On non-fragility of controllers for time delay systems: A numerical approach     

Guillermo Oaxaca-Adams  Raúl Villafuerte-Segura  Baltazar Aguirre-Hernández 《Journal of The Franklin Institute》2021,358(9):4671-4686

In this paper an explicit numerical procedure is proposed to determine the non-fragility of parameters of controllers used to stabilize a class of time delay systems. The proposed procedure finds the largest possible circle inscribed in a stability subregion delimited by a simple closed curve in the plane of the controller parameters. The center of this circle is declared to be the controller’s least fragile parameters. The obtained theoretical results are applied and compared with some of the most relevant examples found in the literature. This illustrates that the proposed procedure improves previous results found in the literature so far.  相似文献   

Writing intervention with elementary students struggling with writing: examining approach profiles to the teacher feedback on writing quality and motivational variables     

Högemann  Julia  Cunha  Jennifer  Núñez  José Carlos  Vallejo  Guillermo  Rodríguez  Celestino  Rosário  Pedro 《Reading and writing》2021,34(7):1681-1710

Reading and Writing - Many young students experience difficulties mastering writing, and are designated as students struggling with writing. Teacher feedback on writing is an educational tool...  相似文献   

An international collaborative investigation of beginning seventh grade students' understandings of scientific inquiry: Establishing a baseline     

Judith Lederman  Norman Lederman  Selina Bartels  Juan Jimenez  Mark Akubo  Shereen Aly  Chengcheng Bao  Estelle Blanquet  Ron Blonder  Mariana Bologna Soares de Andrade  Catherine Buntting  Mustafa Cakir  Heba EL-Deghaidy  Ahmed ElZorkani  Estelle Gaigher  Shuchen Guo  Arvi Hakanen  Soraya Hamed Al-Lal  Cigdem Han-Tosunoglu  Annemarie Hattingh  Anne Hume  Serhat Irez  Gillian Kay  Ozgur Kivilcan Dogan  Kerstin Kremer  Pi-Chu Kuo  Jari Lavonen  Shu-Fen Lin  Cheng Liu  Enshan Liu  Shiang-Yao Liu  Bin Lv  Rachel Mamlok-Naaman  Christine McDonald  Irene Neumann  Yaozhen Pan  Eric Picholle  Ana Rivero García  Carl-Johan Rundgren  David Santibáñez-Gómez  Kathy Saunders  Renee Schwartz  Frauke Voitle  Jakob von Gyllenpalm  Fangbing Wei  Jocelyn Wishart  Zhifeng Wu  Huang Xiao  Yalcin Yalaki  Qiaoxue Zhou 《科学教学研究杂志》2019,56(4):486-515

Although understandings of scientific inquiry (as opposed to conducting inquiry) are included in science education reform documents around the world, little is known about what students have learned about inquiry during their elementary school years. This is partially due to the lack of any assessment instrument to measure understandings about scientific inquiry. However, a valid and reliable assessment has recently been developed and published, Views About Scientific Inquiry (VASI; Lederman et al. [2014], Journal of Research in Science Teaching, 51, 65–83). The purpose of this large-scale international project was to collect the first baseline data on what beginning middle school students have learned about scientific inquiry during their elementary school years. Eighteen countries/regions spanning six continents including 2,634 students participated in the study. The participating countries/regions were: Australia, Brazil, Chile, Egypt, England, Finland, France, Germany, Israel, Mainland China, New Zealand, Nigeria, South Africa, Spain, Sweden, Taiwan, Turkey, and the United States. In many countries, science is not formally taught until middle school, which is the rationale for choosing seventh grade students for this investigation. This baseline data will simultaneously provide information on what, if anything, students learn about inquiry in elementary school, as well as their beginning knowledge as they enter secondary school. It is important to note that collecting data from all of the approximately 200 countries globally was not humanly possible, and it was also not possible to collect data from every region of each country. The results overwhelmingly show that students around the world at the beginning of grade seven have very little understandings about scientific inquiry. Some countries do show reasonable understandings in certain aspects but the overall picture of understandings of scientific inquiry is not what is hoped for after completing 6 years of elementary education in any country.  相似文献   

Teaching CAD/CAM/CAE tools with project-based learning in virtual distance education     

Sola-Guirado  Rafael R.  Guerrero-Vacas  Guillermo  Rodr&#;guez-Alabanda  &#;scar 《Education and Information Technologies》2022,27(4):5051-5073

Education and Information Technologies - Computer-aided design, manufacturing and engineering technologies (CAD/CAM/CAE) are a mainstay in today’s industry and therefore they should be an...  相似文献   

ICT in Portuguese reference schools for the education of blind and partially sighted students     

Sara Isabel Moça Ramos  António Manuel Valente de Andrade 《Education and Information Technologies》2016,21(3):625-641

