http://hdl.handle.net/2117/3601 Sat, 18 May 2013 16:39:03 GMT 2013-05-18T16:39:03Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19014 Title: Aula virtual de soporte a la docencia y al autoaprendizaje del cálculo para estudiantes universitarios con material docente y aplicaciones basadas en software libre Authors: Jarauta Bragulat, Eusebio; Pelayo Melero, Ignacio Manuel Fri, 26 Apr 2013 12:40:48 GMT http://hdl.handle.net/2117/19014 2013-04-26T12:40:48Z Jarauta Bragulat, Eusebio; Pelayo Melero, Ignacio Manuel no http://hdl.handle.net/2117/19012 Title: Aula virtual de apoyo a la docencia y al autoaprendizaje de cálculo para estudiantes universitarios con material docente y aplicaciones basadas en software libre Authors: Jarauta Bragulat, Eusebio; Pelayo Melero, Ignacio Manuel Fri, 26 Apr 2013 12:30:02 GMT http://hdl.handle.net/2117/19012 2013-04-26T12:30:02Z Jarauta Bragulat, Eusebio; Pelayo Melero, Ignacio Manuel no http://hdl.handle.net/2117/18913 Title: An improvement of Ostrowski root-finding method Authors: Grau Sánchez, Miguel; Díaz Barrero, José Luis Abstract: An improvement to the iterative method based on the Ostrowski one to compute nonlinear equation solutions, which increases the local order of convergence is suggested. The adaptation of a strategy presented here gives a new iteration function with an additional evaluation of the function. It also shows a smaller cost if we use adaptive multi-precision arithmetic. The numerical results computed using this system with a floating point system representing 200 decimal digits support this theory. Description: "Applied Mathematics and Computation Top Cited Article 2005-2010" Mon, 22 Apr 2013 10:46:22 GMT http://hdl.handle.net/2117/18913 2013-04-22T10:46:22Z Grau Sánchez, Miguel; Díaz Barrero, José Luis no An improvement to the iterative method based on the Ostrowski one to compute nonlinear equation solutions, which increases the local order of convergence is suggested. The adaptation of a strategy presented here gives a new iteration function with an additional evaluation of the function. It also shows a smaller cost if we use adaptive multi-precision arithmetic. The numerical results computed using this system with a floating point system representing 200 decimal digits support this theory. http://hdl.handle.net/2117/18544 Title: Self-video recording for the integration and assessment of generic competencies Authors: Masip Álvarez, Albert; Hervada Sala, Carme; Pàmies Gómez, Teresa; Arias Pujol, Antoni; Jaen Fernandez, Carles; Rodríguez Sorigué, M. Cristina; Romero Durán, David; Nejjari Akhi-Elarab, Fatiha; Álvarez del Castillo, María Dolores; Roca Lefler, Marta; Hernández Farràs, Jorge; Montferrer Liñan, Raul Abstract: This document presents the use of a self-video-recording service for the integration and assessment of certain generic competences (oral and written communication, teamwork and third (English) language) in all degree programs related to the Industrial area at the Terrassa School of Engineering (EET). The resulting service allows to carry out the assessment through active and collaborative learning methodologies using ICT as a support, becoming an educational resource where students are encouraged to evaluate their own activity, individually and in groups (co-evaluation), and with which the faculty can enhance certain sections of the syllabus while also evaluating generic competences. This paper outlines the rationale and design of the system based on self-recording-video that assists work on some generic competences. A preliminary experience has taken place and it has been carried out by volunteer students and some professors from the promoting team. It consisted of following all steps to obtain the video-recording as a result and fulfil the further assessment. Preparing the defence of the final project career, explaining the way a problem is faced are examples of use of the service endowed to assist the assessment of some generic competences. A good number of students and professors have participated in this preliminary experiment carried out on some subjects and in which oral effective communication will be assessed. A specific rubric for the assessment of generic competences has been used both for students and faculty. There is a summary of qualitative feedback from both students and instructors, and where several issues related to improving the self-assessment and self-video-recording system, are discussed. Finally, a survey is proposed, whose results will be helpful for its improvement. Tue, 02 Apr 2013 14:02:57 GMT http://hdl.handle.net/2117/18544 