Hybrid ABC optimized MARS-based modeling of the milling tool wear from milling run experimental data

Milling cutters are important cutting tools used in milling machines to perform milling operations, which are prone to wear and subsequent failure. In this paper, a practical new hybrid model to predict the milling tool wear in a regular cut, as well as entry cut and exit cut, of a milling tool is proposed. The model was based on the optimization tool termed artificial bee colony (ABC) in combination with multivariate adaptive regression splines (MARS) technique. This optimization mechanism involved the parameter setting in the MARS training procedure, which significantly influences the regression accuracy. Therefore, an ABC–MARS-based model was successfully used here to predict the milling tool flank wear (output variable) as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc. Regression with optimal hyperparameters was performed and a determination coefficient of 0.94 was obtained. The ABC–MARS-based model's goodness of fit to experimental data confirmed the good performance of this model. This new model also allowed us to ascertain the most influential parameters on the milling tool flank wear with a view to proposing milling machine's improvements. Finally, conclusions of this study are exposed

Utilización del MATLAB para la realización de animaciones que simulen procesos iterativos para la resolución de ecuaciones no lineales

En el presente artículo se desarrollan simulaciones de procesos iterativos de punto fijo, mediante animaciones en tiempo real realizadas con MATLAB. Así se muestran las posibilidades didácticas de dicho programa en este tema ya que permite la visualización de gran variedad de casos y ejemplos, contemplando la convergencia o divergencia, velocidad y orden de convergencia, así como casos prácticos aplicados a la vida real

Learning of paediatric dentistry with the flipped classroom model

Introduction: The flipped classroom (FC) is a pedagogical model that can be very useful in obtaining a dentistry degree. The main objective of this study was to compare learning between student groups introducing FC in the area of paediatric dentistry at the Complutense University of Madrid in 2019. Materials and Methods: In this study, 76 students enrolled for the first time in the Pediatric Dentistry programme and completed a questionnaire (pre-Q) regarding specific theoretical knowledge about pulpotomies. Subsequently, they were divided into two groups: group A, which had free access before the class to an explanatory video about the indications and techniques of pulpotomy and group B, which viewed the same video only one time in class. After that, all students completed the same questionnaire (post-Q) again and a survey on the degree of satisfaction about the teaching method. Results: The differences in score between the post-Q and pre-Q in group A had a mean (SD) value of 3.5 (2.4) and in group B, a mean (SD) of 2.5 (2.2), with a p value of .07. In questions 3, 5 and 8, learning was greater in the experimental group (p = .007, p = .02 and p = .001, respectively). For 74.4% of the students in group A, accessing the video previous to the class was a very useful tool. Conclusions: These results suggest that implementing FC in paediatric dentistry classes help students to acquire more theoretical knowledge, which is necessary before practical teaching

Optical design for MEGARA: a multi-object spectrograph for the GTC

MEGARA is a multi-object spectrograph project for the 10.4m Gran Telescopio Canarias with medium to high resolution: R ~ 5600 - 17000. The instrument operates in three modes that cover different sky areas and that can run simultaneously: (1) the compact mode through a large central Integral Field Unit with minimum fiber pitch, covering a field of view on sky of 12 arcsec × 14 arcsec, (2) the sparse mode with fibers covering 1 arcmin × 1arcmin in three pointings and (3) the dispersed mode with a grid of nearly 100 robotics positioners able to place 7-fiber minibundles over a large field of view of 3.5 arcmin × 3.5 arcmin. The spectrograph is composed by a pseudo-slit, where the fibers are placed simulating a long slit; a slit shutter is placed just behind the pseudo-slit, a collimator, a 162mm pupil where the volume phase holographic gratings are placed, and the camera with the detector. Here we describe the spectrograph optical rationale, the conceptual optical design and the expected system performance

Incorporación del aula invertida (flipped classroom) a la metodología docente de las prácticas de Odontopediatría

Incorporar el aula invertida en las prácticas de Odontopediatría permite que los estudiantes, ayudados por vídeos, realicen un aprendizaje activo mediante preguntas, discusiones y actividades guiadas por el docente sobre los conocimientos adquiridos

MEGARA Optical design: the new integral field unit and multi-object spectrograph for the GTC 10m telescope

