sUAS Swarm Navigation using Inertial, Range Radios and Partial GNSS

Small Unmanned Aerial Systems (sUAS) operations are increasing in demand and complexity. Using multiple cooperative sUAS (i.e. a swarm) can be beneficial and is sometimes necessary to perform certain tasks (e.g., precision agriculture, mapping, surveillance) either independent or collaboratively. However, controlling the flight of multiple sUAS autonomously and in real-time in a challenging environment in terms of obstacles and navigation requires highly accurate absolute and relative position and velocity information for all platforms in the swarm. This information is also necessary to effectively and efficiently resolve possible collision encounters between the sUAS. In our swarm, each platform is equipped with a Global Navigation Satellite System (GNSS) sensor, an inertial measurement unit (IMU), a baro-altimeter and a relative range sensor (range radio). When GNSS is available, its measurements are tightly integrated with IMU, baro-altimeter and range-radio measurements to obtain the platform’s absolute and relative position. When GNSS is not available due to external factors (e.g., obstructions, interference), the position and velocity estimators switch to an integrated solution based on IMU, baro and relative range meas-urements. This solution enables the system to maintain an accurate relative position estimate, and reduce the drift in the swarm’s absolute position estimate as is typical of an IMU-based system. Multiple multi-copter data collection platforms have been developed and equipped with GNSS, inertial sensors and range radios, which were developed at Ohio University. This paper outlines the underlying methodology, the platform hardware components (three multi-copters and one ground station) and analyzes and discusses the performance using both simulation and sUAS flight test data

O discurso das orientações didático-pedagógicos em livros didáticos de língua portuguesa: em torno da prática de análise linguística

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Linguística, Florianópolis, 2017.O termo prática de análise linguística tem sido amplamente utilizado para referendar práticas contextualizadas de análise e reflexão linguísticas em contraposição à gramática tradicional. Contudo, por vezes, ocorre a renovação dos termos, mas não das práticas em si. Atentos a esses fatos, analisamos as orientações constantes do manual do professor intercalado ao livro didático, no objetivo de compreender como se constitui o discurso desses manuais quanto à questão da prática de análise linguística nas aulas de Língua Portuguesa no Ensino Médio. Nossos objetivos específicos são (i) analisar os discursos já-ditos a que as orientações respondem/reenunciam; (ii) analisar as orientações discursivizadas no manual do professor em torno da gramática tradicional e da análise linguística nas aulas de LP. Para tanto, dois matizes teórico-metodológicos embasam nosso trabalho: I) os escritos do Círculo de Bakhtin e as pesquisas de seus interlocutores na contemporaneidade como fundamento para a Análise Dialógica de/do Discurso; II) os estudos contemporâneos em Linguística Aplicada sobre o ensino operacional e reflexivo da linguagem na escola de Educação Básica como fundamento para a compreensão de como os livros de LP têm reenunciado/respondido/evocado as(às) discussões sobre a prática de análise linguística na/para escola. Os dados foram gerados a partir das três coleções de livros didáticos mais utilizados na rede pública de ensino do estado de Santa Catarina (SC), escolhidos pelos professores por meio do Programa Nacional do Livro Didático, triênio 2015-2017 ? Coleção Língua Portuguesa: linguagem e interação, Coleção Novas Palavras e Coleção Português: Linguagens. As análises desenvolvidas revelaram um cronotopo de crise do ensino de línguas, marcado pelo discurso do conflito, no qual interagem, por meio do manual do professor, o autor-editor sócio-hierarquicamente situado como pesquisador-professor que detém o discurso de autor(idade) em relação a projeção ideológico-valorativa da imagem de professor, o seu interlocutor final. A imagem de professor discursivizada cronotopicamente no manual é a de um sujeito heterogênio em relação aos seus pares no que diz respeito a sua formação e atuação profissional, mas que, devido às condições impostas pela desvalorização da carreira de professor, é muito ocupado por sua carga horária excessiva de trabalho, o que reflete em seu planejamento e no uso que faz do livro didático. Respondendo, também, às pressões exercidas pelos documentos oficiais ? PCN e PNLD ? como forma de obter a aprovação na avaliação do MEC (seu interlocutor intermediário). No intento de atender às expectativas desses dois interlocutores (entre tantos outros possíveis), precisa conjugar práticas conflituosas e por vezes contraditórias, preenchendo o entrelugar da gramática e da análise linguística com um discurso de conflito por meio de assonâncias e dissonâncias e aproximações e distanciamentos com discursos já-ditos.Abstract : The term practice of linguistic analysis has been widely used to refer contextualized practices of linguistic analysis and reflection in contrast to the practice of traditional grammar. However, sometimes the renewal of terms occurs, but not of the practices themselves. Aware of these facts, we analyze the guidelines included in the teacher's manual intercalated with the textbook, to understand how the discourse of these manuals is constituted in relation to the question of the practice of linguistic analysis in Portuguese Language classes in High School. Our specific objectives are to (i) analyze the already spoken discourses to which the guidelines respond / re-announce; B) analyze the discursive orientations in the teacher's manual about traditional grammar and linguistic analysis in LP classes. In order to do so, two theoretical-methodological shades support our work: I) the writings of Bakhtin's Circle and the researches of its interlocutors in contemporary times as the basis for the Dialogic Analysis of the Discourse; II) the contemporary studies in Applied Linguistics on operational and reflexive language teaching in the Basic Education school as a basis for understanding how LP books have re-issued / answered / evoked the discussions about the practice of linguistic analysis in / For school. The data were generated from the three collections of textbooks most commonly used in public schools in the state of Santa Catarina (SC), chosen by teachers through the National Program of Didactic Book, triennium 2015-2017 - Portuguese Language Collection: language and interaction, New Words Collection and Portuguese Collection: Languages. The developed analyzes revealed a chronotope of language teaching crisis, marked by the discourse of conflict, in which the author-editor, socio-hierarchically situated as researcher-teacher, holds the author's discourse (age) In relation to the ideological-evaluative projection of the image of teacher, his final interlocutor. The teacher image, reflected in the manual discourse, is that of a heterogeneous subject in relation to his / her peers with respect to their professional training and performance, but who, due to the conditions imposed by the devaluation of the teacher's career, is very occupied by His excessive workload, which reflects on his planning and the use he makes of the textbook. It also responds to the pressures exerted by the official documents - PCN and PNLD - as a means of obtaining approval in the evaluation of the MEC (its intermediary). To meet the expectations of these two interlocutors (among many others possible), it needs to combine conflicting and sometimes contradictory practices, filling the interlude of grammar and linguistic analysis with a discourse of conflict through assonances and dissonances and approximations and distances with already-spoken discourses

