Orientation Estimation by Means of Extended Kalman Filter, Quaternions, and Charts

An orientation estimation algorithm is presented. This algorithm is based on the Extended Kalman Filter, and uses quaternions as the orientation descriptor. For the filter update, we use measurements from an Inertial Measurement Unit (IMU). The IMU consists in a triaxial angular rate sensor, and an also triaxial accelerometer. Quaternions describing orientations live in the unit sphere of R4. Knowing that this space is a manifold, we can apply some basic concepts regarding these mathematical objects, and an algorithm that reminds the also called “Multiplicative Extended Kalman Filter” arises in a natural way. The algorithm is tested in a simulated experiment, and in a real one

Análisis, diseño paramétrico y construcción de apéndices de veleros de competición

Este trabajo presenta, estudia y discute un proceso de diseño de apéndices para veleros de competición. Se ha formalizado un modelo de análisis de apéndices que se puede realizar mediante implementación en ordenador en tiempos reducidos, de forma que se pueda integrar en un proceso de optimización. Se ha formalizado un modelo de parametrización de apéndices que abarca la mayoría de apéndices utilizados en veleros. Únicamente no es adecuado para bulbos de tipo torpedo, para los que se ha formalizado una parametrización específica. Tanto los modelos de análisis como las herramientas de parametrización se han integrado en un sistema CAD, con el que se han realizado diversos diseños de apéndices. Estos apéndices se analizan y discuten como casos de estudio, y para los que se detallan los procesos de fabricación, desde las técnicas constructivas hasta los cálculos estructurales. Estos apéndices, en la actualidad, están siendo utilizados en embarcaciones de equipos de alto nivel.Escuela Técnica Superior de Ingeniería Naval y OceánicaUniversidad Politécnica de Cartagen

Independencia del auditor, determinación conjunta de los honorarios de auditoría y de servicios adicionales y la incidencia de los informes de auditoría con salvedades

The aim of this study is to examine whether the provision of non-audit services by the incumbent auditor compromises auditor independence in a low litigation risk environment such as in the case of Spain, where the audit litigation risk is not likely to be the main external deterrent for audit malpractices. To achieve this goal we analyse whether audit and non-audit fees are simultaneously determined, and we also test whether the joint provision of audit and non-audit services reduces the incidence of qualified audit reports. Confirming prior research, when running single equation models the results obtained are supportive of the presence of knowledge spillovers between the two services. Nevertheless, we also empirically establish that audit and non-audit fees are jointly determined and when applying a simultaneous-equation model, then, the flows of knowledge spillovers cannot be proved. We also find that auditors are not less likely to issue qualified audit reports when they jointly supply audit and non-audit servicesEl objetivo de este trabajo es analizar si la independencia del auditor de una empresa se ve comprometida cuando presta de forma conjunta servicios de auditoría y servicios adicionales a la misma, en un entorno con bajo riesgo de litigio como es el español, donde no es probable que el auditor de cuentas se enfrente a algún litigio por haber llevado a cabo una mala praxis. Para alcanzar este objetivo, nosotros estudiamos si los honorarios de la auditoría y de los servicios adicionales a la misma se determinan de forma conjunta, así como también si la provisión conjunta de ambos servicios reduce la incidencia de informes de auditoría con salvedades. Al igual que la evidencia previa, nosotros concluimos que cuando aplicamos un sistema de ecuaciones simples se pone de manifiesto transferencia de conocimientos entre los dos servicios. No obstante, nosotros también contrastamos empíricamente que los servicios de auditoría y de los servicios adicionales a la misma se determinan conjuntamente y cuando aplicamos un modelo de ecuaciones simultáneas, los resultados no revelan transferencia de conocimientos. Por otra parte, también evidenciamos que los auditores que prestan de forma conjunta los dos servicios no son más proclives a reducir la emisión de informes de auditoría con salvedade