2013-04-02T14:02:57Z Masip Álvarez, Albert; Hervada Sala, Carme; Pàmies Gómez, Teresa; Arias Pujol, Antoni; Jaen Fernandez, Carles; Rodríguez Sorigué, M. Cristina; Romero Durán, David; Nejjari Akhi-Elarab, Fatiha; Álvarez del Castillo, María Dolores; Roca Lefler, Marta; Hernández Farràs, Jorge; Montferrer Liñan, Raul no This document presents the use of a self-video-recording service for the integration and assessment of certain generic competences (oral and written communication, teamwork and third (English) language) in all degree programs related to the Industrial area at the Terrassa School of Engineering (EET). The resulting service allows to carry out the assessment through active and collaborative learning methodologies using ICT as a support, becoming an educational resource where students are encouraged to evaluate their own activity, individually and in groups (co-evaluation), and with which the faculty can enhance certain sections of the syllabus while also evaluating generic competences. This paper outlines the rationale and design of the system based on self-recording-video that assists work on some generic competences. A preliminary experience has taken place and it has been carried out by volunteer students and some professors from the promoting team. It consisted of following all steps to obtain the video-recording as a result and fulfil the further assessment. Preparing the defence of the final project career, explaining the way a problem is faced are examples of use of the service endowed to assist the assessment of some generic competences. A good number of students and professors have participated in this preliminary experiment carried out on some subjects and in which oral effective communication will be assessed. A specific rubric for the assessment of generic competences has been used both for students and faculty. There is a summary of qualitative feedback from both students and instructors, and where several issues related to improving the self-assessment and self-video-recording system, are discussed. Finally, a survey is proposed, whose results will be helpful for its improvement. http://hdl.handle.net/2117/18506 Title: Future educators' explaning voices Authors: Minelli de Oliveira, Janaina; Buenestado Caballero, Pablo; Camacho, Mar Abstract: Teacher education programs must offer pre-service students innovative technology-supported learning environments, guiding them in the revision of their preconceptions on literacy and technology. This present paper presents a case study that uses podcast to inquiry into future educators’ views on technology and the digital age. Results show future educators present rather conservative views on technology use and few of them relate to the theme from their future professional identity. Courses aimed at preparing future educators to make pedagogical use of technology should explicitly address students’ preconceptions so as to favor the educational approaches required for the development of the twentieth century skills. Tue, 26 Mar 2013 12:15:43 GMT http://hdl.handle.net/2117/18506 2013-03-26T12:15:43Z Minelli de Oliveira, Janaina; Buenestado Caballero, Pablo; Camacho, Mar no Teacher education programs must offer pre-service students innovative technology-supported learning environments, guiding them in the revision of their preconceptions on literacy and technology. This present paper presents a case study that uses podcast to inquiry into future educators’ views on technology and the digital age. Results show future educators present rather conservative views on technology use and few of them relate to the theme from their future professional identity. Courses aimed at preparing future educators to make pedagogical use of technology should explicitly address students’ preconceptions so as to favor the educational approaches required for the development of the twentieth century skills. http://hdl.handle.net/2117/18165 Title: Aprendizaje colaborativo en base a problemas mediante el uso del foro electrónico Authors: Buenestado Caballero, Pablo; Minelli de Oliveira, Janaina; Moragas Gascons, Lluís; Rodríguez Pérez, Ana Carmen; Cañadas Lorenzo, Juan Carlos; Pelayo Melero, Ignacio Manuel Abstract: La incorporación de las plataformas digitales en la educación impulsa nuevas maneras de aprender. La universidad promueve la participación sincrónica y asincrónica entre sujetos que no están en el mismo lugar, ni al mismo tiempo. Una de las herramientas tecnológicas que favorece la interacción a distancia y asincrónica es el Foro Virtual, herramienta que ayuda a compartir reflexiones y búsquedas