HEOSAT: A mean elements orbit propagator program for Highly Elliptical Orbits

The algorithms used in the construction of a semi-analytical propagator for the long-term propagation of Highly Elliptical Orbits (HEO) are described. The software propagates mean elements and include the main gravitational and non-gravitational effects that may affect common HEO orbits, as, for instance, geostationary transfer orbits or Molniya orbits. Comparisons with numerical integration show that it provides good results even in extreme orbital configurations, as the case of SymbolX.Comment: 18 pages, 5 figure

The effect of ownership composition on earnings management: evidence for the Mexican stock exchange

Purpose – This paper aims to examine the relationship between different types of shareholders that command share ownership family institutions or external block holders and earnings management. In addition it examines the effect of company size on earnings management. Design/methodology/approach – The sample includes 67 companies listed in the Mexican Stock Exchange for the period 2005-2015. The sample composition is quite industry-balanced. A cross-sectional version of the Jones model (1991) is to measure the earnings management. The GMM (generalized method of moments) model is also estimated. Findings – The results show that family and institutional ownership reduce the earnings management but the impact is different depending on the company size. Research limitations/implications – The results show that there is a clear relationship between increasing participation of family and institutional investors and a reduction in earnings management. This is consistent with the literature that establishes that ownership is an effective regulatory mechanism that limits earnings management through closer supervision and involvement in management. Practical/implications – For companies’ corporate governance and regulatory authorities the results of this study may serve to improve the decision-making. Originality/value – This study shows that ownership structure can provide corporate governance in Mexican listed companies with different monitoring and control capacities to influence companies’ strategies particularly in relation to the discretion of earnings management.Propósito - Este documento tiene como objetivo examinar la relación entre los diferentes tipos de accionistas que controlan la propiedad de acciones familiares instituciones o bloqueadores externos y la administración de ganancias. Además examina el efecto del tamaño de la empresa en la gestión de ganancias. Diseño/metodología/enfoque - La muestra incluye 67 compañías que cotizan en la Bolsa Mexicana de Valores para el período 2005-2015. La composición de la muestra es bastante equilibrada en la industria. Una versión transversal del modelo de Jones (1991) es para medir la gestión de ganancias. También se estima el modelo GMM (método generalizado de momentos).Resultados - Los resultados muestran que la propiedad familiar e institucional reduce la administración de ganancias pero el impacto es diferente según el tamaño de la empresa. Limitaciones/implicaciones de la investigación - Los resultados muestran que existe una relación clara entre el aumento de la participación de los inversionistas familiares e institucionales y una reducción en la gestión de ganancias. Esto es consistente con la literatura que establece que la propiedad es un mecanismo regulador efectivo que limita la administración de ganancias a través de una supervisión más cercana y la participación en la administración. Implicaciones prácticas - Para el gobierno corporativo y las autoridades reguladoras de las empresas los resultados de este estudio pueden servir en la mejora de la toma de decisiones. Originalidad/valor - Este estudio muestra que la estructura de propiedad puede proporcionar un gobierno corporativo en las empresas que cotizan en Bolsa con diferentes capacidades de monitorización y control para influir en las estrategias de las empresas particularmente en relación con la discreción de la administración de ganancias

A Statistical Inverse Method for Gridding Passive Microwave Data with Mixed Measurements

When a passive microwave footprint intersects objects on the ground with different spectral characteristics, the corresponding observation is mixed. The retrieval of geophysical parameters is limited by this mixture. We propose to partition the study region into objects following an object-based image analysis procedure and then to refine this partition into small cells. Then, we introduce a statistical method to estimate the brightness temperature (TB) of each cell. The method assumes that TB of the cells corresponding to the same object is identically distributed and that the TB heterogeneity within each cell can be neglected. The implementation is based on an iterative expectation-maximization algorithm. We evaluated the proposed method using synthetic images and applied it to grid the TBs of sample AMSR -2 real data over a coastal region in Argentina.Fil: Grimson, Rafael. Universidad Nacional de San Martín; ArgentinaFil: Bali, Juan Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rajngewerc, Mariela. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; ArgentinaFil: Martin, Laura San. Universidad Nacional de San Martín; ArgentinaFil: Salvia, Maria Mercedes. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

A First Order Analytical Solution for Spacecraft Motion about (433)Eros

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76061/1/AIAA-2002-4543-167.pd

Spanish generation from Spanish Sign Language using a phrase-based translation system

This paper describes the development of a Spoken Spanish generator from Spanish Sign Language (LSE – Lengua de Signos Española) in a specific domain: the renewal of Identity Document and Driver’s license. The system is composed of three modules. The first one is an interface where a deaf person can specify a sign sequence in sign-writing. The second one is a language translator for converting the sign sequence into a word sequence. Finally, the last module is a text to speech converter. Also, the paper describes the generation of a parallel corpus for the system development composed of more than 4,000 Spanish sentences and their LSE translations in the application domain. The paper is focused on the translation module that uses a statistical strategy with a phrase-based translation model, and this paper analyses the effect of the alignment configuration used during the process of word based translation model generation. Finally, the best configuration gives a 3.90% mWER and a 0.9645 BLEU