On Software Engineering Repositories and Their Open Problems

In the last decade, a large number of software repositories have been created for different purposes. In this paper we present a survey of the publicly available repositories and classify the most common ones as well as discussing the problems faced by researchers when applying machine learning or statistical techniques to them.

A flexible open source web platform to facilitate Learning Object evaluation

Systematic evaluation of Learning Objects is essential to make high quality Web-based education possible. For this reason, several educational repositories and e-Learning systems have developed their own evaluation models and tools. However, the differences of the context in which Learning Objects are produced and consumed suggest that no single evaluation model is sufficient for all scenarios. Besides, no much effort has been put in developing open tools to facilitate Learning Object evaluation and use the quality information for the benefit of end users. This paper presents LOEP, an open source web platform that aims to facilitate Learning Object evaluation in different scenarios and educational settings by supporting and integrating several evaluation models and quality metrics. The work exposed in this paper shows that LOEP is capable of providing Learning Object evaluation to e-Learning systems in an open, low cost, reliable and effective way. Possible scenarios where LOEP could be used to implement quality control policies and to enhance search engines are also described. Finally, we report the results of a survey conducted among reviewers that used LOEP, showing that they perceived LOEP as a powerful and easy to use tool for evaluating Learning Objects.

A Model-based Repository for Open Source Service and Component Integration.

Open source is a software development paradigm that has seen a huge rise in recent years. It reduces IT costs and time to market, while increasing security and reliability. However, the difficulty in integrating developments from different communities and stakeholders prevents this model from reaching its full potential. This is mainly due to the challenge of determining and locating the correct dependencies for a given software artifact. To solve this problem we propose the development of an extensible software component repository based upon models. This repository should be capable of solving the dependencies between several components and work with already existing repositories to access the needed artifacts transparently. This repository will also be easily expandable, enabling the creation of modules that support new kinds of dependencies or other existing repository technologies. The proposed solution will work with OSGi components and use OSGi itself.

Intensive Metrics for the Study of the Evolution of Open Source Projects: Case Studies from Apache Software Foundation Projects

Based on the empirical evidence that the ratio of email messages in public mailing lists to versioning system commits has remained relatively constant along the history of the Apache Software Foundation (ASF), this paper has as goal to study what can be inferred from such a metric for projects of the ASF. We have found that the metric seems to be an intensive metric as it is independent of the size of the project, its activity, or the number of developers, and remains relatively independent of the technology or functional area of the project. Our analysis provides evidence that the metric is related to the technical effervescence and popularity of project, and as such can be a good candidate to measure its healthy evolution. Other, similar metrics -like the ratio of developer messages to commits and the ratio of issue tracker messages to commits- are studied for several projects as well, in order to see if they have similar characteristics.

On linear instability mechanisms in incompressible open cavity flow

A theoretical study of linear global instability of incompressible flow over a rectangular spanwise-periodic open cavity in an unconfined domain is presented. Comparisons with the limited number of results available in the literature are shown. Subsequently, the parameter space is scanned in a systematic manner, varying Reynolds number, incoming boundary-layer thickness and length-to-depth aspect ratio. This permits documenting the neutral curves and leading eigenmode characteristics of this flow. Correlations constructed using the results obtained collapse all available theoretical data on the three-dimensional instabilities.

Estudio de las posibilidades de los datos abiertos enlazados (Linked Open Data) para la realización de mashups de ámbito geográfico.

