79 research outputs found
Relation-based Galois connections: towards the residual of a relation
No full textInma P. Cabrera, Pablo Cordero, Manuel Ojeda-Aciego, Relation-based Galois connections: towards the residual of a relation, CMMSE 2017: Proceedings of the 17th International Conference on Mathematical Methods in Science and Engineering ( ISBN: 978-84-617-8694-7) , pp. 469--475We explore a suitable generalization of the notion of Galois connection in which their components are binary relations. Many different approaches are possible depending both on the (pre-)order relation between subsets in the underlying powerdomain and the chosen type of relational composition.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol
No full textAnalysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood) Project, a prospective cohort study.; Indirect (proximity to emission sources, questionnaires on sources use and geospatial propagation models) and direct methods (spot and fixed longer-term measurements and personal measurements) were conducted in order to assess exposure levels of study participants aged between 7 and 18 years old. The methodology used varies depending on the frequency of the EMF-NIR and the environment (homes, schools and parks). Questionnaires assessed the use of sources contributing both to Extremely Low Frequency (ELF) and Radiofrequency (RF) exposure levels. Geospatial propagation models (NISMap) are implemented and validated for environmental outdoor sources of RFs using spot measurements. Spot and fixed longer-term ELF and RF measurements were done in the environments where children spend most of the time. Moreover, personal measurements were taken in order to assess individual exposure to RF. The exposure data are used to explore their relationships with proximity and/or use of EMF-NIR sources.; Characterisation of the EMF-NIR exposure by this combination of methods is intended to overcome problems encountered in other research. The assessment of exposure of INMA cohort children and adolescents living in different regions of Spain to the full frequency range of EMF-NIR extends the characterisation of environmental exposures in this cohort. Together with other data obtained in the project, on socioeconomic and family characteristics and development of the children and adolescents, this will enable to evaluate the complex interaction between health outcomes in children and adolescents and the various environmental factors that surround them
Subdirectly Irreducible and Semisimple Double Boolean Algebras
No full textDouble Boolean algebras are algebras of type (2, 2, 1, 1, 0, 0) introduced by Rudolf Wille to capture the equational theory of protoconcept algebras. A famous theorem of Birkhoff says that any variety is determined by its subdirectly irreducible members. In this work we give a construction that leads to a concrete embedding of double Boolean algebras into the protoconcept algebra. We characterize subdirectly irreducible, simple and semisimple double Boolean algebras
Using the Chu Construction for generalizing formal concept analysis
No full textL. Antoni, I. P. Cabrera, S. Krajči, O. Krídlo, and M. Ojeda-Aciego. Using the Chu construction for generalizing formal concept analysis. In CLA 2015, pp. 147–158, Blaise Pascal University, LIMOS laboratory, Clermont-Ferrand, 2015El objetivo de este artículo es mostrar la conexión entre generalizaciones de Análisis de Conceptos Formales y la construcción de Chu sobre la categoría ChuCors de contextos formales y correspondencias de Chu. Todas las propiedades categóricas necesarias para la comprensión de los resultados de este trabajo como producto categórico, producto tensorial o propiedades de su bifuntor se presentan y demuestran. Finalmente, la generalización de Análisis de Conceptos Formales de segundo orden se representa por una categoría construida en términos de la Construcción de Chu
Natural extension of choice functions
No full textInternational Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems, IPMU (17 th, 2018, Cádiz, Spain)The research in this paper has been supported by project TIN2014-59543-P
High aspirations: transforming dance students from print consumers to digital producers
No full textDuring 2012, the Dance Department at the University of Surrey developed a set of Open Educational Resources with a Creative Commons license (Attribution, Non- Commercial, Share Alike) for dance studies as part of the JISC-funded project Contexts, Culture and Creativity: Enriching E-learning in Dance (CCC:EED) see http://contextscultureandcreativity.wordpress.com/ for details. These OERs exemplify a pedagogical model of openness by unleashing creative learning ideas that combine revised subject specific activities, freely available audio-visual resources, and newly digitised materials from the National Resource Centre for Dance archive. With its emphasis on technology, this project enabled both lecturers and students to see the interrelationship between the articulation of knowledge through creative processes and digital literacy, and to appreciate how these connections allow for new developments in pedagogy, performance and practice.