Producción musical y promoción de una canción

El presente trabajo se centra en el desarrollo de un plan de distribución de una canción, por lo que el objetivo principal de este plan es lograr una amplia difusión y visibilidad de la canción, conectando de manera efectiva con el público y generando un impacto significativo en su audiencia. La metodología usada se basa en una combinación de estrategias de promoción digital y offline. En lo digital, se implementaron acciones como la creación de perfiles en redes sociales relevantes para el público objetivo, la publicación regular de contenido relacionado con la canción, la interacción con seguidores y la colaboración con influencers o artistas afines. Además, se aprovecharon plataformas de streaming y distribución de música digital para alcanzar a un público más amplio. En el ámbito offline, se diseñó una estrategia de presentaciones en vivo en bares y locales de música, aprovechando la energía y el contacto directo con el público. Los objetivos del plan de difusión incluyen aumentar el número de reproducciones y descargas de la canción, aumentar la base de seguidores en redes sociales, generar interacción y participación del público, así como reforzar la presencia y reconocimiento del artista. Tras aplicar las acciones de distribución, la canción obtuvo un incremento significativo en las reproducciones y descargas, logrando una mayor visibilidad en plataformas de música digital. Además, se registró un incremento en el número de seguidores y en la interacción en redes sociales. Las presentaciones en vivo también resultaron positivas, generando mayor interés en la canción y atrayendo a nuevos seguidores.This paper focuses on the development of a promotion plan for a song, addressing its methodology, objectives, and the results achieved. The main objective of the plan is to achieve widespread dissemination and visibility of the song by effectively connecting with the target audience and generating a significant impact on its listeners. The methodology employed is based on a combination of digital and offline promotion strategies. In the digital realm, actions such as creating profiles on relevant social media platforms for the target audience, regularly publishing content related to the song, engaging with followers, and collaborating with influencers or like-minded artists were implemented. Additionally, streaming platforms and digital music distribution channels were leveraged to reach a broader audience. In the offline domain, a strategy of live performances in bars and music venues was designed to capitalize on the energy and direct interaction with the audience. The objectives of the promotion plan include increasing the number of song plays and downloads, growing the social media follower base, generating audience interaction and engagement, as well as strengthening the artist's presence and recognition. The results obtained were satisfying. The song experienced a significant increase in plays and downloads, attaining greater visibility on digital music platforms. Additionally, there was a rise in the number of followers and engagement on social media, including comments, shares, and likes. The live performances also proved successful in generating heightened interest in the song and attracting new fans. In conclusion, the implemented promotion plan successfully achieved its objectives by enhancing the dissemination and recognition of the song and artist. The combination of digital and offline strategies effectively connected with the audience and made a positive impact on the music promotion

Improved 3D sparse maps for high-performance SFM with low-cost omnidirectional robots

We consider the use of low-budget omnidirectional platforms for 3D mapping and self-localisation. These robots specifically permit rotational motion in the plane around a central axis, with negligible displacement. In addition, low resolution and compressed imagery, typical of the platform used, results in high level of image noise (_ ∽ 10). We observe highly sparse image feature matches over narrow inter-image baselines. This particular configuration poses a challenge for epipolar geometry extraction and accurate 3D point triangulation, upon which a standard structure from motion formulation is based. We propose a novel technique for both feature filtering and tracking that solves these problems, via a novel approach to the management of feature bundles. Noisy matches are efficiently trimmed, and the scarcity of the remaining image features is adequately overcome, generating densely populated maps of highly accurate and robust 3D image features. The effectiveness of the approach is demonstrated under a variety of scenarios in experiments conducted with low-budget commercial robots

Efficient distributed approach for density-based topology optimization using coarsening and h-refinement

This work presents an efficient parallel implementation of density-based topology optimization using Adaptive Mesh Refinement (AMR) schemes to reduce the computational burden of the bottleneck of the process, the evaluation of the objective function using Finite Element Analysis (FEA). The objective is to obtain an equivalent design to the one generated on a uniformly fine mesh using distributed memory computing but at a much cheaper computational cost. We propose using a fine mesh for the optimization and a coarse mesh for the analysis using coarsening and refinement criteria based on the thresholding of design variables. We evaluate the functional on the coarse mesh using a distributed conjugate gradient solver preconditioned by an algebraic multigrid (AMG) method showing its computational advantages in some cases by comparing with geometric multigrid (GMG) and AMG methods in two- and three-dimensional problems. We use different computational resources with small regularization distances for such comparisons. We also evaluate the performance and scalability of the proposal using a different number of computing cores and distributed computing hosts. The numerical results show a significant increment of the computing performance for the overall computing time of the proposal combining dynamic coarsening, adaptive mesh refinement, and distributed memory computing architecturesThis work has been supported by the AEI/FEDER and UE under the contract DPI2016-77538-R

