Alternative Transfers to the NEOs 99942 Apophis, 1994 WR12, and 2007 UW1 via Derived Trajectories from Periodic Orbits of Family G

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FROZEN ORBITS AROUND EUROPA

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Low-altitude, near-polar and near-circular orbits around Europa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Planetary Satellite Orbiters: Applications for the Moon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stability regions around the components of the triple system 2001 SN263

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interplanetary natural routes via Moon and Lagrangiam points L1 and L2

Swing-by techniques are extensively used in interplanetary missions to minimize fuel consumption and to raise payloads of spaceships. The effectiveness of this type of maneuver has been proven since the beginning of space exploration. According to this premise, we have explored the existence of a natural and direct links between low Earth orbits and the lunar sphere of influence, to obtain low-energy interplanetary trajectories through swing-bys with the Moon and the Earth. The existence of these links are related to a family of retrograde periodic orbits around the Lagrangian equilibrium point L1 predicted for the circular, planar, restricted three-body Earth-Moon-particle problem. The trajectories in these links are sensitive to small disturbances. This enables them to be conveniently diverted reducing so the cost of the swing-by maneuver. These maneuvers allow us a gain in energy sufficient for the trajectories to escape from the Earth-Moon system and to stabilize in heliocentric orbits between the Earth and Venus or Earth and Mars. On the other hand, still within the Earth sphere of influence, and taking advantage of the sensitivity of the trajectories, is possible to design other swing-bys with the Earth or Moon. This allows the trajectories to have larger reach, until they can reach the orbit of other planets as Venus and Mars.(3σ)Broucke, R.A., Periodic Orbits in the Restricted Three-Body Problem with Earth-Moon Masses, JPL Technical Report 32-1168, 1968.

Optimization of satellite constellations in the moon

Nowadays, we return to live a period of lunar exploration. China, Japan and India heavily invest in missions to the moon, and then try to implement manned bases on this satellite. These bases must be installed in polar regions due to the apparent existence of water. Therefore, the study of the feasibility of satellite constellations for navigation, control and communication recovers importance. The Moon's gravitational potential and resonant movements due to the proximity to Earth as the Kozai-Lidov resonance, must be considered in addition to other perturbations of lesser magnitude. The usual satellite constellations provide, as a basic feature, continuous and global coverage of the Earth. With this goal, they are designed for the smallest number of objects possible to perform a specific task and this amount is directly related to the altitude of the orbits and visual abilities of the members of the constellation. However the problem is different when the area to be covered is reduced to a given zone. The required number of space objects can be reduced. Furthermore, depending on the mission requirements it may be not necessary to provide continuous coverage. Taking into account the possibility of setting up a constellation that covers a specific region of the Moon on a non-continuous base, in this study we seek a criterion of optimization related to the time between visits. The propagation of the orbits of objects in the constellation in conjunction with the coverage constraints, provide information on the periods of time in which points of the surface are covered by a satellite, and time intervals in which they are not. So we minimize the time between visits considering several sets of possible constellations and using genetic algorithms.

Development of a support vector machine-based navigation system for driving a mobile robot through paths in plantations

The use of mobile robots turns out to be interesting in activities where the action of human specialist is difficult or dangerous. Mobile robots are often used for the exploration in areas of difficult access, such as rescue operations and space missions, to avoid human experts exposition to risky situations. Mobile robots are also used in agriculture for planting tasks as well as for keeping the application of pesticides within minimal amounts to mitigate environmental pollution. In this paper we present the development of a system to control the navigation of an autonomous mobile robot through tracks in plantations. Track images are used to control robot direction by preprocessing them to extract image features. Such features are then submitted to a support vector machine in order to find out the most appropriate route. The overall goal of the project to which this work is connected is to develop a real time robot control system to be embedded into a hardware platform. In this paper we report the software implementation of a support vector machine, which so far presented around 93% accuracy in predicting the appropriate route. © 2012 IEEE.

Imigração e médicos italianos em São Paulo na primeira república

A imigração européia para a região sudeste do país, que foi responsável pela introdução da mão-de-obra assalariada, para atender às necessidades da cultura cafeeira, nas últimas décadas do século XIX e primeiras do século XX, tem sido suficientemente estudada pela historiografia da imigração. O que tem sido explorado em menor grau, é a inter-relação entre a imigração e a reforma sanitária que ocorreu no período. O estado de São Paulo, particularmente, foi palco de uma triste história de imigrantes italianos chegados e expostos à virulência das epidemias. Esse foi o ponto de partida para o início do movimento de reforma da saúde pública. Os fazendeiros consideravam a imigração uma necessidade vital para a economia cafeeira, havendo um consenso bastante forte entre as elites e o governo da necessidade de mostrar ao mundo que o Brasil estava disposto a combater sua má reputação em matéria de saúde pública. O pensamento reformista e a ação elegeramos imigrantes como principal alvo da política de saúde. Desta forma, o presente trabalho apresenta dados sobre essas ações e discute a maneira como os países estrangeiros – particularmente a Itália – enviaram ao Brasil agentes e inspetores, médicos, engenheiros e outros profissionais, no sentido de verificarem as reais condições de vida, de trabalho e de saúde de seus conterrâneos tanto nas áreas rurais como nas urbanas. Um dos fenômenos que resultaram dos esforços dos inspetores sanitários foi a consolidação de um mercado de trabalho para médicos italianos e a abertura de hospitais italianos em São Paulo e outras regiões do estado. O impacto da imigração e a consolidação da profissão médica, afetados pela vinda desses profissionais a São Paulo, são os focos principais deste trabalho.