favoreciendo, al mismo tiempo, el desarrollo de habilidades sociales y la mejora de la comunicación escrita. La relación en el Foro refuerza el aprendizaje de los individuos. El objetivo de esta comunicación es presentar un método eficiente para que un estudiante aprenda en colaboración con el grupo de compañeros mediante la resolución de problemas, el análisis y la crítica interactiva usando el foro electrónico de la plataforma digital. Mon, 11 Mar 2013 10:26:43 GMT http://hdl.handle.net/2117/18165 2013-03-11T10:26:43Z Buenestado Caballero, Pablo; Minelli de Oliveira, Janaina; Moragas Gascons, Lluís; Rodríguez Pérez, Ana Carmen; Cañadas Lorenzo, Juan Carlos; Pelayo Melero, Ignacio Manuel no La incorporación de las plataformas digitales en la educación impulsa nuevas maneras de aprender. La universidad promueve la participación sincrónica y asincrónica entre sujetos que no están en el mismo lugar, ni al mismo tiempo. Una de las herramientas tecnológicas que favorece la interacción a distancia y asincrónica es el Foro Virtual, herramienta que ayuda a compartir reflexiones y búsquedas favoreciendo, al mismo tiempo, el desarrollo de habilidades sociales y la mejora de la comunicación escrita. La relación en el Foro refuerza el aprendizaje de los individuos. El objetivo de esta comunicación es presentar un método eficiente para que un estudiante aprenda en colaboración con el grupo de compañeros mediante la resolución de problemas, el análisis y la crítica interactiva usando el foro electrónico de la plataforma digital. http://hdl.handle.net/2117/15527 Title: Checking model-data weather hazard occurrence fit in the context of climate change Authors: Tolosana Delgado, Raimon; Ortego Martínez, María Isabel; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín Abstract: In climate change impact studies it is common to run a given response model (from ecosystem changes to wavestorm or landslide occurrence) nested into one of the available long-term Global or Regional Circulation Models (GCM, RCM) reproducing the climate for the XX century or predicting it for the XXI. In this way, it is expected to capture the average behaviour of the studied system to a changing climate forcing: in other words, with such response forecasts, one does not actually expect to be able to reproduce each and every single event, but rather its statistical behaviour. Regarding weather-related hazard, the relevant statistical properties are the occurrence return period of events, and their expected magnitude. The present study focuses on wave storm occurrence, and aims at presenting a general methodology to check the adequate reproduction of the return period of hazardous weather-related events by such response forecast models. This is attained by analysing a compound data set formed by series of real data (typically of around 20-30 years in the last decades of the XX century or the beginning of the XXI one) and longer hind- or forecast series. Occurrence of a stormy event is considered to follow an inhomogeneous Poisson process, with: a linear trend to capture climate change, and a step in the junction real data-forecast data to capture systematic model biases. A Bayesian method is proposed to assess the influence of these two elements, i.e the presence/absence of a climate trend and the adequate reproduction of the statistical properties of wavestorm occurrence by forecasting models. Results suggest a non-significant trend albeit negative trend in the storm occurrence, and an inability of the used forecast model to reproduce wavestorm occurrence. Thu, 08 Mar 2012 12:06:21 GMT http://hdl.handle.net/2117/15527 2012-03-08T12:06:21Z Tolosana Delgado, Raimon; Ortego Martínez, María Isabel; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín no In climate change impact studies it is common to run a given response model (from ecosystem changes to wavestorm or landslide occurrence) nested into one of the available long-term Global or Regional Circulation Models (GCM, RCM) reproducing the climate for the XX century or predicting it for the XXI. In this way, it is expected to capture the average behaviour of the studied system to a changing climate forcing: in other words, with such response forecasts, one does not actually expect to be able to reproduce each and every single event, but rather its statistical behaviour. Regarding weather-related hazard, the relevant statistical properties are the occurrence return period of events, and their expected magnitude. The present study focuses on wave storm occurrence, and aims at presenting a general methodology to check the adequate