Periodisation as an approach in historiographic research in mathematics teaching: reflections on two case studies

Background: the study of the history of mathematics teaching can be approached from different perspectives, defining contours from which the researcher performs the analysis focused on a process characterised by continuity, or by adopting periodisation. Objective: in this article, we seek to conduct a study based on the delimitation of periods, according to Le Goff’s (2014) argument, and in the light of the depth hermeneutics, based on Thompson (2011). Design: given the premises above, we conducted a documentary analysis of two historical processes within the scope of mathematics teaching, one focusing on the municipal public schools of canoas, and the other on a technical course in chemistry of a school in the city of novo Hamburgo, both in the state of Rio Grande do Sul. Setting and participants: a timeline with conspicuous events used to periodicise both historical processes analysed by the authors. Data collection and analysis: analysis of documents relevant to the history of the technical school investigated and education in the municipality of canoas. Results: in both cases, it was possible to characterise the historical processes in periods based on events and official documents that generate changes in mathematics teaching. Conclusions: the historical processes analysed are characterised by ruptures resulting from changes, especially in the legislation, both in the municipal public network and in the technical education institution researched, enabling the realisation of changes and the characterisation of distinct periods, with their nuances

Mass and luminosity evolution of young stellar objects

A model of protostar mass and luminosity evolution in clusters gives new estimates of cluster age, protostar birthrate, accretion rate and mean accretion time. The model assumes constant protostar birthrate, core-clump accretion, and equally likely accretion stopping. Its parameters are set to reproduce the initial mass function, and to match protostar luminosity distributions in nearby star-forming regions. It obtains cluster ages and birthrates from the observed numbers of protostars and pre-main sequence (PMS) stars, and from the modal value of the protostar luminosity. In 31 embedded clusters and complexes the global cluster age is 1-3 Myr, matching available estimates based on optical spectroscopy and evolutionary tracks. This method of age estimation is simpler than optical spectroscopy, and is more useful for young embedded clusters where optical spectrocopy is not possible. In the youngest clusters, the protostar fraction decreases outward from the densest gas, indicating that the local star-forming age increases outward from a few 0.1 Myr in small protostar-dominated zones to a few Myr in large PMS-dominated zones.Comment: To appear in The Astrophysical Journal, Part