Forças armadas, orçamento e autonomia militar

Avalia-se aqui como evoluíram as relações entre governo e Forças Armadas, e o comportamento destas no interior da burocracia de Estado com base na análise dos orçamentos federais desde o governo autoritário até o atual (1964-2001). Os dados indicam um declínio lento e constante dos gastos com a defesa, entremeados por repiques elevatórios no início de novos gover­nos. De maneira geral, sugerem que os governos civis definem o padrão orça­mentário sem interferência militar, embora os recursos sejam usados sem um acompanhamento adequado das atividades castrenses. Indica-se ainda que a autonomia castrense, isto é, a sua capacidade de definir seu campo de atua­ção, as normas que a norteiam e as missões a desempenhar, pode ser revigo­rada. Essa autonomia endêmica não é fruto de escolhas militares, mas da omissão do poder civil.

Estabilidade de órbitas congeladas em torno de satélites planetários utilizando o sistema hamiltoniano na forma normal

Pós-graduação em Física - FEG

Comparing support vector machines and artificial neural networks in the recognition of steering angle for driving of mobile robots through paths in plantations

The use of mobile robots turns out to be interesting in activities where the action of human specialist is difficult or dangerous. Mobile robots are often used for the exploration in areas of difficult access, such as rescue operations and space missions, to avoid human experts exposition to risky situations. Mobile robots are also used in agriculture for planting tasks as well as for keeping the application of pesticides within minimal amounts to mitigate environmental pollution. In this paper we present the development of a system to control the navigation of an autonomous mobile robot through tracks in plantations. Track images are used to control robot direction by pre-processing them to extract image features. Such features are then submitted to a support vector machine and an artificial neural network in order to find out the most appropriate route. A comparison of the two approaches was performed to ascertain the one presenting the best outcome. The overall goal of the project to which this work is connected is to develop a real time robot control system to be embedded into a hardware platform. In this paper we report the software implementation of a support vector machine and of an artificial neural network, which so far presented respectively around 93% and 90% accuracy in predicting the appropriate route. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer review under responsibility of the organizers of the 2013 International Conference on Computational Science

Una lapide in via Mazzini: os sofrimentos em Auschwitz e os desafios da tradução

Giorgio Bassani in his book Una lapide in via Mazzin seeks to show to the readers all the sufferings passed by Italians during the Second World War and emphasized those persists until today. Aiming to make an unprecedented translation of this tale, it is expected that the text provides us great experiences in the language and we could see the actual difficulties and differences with the Portuguese language, despite being considered these languages closed ones. The objective of this work is to produce a translation that allows us to transmit all anxieties and reflections suffered by the main character of the tale. After the war, the survivor of the concentration camp can go back to your city. He appears exactly at the moment is being placed a headstone on the synagogue wall in homage to Jews deported and killed in the camps. Given the gaunt figure of the man with his striped pajamas, the population is driven to rethink their own indifference and , in a way, its share of blame. Thus, the return should be celebrated is rejected and the figure of the survivor becomes a nuisance. The function of the headstone is actually and literally put a stone on the story. To achieve the proposed objective for this work, we analyzed all the chapters of the story Una lapide in via Mazzini and tried to find equivalents in Portuguese. However, we not ignored the traces of meaning that Giorgio Bassani invested in his work. Therefore, it was necessary to use both printed and virtual dictionaries. With the advancement of the translation work, we realized the difficulty of finding appropriate solutions to achieve the desired effect . The fidelity proposed by the author became increasingly difficult as our work progressed. In the course of all the discussions, it was concluded that , in fact , when it comes to translation, maintaining fidelity to the original text in a foreign language is a difficult and laborious process

Searching for capture and escape trajectories around Jupiter using its Galilean satellites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Stability analysis of the attitude of artificial satellites subject to gravity gradient torque

Using a canonical formulation, the stability of the rotational motion of artificial satellites is analyzed considering perturbations due to the gravity gradient torque. Here Andoyer's variables are used to describe the rotational motion. One of the approaches that allow the analysis of the stability of Hamiltonian systems needs the reduction of the Hamiltonian to a normal form. Firstly equilibrium points are found. Using generalized coordinates, the Hamiltonian is expanded in the neighborhood of the linearly stable equilibrium points. In a next step a canonical linear transformation is used to diagonalize the matrix associated to the linear part of the system. The quadratic part of the Hamiltonian is normalized. Based in a Lie-Hori algorithm a semi-analytic process for normalization is applied and the Hamiltonian is normalized up to the fourth order. Once the Hamiltonian is normalized up to order four, the analysis of stability of the equilibrium point is performed using the theorem of Kovalev and Savichenko. This semi-analytical approach was applied considering some data sets of hypothetical satellites. For the considered satellites it was observed few cases of stable motion. This work contributes for space missions where the maintenance of spacecraft attitude stability is required.