Pappus type theorems for motions along a submanifold

AbstractWe study the volumes volume(D) of a domain D and volume(C) of a hypersurface C obtained by a motion along a submanifold P of a space form Mnλ. We show: (a) volume(D) depends only on the second fundamental form of P, whereas volume(C) depends on all the ith fundamental forms of P, (b) when the domain that we move D0 has its q-centre of mass on P, volume(D) does not depend on the mean curvature of P, (c) when D0 is q-symmetric, volume(D) depends only on the intrinsic curvature tensor of P; and (d) if the image of P by the ln of the motion (in a sense which is well-defined) is not contained in a hyperplane of the Lie algebra of SO(n−q−d), and C is closed, then volume(C) does not depend on the ith fundamental forms of P for i>2 if and only if the hypersurface that we move is a revolution hypersurface (of the geodesic (n−q)-plane orthogonal to P) around a d-dimensional geodesic plane

Evaluation of an augmented reality application for learning neuroanatomy in psychology

Neuroanatomy is difficult for psychology students because of spatial visualization and the relationship among brain structures. Some technologies have been implemented to facilitate the learning of anatomy using three-dimensional (3D) visualization of anatomy contents. Augmented reality (AR) is a promising technology in this field. A mobile AR application to provide the visualization of morphological and functional information of the brain was developed. A sample of 67 students of neuropsychology completed tests for visuospatial ability, anatomical knowledge, learning goals, and experience with technologies. Subsequently, they performed a learning activity using one of the visualization methods considered: a 3D method using the AR application and a two-dimensional (2D) method using a textbook to color, followed by questions concerning their satisfaction and knowledge. After using the alternative method, the students expressed their preference. The two methods improved knowledge equally, but the 3D method obtained higher satisfaction scores and was more preferred by students. The 3D method was also more preferred by the students who used this method during the activity. After controlling for the method used in the activity, associations were found between the preference of the 3D method because of its usability and experience with technologies. These results found that the AR application was highly valued by students to learn and was as effective as the textbook for this purpose

Learning words using augmented reality

[EN] This paper presents an Augmented Reality (AR) game for learning words. Thirty-two children played the AR game and the equivalent real game. We have compared the results of the two games. The results indicate that children did not found significant differences between the two games except for one question, but 81% of the children liked most the AR game.We would like to thank: - This work was partially funded by: the APRENDRA project (TIN2009-14319-C02-01). The UPV project (PAID09015). - Tania Llop for her assistance in the development of the game. - Loles Marzal and Concha Carbo for their assistance in the study. - "La Encarnacion" School Centre for its collaboration and for allowing us to include these two games as activities.Juan, M.; Llop, E.; Abad Cerdá, FJ.; Lluch Crespo, J. (2010). Learning words using augmented reality. IEEE Computer Society. 1-9. https://doi.org/10.1109/ICALT.2010.1231

Evaluation of learning outcomes using an educational iPhone game vs. traditional game

In this paper, we present an initial study to determine the subject preferences for educational computer games for children, in which 150 education professionals participated. From the results of this first study, we have developed an iPhone game for transmitting knowledge as part of multiculturalism, solidarity and tolerance following established learning theories, several design principles, and the objectives and competences of the Spanish law for primary education. We also report on a second study to determine whether the iPhone game has better learning outcomes than a traditional game by analyzing the participation of 84 children ranging in age from 8 to 10 years old. The frequency of playing with consoles or computer games was also taken into account in this second study, and the worldwide trend of previous studies has been corroborated. For learning outcomes, the results did not show significant differences between the two groups. However, 96% of the children indicated that they would like to play with the iPhone game again, and 90% indicated that they preferred the experience with the iPhone game over the traditional one. From these results, we can conclude that the children achieved similar knowledge improvements using both the autonomous game (iPhone game) and the custom, guided game (traditional game). This could facilitate versatility in the learning process since the learning activity could be performed at any place and time without requiring supervision. Therefore, it could be a useful tool in the learning process and help teachers to fulfill students' training needs. 2013 Elsevier Ltd. All rights reserved.This work was funded by the Spanish APRENDRA project (TIN2009-14319-C02).Furió Ferri, D.; González Gancedo, S.; Juan, M.; Seguí, I.; Rando, N. (2013). Evaluation of learning outcomes using an educational iPhone game vs. traditional game. Computers and Education. 64:1-23. https://doi.org/10.1016/j.compedu.2012.12.001S1236

