Improved Chebyshev series ephemeris generation capability of GTDS

An improved implementation of the Chebyshev ephemeris generation capability in the operational version of the Goddard Trajectory Determination System (GTDS) is described. Preliminary results of an evaluation of this orbit propagation method for three satellites of widely different orbit eccentricities are also discussed in terms of accuracy and computing efficiency with respect to the Cowell integration method. An empirical formula is deduced for determining an optimal fitting span which would give reasonable accuracy in the ephemeris with a reasonable consumption of computing resources

Supranational Identity Politics: Sovereignism in the EU

The implementation of identity politics policies conceived at a supranational level appears to motivate the coordination of populist movements, the radicalization of their discourses, and an increasing resentment towards minority groups. I investigate the reaction of populist sovereignist political movements, among recently admitted EU member states, to the implementation of European Union policies that involve the positive discrimination of minority groups and mandated refugee relocations. The implementation of such policies seems to have contributed to the resentment toward policy-favored minorities, the increase of anti-immigration values, the success of extremist political expressions, and the mistrust of political institutions and traditional parties. The research relies on a multiple case studies approach to identify the effects of the implementation of EU-mandated affirmative action and immigration policies. The political and economic landscapes of study cases, taken from post-communist Eastern Europe (primarily, Poland, Slovakia, and Hungary), are described based on the existing literature. The general arguments are supported through a review of quantitative studies that incorporate regression analyses on electoral data and web content analysis. Arguments are also complemented by a review of World Bank, OECD and Eurostat reports, election results, as well as the theoretical literature on ethnic competition, welfare spending, multiculturalism, and the specifics of the political parties and systems of the selected countries

Differential correction capability of the GTDS using TDRSS data

A differential correction (DC) capability was implemented in the Goddard Trajectory Determination System (GTDS) to process satellite tracking data acquired via the Tracking and Data Relay Satellite System (TRDRSS). Configuration of the TDRSS is reviewed, observation modeling is presented, and major features of the capability are discussed. The following types of TDRSS data can be processed by GTDS: two way relay range and Doppler measurements, hybrid relay range and Doppler measurements, one way relay Doppler measurements, and differenced one way relay Doppler measurements. These data may be combined with conventional ground based direct tracking data. By using Bayesian weighted least squares techniques, the software allows the simultaneous determination of the trajectories of up to four different satellites - one user satellite and three relay satellites. In addition to satellite trajectories, the following parameters can be optionally solved: for drag coefficient, reflectivity of a satellite for solar radiation pressure, transponder delay, station position, and biases

Bird flu: a real or imaginary threat

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Machine learning for audio on the web

In this report, we present our Capstone project for the Course of Computer Science and Management at Polytech Montpellier that we developed in partnership with the SigSep team (Inria, LIRMM) [1]. The project consists of creating an application that allows a user to unmix a song, i.e. to separate each instrument (such as guitar, bass, vocals) from a song, on the web, straight on their browser. In this context, we use JavaScript to develop a program that uses both Digital Signal Processing (DPS) and machine learning techniques and can be run completely on the browser without the need for a server. Our approach consists of manually implementing DSP operations that do not exist in JavaScript, converting a pre-trained model to TensorFlowJS [2] and creating an intuitive and minimalistic UI using Vue.Dans ce rapport, nous présentons notre Projet de Fin d’études pour le cursus Informatique et Gestion à Polytech Montpellier. Nous avons développé ce projet en partenariat avec l'équipe SigSep (Inria, LIRMM). Le projet consiste à créer une application qui permet à un utilisateur de démixer une chanson, c'est-à-dire de séparer chaque instrument (comme la guitare, la basse, le chant) d'une chanson, sur le web, directement sur son navigateur. Dans ce contexte, nous utilisons JavaScript pour développer un programme qui utilise à la fois le traitement numérique du signal et les techniques d'apprentissage machine et qui peut être exécuté entièrement sur le navigateur sans avoir besoin d'un serveur. Notre approche consiste à implémenter manuellement des opérations DSP qui n'existent pas en JavaScript, à convertir un modèle écrit en TensorFlowJS et à créer une interface utilisateur intuitive et minimaliste à l'aide du framework JavaScript Vue

Foreign language instruction: Students' perception of a virtual learning environment

TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Curso de Graduação em Língua e Literatura Estrangeira.Ambientes Virtuais de aprendizagem (AVA) são recursos e ferramentas tecnológicas adaptadas para serem usados com objetivos educacionais. Apesar de ser diretamente relacionado ao ensino a distância, nos últimos anos, ambientes virtuais de aprendizagem também estão sendo usados como suporte de aulas presenciais. O objetivo desta pesquisa qualitativa é investigar o uso do ambiente virtual de aprendizagem - Moodle na disciplina do curso de Letras Inglês LLE7495 - Compreensão e Produção Escrita V, com foco na percepção dos alunos em relação a este ambiente virtual. Um questionário foi elaborado e aplicado aos estudantes que cursaram a disciplina no semestre 2011.1. Ao final da pesquisa foi possível concluir que os estudantes estão conscientes das possibilidades que o uso do ambiente virtual pode oferecer para seu processo de aprendizagem. Também que professores precisam estar cientes das possibilidades permitidas pelo uso do ambiente e devem estar preparados para o uso do mesmo. Também foi possível concluir que os estudantes estão cientes do seu papel no processo de aprendizagem.Virtual learning environments (VLE) are technological resources and tools adapted and used for educational purposes. Although they are directly related to distance education, in the last years, VLE have been also used to support on-campus classes. The aim of this qualitative research is to investigate the use of the virtual learning environment - Moodle in the Letras Inglês Course LLE7495 - Compreensão e Produção Escrita V, focusing on students' perceptions in relation to this virtual environment. A questionnaire was devised and applied to students who took this course in the semester 2011.1. At the end of the study it was concluded that students are aware of the possibilities that the use of the virtual environment can provide for their learning process, and also that teachers need to be aware of the possibilities afforded by the use of the environment and must be prepared to use it. Furthermore, that the students are aware of their role in the learning process

When mathematics touches physics: Henri Poincaré on probability

Probability plays a crucial role regarding the understanding of the relationship which exists between mathematics and physics. It will be the point of departure of this brief reflection concerning this subject, as well as about the placement of Poincaré’s thought in the scenario offered by some contemporary perspectives

Spectrophotometric determination of cobalt by the 2,2'-dipyridil ketoxime method (II) - Choice of solvent and studies about colored compound extration

This paper belongs to a series of articles about the 2,2'-dipyridyl ketoxime method for the espectrophotometric determination of cobalt. It presents a study on the extration procedure of the color compound formed by using chloroform or dichloromethane. It was established that the former is more efficient than the latter one. The region of maximum absorption of the color compound in chloroform is between 375 and 390 nm. On the other hand, 3.0 ml of the solvent, is sufficient for the extration of the water-soluble chelate obtained from 5.0 micrograms of cobalt, with a shaking time of 15 seconds. The color compound is stabile both in contact with the solutions (120 minutes) and after extration with chloroform (180 minutes).Foram continuados os estudos da parte experimental do método da 2,2'-dipiridil cetoxima, cuja finalidade é o estabelecimento de uma técnica adequada para a determinação do cobalto em material vegetal. Estudos sobre o preparo, concentração e conservação do reativo, sobre a influência do pH na formação e extração do composto colorido e sobre o sistema tampão, já foram efetuados na etapa inicial. Nesta oportunidade, procurou-se estudar o solvente; sua seleção, a sensibilidade, o tempo de extração, a influência do contato entre as fases e a estabilidade da cor do composto