Designing and testing OERs revealed, on the one hand, a number of needs with respect to the institutional involvement and technological infrastructure, namely, acquired software, Virtual Learning Environment design, staff technical competence, and support. It also encountered some obstacles related to educational expectations (such as content responsibility and degree of learning autonomy), levels of digital literacy (including lack of awareness of adequate copyright practices, and of online help), accessibility to technology, and perception of the role of technology in formal learning in theory and practice based dance modules. On the other hand, the creation of these resources showed great flexibility and unexpected creativity from the learners. More importantly, it meant a transformation of both classroom-based and independent learning. This work moved teaching practices from the distribution of print materials to the facilitation of online activities for personal reflection, self-testing and collaboration. The introduction of e-learning packages pushed the development of staff and students' digital skills, and initiated a move to a learning model where learners influence objectives and methods (OPAL, 2011, p. 3).
This paper highlights the potential transformative impact of OER production and reuse for Higher Education dance students. It focuses in particular on the challenges and opportunities that arise from aiming at encouraging students to become producers of digital objects by engaging with digital resources. The idea of the 'student as producer' has been highlighted by Mike Neary (2009) based on Walter Benjamin's concept of the author as producer. Neary argues that we need "to reinvent the relationship between teacher and student, so that the student is not simply consuming knowledge that is transmitted to them but becomes actively engaged in the production of knowledge with academic content and value" (2009, p. 8). Neary's proposal is that we should facilitate research or research-like experiences in our undergraduate programmes in order to transform them into "productive collaborators" (Neary 2009, p. 9). The design of the OERs in the CCC:EED project were inspired by these pedagogical ideas
The Aviary Transect—a practical welfare assessment tool to improve the management of cage-free laying hens
No full textThe Aviary Transect (AT) is a method for assessing welfare in cage-free laying hen flocks, and comprises standardized walks along each aisle screening the flock for selected welfare indicators: feather loss (FL) on head, back, breast, and tail, wounds on head, back, tail, and feet, dirty plumage, enlarged crop, sickness, and birds found dead. The method is quick (20 min for a flock of 7,500 hens), has good interobserver agreement and shows positive correlations with individual bird sampling methods. However, it is less clear whether AT can be used to detect differences in flock health and welfare related to housing and management. The aim of this study was to evaluate how AT findings varied in relation to 23 selected housing, management, environmental, and production factors. The study was conducted on 33 commercial nonbeak-trimmed, white-feathered layer flocks of similar age (70–76 wk) kept in multitiered aviaries in Norway. The most prevalent findings across flocks were feather loss on the back (mean 0.97% of flock) and breast (0.94%) followed by feather loss on the head (0.45%) and tail (0.36%) with differences in feather pecking damage according to the hybrid used (P < 0.05). Better litter quality was associated with a lower prevalence of feather loss on the head and breast (P < 0.05), and addition of fresh litter during the production cycle resulted in fewer birds with feather loss on the head (P < 0.05) and tail (P < 0.001). Lower dust levels were linked to a lower prevalence of feather loss on the head, back, and breast (P < 0.05), and when access to the floor area underneath the aviary was provided at an earlier stage of production, fewer birds had wounds (P < 0.001), but more birds were observed with an enlarged crop (P < 0.05) and found dead (P < 0.05). In conclusion, findings from AT showed that results of the assessment varied according to housing conditions. These results support the validity of AT as a relevant welfare assessment tool for evaluating cage-free management practices. © 2023 The AuthorsACKNOWLEDGMENTS: We want to thank all the farmers who allowed us to observe their hens. The study was funded by the Research Council of Norway project no. 309159. Author Contributions: Guro Vasdal: conceptualizing, data sampling, writing; Ruth Newberry: analyses, writing; Inma Estevez: analyses, writing; Kathe Kittelsen: data sampling, writing; Joanna Marchewka: analyses, writing
The median procedure as an example of penalty-based aggregation of binary relations
No full textThe aggregation of binary relations is a common topic in many fields of application such as social choice and cluster analysis. In this paper, we discuss how the median procedure - probably the most common method for aggregating binary relations - fits in the framework of penalty-based data aggregation
A Riemannian limited-memory BFGS algorithm for computing the matrix geometric mean
No full textAbstractVarious optimization algorithms have been proposed to compute the Karcher mean (namely the Riemannian center of mass in the sense of the affine-invariant metric) of a collection of symmetric positive-definite matrices. Here we propose to handle this computational task with a recently developed limited-memory Riemannian BFGS method using an implementation tailored to the symmetric positive-definite Karcher mean problem. We also demonstrate empirically that the method is best suited for large-scale problems in terms of computation time and robustness when comparing to the existing state-of-the-art algorithms
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