Principal component analysis to compress acquired data offshore

Telecommunications offshore have connectivity in virtually all parts of the globe via satellite, with increasing bandwidth and lower cost, but still far from levels that are onshore. The principal component analysis (PCA) is a statistical technique that has found application in fields such as biometrics or compression of images, being a common tool for finding patterns in multidimensional data sets. The hypothesis for this work was that it was possible to use the theory of PCA to compress, with sufficient accuracy, the large amount of data that are collected on board to a vessel and then sent by satellite in a more economical or rapid way than the traditional one. The material used were 44 samples of 182 different signals, collected from 19 different equipment on board to “Castillo de Villalba” Liquid Natural Gas carrier vessel. With these data, the PCA algorithm was applied using a computer program developed by the authors, generating new data packets to send by satellite. Different strategies were used in order to ensure that the coefficient of correlation r between original and reconstructed data onshore were equal or greater than 0.95. The results showed that it was possible to save 46.9% in the number of data sent via satellite, in the case of grouping all the 182 signs, with a mean r = 0.95 ± 0.08. This strategy is appropriate for onshore vessel equipment telediagnostic and maintenance decision making, with telecommunication cost or time savings.Peer Reviewe

Principal component analysis to compress acquired data offshore

Telecommunications offshore have connectivity in virtually all parts of the globe via satellite, with increasing bandwidth and lower cost, but still far from levels that are onshore. The principal component analysis (PCA) is a statistical technique that has found application in fields such as biometrics or compression of images, being a common tool for finding patterns in multidimensional data sets. The hypothesis for this work was that it was possible to use the theory of PCA to compress, with sufficient accuracy, the large amount of data that are collected on board to a vessel and then sent by satellite in a more economical or rapid way than the traditional one. The material used were 44 samples of 182 different signals, collected from 19 different equipment on board to “Castillo de Villalba” Liquid Natural Gas carrier vessel. With these data, the PCA algorithm was applied using a computer program developed by the authors, generating new data packets to send by satellite. Different strategies were used in order to ensure that the coefficient of correlation r between original and reconstructed data onshore were equal or greater than 0.95. The results showed that it was possible to save 46.9% in the number of data sent via satellite, in the case of grouping all the 182 signs, with a mean r = 0.95 ± 0.08. This strategy is appropriate for onshore vessel equipment telediagnostic and maintenance decision making, with telecommunication cost or time savings.Peer Reviewe

Assessment of the treatment, production and characteristics of WWTP sludge in Andalusia by multivariate analysis

5 Figuras.-- 4 TablasAgricultural recovery is the primary option for the final destination of sewage sludge, which must be properly treated, stabilized and sanitized. However, these processes are occasionally eliminated or not carried out properly for economic reasons or due to the design and size of the treatment plant. In this study, 62 samples of sewage sludge (21 and 41 samples from Seville and from Huelva, respectively) were characterized. Variable annual sludge production and equivalent inhabitants are virtually proportional (related by a potential power function of 0.9134). The results were evaluated through multivariate statistical analysis in order to assess the operability status of the WWTPs and the final quality of the sludge generated in the processes. Principal components analysis provided information on two separate groups for the bulk of waste water treatment plant (WWTPs) analyzed: (1) a nickel group, where the samples showed outliers above 50 mg/kg with respect to other WWTPs; and (2) the group where total nitrogen, organic matter and total potassium (KO) showed abnormally high values. Linear discriminant analysis models allowed the detection of WWTPs that used inadequate treatments but where geographical area and number of equivalent inhabitants were not significant.The authors are very grateful to the Water Agency of Andalusia, now integrated into the Environment and Water Agency of the Regional Ministry of the Environment and Territorial Planning, UTE Ingeniería y Gestión del Sur-Biomasa Peninsular and the Government of Andalusia for funding this research in the framework of the “Estudio de alternativas para el tratamiento de lodos en las provincias de Sevilla y Huelva” (Study of alternatives for the treatment of sludge in the provinces of Seville and Huelva). We also wish to express our gratitude to the Spanish Ministry of Science and Innovation for funding this research through Project CTQ2014-60050-R

Evolución y Características de las Publicaciones Biomédicas Peruanas, 1985 – 1993

A study about the evolution and main characteristics of scientific articles related to research conducted in Peru publish both in national and, international journals between 1985 - 1993, was made. We identified 2412 scientific articles published in 32 national journals, and 297 articles in 134 international journals. There was found that national journals had published sporadically, and the amount of articles increased only 12% in 8 years. In addition, the autor’s features, the type of scientific articles and the topics studied, are described. Finally some explanations about the factors associated to evolution and characteristics observed, are given.Se realizó un estudio de la evolución y principales características de los artículos científicos de investigaciones realizadas en el Perú, publicadas en revistas nacionales y extranjeras en el período 1985 – 1993. Durante este período se logró identificar 2412 artículos científicos publicados en 32 revistas biomédicas nacionales, y 297 artículos aparecidos en 134 revistas extranjeras. Se observó que la mayoría de revistas médicas nacionales tiene una periodicidad irregular, siendo las revistas de sociedades científicas las más constantes. También se observó que en 8 años el volumen de artículos científicos en revistas nacionales sólo se incrementó en 12%. Además, se describen las características de las autores nacionales y extranjeros, los tipos de artículo que se publican y las áreas temáticas. Finalmente, se hacen alcances acerca de los factores relacionados a las características y tendencias observadas