Technology has become an essential component in our society and considering its impact in the educational system, Information and Communication Technologies (ICT) cannot be dissociated from the educational process and, in particular, from pedagogical practices adopted for students who are blind or partially sighted. This study focuses on Portuguese reference schools for the education of blind and partially sighted students, regulated by the Decree-Law No. 3/2008, in which are concentrated the human and material resources that can offer an educational response with quality for these students with special education needs. The study intends to analyse the perceptions of the teachers, who teach visually impaired students in middle school and secondary school education in these reference schools, of their knowledge, teaching and training in the area of ICT, as well as of the real ICT integration in the teaching and learning of these students. A survey, which has been applied to these teachers in the 2012/13 school year, was adopted as a method of data collection. The results reveal a sample confident in their technological capabilities, however with little resourcefulness in some tools and software specific to the area of visual impairment and a very significant number of teachers ignoring many of these. The implementation of ICT with students who have visual disabilities is lower compared with the sighted students. The lack of specific training is considered to be the main obstacle for teachers, with regard to the real integration of ICT in the teaching and learning of these students.  相似文献   

Preservation of relevant properties of interconnected dynamical systems over complex networks     

Guillermo Fernández-Anaya  Eric Campos-Cantón  Sergej Čelikovský  Antonio Loria 《Journal of The Franklin Institute》2013,350(10):2849-2852

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Estimation of teacher practices based on text transcripts of teacher speech using a support vector machine algorithm     

Roberto Araya  Francisco Plana  Pablo Dartnell  Jorge Soto‐Andrade  Gina Luci  Elena Salinas  Marylen Araya 《British journal of educational technology : journal of the Council for Educational Technology》2012,43(6):837-846

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Association of physical fitness,body composition,cardiometabolic markers and adherence to the Mediterranean diet with bone mineral density in perimenopausal women. The FLAMENCO project     

Virginia A. Aparicio  Pilar Ruiz-Cabello  Milkana Borges-Cosic  Ana Andrade  Irene Coll-Risco  Pedro Acosta-Manzano 《Journal of sports sciences》2017,35(9):880-887

This study aimed to analyse the association of different components of physical fitness, body composition, cardiometabolic markers and the Mediterranean diet with bone mineral density (BMD) in perimenopausal women, and to test which of these components are independently associated with BMD. The sample comprised 197 perimenopausal women (52.6 ± 4.5 years). Physical fitness was assessed with the “Senior Fitness Test” battery and the handgrip strength and Bruce tests. Fat and lean mass and BMD were measured using dual-energy X-ray absorptiometry. We analysed the markers of metabolic syndrome, C-reactive protein, and components of the Mediterranean diet. Handgrip muscle strength (β = 0.212, P = 0.005), body weight (β = 0.244, P = 0.001), BMI (β = 0.180, P = 0.011) and lean mass (β = 0.379, P < 0.001) were positively associated with BMD. No associations were observed between cardiometabolic markers or the Mediterranean diet with BMD (all P > 0.05). When all relevant indicators of BMD were simultaneously considered, lean mass was the only 1 showing an independent association with BMD (β = 0.392, P < 0.001), explaining 14% of the BMD variability. In conclusion, muscle strength might be a marker of BMD in perimenopausal women. However, lean mass was the only factor independently associated with BMD. Future research to determine whether increasing lean mass through specific exercise-based interventions contributes to increasing BMD is warranted.  相似文献   

Andres Bonifacio: proletarian hero of the Philippines and Indonesia     

Ramon Guillermo 《Inter-Asia Cultural Studies》2017,18(3):338-346

The concluding chapter of Tan Malaka’s (1897–1949) large philosophical work entitled Madilog: Materialisme, Dialektika, Logika contains interesting reflections on the extent and scope of the future liberated and sovereign Indonesian nation and on the concept of “Indonesian” heroism and nationality. However, most striking of all is the uppermost position he allots in his schema for Philippine national heroes such as Dr. Jose Rizal, the patriot and writer, and Andres Bonifacio, the leader and founder of the Katipunan, the most successful Philippine revolutionary anti-colonial organization.  相似文献   

Determination of a quantitative parameter to evaluate swimming technique based on the maximal tethered swimming test     

Rafael Soncin  Bruno Mezêncio  Jacielle Carolina Ferreira  Sara Andrade Rodrigues  Rudolf Huebner  Julio Cerca Serrão 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):248-257

The aim of this study was to propose a new force parameter, associated with swimmers’ technique and performance. Twelve swimmers performed five repetitions of 25 m sprint crawl and a tethered swimming test with maximal effort. The parameters calculated were: the mean swimming velocity for crawl sprint, the mean propulsive force of the tethered swimming test as well as an oscillation parameter calculated from force fluctuation. The oscillation parameter evaluates the force variation around the mean force during the tethered test as a measure of swimming technique. Two parameters showed significant correlations with swimming velocity: the mean force during the tethered swimming (r = 0.85) and the product of the mean force square root and the oscillation (r = 0.86). However, the intercept coefficient was significantly different from zero only for the mean force, suggesting that although the correlation coefficient of the parameters was similar, part of the mean velocity magnitude that was not associated with the mean force was associated with the product of the mean force square root and the oscillation. Thus, force fluctuation during tethered swimming can be used as a quantitative index of swimmers’ technique.  相似文献