Liturgia del primer grado: (Rito Esc.: Ant.: y Acep.:) formada por los HH.: A.G. y F.: & T. GGr.: 33.: Mandada observar por la Gr.:Log.: del Distrito Federal a todas las Log.: de su jurisdicción

UANL

Characterizations of distributions using log odds rate

In this paper, we examine the relationships between log odds rate and various reliability measures such as hazard rate and reversed hazard rate in the context of repairable systems. We also prove characterization theorems for some families of distributions viz. Burr, Pearson and log exponential models. We discuss the properties and applications of log odds rate in weighted models. Further we extend the concept to the bivariate set up and study its properties.

La predicci??n del rendimiento acad??mico : regresi??n lineal versus regresi??n log??stica

Resumen de los autores. Res??menes en espa??ol e ingl??s

Visual SLAM for underwater vehicles using video velocity log and natural landmarks

A visual SLAM system has been implemented and optimised for real-time deployment on an AUV equipped with calibrated stereo cameras. The system incorporates a novel approach to landmark description in which landmarks are local sub maps that consist of a cloud of 3D points and their associated SIFT/SURF descriptors. Landmarks are also sparsely distributed which simplifies and accelerates data association and map updates. In addition to landmark-based localisation the system utilises visual odometry to estimate the pose of the vehicle in 6 degrees of freedom by identifying temporal matches between consecutive local sub maps and computing the motion. Both the extended Kalman filter and unscented Kalman filter have been considered for filtering the observations. The output of the filter is also smoothed using the Rauch-Tung-Striebel (RTS) method to obtain a better alignment of the sequence of local sub maps and to deliver a large-scale 3D acquisition of the surveyed area. Synthetic experiments have been performed using a simulation environment in which ray tracing is used to generate synthetic images for the stereo system

La financiaci??n p??blica de los centros privados de ense??anza no universitaria en Espa??a