reproduction of the return period of hazardous weather-related events by such response forecast models. This is attained by analysing a compound data set formed by series of real data (typically of around 20-30 years in the last decades of the XX century or the beginning of the XXI one) and longer hind- or forecast series. Occurrence of a stormy event is considered to follow an inhomogeneous Poisson process, with: a linear trend to capture climate change, and a step in the junction real data-forecast data to capture systematic model biases. A Bayesian method is proposed to assess the influence of these two elements, i.e the presence/absence of a climate trend and the adequate reproduction of the statistical properties of wavestorm occurrence by forecasting models. Results suggest a non-significant trend albeit negative trend in the storm occurrence, and an inability of the used forecast model to reproduce wavestorm occurrence. http://hdl.handle.net/2117/13043 Title: Sistemas internos de garantía de la calidad (SIGC): necesidad y reto Authors: Carral Mahia, Eva Mª; Pérez Gracia, María de la Vega; Codinas, Xavier; López López, José; García Alzórriz, Juan Antonio; Buenestado Caballero, Pablo; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo Abstract: La Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB) está diseñando su SIGC propio, teniendo en cuenta las características del centro, las directrices de la Universidad Politécnica de Cataluña y de las agencias de calidad, la formación que se requiere para sus estudiantes y los resultados que se observan en otros centros de éste y de otros países en los que ya se han implantado los sistemas de calidad. En una época de crisis y de cambios, en la que las titulaciones deben adaptarse al Espacio Europeo de Educación Superior (EEES), el diseño de un sistema de calidad deviene una necesidad y un reto para la EUETIB. Tue, 26 Jul 2011 08:01:13 GMT http://hdl.handle.net/2117/13043 2011-07-26T08:01:13Z Carral Mahia, Eva Mª; Pérez Gracia, María de la Vega; Codinas, Xavier; López López, José; García Alzórriz, Juan Antonio; Buenestado Caballero, Pablo; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo no La Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB) está diseñando su SIGC propio, teniendo en cuenta las características del centro, las directrices de la Universidad Politécnica de Cataluña y de las agencias de calidad, la formación que se requiere para sus estudiantes y los resultados que se observan en otros centros de éste y de otros países en los que ya se han implantado los sistemas de calidad. En una época de crisis y de cambios, en la que las titulaciones deben adaptarse al Espacio Europeo de Educación Superior (EEES), el diseño de un sistema de calidad deviene una necesidad y un reto para la EUETIB. http://hdl.handle.net/2117/13042 Title: Correlación entre la nota de ingreso a los estudios de grado de ámbito industrial y los resultados académicos obtenidos en el primer año de estudios de grado Authors: López López, José; Buenestado Caballero, Pablo; Pérez Gracia, María de la Vega; García Alzórriz, Juan Antonio; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo Abstract: El presente trabajo estudia la relación de la nota de acceso al centro con las calificaciones académicas obtenidas por los estudiantes de primer curso de Grado una vez transcurrido el primer año de implantación en la Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB). En este trabajo se discute sobre los resultados obtenidos en función de la procedencia de los estudiantes, Bachillerato o Ciclos formativos de grado superior. Tue, 26 Jul 2011 07:45:33 GMT http://hdl.handle.net/2117/13042 2011-07-26T07:45:33Z López López, José; Buenestado Caballero, Pablo; Pérez Gracia, María de la Vega; García Alzórriz, Juan Antonio; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo no El presente trabajo estudia la relación de la nota de acceso al centro con las calificaciones académicas obtenidas por los estudiantes de primer curso de Grado una vez transcurrido el primer año de implantación en la Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB). En este trabajo se discute sobre los resultados obtenidos en función de la procedencia de los estudiantes, Bachillerato o Ciclos formativos de grado superior. http://hdl.handle.net/2117/12783 Title: Pluviometric regionalization of Catalunya: a compositional data methodology Authors: Gibergans Baguena, José; Ortego Martínez, María Isabel; Tolosana Delgado, Raimon Abstract: The aim of this paper is to introduce a methodology for de¯ning groups from regionalized com- positional