A multi-domain approach to asteroid families identification

Previous works have identified families halos by an analysis in proper elements domains, or by using Sloan Digital Sky Survey-Moving Object Catalog data, fourth release (SDSS-MOC4) multi-band photometry to infer the asteroid taxonomy, or by a combination of the two methods. The limited number of asteroids for which geometric albedo was known until recently discouraged in the past the extensive use of this additional parameter, which is however of great importance in identifying an asteroid taxonomy. The new availability of geometric albedo data from the Wide-field Infrared Survey Explorer (WISE) mission for about 100,000 asteroids significantly increased the sample of objects for which such information, with some errors, is now known. In this work we proposed a new method to identify families halos in a multi-domain space composed by proper elements, SDSS-MOC4 (a*,i-z) colors, and WISE geometric albedo for the whole main belt (and the Hungaria and Cybele orbital regions). Assuming that most families were created by the breakup of an undifferentiated parent body, they are expected to be homogeneous in colors and albedo. The new method is quite effective in determining objects belonging to a family halo, with low percentages of likely interlopers, and results that are quite consistent in term of taxonomy and geometric albedo of the halo members.Comment: 23 pages, 18 figures, 6 tables. Accepted for publication in MNRA

A Study of Single- and Double-Averaged Second-Order Models to Evaluate Third-Body Perturbation Considering Elliptic Orbits for the Perturbing Body

The equations for the variations of the Keplerian elements of the orbit of a spacecraft perturbed by a third body are developed using a single average over the motion of the spacecraft, considering an elliptic orbit for the disturbing body. A comparison is made between this approach and the more used double averaged technique, as well as with the full elliptic restricted three-body problem. the disturbing function is expanded in Legendre polynomials up to the second order in both cases. the equations of motion are obtained from the planetary equations, and several numerical simulations are made to show the evolution of the orbit of the spacecraft. Some characteristics known from the circular perturbing body are studied: circular, elliptic equatorial, and frozen orbits. Different initial eccentricities for the perturbed body are considered, since the effect of this variable is one of the goals of the present study. the results show the impact of this parameter as well as the differences between both models compared to the full elliptic restricted three-body problem. Regions below, near, and above the critical angle of the third-body perturbation are considered, as well as different altitudes for the orbit of the spacecraft.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilCNPq: 150195/2012-5CNPq: 304700/2009-6FAPESP: 2011/09310-7FAPESP: 2011/08171-3Web of Scienc

ANTS2 package: simulation and experimental data processing for Anger camera type detectors

ANTS2 is a simulation and data processing package developed for position sensitive detectors with Anger camera type readout. The simulation module of ANTS2 is based on ROOT package from CERN, which is used to store the detector geometry and to perform 3D navigation. The module is capable of simulating particle sources, performing particle tracking, generating photons of primary and secondary scintillation, tracing optical photons and generating photosensor signals. The reconstruction module features several position reconstruction methods based on the statistical reconstruction algorithms (including GPU-based implementations), artificial neural networks and k-NN searches. The module can process simulated as well as imported experimental data containing photosensor signals. A custom library for B-spline parameterization of spatial response of photosensors is implemented which can be used to calculate and parameterize the spatial response of a detector. The package includes a graphical user interface with an extensive set of configuration, visualization and analysis tools. ANTS2 is being developed with the focus on the iterative (adaptive) reconstruction of the detector response using flood field irradiation data. The package is implemented in C++ programming language and it is a multiplatform, open source project.Peer Reviewe

Consórcio sorgo-feijão: efeito de arranjos de fileiras no rendimento de grãos.