El objetivo principal es analizar el impacto, en t??rminos de eficiencia y equidad, de la financiaci??n de origen p??blico destinada al sector privado de la ense??anza no universitaria en Espa??a, a lo largo del per??odo 1981-1995. Las hip??tesis son: 1. Hip??tesis generales sobre el sistema de conciertos con la ense??anza privada en Espa??a: 1.1 Como consecuencia de la pol??tica de conciertos con la ense??anza privada, se ha producido un aumento importante en el volumen de recursos p??blicos canalizado hacia este sector de la ense??anza. 1.2 La concertaci??n no se ha extendido por igual en todas las Comunidades Aut??nomas. 1.3 La asignaci??n de recursos p??blicos a la ense??anza privada no garantiza la gratuidad de los centros concertados. 2. Hip??tesis relativas a la equidad: 2.1 El gasto p??blico en ense??anza privada no universitaria en Espa??a tiene efectos regresivos. No obstante, se ha producido una disminuci??n de la regresividad, como consecuencia de la pol??tica de conciertos con la ense??anza privada. 2.2 Las clases medias son las que m??s se benefician de la financiaci??n p??blica en la ense??anza privada. 2.3 La regresividad del gasto p??blico en ense??anza privada es inferior en los niveles de ense??anza primaria que en los niveles de ense??anza secundaria y dentro de los niveles de ense??anza secundaria es inferior en la rama profesional que en la acad??mica. 2.4 La pol??tica de conciertos con la ense??anza privada no ha hecho desaparecer todas las barreras al acceso a centros privados. 2.5 La existencia de actividades complementarias que deben ser financiadas por las familias limita la participaci??n de los grupos de menor renta en los centros concertados. 3. Hip??tesis relativas a la eficiencia: 3.1 El grado de efectividad de las pol??ticas destinadas a ampliar las oportunidades de elecci??n de centro de padres y alumnos depende, en gran medida, de la estructura de la oferta educativa. 3.2 Durante 1981-1995, se ha producido un acercamiento en las condiciones de producci??n del servicio educativo en centros privados y en centros p??blicos. 3.3 Las diversas pol??ticas de apoyo p??blico a la ense??anza privada impulsadas en las distintas Comunidades Aut??nomas se han traducido en distintos niveles de costes medios por alumno. 3.4 La competencia entre centros privados y p??blicos de ense??anza no universitaria no ha conducido a una disminuci??n de los costes de producci??n de los servicios educativos en estos centros. 3.5 La pol??tica de conciertos con la ense??anza privada no ha ampliado las posibilidades de elecci??n de todos los usuarios. 21 inspectores educativos de la Comunidad Aut??noma de Catalu??a. El estudio se estructura en varios an??lisis te??ricos y emp??ricos. En los an??lisis te??ricos se presentan las reformas introducidas principalmente en el mundo anglosaj??n, que han supuesto la formaci??n de cuasimercados en distintas ??reas del estado del bienestar, tambi??n en el ??mbito educativo. Se examina la evoluci??n del sector privado educativo en Alemania, Francia, Inglaterra, Gales y los Pa??ses Bajos. Finalmente se presenta el caso espa??ol. En los an??lisis emp??ricos, tras un an??lisis descriptivo de la evoluci??n que ha experimentado el gasto p??blico en ense??anza privada, se analizan algunos de sus efectos m??s destacados en el ??mbito de la equidad y de la eficiencia. Desde la perspectiva de la equidad se lleva a cabo un an??lisis de los efectos redistributivos del gasto p??blico en ense??anza privada; se analiza el acceso a centros de ense??anza privada; y desde una aproximaci??n cualitativa, se analizan los problemas de selecci??n del alumnado que plantea la financiaci??n p??blica de estos centros en Catalu??a. Desde la perspectiva de la eficiencia, se realiza un an??lisis sobre la estructura de esta oferta educativa en los niveles no universitarios; se realiza tambi??n una an??lisis de los costes medios de producci??n del servicio educativo en centros privados y p??blicos; y desde una aproximaci??n cualitativa, se presenta un an??lisis de la capacidad de elecci??n de los usuarios en el marco de la ense??anza no universitaria. Para el an??lisis de la financiaci??n de la ense??anza privada no universitaria en Espa??a se utilizan distintos indicadores: el gasto p??blico en ense??anza privada por alumno, el gasto p??blico en ense??anza privada en relaci??n con el PIB y el gasto p??blico en ense??anza privada en relaci??n con el gasto p??blico educativo. Para estimar la probabilidad de que un ni??o espa??ol entre los 6 y 14 a??os acuda a un centro educativo de titularidad privada se utiliza la regresi??n log??stica. Para analizar el nivel de concentraci??n de la oferta educativa se aplica el ??ndice de Herfindahl. Para el an??lisis de las caracter??sticas de los cuasimercados y de los sistemas educativos de Alemania, Francia e Inglaterra, se realiza una revisi??n de la literatura. Para el an??lisis del sistema educativo espa??ol se realiza una revisi??n de la legislaci??n. Para analizar el alcance real de las pol??ticas destinadas a ampliar la capacidad de elecci??n de los usuarios en un sistema de financiaci??n p??blica de la ense??anza no universitaria, as?? como para analizar las posibles pr??cticas de selecci??n del alumnado por parte de los centros concertados se utilizan entrevistas de ??lite a inspectores educativos. 1.1 Se ha producido un aumento importante en el gasto p??blico canalizado hacia la ense??anza privada, hasta una tasa acumulativa del 1.78 por cierto. 1.2 Se demuestra que las comunidades con un PIB per c??pita superior son las que m??s recursos p??blicos canalizan hacia la ense??anza privada. 1.3 Existen ciertas pr??cticas que son una fuente de financiaci??n indirecta de los centros privados que enturbian el principio de gratuidad de la ense??anza en centros concertados. 2.1 Se muestra una disminuci??n en la regresividad del gasto p??blico canalizado hacia centros privados. 2.2 Se pone de manifiesto que el sistema de conciertos ha beneficiado a las clases medias. 2.3 Se muestra una mayor regresividad del gasto p??blico destinado a los niveles superiores del sistema de ense??anza no universitaria. 2.4 El nivel de renta familiar no afecta directamente a la decisi??n de acceder a un centro privado. 2.5 Las aportaciones que las familias realizan por la prestaci??n de actividades complementarias limitan el acceso a centros concertados de los grupos de menor renta. 3.1 Se demuestra el car??cter competitivo de la estructura del sector educativo no universitario en los 10 distritos universitarios de Barcelona. 3.2 Se muestra c??mo se ha producido s??lo un ligero acercamiento en la importancia relativa de los distintos componentes en ambos sectores educativos. 3.3 Se pone de relieve la relaci??n existente entre los niveles de apoyo p??blico a la ense??anza privada y los costes medios por alumno en centros privados. 3.4 Hay una evoluci??n positiva en los costes medios por alumno entre 1981 y 1995 en ambos sectores educativos. 3.5 Se pone de relieve el limitado alcance de las pol??ticas de conciertos con la ense??anza privada para ampliar las posibilidades de elecci??n de todos los usuarios.