La web ha sufrido una drástica transformación en los últimos años, debido principalmente a su popularización y a la enorme cantidad de información que alberga. Debido a estos factores se ha dado el salto de la denominada Web de Documentos, a la Web Semántica, donde toda la información está relacionada con otra. Las principales ventajas de la información enlazada estriban en la facilidad de reutilización, accesibilidad y disponibilidad para ser encontrada por el usuario. En este trabajo se pretende poner de manifiesto la utilidad de los datos enlazados aplicados al ámbito geográfico y mostrar como pueden ser empleados hoy en día. Para ello se han explotado datos enlazados de carácter espacial provenientes de diferentes fuentes, a través de servidores externos o endpoints SPARQL. Además de eso se ha trabajado con un servidor privado capaz de proporcionar información enlazada almacenada en un equipo personal. La explotación de información enlazada se ha implementado en una aplicación web en lenguaje JavaScript, tratando de abstraer totalmente al usuario del tratamiento de los datos a nivel interno de la aplicación. Esta aplicación cuenta además con algunos módulos y opciones capaces de interactuar con las consultas realizadas a los servidores, consiguiendo un entorno más intuitivo y agradable para el usuario. ABSTRACT: In recent years the web has suffered a drastic transformation because of the popularization and the huge amount of stored information. Due to these factors it has gone from Documents web to Semantic web, where the data are linked. The main advantages of Linked Data lie in the ease of his reuse, accessibility and availability to be located by users. The aim of this research is to highlight the usefulness of the geographic linked data and show how can be used at present time. To get this, the spatial linked data coming from several sources have been managed through external servers or also called endpoints. Besides, it has been worked with a private server able to provide linked data stored in a personal computer. The use of linked data has been implemented in a JavaScript web application, trying completely to abstract the internally data treatment of the application to make the user ignore it. This application has some modules and options that are able to interact with the queries made to the servers, getting a more intuitive and kind environment for users.

Open Source website

La idea de este proyecto es acercar la imagen de Libertad de Información y su conocida variante Open Source, donde cubriremos en detalle la multitud de puntos que abarca. Está dirigida a todos los usuarios que quieran conocer de primera mano cómo se inició la idea de Libertad Tecnológica hasta sus aplicaciones. No solo para aquellos que quieran emplearla, sino tambien para aquellos que la ya la usan y necesitan recursos para nuevas ideas. De esta forma, nos acercaremos tambien a la idea de libertad que en la tecnología está actualmente en debate. El contenido se estructura siguiendo las siguientes ramas:  Historia, desde sus orígenes hasta el presente.  Economía, ventajas y desventajas de esta libertad.  Problemas legales en distintos niveles  Noticias y actualizaciones de aplicaciones.  Sociedad, entorno a la aceptación y rechazo por los usuarios, ademas de su influencia en la ética, educación e innovación.  Aplicaciones, donde se incluirán la mayoría de las aplicaciones más conocidas en cada una de las ramas de Open Source. ---ABSTRACT---The topic finally chosen in the list of Professional Skills and Issues has been the Freedom of Information and its best known variant Open Source. We will try to cover in detail most of the points that includes history, economics, law, society and the various applications in which it have influenced. It allows all the public to see first-hand the term of Open Source, from its beginnings to applications. Not just for those who want to use it, but for those who already use it and want to find sources and new ideas. It will also get a step closer to the idea of Freedom of Information as currently being debated. The main branches are going to address:  History, from its origins to the present.  Economic, advantages and disadvantages of being free.  Laws, problems in different continents at the legal level.  News, latest in its various applications.  Society, acceptance or rejection by the people, addition to the factors that influence as ethics, education, and arts innovation.  Applications, where most try to include most current applications of each of the variants.