data, through a hierarchical clustering algorithm aware of both the spatial dependence and the compositional character of the data set. This method is used to de¯ne a regionalization of Catalunya (NE Spain) with respect to its precipitation patterns in the Winter season. This region is characterized by a highly contrasted topography, which plays a dominant role in the spatial distribution of precipitation. Each rain gauge station is characterized by the relative frequencies of occurrence of six intervals of daily precipitation amount (classes ranging from \no rain" for precipitation below 3 mm, to \heavy storm" above 50 mm). Recognizing that frequencies are com-positional data, the spatial dependence of this data set has been characterized by variograms of the set of all pair-wise log-ratios, in the fashion of the variation matrix. Then, a Mahalanobis distance between stations has been de¯ned using these variograms to ensure that gauges with high spatial correlation get smaller distances. This spatially-dependent distance criterion has been used in a Ward hierarhical cluster method to de¯ne the regions. Results reveal 5 quite homogeneous groups of stations, which can be mostly ascribed a physical meaning. Finally, possible links to regional circulation patterns are discussed. Thu, 16 Jun 2011 08:58:20 GMT http://hdl.handle.net/2117/12783 2011-06-16T08:58:20Z Gibergans Baguena, José; Ortego Martínez, María Isabel; Tolosana Delgado, Raimon no The aim of this paper is to introduce a methodology for de¯ning groups from regionalized com- positional data, through a hierarchical clustering algorithm aware of both the spatial dependence and the compositional character of the data set. This method is used to de¯ne a regionalization of Catalunya (NE Spain) with respect to its precipitation patterns in the Winter season. This region is characterized by a highly contrasted topography, which plays a dominant role in the spatial distribution of precipitation. Each rain gauge station is characterized by the relative frequencies of occurrence of six intervals of daily precipitation amount (classes ranging from \no rain" for precipitation below 3 mm, to \heavy storm" above 50 mm). Recognizing that frequencies are com-positional data, the spatial dependence of this data set has been characterized by variograms of the set of all pair-wise log-ratios, in the fashion of the variation matrix. Then, a Mahalanobis distance between stations has been de¯ned using these variograms to ensure that gauges with high spatial correlation get smaller distances. This spatially-dependent distance criterion has been used in a Ward hierarhical cluster method to de¯ne the regions. Results reveal 5 quite homogeneous groups of stations, which can be mostly ascribed a physical meaning. Finally, possible links to regional circulation patterns are discussed. http://hdl.handle.net/2117/12489 Title: Wave height data assimilation using non-stationary kriging Authors: Tolosana Delgado, Raimon; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín; Gómez Aguar, Jesús Javier Abstract: Data assimilation into numerical models should be both computationally fast and physically meaningful, in order to be applicable in online environmental surveillance. We present a way to improve assimilation for computationally intensive models, based on non-stationary kriging and a separable space–time covariance function. The method is illustrated with significant wave height data. The covariance function is expressed as a collection of fields: each one is obtained as the empirical covariance between the studied property(significant wave height in log-scale)at a pixel where a measurement is located (a wave-buoy is available)and the same parameter at every other pixel of thef ield. These covariances are computed from the available history of forecasts. The method provides a set of weights, that can be mapped for each measuring location, and that do not vary with time. Resulting weights may be used in a weighted average of the differences between the forecast and measured parameter. In the case presented, these weights may show long-range connection patterns, such as between the Catalan coast and the eastern coast of Sardinia, associated to common prevailing meteo-oceanographic conditions. When such patterns are considered as non-informative of the present situation, it is always possible to diminish their influence by relaxing the covariance maps. Fri, 06 May 2011 08:06:38 GMT http://hdl.handle.net/2117/12489 2011-05-06T08:06:38Z Tolosana Delgado, Raimon; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín; Gómez