Experiências de uso de rochas silicáticas como fonte de nutrientes

O presente artigo aborda os benefícios produtivos, sociais e ambientais da incorporação da técnica de Rochagem para o setor agrícola, especialmente para o grupo dos agricultores familiares. A Rochagem é uma tecnologia social de baixo impacto, que pode ser entendida como um rejuvenescimento ou recondicionamento de solos empobrecidos quimicamente pelo uso intensivo ou pelo desgaste natural. Baseia-se no uso do pó de determinados tipos de rochas que contenham, preferencialmente, quantidades apreciáveis de macronutrientes (cálcio, potássio, fósforo e magnésio) e de micronutrientes (cobalto, molibdênio, vanádio, boro, cobre etc). Os resultados descritos neste trabalho refletem cerca de 12 anos de pesquisa desenvolvida pela equipe da UnB (NEAGRI/ CEAM/CDS) junto a agricultores familiares assentados, quilombolas e ribeirinhos. _____________________________________________________________________________________________________________ ABSTRACTThe present work approaches the productive, social and environmental benefits of the incorporation of the Stonemeal technique for the agricultural sector, especially for the family farmers group. Stonemeal is a low impact technology (or social) that can be understood as a renewal or reconditioning of soils chemically impoverished by the intensive use or by the weathering. It is based on the use of dust from established rock types that have, preferably, considerable amounts of macronutrients (calcium, potassium, phosphorus and magnesium) and micronutrients (cobalt, molybdenum, vanadium, boron, copper etc). The results described in this work are the reflection of 12 years of research developed by an UnB (NEAGRI/CEAM/CDS) team together with the family farmers settled, “quilombolas” and waterside

Stonemeal of amazon soils with sediments from reservoirs: a case study of remineralization of the tucuruí degraded land for agroforest reclamation

Este estudo sugere o emprego dos sedimentos acumulados no reservatório de Tucuruí (Pará/Brasil) para remineralizar os solos degradados do seu entorno. A abordagem foi baseada nos princípios da tecnologia da Rochagem. Isto sugere que o solo pode ser rejuvenescido pela adição de rochas moídas ricas em macro e micronutrientes. A remoção dos sedimentos para uso agrícola trará benefícios para os agricultores familiares da região, além de facilitar o aumento da vida útil do Reservatório e, portanto, da geração da energia. Dados geoquímicos dos sedimentos retidos, de solos e de rochas da área de influência do Reservatório foram avaliados no que diz respeito aos mecanismos de transporte e do potencial de nutrientes para fertilizar os solos. Os resultados mostram que os sedimentos do reservatório contêm níveis de nutrientes de no mínimo um grau de grandeza superior à média dos solos da Amazônia. Nossos dados produzidos nesta pesquisa sobre uso e ocupação do solo na região mostram as áreas degradadas que poderão ser recuperados pela técnica da Rochagem. Para comprovar os efeitos da remineralização dos solos foi instalado um Sistema Agroflorestal, com 12 parcelas onde diferentes misturas de sedimentos retirados do reservatório foram utilizadas juntamente com rocha moída com ou sem a adição de NPK e de composto orgânico. Os testes mostraram que a melhor produtividade agrícola e de crescimento das plantas foram obtidos nas parcelas onde a mistura de sedimentos, rochas moídas e composto orgânico foram adicionados. _____________________________________________________________________________________________________________ ABSTRACTThis study suggests the employment of accumulated sediments in the reservoir of Tucuruí (Pará /Brazil) to remineralize the surrounding degraded soils. The approach was based on the principles of stonemeal technology. It suggests that the soil can be rejuvenated by crushed rocks rich in macro and micronutrients. Removal of the sediments for agricultural use will bring benefits to family farmers and increase the life cycle of the reservoir and, therefore, energy generation. Geochemical data on retained sediments, soils and rocks in the area of influence of the reservoir were evaluated regarding nutrient transport mechanisms and soil-fertility potential. Results show that sediments from the reservoir contain nutrients levels at least one order of magnitude greater than average Amazon region soils. Our data on soil use and occupation in the region show the degradation areas which could be recovered by stonemeal techniques. Thence, an Agroforestry System was installed, with 12 plots where different mixtures of sediments removed from the reservoir were used, along with crushed rock with or without the addition of NPK and manure. The experiments showed that maximum crop yield and plant growth were attained in the plots where a mixture of sediments, crushed rocks and manure were added