Instability Analysis of Incompressible Open Cavity Flows

El problema del flujo sobre una cavidad abierta ha sido estudiado en profundidad en la literatura, tanto por el interés académico del problema como por sus aplicaciones prácticas en gran variedad de problemas ingenieriles, como puede ser el alojamiento del tren de aterrizaje de aeronaves, o el depósito de agua de aviones contraincendios. Desde hace muchos a˜nos se estudian los distintos tipos de inestabilidades asociadas a este problema: los modos bidimensionales en la capa de cortadura, y los modos tridimensionales en el torbellino de recirculación principal dentro de la cavidad. En esta tesis se presenta un estudio paramétrico completo del límite incompresible del problema, empleando la herramienta de estabilidad lineal conocida como BiGlobal. Esta aproximación permite contemplar la estabilidad global del flujo, y obtener tanto la forma como las características de los modos propios del problema físico, sean estables o inestables. El estudio realizado permite caracterizar con gran detalle todos los modos relevantes, así como la envolvente de estabilidad en el espacio paramétrico del problema incompresible (Mach nulo, variación de Reynolds, espesor de capa límite incidente, relación altura/profundidad de la cavidad, y longitud característica de la perturbación en la dirección transversal). A la luz de los resultados obtenidos se proponen una serie de relaciones entre los parámetros y características de los modos principales, como por ejemplo entre el Reynolds crítico de un modo, y la longitud característica del mismo. Los resultados numéricos se contrastan con una campaña experimental, siendo la principal conclusión de dicha comparación que los modos lineales están presentes en el flujo real saturado, pero que existen diferencias notables en frecuencia entre las predicciones teóricas y los experimentos. Para intentar determinar la naturaleza de dichas diferencias se realiza una simulación numérica directa tridimensional, y se utiliza un algoritmo de DMD (descomposición dinámica de modos) para describir el proceso de saturación. ABSTRACT The problem of the flow over an open cavity has been studied in depth in the literature, both for being an interesting academical problem and due to the multitude of industrial applications, like the landing gear of aircraft, or the water deposit of firefighter airplanes. The different types of instabilities appearing in this flow studied in the literature are two: the two-dimensional shear layer modes, and the three-dimensional modes that appear in the main recirculating vortex inside the cavity. In this thesis a parametric study in the incompressible limit of the problem is presented, using the linear stability analysis known as BiGlobal. This approximation allows to obtain the global stability behaviour of the flow, and to capture both the morphological features and the characteristics of the eigenmodes of the physical problem, whether they are stable or unstable. The study presented here characterizes with great detail all the relevant eigenmodes, as well as the hypersurface of instability on the parameter space of the incompressible problem (Mach equal to zero, and variation of the Reynolds number, the incoming boundary layer thickness, the length to depth aspect ratio of the cavity and the spanwise length of the perturbation). The results allow to construct parametric relations between the characteristics of the leading eigenmodes and the parameters of the problem, like for example the one existing between the critical Reynolds number and its characteristic length. The numerical results presented here are compared with those of an experimental campaign, with the main conclusion of said comparison being that the linear eigenmode are present in the real saturated flow, albeit with some significant differences in the frequencies of the experiments and those predicted by the theory. To try to determine the nature of those differences a three-dimensional direct numerical simulation, analyzed with Dynamic Mode Decomposition algorithm, was used to describe the process of saturation.

Crowdsourcing de información geográfica: proyectos Open Source y desarrollo de una plataforma móvil para mantenimiento de infraestructura urbana.

El presente trabajo se centra en la investigación del modelo de crowdsourcing y su relación con la Información Geográfica Voluntaria y otras actividades participativas para la creación de conocimiento geográfico de forma colaborativa. Primero se expone una introducción al concepto y distintos ámbitos de aplicación y uso en la adquisición,visualización y análisis de datos geográficos, presentándose las herramientas, tecnologías web y móviles que han hecho posible su implementación. Después se hace una breve revisión de algunas plataformas de código abierto que faciliten la creación de contenido geolocalizado por el usuario y proporcionen funcionalidades para el análisis básico y manipulación de información mediante la implementación de estrategias de crowdsourcing. En los apartados siguientes, se hace un breve análisis de requisitos para el caso de uso específico de una aplicación móvil de crowdsourcing para el mantenimiento urbano, sirviendo este, como base en el desarrollo de una plataforma Web-móvil que facilite la gestión de este tipo de infraestructura. El diseño de la plataforma propuesta permite consultar y actualizar información por medio de etiquetas NFC (Near Field Communications o comunicación de campo cercano) utilizadas en el mobiliario urbano inventariado y empleando dispositivos inteligentes habilitados con la misma tecnología y conexión a Internet, para dar seguimiento y reportar el estado de la infraestructura. También, es posible generar reportes geolocalizados sobre problemas en instalaciones urbanas no inventariadas, así como crear eventos geolocalizados que convoquen a tareas participativas para la mejora de la ciudad. Además, integra entradas de conversación de redes sociales para contribuir a la participación activa de los ciudadanos en la vigilancia y mantenimiento urbano. Por último, el trabajo presenta algunas conclusiones y líneas futuras.