Aguar, Jesús Javier no Data assimilation into numerical models should be both computationally fast and physically meaningful, in order to be applicable in online environmental surveillance. We present a way to improve assimilation for computationally intensive models, based on non-stationary kriging and a separable space–time covariance function. The method is illustrated with significant wave height data. The covariance function is expressed as a collection of fields: each one is obtained as the empirical covariance between the studied property(significant wave height in log-scale)at a pixel where a measurement is located (a wave-buoy is available)and the same parameter at every other pixel of thef ield. These covariances are computed from the available history of forecasts. The method provides a set of weights, that can be mapped for each measuring location, and that do not vary with time. Resulting weights may be used in a weighted average of the differences between the forecast and measured parameter. In the case presented, these weights may show long-range connection patterns, such as between the Catalan coast and the eastern coast of Sardinia, associated to common prevailing meteo-oceanographic conditions. When such patterns are considered as non-informative of the present situation, it is always possible to diminish their influence by relaxing the covariance maps. http://hdl.handle.net/2117/12477 Title: A technique to composite a modified Newton's method for solving nonlinear equations Authors: Grau Sánchez, Miguel; Díaz Barrero, José Luis Abstract: A zero-finding technique for solving nonlinear equations more efficiently than they usually are with traditional iterative methods in which the order of convergence is improved is presented. The key idea in deriving this procedure is to compose a given iterative method with a modified Newton’s method that introduces just one evaluation of the function. To carry out this procedure some classical methods with different orders of convergence are used to obtain root-finders with higher efficiency index. Description: Nova tècnica que permet construir mètodes iteratius d'ordre alt. Thu, 05 May 2011 11:44:52 GMT http://hdl.handle.net/2117/12477 2011-05-05T11:44:52Z Grau Sánchez, Miguel; Díaz Barrero, José Luis no A zero-finding technique for solving nonlinear equations more efficiently than they usually are with traditional iterative methods in which the order of convergence is improved is presented. The key idea in deriving this procedure is to compose a given iterative method with a modified Newton’s method that introduces just one evaluation of the function. To carry out this procedure some classical methods with different orders of convergence are used to obtain root-finders with higher efficiency index. http://hdl.handle.net/2117/12475 Title: On computational order of convergence of some multi-precision solvers of nonlinear systems of equations Authors: Grau Sánchez, Miguel; Grau Gotés, Mª Ángela; Díaz Barrero, José Luis Abstract: In this paper the local order of convergence used in iterative methods to solve nonlinear systems of equations is revisited, where shorter alternative analytic proofs of the order based on developments of multilineal functions are shown. Most important, an adaptive multi-precision arithmetics is used hereof, where in each step the length of the mantissa is defined independently of the knowledge of the root. Furthermore, generalizations of the one dimensional case to m-dimensions of three approximations of computational order of convergence are defined. Examples illustrating the previous results are given. Description: Report d'un treball de recerca on es presenten noves tècniques de càlcul de l'ordre de convergència amb una aritmètica adaptativa. Thu, 05 May 2011 11:25:05 GMT http://hdl.handle.net/2117/12475 2011-05-05T11:25:05Z Grau Sánchez, Miguel; Grau Gotés, Mª Ángela; Díaz Barrero, José Luis no In this paper the local order of convergence used in iterative methods to solve nonlinear systems of equations is revisited, where shorter alternative analytic proofs of the order based on developments of multilineal functions are shown. Most important, an adaptive multi-precision arithmetics is used hereof, where in each step the length of the mantissa is defined independently of the knowledge of the root. Furthermore, generalizations of the one dimensional case to m-dimensions of three approximations of computational order of convergence are defined. Examples illustrating the previous results are given. http://hdl.handle.net/2117/12014 Title: Bayes linear