We describe the optical design of MEGARA, the future optical Integral Field Unit (IFU) and Multi-Object Spectrograph (MOS) for the 10.4-m Gran Telescopio CANARIAS (GTC). MEGARA is being built by a Consortium of public research institutions led by the Universidad Complutense de Madrid (UCM, Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain)

El aula invertida (flipped classroom) como método docente de las prácticas preclínicas de Odontopediatría. Evaluación de aplicaciones digitales educativas

El Aula Invertida es una modalidad de aprendizaje semipresencial en la que el alumno obtiene información en un tiempo y lugar que no requiere la presencia física del profesor, por lo que es necesario el uso de nuevas tecnologías, especialmente del campo audiovisual. En el Grado de Odontología, la materia de Odontopediatría debe capacitar al alumno en la adquisición de las destrezas necesarias para su incorporación a las prácticas clínicas con pacientes en edad infantil. El uso de vídeos educativos nos ha permitido enseñar determinadas maniobras que sería complejo describir de forma teórica y que al ser visualizadas, han facilitado al alumno su entendimiento y posterior ejecución. Hemos evaluado la aplicación educativa diseñada para el desarrollo del aula invertida "Ed-puzzle" que permite al profesor mejorar sus propios vídeos e incorporar preguntas en cualquier punto de su contenido, además de hacer seguimiento de los estudiantes, sus respuestas y visualizaciones. Se ha realizado un estudio comparativo con el uso del "Campus Virtual UCM", respecto al aprendizaje de los alumnos

Aprendizaje colaborativo usando Microsoft Teams en la asignatura de Odontopediatría II

El aprendizaje colaborativo es una técnica didáctica que promueve desarrollar la colaboración entre individuos con el fin de compartir, conocer y ampliar información que tienen cada uno de ellos sobre un tema. No significa repartirse las tareas sino que cada miembro aporte su información para que así el grupo lo pueda modificar, ampliar y así pasar de un trabajo individual a uno más completo. Este aprendizaje colaborativo se puede hacer de manera presencial o virtual. Para la realización de manera virtual contamos con multitud de plataformas para crear grupos y aprender de forma colaborativa. Nosotros hemos elegido la plataforma Microsoft Teams ya que en la Universidad Complutense de Madrid se está implementado está plataforma para la docencia online. Microsoft Teams (MT) es una plataforma unificada de comunicación y colaboración en la que un grupo puede mantener la comunicación. Dentro de los canales que dispone MT, pueden organizarse reuniones, mantener conversaciones, compartir y almacenar archivos e integrar aplicaciones. En el curso 2021/2022 hemos creado varios Equipo de trabajo en MT con los alumnos matriculados en el asignatura de Odontopeadiatría II. Los profesores hemos subido casos clínicos, preguntas así como temas de debates relacionados con la Odontopediatría, donde se crearon debates entre los alumnos y los profesores de manera on-line. Posteriormente se les pasó a los alumnos encuesta de satisfacción donde valoraron el aprendizaje con este tipo de docencia y esta plataforma. Una vez obtenidas las respuestas, hemos analizados los resultados y elaborado un documento para mejorar el Aprendizaje colaborativo con MT de manera online, intentando establecer mejoras para posteriores años académico

Analysis of the information about Doctoral Degrees presented in the Spanish universities websites.

Globalization has intensified competition, as evidenced by the growing number of international classification systems (rankings) and the attention paid to them. Doctoral education has an international character in itself. It should promote opportunities for graduate students lo participate in these international studies. The quality and competitiveness are two of the most important issues for universities. To promote the interest of graduates to continue their education after the graduate level, it would be necessary to improve the published information of ihe doctoral programs. It should increase the visibility and provide high-quality, easily accessible and comparable information which includes all the relevant aspects of these programs. The authors analysed the website contents of doctoral programs, it was observed a lack of quality of them and very poor information about the contents, so that it was decided that any of them could constitute a model for creating new websites. The recommendations on the format and contents in the web were made by a discussion group. They recommended an attractive design; a page with easy access to contents and easy to find on Ihe net and with the information in more than one language. It should include complete program and academic staff information. It should also be included the study's results which should be easily accessible and includes quantitative data, such as number of students who completed scholars, publications, research projects, average duration of the studies, etc. It will facilitate the choice of progra

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group