivariados. Uma comparação com as técnicas concorrentes mostra que nossa abordagem é consideravelmente mais rápida e escala significativamente melhor que as técnicas anteriores, sendo a primeira solução prática para detecção determinística de planos em nuvens de pontos grandes e não estruturadas. / Automatic detection of planar regions in point clouds is an important step for many graphics, image processing, and computer vision applications. While laser scanners and digital photography have allowed us to capture increasingly larger datasets, previous techniques are computationally expensive, being unable to achieve real-time performance for datasets containing tens of thousands of points, even when detection is performed in a non-deterministic way. We present a deterministic technique for plane detection in unorganized point clouds whose cost is O(n log n) in the number of input samples. It is based on an efficient Hough-transform voting scheme and works by clustering approximately co-planar points and by casting votes for these clusters on a spherical accumulator using a trivariate Gaussian kernel. A comparison with competing techniques shows that our approach is considerably faster and scales significantly better than previous ones, being the first practical solution for deterministic plane detection in large unorganized point clouds.