spaces Authors: Van den Boogaart, Karl Gerard; Egozcue Rubí, Juan José; Pawlowsky-Glahn, Vera Abstract: Linear spaces consisting of $\sigma$-finite probability measures and infinite measures (improper priors and likelihood functions) are defined. The commutative group operation, called perturbation, is the updating given by Bayes theorem; the inverse operation is the Radon-Nikodym derivative. Bayes spaces of measures are sets of classes of proportional measures. In this framework, basic notions of mathematical statistics get a simple algebraic interpretation. For example, exponential families appear as affine subspaces with their sufficient statistics as a basis. Bayesian statistics, in particular some well-known properties of conjugated priors and likelihood functions, are revisited and slightly extended. Tue, 22 Mar 2011 11:12:58 GMT http://hdl.handle.net/2117/12014 2011-03-22T11:12:58Z Van den Boogaart, Karl Gerard; Egozcue Rubí, Juan José; Pawlowsky-Glahn, Vera no Linear spaces consisting of $\sigma$-finite probability measures and infinite measures (improper priors and likelihood functions) are defined. The commutative group operation, called perturbation, is the updating given by Bayes theorem; the inverse operation is the Radon-Nikodym derivative. Bayes spaces of measures are sets of classes of proportional measures. In this framework, basic notions of mathematical statistics get a simple algebraic interpretation. For example, exponential families appear as affine subspaces with their sufficient statistics as a basis. Bayesian statistics, in particular some well-known properties of conjugated priors and likelihood functions, are revisited and slightly extended. http://hdl.handle.net/2117/10476 Title: An experimental comparison of cokriging of regionalised compositional data using four different methods: case study3A Bauxites in Hungary-2 Authors: Jarauta Bragulat, Eusebio; Hervada Sala, Carme; Diblasi, Angela Abstract: An important problem in the geosciences is the etimation or prediction or regionalized compositions. In fact, it is usual to deal with data such as percentages, concentrations, ppm,..., and use them to estimate values in other locations. Compositional data have been regarded as difficult to work with because of the so-called constant sum constraint. Following Aitchison(1986), any meaningful satatement abaut a composition can be expressed in terms of logratios, but those transformations, and their backtransformations, are not always easy to deal with. The aim of this paper is to compare results obtained applying different methodologies developed in geostatistics, with samples of compositional data from a bauxite deposit in Halimba II (Hungary). Firstly, a classical geostatistics study is done usin raw data; secondly applyin two wellknown transormations in compositional data analysis: additive logratio (ALR) and centered logratio (CLR); thirdly, the Fast Fourier Transform (FFT) methodology to calculate the spatial variance-covariance matrix is used in cokriging. To be able to compare predictive values and kriging erros respective backtransforms are found. At last, results obtained with the different approaches are discussed and compared. Tue, 30 Nov 2010 16:38:37 GMT http://hdl.handle.net/2117/10476 2010-11-30T16:38:37Z Jarauta Bragulat, Eusebio; Hervada Sala, Carme; Diblasi, Angela no An important problem in the geosciences is the etimation or prediction or regionalized compositions. In fact, it is usual to deal with data such as percentages, concentrations, ppm,..., and use them to estimate values in other locations. Compositional data have been regarded as difficult to work with because of the so-called constant sum constraint. Following Aitchison(1986), any meaningful satatement abaut a composition can be expressed in terms of logratios, but those transformations, and their backtransformations, are not always easy to deal with. The aim of this paper is to compare results obtained applying different methodologies developed in geostatistics, with samples of compositional data from a bauxite deposit in Halimba II (Hungary). Firstly, a classical geostatistics study is done usin raw data; secondly applyin two wellknown transormations in compositional data analysis: additive logratio (ALR) and centered logratio (CLR); thirdly, the Fast Fourier Transform (FFT) methodology to calculate the spatial variance-covariance matrix is used in cokriging. To be able to compare predictive values and kriging erros respective backtransforms are found. At last, results obtained with the different approaches are discussed and compared.