A fertilização da terra pela terra : uma alternativa para a sustentabilidade do pequeno produtor rural

Tese (doutorado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, 2000.O presente trabalho estabelece como ponto de partida a revisão da historia do setor agrícola no Brasil, buscando entender as causas que, ao longo de décadas, convergiram o país para uma situação de desajuste econômico, social, fundiário e ecológico, em seu meio rural. Na ultima metade deste século, com a introdução de tecnologias que revolucionaram as formas de se produzir alimentos, agravaram-se as relações do homem com a terra. Nesse aspecto, o trabalho procura mostrar que tais desajustes ocorrem de forma intensa na região do Cerrado Brasileiro. São discutidos os impactos, limites e perspectivas para o setor agrícola da região, consideradas as premissas associadas ao conceito do desenvolvimento sustentável. Em seguida, e apresentado um caso de construção de uma nova realidade no meio rural, envolvendo agricultores assentados pelo Programa de Reforma Agrária, sendo enfocados aspectos sociais, organizacionais, econômicos e ambientais daquela população. De posse de todas essas informações, e considerando a proposta de, ao longo de todo o trabalho, estabelecer-se uma abordagem multidisciplinar, e apresentada uma tecnologia baseada no uso de pó de rocha - Rochagem - que prevê, em sua essência, a busca do equilíbrio ambiental com a manutenção da produtividade, tendo como base uma nova forma de fertilização. Nesse sentido, a fertilização da terra pela própria terra abre a possibilidade de entendimento dos processos naturais que definem as especificidades do planeta. São apresentados os resultados dos experimentos de campo realizados em vários lotes do Assentamento Fruta D’Anta, em Minas Gerais, e em uma fazenda de produção orgânica, localizada no Distrito Federal. Tais experimentos confirmaram a viabilidade econômica, ecológica e produtiva da técnica de Rochagem, comprovadas por analise custo/beneficio. Por fim, são sugeridas algumas premissas para a construção de um novo modelo de desenvolvimento agrícola, baseado em tecnologias alternativas capazes de recriar oportunidades de inserção e manutenção de uma grande parcela da população que, hoje, encontra-se excluída dos processos produtivos e do direito a cidadania. Portanto, o eixo central desta tese situa-se na abordagem de temas tecnológicos - como o uso do método de Rochagem - e na analise e identificação de algumas características do espaço rural que permeiam a relação dos indivíduos com a terra, em face do atual momento de crise global provocada pela mudança de paradigmas. ______________________________________________________________________________________________ ABSTRACTThe present work establishes as a starting point the review on the history of the Brazilian Agricultural sector, aiming to understand the causes that throughout decades, led the country to a situation of economic, social, land division and ecological instability in its countryside. In the last half of this century, with the introduction of technologies which revolutioned the means of food production, the relationship between man and the land worsen. In this subject, this work tries to show that such maladjustments occur in an intensive way in the region of the “Brazilian Cerrado”. The impacts, limits and perspectives to the Agricultural sector of the region are discussed considering, the premises associated to the concept of sustainable development. Soon afterwards, a construction case of a new reality in a rural environment is presented, involving farmers setted by the Agrarian Reform Program, focusing social, organizational, economical and environmental aspects of that population. Having all this information, and considering the proposal that during all the work, having established a multidisciplinary approach, it is presented a technology based on the use of Stonemeal, which foresees in deep, the search for productivity, and having as a basis a new form of fertization. In this sense, the fertilization of the soil by the soil, opens the possibility of understanding natural processes which define the planet's especialities. The results of the field experiments conducted in many parts of the” Fruta D'Anta Settlement “ in Minas Gerais State, and in a farm of organic production located in the Federal District, are presented. Such experiments confirmed the economical, ecological and productive viability proved by the analysis of cost and benefits. To sum up, some premises are suggested for the construction of a new model of agricultural development, based in alternative technologies capable