Análisis del software ImageJ para el análisis científico de imágenes

ImageJ es un programa informático de tratamiento digital de imagen orientado principalmente hacia el ámbito de las ciencias de la salud. Se trata de un software de dominio público y de código abierto desarrollado en lenguaje Java en las instituciones del National Institutes of Health de Estados Unidos. Incluye por defecto potentes herramientas para editar, procesar y analizar imágenes de casi cualquier tipo y formato. Sin embargo, su mayor virtud reside en su extensibilidad: las funcionalidades de ImageJ pueden ampliarse hasta resolver casi cualquier problema de tratamiento digital de imagen mediante macros, scripts y, especialmente, plugins programables en lenguaje Java gracias a la API que ofrece. Además, ImageJ cuenta con repositorios oficiales en los que es posible obtener de forma gratuita macros, scripts y plugins aplicables en multitud de entornos gracias a la labor de la extensa comunidad de desarrolladores de ImageJ, que los depura, mejora y amplia frecuentemente. Este documento es la memoria de un proyecto que consiste en el análisis detallado de las herramientas de tratamiento digital de imagen que ofrece ImageJ. Tiene por objetivo determinar si ImageJ, a pesar de estar más enfocado a las ciencias de la salud, puede resultar útil en el entorno de la Escuela Técnica Superior de Ingeniería y Sistemas de Telecomunicación de la Universidad Politécnica de Madrid, y en tal caso, resaltar las características que pudieran resultar más beneficiosas en este ámbito y servir además como guía introductoria. En las siguientes páginas se examinan una a una las herramientas de ImageJ (versión 1.48q), su funcionamiento y los mecanismos subyacentes. Se sigue el orden marcado por los menús de la interfaz de usuario: el primer capítulo abarca las herramientas destinadas a la manipulación de imágenes en general (menú Image); el segundo, las herramientas de procesado (menú Process); el tercero, las herramientas de análisis (menú Analyze); y el cuarto y último, las herramientas relacionadas con la extensibilidad de ImageJ (menú Plugins). ABSTRACT. ImageJ is a digital image processing computer program which is mainly focused at the health sciences field. It is a public domain, open source software developed in Java language at the National Institutes of Health of the United States of America. It includes powerful built-in tools to edit, process and analyze almost every type of image in nearly every format. However, its main virtue is its extensibility: ImageJ functionalities can be widened to solve nearly every situation found in digital image processing through macros, scripts and, specially, plugins programmed in Java language thanks to the ImageJ API. In addition, ImageJ has official repositories where it is possible to freely get many different macros, scripts and plugins thanks to the work carried out by the ImageJ developers community, which continuously debug, improve and widen them. This document is a report which explains a detailed analysis of all the digital image processing tools offered by ImageJ. Its final goal is to determine if ImageJ can be useful to the environment of Escuela Tecnica Superior de Ingenierfa y Sistemas de Telecomunicacion of Universidad Politecnica de Madrid, in spite of being focused at the health sciences field. In such a case, it also aims to highlight the characteristics which could be more beneficial in this field, and serve as an introductory guide too. In the following pages, all of the ImageJ tools (version 1.48q) are examined one by one, as well as their work and the underlying mechanics. The document follows the order established by the menus in ImageJ: the first chapter covers all the tools destined to manipulate images in general (menu Image); the second one covers all the processing tools (menu Process); the third one includes analyzing tools (menu Analyze); and finally, the fourth one contains all those tools related to ImageJ extensibility (menu Plugins).