C??mo obtener un Modelo de Regresi??n Log??stica Binaria con SPSS

Resumen basado en el de la publicaci??n

Un modelo de regresi??n log??stica asim??trico que puede explicar la probabilidad de ??xito en el rendimiento acad??mico

Resumen basado en el de la publicaci??n

On estimation and influence diagnostics for log-Birnbaum-Saunders Student-t regression models: Full Bayesian analysis

The purpose of this paper is to develop a Bayesian approach for log-Birnbaum-Saunders Student-t regression models under right-censored survival data. Markov chain Monte Carlo (MCMC) methods are used to develop a Bayesian procedure for the considered model. In order to attenuate the influence of the outlying observations on the parameter estimates, we present in this paper Birnbaum-Saunders models in which a Student-t distribution is assumed to explain the cumulative damage. Also, some discussions on the model selection to compare the fitted models are given and case deletion influence diagnostics are developed for the joint posterior distribution based on the Kullback-Leibler divergence. The developed procedures are illustrated with a real data set. (C) 2010 Elsevier B.V. All rights reserved.

The log-exponentiated Weibull regression model for interval-censored data

In interval-censored survival data, the event of interest is not observed exactly but is only known to occur within some time interval. Such data appear very frequently. In this paper, we are concerned only with parametric forms, and so a location-scale regression model based on the exponentiated Weibull distribution is proposed for modeling interval-censored data. We show that the proposed log-exponentiated Weibull regression model for interval-censored data represents a parametric family of models that include other regression models that are broadly used in lifetime data analysis. Assuming the use of interval-censored data, we employ a frequentist analysis, a jackknife estimator, a parametric bootstrap and a Bayesian analysis for the parameters of the proposed model. We derive the appropriate matrices for assessing local influences on the parameter estimates under different perturbation schemes and present some ways to assess global influences. Furthermore, for different parameter settings, sample sizes and censoring percentages, various simulations are performed; in addition, the empirical distribution of some modified residuals are displayed and compared with the standard normal distribution. These studies suggest that the residual analysis usually performed in normal linear regression models can be straightforwardly extended to a modified deviance residual in log-exponentiated Weibull regression models for interval-censored data. (C) 2009 Elsevier B.V. All rights reserved.

Generalized log-gamma regression models with cure fraction

In this paper, the generalized log-gamma regression model is modified to allow the possibility that long-term survivors may be present in the data. This modification leads to a generalized log-gamma regression model with a cure rate, encompassing, as special cases, the log-exponential, log-Weibull and log-normal regression models with a cure rate typically used to model such data. The models attempt to simultaneously estimate the effects of explanatory variables on the timing acceleration/deceleration of a given event and the surviving fraction, that is, the proportion of the population for which the event never occurs. The normal curvatures of local influence are derived under some usual perturbation schemes and two martingale-type residuals are proposed to assess departures from the generalized log-gamma error assumption as well as to detect outlying observations. Finally, a data set from the medical area is analyzed.