of recreating opportunities of inclusion and maintenance of great amount of the population that nowadays is found excluded from the productive processes and the rights to citizenship. Therefore, the main idea of this thesis deals with technological themes such as the use of the Stonemeal method and in the analysis and identification of some characteristics of the rural environment which allows the relationship of people with the land, due to the current moment of global crisis provoked by changes of paradigms. ______________________________________________________________________________________________ RESUMENCe travail part de l’histoire du secteur agricole au Brésil et cherche a comprendre les causes qui, tout au long des décennies, ont conduit le milieu rural à une situation de rupture economique, sociale, foncière et écologique. Avec l’introduction de technologies qui ont revolutionne la production alimentaire, les relations entre l’homme et la terre se sont aggravées dans la seconde moitié du siècle. Dans ce sens, ce travail cherche à montrer que ces ruptures sont intenses dans la région du cerrado brésilien. Il traite des impacts, des limites et des perspectives pour le secteur agricole de la region, des perspectives considerees comme les premisses associees au concept de développement soutenable. Est ensuite présenté un cas de construction d’une nouvelle réalité en milieu rural qui concerne des agriculteurs fixés dans des assentamentos par le Programme de Réforme Agraire. Y sont soulignés les aspects sociaux, organisationnels, économiques et environnementaux de cette population. En possession de toutes ces informations et considerant la proposition d’etablir, tout au long du travail, une approche interdisciplinaire, nous presentons une technologie fondee sur l’usage d’une poudre de roche - technique dite du “Rochage” - qui prévoit, dans son essence, la recherche d’un équilibre environnemental avec le maintien de la productivité basé sur une nouvelle forme de fertilisation. Dans ce sens, la fertilisation de la terre par la terre elle-même permet de comprendre les processus naturels qui définissent les spécificités de la planète. Sont présentés les résultats d’expériences de terrain menées sur plusieurs lopins de 1’Assentamento Fruta D’Anta, dans l’état de Minas Gerais, et dans une ferme de production organique située dans le District Fédéral. Ces expériences ont confirmé la viabilite économique, écologique et productive de la “technique du rochage”, une viabilite prouvée par une analyse coût/bénefice. Enfin, nous suggérons certaines prémisses à la construction d’un nouveau modèle de développement agricole basé sur des technologies alternatives capables de récreer des opportunités d’insertion et de maintien sur place d’une grande partie de la population aujourd’hui exclue des processus de production et du droit a la citoyenneté. L’axe central de cette these se situe donc au niveau de l’approche de questions technologiques - comme l’emploi de la méthode du Rochage - et de l’analyse et l’identification de certaines caracteristiques de l’espace rural qui traversent la relation des individus avec la terre, dans une époque de crise globale provoquée par le changement de paradigmes

Embedded Stellar Populations towards Young Massive Star Formation Regions I. G305.2+0.2

We present deep, wide-field J, H and Ks images taken with IRIS2 on the Anglo Australian Telescope, towards the massive star formation region G305.2+0.2. Combined with 3.6, 4.5, 5.8 and 8.0 micron data from the GLIMPSE survey on the Spitzer Space Telescope, we investigate the properties of the embedded stellar populations. After removing contamination from foreground stars we separate the sources based on their IR colour. Strong extended emission in the GLIMPSE images hampers investigation of the most embedded sources towards the known sites of massive star formation. However, we find a sizeable population of IR excess sources in the surrounding region free from these completeness effects. Investigation reveals the recent star formation activity in the region is more widespread than previously known. Stellar density plots show the embedded cluster in the region, G305.24+0.204, is offset from the dust emission. We discuss the effect of this cluster on the surrounding area and argue it may have played a role in triggering sites of star formation within the region. Finally, we investigate the distribution of IR excess sources towards the cluster, in particular their apparent lack towards the centre compared with its immediate environs.Comment: 16 pages, 16 figures (significantly size reduced), 2 tables, accepted MNRA