Com o objetivo de estudar os efeitos de arranjos de fileiras no consorcio sorgo-feijao, instalou-se um experimento (marco de 1992) no CNPMS/EMBRAPA, Sete Lagoas, MG, Brasil. usaram-se duas linhagens de sorgo granifero (BR 007B e CMSXS 210B) em monocultura e em tres arranjos de fileiras (plantio na mesma fileira, plantio em fileiras alternadas e duas fileiras de feijao nas entrelinhas do sorgo), mais um tratamento adicional (feijao em monocultura), no esquema fatorial (2 x 4) + 1 e delineamento de blocos inteiramente casualizados, com quatro repeticoes. Foi utilizado cultivar de feijao Ouro, de habito de crescimento indeterminado (tipo II). Os rendimentos individuais das culturas foram maiores no arranjo em fileiras alternadas, mas suas medias nao diferiram das obtidas nos seus respectivos monocultivos. Independentemente da linhagem, os maiores rendimentos totais foram obtidos nos arranjos de fileiras alternadas e de duas fileiras de feijao nas entrelinhas do sorgo. Quando o consorcio foi feito usando a CMSXS 210B no arranjo de duas fileiras de feijao nas entrelinhas do sorgo, houve reducao do rendimento de feijao e dos indices de equivalencia de area (IEAs), devido a reducao do numero de vagens por planta. Concluiu-se que os arranjos em fileira alternadas e de duas fileiras de feijao nas entrelinhas do sorgo podem ser usados no consorcio sorgo-feijao, todavia este ultimo arranjo seria adequado apenas com cultivares de sorgo menos competitivos

Escher: Arte e Matemática desenhadas por alunos portugueses

Parte substancial da obra de Escher é dedicada ao estudo do Plano Euclidiano, nomeadamente numa perspetiva de o pavimentar. É sobre este tópico da obra de Escher que incide o presente trabalho o qual pode ser encardao como um ‘tributo’ a Escher e à sua arte. À semelhança de muitos outros já existentes na literatura, este trabalho retrata a harmonia e afinidade existente entre a Arte e a Matemática nas criações do artista. Porém, face a algumas particularidades, julgamos que o nosso estudo prima por alguma singularidade, sendo exemplo elucidativo da expressão gráfica nas Artes Visuais e na Matemática, associado ao relato de uma experiência vivida em contexo escolar. Sustentando-se numa análise e apresentação cuidada dos procedimentos seguidos por Escher para pavimentar o plano, um grupo de alunos em risco de abandono escolar (com idades compreendidas entre os 16 e os 19 anos que não tinham concluído o ensino básico), (re)criou a obra de Escher em painéis de azulejo, mediante produções artísticas originais

Da Arte à Matemática… da Matemática à Arte: uma experiência no Ensino Português

The struggling on identifying strategies and factors that could help to improve the teaching/learning process, regarding the existence of multiple realities, is a subject much discussed in literature. Finding new ways of answer challenges which we came across, is the main reason why this study has been made. The primary goal is centred in applying a Geometry curriculum including many different learning situations based in vocational training. The students were between 16 and 19 years old. Making use of Art is analysed as a potential method to improve Mathematics teaching. Being Escher’s work an element of undiscussable richness with highlights to “Exploration Tessellations”, an investigation has been made to show how some Escher’s works could be a starting point to the introduction of mathematical concepts/contents. It was noticed in a further case that using Art could lead not just to the student’s effective cooperation in the teaching/learning process, as could be a very strong acquisition and way to apply new solid mathematical concepts

Practical probabilistic programming with monads

The machine learning community has recently shown a lot of interest in practical probabilistic programming systems that target the problem of Bayesian inference. Such systems come in different forms, but they all express probabilistic models as computational processes using syntax resembling programming languages. In the functional programming community monads are known to offer a convenient and elegant abstraction for programming with probability distributions, but their use is often limited to very simple inference problems. We show that it is possible to use the monad abstraction to construct probabilistic models for machine learning, while still offering good performance of inference in challenging models. We use a GADT as an underlying representation of a probability distribution and apply Sequential Monte Carlo-based methods to achieve efficient inference. We define a formal semantics via measure theory. We demonstrate a clean and elegant implementation that achieves performance comparable with Anglican, a state-of-the-art probabilistic programming system.The first author is supported by EPSRC and the Cambridge Trust.This is the author accepted manuscript. The final version is available from ACM via http://dx.doi.org/10.1145/2804302.280431

Feno da parte aérea da mandioca para a produção de ruminantes em sistemas organicos.

As produtividades de feno observadas neste estudo indicam que o aproveitamento da parte aérea da mandioca pode representar uma estratégia de integração das atividades produtivas em uma mesma propriedade apropriada para a alimentação de ruminantes durante o período de escassez das pastagens, constituindo em um recurso disponível para manter índices adequados de produtividade dos rebanhos da região manejados de acordo com as diretrizes da produção orgânica.bitstream/CPAP-2010/57326/1/CT88.pd