An educational tool to assist the design process of switched reluctance machines

The design of electric machines is a hot topic in the syllabuses of several undergraduate and graduate courses. With the development of hybrid and electrical vehicles, this subject is gaining more popularity, especially in electrical engineering courses. This paper presents a computeraided educational tool to guide engineering students in the design process of a switched reluctance machine (SRM). A step-by-step design procedure is detailed and a user guide interface (GUI) programmed in the Matlab® environment developed for this purpose is shown. This GUI has been proved a useful tool to help the students to validate the results obtained in their lecture assignments, while aiding to achieve a better understanding of the design process of electric machines. A validation of the educational tool is done by means of finite element method (FEM) simulations.Postprint (author's final draft

Distribution patterns of Hydropsychids and Rhyacophilids species (Trichoptera) in a not regulated Mediterranean river (SW Spain)

This paper investigates the longitudinal ordination of the Hydropsychidae and Rhyacophilidae species present in the high basin of the Hozgarganta River. The ordination of the Hydropsychids species present in the basin show three distribution patterns: Diplectrona felix and Hydropsyche infernalis are confined to the head streams; H. siltalai and H. iberomaroccana are distributed throughout the entire study zone, although the second one does not reach the highest sections of the basin; finally, H. lobata occupies the lowest sections, specially in the main axis of the river. The two Rhyacophila species studied show also a well differentiated distribution. R. fonticola is more abundant in the gorges and high sections, whereas R. munda prefers the riverbed of the main river, although it's also found in some tributaries. Even in these intermediate sections, the segregation between the two species is almost perfect. The water permanence in the riverbeds influences the distribution of some species.We have found that D. felix and H. infernalis inhabit the permanent sections of the stream heads whereas H. iberomaroccana significantly dominates the intermittent ones. H. siltalai, H. lobata, R. fonticola, and R. munda do not show a significant preference for any type of riverbed (permanent, intermittent, or ephemeral). It is interesting to highlight the survival of some H. iberomaroccana larvae in isolated pools during the summer. We suggest the possibility that these larvae survive thanks to the existence of a weak underground flow of subsurface origin between adjacent pools.En el presente trabajo se investiga la ordenación longitudinal de las especies de Hydropsychidae y Rhyacophilidae presentes en la cuenca alta del río Hozgarganta. La ordenación de las especies de Hydropsychidae presentes en la cuenca muestra tres patrones de distribución: Diplectrona felix e Hydropsyche infernalis están confinadas en los arroyos de cabecera; H. siltalai e H. iberomaroccana están distribuidas por toda la zona de estudio, aunque la segunda no alcanza los tramos más altos de la cuenca; por último, H. lobata ocupa los tramos más bajos, especialmente en el eje principal del río. Las dos especies de Rhyacophila estudiadas también muestran una distribución bien diferenciada. R. fonticola es más abundante en las gargantas y tramos altos, mientras que R. munda prefiere el cauce del río principal, aunque también se encuentra presente en algunos tributarios. Incluso en estos tramos intermedios la segregación entre ambas especies es casi perfecta. La permanencia del agua en los cauces influye en la distribución de algunas especies. Hemos encontrado que D. felix e H. infernalis habitan los tramos permanentes de cabecera, mientras que H. iberomaroccana domina de forma significativa en los intermitentes. H. siltalai, H. lobata, R. fonticola y R. munda no muestran una preferencia significativa por algún tipo de cauce (permanente, intermitente o efímero). Es interesante resaltar la supervivencia de algunas larvas de H. iberomaroccana en pozas aisladas durante el verano. Sugerimos la posibilidad de que estas larvas sobrevivan gracias a la existencia de un débil flujo subterráneo de origen freático entre pozas adyacentes

Impact on soil degradation factors of changes in rain intensity patterns in southern Spain

In southern of Spain, the torrential nature of the rainfalls alters the soil water availability for vegetation and, consequently, its spatially and temporally pattern. This fact, combined with the current global warming, raises a modification of the eco-geomorphological processes dynamics in Mediterranean areas

An urban walking tour for the recognition of rocks. A new didactic resource for teaching Geology