Expected impact quantification–based reliability assessment methodology for Chilean copper smelting process: A case study

Currently, a lack of interpretation tools and methodologies hinders the ability to assess the performance of a single piece of equipment or a total system. Therefore, a reliability, availability, and maintainability analysis must be combined with a quantitative reliability impact analysis to interpret the actual performance and identify bottlenecks and improvement opportunities. This article proposes a novel methodology that uses reliability, availability, and maintainability analysis to quantify the expected impact. The strengths of the failure expected impact methodology include its ability to systematically and quantitatively assess the expected impact in terms of reliability, availability, and maintainability indicators and the logical configuration of subsystems and individual equipment, which show the direct effects of each element on the total system. This proposed analysis complements plant modeling and analysis. Determining the operational effectiveness impact, as the final result of the computation process, enables the quantitative and unequivocal prioritization of the system elements by assessing the associated loss as a ‘‘production loss’’ regarding its unavailability and effect on the system process. The Chilean copper smelting process study provides useful results for developing a hierarchization that enables an analysis of improvement actions that are aligned with the best opportunities

222Rn as a natural tracer to investigate recharge and groundwater flow dynamics at three Mediterranean karst systems in Southern Spain.

Comprehensive knowledge of groundwater origin and movement into karst aquifers is crucial to establish the adequate management practices. This is of special interest in areas strongly affected by the impact of climate change, such as the Mediterranean region. This work aims to better understand recharge processes determining groundwater flow in 3 mountainous carbonate aquifers in Southern Spain. To achieve this purpose, spring discharge and electrical conductivity data as well as 222Rn activity were measured and interpreted in karst groundwater. Karst groundwater discharge at the investigated springs varies between 3 and 1400 L/s, while electrical conductivity (EC) values range between 227 and 1929 µS/cm. 222Rn activity data are found between 31-3630 Bq/m3. The temporal evolution of EC, water temperature and 222Rn showed relatively constant values during dry periods in all examined karst springs but abrupt decreases after intense recharge events. A detailed –daily- control during high waters in the Sierra de Ubrique revealed slight increases in 222Rn activity at the beginning of the rising limb of spring discharge. However, circulation of recently infiltrated rainwater through karst conduits (in turbulent flow regimes) and the mixing with old waters provokes a marked dropping in the measured parameters at karst springs.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Nuevas perspectivas en la gestión de la responsabilidad social en las universidades

Ponències presentades a les jornades “Nuevas perspectivas en la gestión de la responsabilidad social en las universidades” celebrades a Castelló de la Plana el 29 i 30 de novembre de 2016. -- Textos en castellà i català.Com s'està aplicant la responsabilitat social en els campus i quins són les millors i més noves pràctiques en aquest camp? Aquest llibre arreplega les reflexions i propostes plantejades en les jornades «Noves perspectives en la gestió de la responsabilitat social en les universitats», celebrades en la Universitat Jaume I entre el 29 i 30 de novembre de 2016, en les quals es va abordar amb especial atenció a la gestió de la investigació i innovació responsables (RRI, sigles en anglès) com l'aspecte més emergent de la responsabilitat social de les universitats.¿Cómo se está aplicando la responsabilidad social en los campus y cuáles son las mejores y más novedosas prácticas en este campo? Este volumen recoge las reflexiones y propuestas planteadas en las jornadas «Nuevas perspectivas en la gestión de la responsabilidad social en las universidades», celebradas en la Universitat Jaume I entre el 29 y 30 de noviembre de 2016 que dedicaron una especial atención a la gestión de la investigación e innovación responsables (RRI por sus siglas en inglés) como el aspecto más emergente de la responsabilidad social de las universidades