Analysis of advanced European nuclear fuel cycle scenarios including transmutation and economic estimates

Four European fuel cycle scenarios involving transmutation options (in coherence with PATEROS and CPESFR EU projects) have been addressed from a point of view of resources utilization and economic estimates. Scenarios include: (i) the current fleet using Light Water Reactor (LWR) technology and open fuel cycle, (ii) full replacement of the initial fleet with Fast Reactors (FR) burning U?Pu MOX fuel, (iii) closed fuel cycle with Minor Actinide (MA) transmutation in a fraction of the FR fleet, and (iv) closed fuel cycle with MA transmutation in dedicated Accelerator Driven Systems (ADS). All scenarios consider an intermediate period of GEN-III+ LWR deployment and they extend for 200 years, looking for long term equilibrium mass flow achievement. The simulations were made using the TR_EVOL code, capable to assess the management of the nuclear mass streams in the scenario as well as economics for the estimation of the levelized cost of electricity (LCOE) and other costs. Results reveal that all scenarios are feasible according to nuclear resources demand (natural and depleted U, and Pu). Additionally, we have found as expected that the FR scenario reduces considerably the Pu inventory in repositories compared to the reference scenario. The elimination of the LWR MA legacy requires a maximum of 55% fraction (i.e., a peak value of 44 FR units) of the FR fleet dedicated to transmutation (MA in MOX fuel, homogeneous transmutation) or an average of 28 units of ADS plants (i.e., a peak value of 51 ADS units). Regarding the economic analysis, the main usefulness of the provided economic results is for relative comparison of scenarios and breakdown of LCOE contributors rather than provision of absolute values, as technological readiness levels are low for most of the advanced fuel cycle stages. The obtained estimations show an increase of LCOE ? averaged over the whole period ? with respect to the reference open cycle scenario of 20% for Pu management scenario and around 35% for both transmutation scenarios. The main contribution to LCOE is the capital costs of new facilities, quantified between 60% and 69% depending on the scenario. An uncertainty analysis is provided around assumed low and high values of processes and technologies.

Global research alliance modelling platform (GRAMP): an open web platform for modelling greenhouse gas emissions from agro-ecosystems

Carbon (C) and nitrogen (N) process-based models are important tools for estimating and reporting greenhouse gas emissions and changes in soil C stocks. There is a need for continuous evaluation, development and adaptation of these models to improve scientific understanding, national inventories and assessment of mitigation options across the world. To date, much of the information needed to describe different processes like transpiration, photosynthesis, plant growth and maintenance, above and below ground carbon dynamics, decomposition and nitrogen mineralization. In ecosystem models remains inaccessible to the wider community, being stored within model computer source code, or held internally by modelling teams. Here we describe the Global Research Alliance Modelling Platform (GRAMP), a web-based modelling platform to link researchers with appropriate datasets, models and training material. It will provide access to model source code and an interactive platform for researchers to form a consensus on existing methods, and to synthesize new ideas, which will help to advance progress in this area. The platform will eventually support a variety of models, but to trial the platform and test the architecture and functionality, it was piloted with variants of the DNDC model. The intention is to form a worldwide collaborative network (a virtual laboratory) via an interactive website with access to models and best practice guidelines; appropriate datasets for testing, calibrating and evaluating models; on-line tutorials and links to modelling and data provider research groups, and their associated publications. A graphical user interface has been designed to view the model development tree and access all of the above functions.

Virtual science hub: an open source platform to enrich science teaching

This paper presents the Virtual Science Hub platform. It is an open source platform that combines a social network, an e-learning authoring tool, a videoconference service and a learning object repository for science teaching enrichment. These four main functionalities fit very well together. The platform was released in April 2012 and since then it has not stopped growing. Finally we present the results of the surveys conducted and the statistics gathered to validate this approach.

The origin of the open landscapes of the highlands of Gredos (central Spain) during the Holocene: a pedoanthracological approach

Se presentan los resultados de la investigación pedoantracológica en una catena del macizo dcentral de Gredos

Data consistency management in an open smart home management platform

In this paper, the authors introduce a novel mechanism for data management in a middleware for smart home control, where a relational database and semantic ontology storage are used at the same time in a Data Warehouse. An annotation system has been designed for instructing the storage format and location, registering new ontology concepts and most importantly, guaranteeing the Data Consistency between the two storage methods. For easing the data persistence process, the Data Access Object (DAO) pattern is applied and optimized to enhance the Data Consistency assurance. Finally, this novel mechanism provides an easy manner for the development of applications and their integration with BATMP. Finally, an application named "Parameter Monitoring Service" is given as an example for assessing the feasibility of the system.