En las calles de una ciudad es normal encontrar una gran variedad de rocas ornamentales usadas como aplacado en los edificios. Estos tipos de piedras pueden servir para enseñar numerosos conceptos petrográficos y geológicos, de forma muy parecida a como se puede hacer en el campo. Estas observaciones pueden convertirse así en un recurso didáctico inestimable para la enseñanza de la Geología, en distintos niveles educativos. En este trabajo, se proponen actividades prácticas dirigidas a alumnos de 1º Curso del Grado en Educación Primaria (Asignatura de Fundamentos en Ciencias Naturales, Geología) y a 2º Curso del Grado en Ingeniería Civil (Asignatura de Geología Aplicada a la Ingeniería Civil), pero puede adaptarse a cualquier base de conocimiento. Como ejemplo se propone un itinerario por la Avda. Reina Mercedes de Sevilla, donde se han realizado una serie de observaciones que se han recogido en fichas por el profesor, que pueden ser consultadas como referencia de apoyo por parte del alumnado. Para este recurso de aprendizaje se proponen: a) Fase previa a realizar en el aula, para la localización, selección y propuestas de itinerarios. b) Fase de “campo” en la que los alumnos recopilan información de los litotipos y otros materiales encontrados durante la realización del itinerario seleccionado, rellenando fichas y realizando fotografías. c) Fase de aprendizaje en la que de nuevo en el aula, se amplía la información obtenida con bibliografía específica (guías petrográficas, Internet), y se completan las observaciones con aspectos genéticos, procedencia, canteras, acabados, comercialización, etc. Con la información obtenida por los alumnos y la supervisión del profesor se pueden proponer otros itinerarios temáticos por toda la ciudad, que podrían dar lugar a una nueva visión de las calles de Sevilla.The streets of a city show a great variety of ornamental rocks used as construction material. These stones can be used to teach a lot of petrographic and geologic concepts as they can be also seen in the field. These observations constitute an inestimable didactic resource for education in Geology. In this work, we propose practical activities aimed to students of the Primary Education degree (Geology) and Civil Engineer degree (Applied Geology for Civil Engineer), but they can be also adapted to any education level. As an example, an itinerary by the Reina Mercedes Street is proposed. General notes made by the teacher can be used by the students to help to elaborate their own work. The didactical methodology includes the following stages: a) Preliminary stage concerning on the localization, selection and proposal of potential itineraries. b) “Field” stage based on the gathering of observations and recognition of lithotypes and other materials found along the itinerary, taking notes, photographs, etc. c) Learning stage carried out in class using specific bibliography and internet resources to complete the observations with genetic aspects, source area, quarries, finishes, commercialization, etc. With the notes obtained by the students and under the supervision of the teacher, other thematic itineraries can be proposed by the city, which could show a new vision of the streets of Seville

A field trip by the province of Seville through the Geological Time

Uno de los conceptos más difíciles de asimilar en Geología es la relación espacio-tiempo. En este trabajo se proponen una serie de lugares e itinerarios para la observación de materiales y la interpretación de los procesos más significativos que han ocurrido a lo largo de los tiempos geológicos en la provincia de Sevilla. Para ello se han preparado y optimizado itinerarios geológicos para las clases prácticas de campo, dirigidas a alumnos de Grado en Educación Primaria y de Ingeniería Civil. En estos itinerarios se pueden resaltar las unidades de Tiempo geológico, de forma que se presenta a los alumnos una visión cómo si de un viaje en el tiempo se tratara, de cómo y dónde se pueden observar materiales de distintas edades y se establezcan los acontecimientos que ocurrieron durante cada momento de la historia de la Tierra. Se proponen numerosos ejemplos tanto en la Sierra Norte de Sevilla, donde se encuentran las rocas más antiguas (materiales precámbricos y paleozoicos), como en la Sierras al Sur donde es fácil observar materiales mesozoicos y en el valle del Guadalquivir que se presentan los materiales más modernos.One of the most difficult concepts to assimilate in Geology is the relationship between space and time. In this work, we propose several sites and itineraries to observe rocks and to interpret the most significant processes that have occurred through the geological time in the province of Seville. According to this aim, we have prepared and optimized geological field-trips for Primary Education and Civil Engineering students. In these itineraries the chronostratigraphic units are presented to the students as a trip though the time, showing how and where the rocks of different ages can be observed and to establish the events that occurred during every “moment” of the history of the Earth. Many examples are proposed for the Northern Sierra of Seville where the oldest rocks (Precambrian and Paleozoic) of Seville are located, the Southern Sierra where Mesozoic rocks are found and the Guadalquivir Basin that shows Cenozoic materials

Computing the Clique-width of Cactus Graphs

Similar to the tree-width (twd), the clique-width (cwd) is an invariant of graphs. A well known relationship between tree-width and clique-width is that cwd(G) ≤ 3 · 2twd(G)−1. It is also known that tree-width of Cactus graphs is 2, therefore the clique-width for those graphs is smaller or equal than 6. In this paper, it is shown that the clique-width of Cactus graphs is smaller or equal to 4 and we present a polynomial time algorithm which computes exactly a 4-expression

Rheological and microstructural study of concentrated sunflower oil in water emulsions stabilized by food proteins