Log-Burr XII regression models with censored data

In survival analysis applications, the failure rate function may frequently present a unimodal shape. In such case, the log-normal or log-logistic distributions are used. In this paper, we shall be concerned only with parametric forms, so a location-scale regression model based on the Burr XII distribution is proposed for modeling data with a unimodal failure rate function as an alternative to the log-logistic regression model. Assuming censored data, we consider a classic analysis, a Bayesian analysis and a jackknife estimator for the parameters of the proposed model. For different parameter settings, sample sizes and censoring percentages, various simulation studies are performed and compared to the performance of the log-logistic and log-Burr XII regression models. Besides, we use sensitivity analysis to detect influential or outlying observations, and residual analysis is used to check the assumptions in the model. Finally, we analyze a real data set under log-Buff XII regression models. (C) 2008 Published by Elsevier B.V.

Deviance residuals in generalised log-gamma regression models with censored observations

In this article, we compare three residuals based on the deviance component in generalised log-gamma regression models with censored observations. For different parameter settings, sample sizes and censoring percentages, various simulation studies are performed and the empirical distribution of each residual is displayed and compared with the standard normal distribution. For all cases studied, the empirical distributions of the proposed residuals are in general symmetric around zero, but only a martingale-type residual presented negligible kurtosis for the majority of the cases studied. These studies suggest that the residual analysis usually performed in normal linear regression models can be straightforwardly extended for the martingale-type residual in generalised log-gamma regression models with censored data. A lifetime data set is analysed under log-gamma regression models and a model checking based on the martingale-type residual is performed.

The log-bimodal-skew-normal model. A geochemical application

The main objective of this paper is to study a logarithm extension of the bimodal skew normal model introduced by Elal-Olivero et al. [1]. The model can then be seen as an alternative to the log-normal model typically used for fitting positive data. We study some basic properties such as the distribution function and moments, and discuss maximum likelihood for parameter estimation. We report results of an application to a real data set related to nickel concentration in soil samples. Model fitting comparison with several alternative models indicates that the model proposed presents the best fit and so it can be quite useful in real applications for chemical data on substance concentration. Copyright (C) 2011 John Wiley & Sons, Ltd.

Lumber quality of Eucalyptus grandis as a function of diametrical position and log steaming

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

Log smoldering after an Amazonian deforestation fire

The characteristics of log smoldering after an Amazonian deforestation fire are described. The experiment was carried out in 2001 at the Caiabi farm, near the city of Alta Floresta, state of Mato Grosso, Brazil, as part of a set of tests that have been performed in the same area since 1997. A 200 x 200m(2) test area was slashed in the beginning of June and burned on 20 August. The area contained 507 logs with diameter at breast height (DBH) higher than 10 cm, per hectare. In the day following the main burn 59 logs were found to remain smoldering, a number that corresponds to 2.9% of the total in the area. We chose 11 of the 59 logs to have their smoldering process monitored. Their diameter, moisture content and CHN dry biomass composition after the plot burn and before smoldering were determined. Other parameters such as temperature distribution while smoldering, porosity, density and mass volatilized during thermogravimetric test were also determined. Average smoldering speeds were in the range from 0.8 to 1.5 cm h(-1) for logs that smoldered without transition to the flaming regime. The average speed increased to 2.1 cm h(-1) for those logs that oscillated between smoldering and flaming. The speeds were lower overnight as compared to values determined during daytime for the same log. Higher log moisture contents were found to produce decreased speeds. Micro-porous biomass was not observed in the set of the 11 selected logs. Smoldering was observed to occur at substantial intensity in crossing of logs, with no longitudinal propagation. (C) 2003 Elsevier Ltd. All rights reserved.