Se ha realizado un estudio de la distribución del tamaño de gotas y de las propiedades viscoelásticas lineales de emulsio- nes concentradas de aceite en agua, estabilizadas con dife- rentes proteínas (cangrejo, gluten y soja). Los sistemas estu- diados siempre presentan un comportamiento típico de emulsiones altamente concentradas con un alto grado de flo- culación. Se ha observado que un incremento de la velocidad de agitación empleada durante la preparación o de la concen- tración de emulsionante dan lugar a un aumento de los módu- los viscoelásticos (G’ y G’’) y a una disminución del tamaño de gotas. Por tanto se produce un reforzamiento del entramado formado por asociación de las gotas de fase dispersa y como consecuencia, un aumento en la estabilidad de las emulsiones.Droplet Size Distribution (DSD) and linear viscoelastic properties of concentrated o/w emulsions stabilized by different proteins (crayfish, gluten and soybean) have been studied. A typical behaviour of highly concentrated emulsions with a high degree of flocculation has been found. An increase in energy input for the emulsification process or in emulsifier concentration leads to an increase in both viscoelastic moduli (G’, G’’) as well as to a decrease in droplet size. Thus, an enhancement of the entanglement network produced by association of protein molecules that are surrounding oil droplets or are present in the continuous phase takes place, leading to a significant improvement of emulsion stabilit

Meanings of the concept of finite limit of a function at a point: Background and Results

Eight Congress of European Research in Mathematics Education (CERME 8). Manavgat-Side, Antalya - Turkey, 6-10 February 2013.In this paper we present a description of previous work carried out by the authors on the general issue of designing and implementing a didactical planning for Spanish students from non-compulsory secondary education, 16-17 years old. The current research has as its aim to describe the meanings that students associate to specific terms from the language, such as, “to approach,” “to tend,”“to reach,”“to exceed,” and “to converge.” Prior to the study, we reviewed the mathematical use of these terms and we contrast this with the colloquial use of the terms. From the semi- structured interviews used to gather information, we provide an analysis of the written data. It is important to highlight that students have contributed with a variety of meanings, in addition to those from the previous review.This study was performed with aid and financing from Fellowship FPU AP2010- 0906 (MEC-FEDER), project EDU2012-33030 of the National Plan for R&D&R (MICIN), Subprogram EDUC, and group FQM-193 of the 3rd Andalusia Research Plan (PAIDI)

Real-time embedded eye detection system

The detection of a person’s eyes is a basic task in applications as important as iris recognition in biometric identification or fatigue detection in driving assistance systems. Current commercial and research systems use software frameworks that require a dedicated computer, whose power consumption, size, and price are significantly large. This paper presents a hardware-based embedded solution for eye detection in real-time. From an algorithmic point-of-view, the popular Viola-Jones approach has been redesigned to enable highly parallel, single-pass image-processing implementation. Synthesized and implemented in an All-Programmable System-on-Chip (AP SoC), this proposal allows us to process more than 88 frames per second (fps), taking the classifier less than 2 ms per image. Experimental validation has been successfully addressed in an iris recognition system that works with walking subjects. In this case, the prototype module includes a CMOS digital imaging sensor providing 16 Mpixels images, and it outputs a stream of detected eyes as 640 × 480 images. Experiments for determining the accuracy of the proposed system in terms of eye detection are performed in the CASIA-Iris-distance V4 database. Significantly, they show that the accuracy in terms of eye detection is 100%.This work has been partially developed within the project RTI2018-099522-B-C4X, funded by the Gobierno de España and FEDER funds, and the ARMORI project (CEIATECH-10) funded by the University of Málaga. Portions of the research in this paper use the CASIA-Iris V4 collected by the Chinese Academy of Sciences - Institute of Automation (CASIA)

Evolutionary composition of QoS-aware web services: a many-objective perspective

Web service based applications often invoke services provided by third-parties in their workflow. The Quality of Service (QoS) provided by the invoked supplier can be expressed in terms of the Service Level Agreement specifying the values contracted for particular aspects like cost or throughput, among others. In this scenario, intelligent systems can support the engineer to scrutinise the service market in order to select those candidates that best fit with the expected composition focusing on different QoS aspects. This search problem, also known as QoS-aware web service composition, is characterised by the presence of many diverse QoS properties to be simultaneously optimised from a multi-objective perspective. Nevertheless, as the number of QoS properties considered during the design phase increases and a larger number of decision factors come into play, it becomes more difficult to find the most suitable candidate solutions, so more sophisticated techniques are required to explore and return diverse, competitive alternatives. With this aim, this paper explores the suitability of many-objective evolutionary algorithms for addressing the binding problem of web services on the basis of a real-world benchmark with 9 QoS properties. A complete comparative study demonstrates that these techniques, never before applied to this problem, can achieve a better trade-off between all the QoS properties, or even promote specific QoS properties while keeping high values for the rest. In addition, this search process can be performed within a reasonable computational cost, enabling its adoption by intelligent and decision-support systems in the field of service oriented computation.Junta de Andalucía P12-TIC-1867Ministerio de Economía y Competitividad TIN2012-32273Junta de Andalucía TIC-5906Ministerio de Economía y Competitividad TIN2014-55252-PMinisterio de Economía y Competitividad TIN2015- 71841-REDTMinisterio de Educación, Cultura y Deportes FPU13/0146