Some numerical tests for an alternative approach to optimal feedback control     

Roberto Font  Pablo Pedregal 《Journal of The Franklin Institute》2018,355(15):7011-7026

We test a recently proposed approach to optimal feedback control of nonlinear systems leading to an iterative descending strategy [24]. We start by discussing the numerical implementation of this strategy, and propose a number of improvements that can speed up the computation process by up to two orders of magnitude. The resulting algorithm is then applied to a series of test problems of increasing complexity. Results seem to show that this can be a promising strategy to bear in mind for more realistic situations.  相似文献   

Risk markers for disappearance of pediatric Web resources.     

Angel A Hernández-Borges  Alejandro Jiménez-Sosa  Maria L Torres-Alvarez de Arcaya  Pablo Macías-Cervi  Maria A Gaspar-Guardado  Ana Ruíz-Rabaza 《Journal of the Medical Library Association》2005,93(3):374-380

OBJECTIVES: The authors sought to find out whether certain Webometric indexes of a sample of pediatric Web resources, and some tests based on them, could be helpful predictors of their disappearance. METHODS: The authors performed a retrospective study of a sample of 363 pediatric Websites and pages they had followed for 4 years. Main measurements included: number of resources that disappeared, number of inbound links and their annual increment, average daily visits to the resources in the sample, sample compliance with the quality criteria of 3 international organizations, and online time of the Web resources. RESULTS: On average, 11% of the sample disappeared annually. However, 13% of these were available again at the end of follow up. Disappearing and surviving Websites did not show differences in the variables studied. However, surviving Web pages had a higher number of inbound links and higher annual increment in inbound links. Similarly, Web pages that survived showed higher compliance with recognized sets of quality criteria than those that disappeared. A subset of 14 quality criteria whose compliance accounted for 90% of the probability of online permanence was identified. Finally, a progressive increment of inbound links was found to be a marker of good prognosis, showing high specificity and positive predictive value (88% and 94%, respectively). CONCLUSIONS: The number of inbound links and annual increment of inbound links could be useful markers of the permanence probability for pediatric Web pages. Strategies that assure the Web editors' awareness of their Web resources' popularity could stimulate them to improve the quality of their Websites.  相似文献   

Comparative analysis of academic grades in compulsory secondary education in Spain using statistical techniques     

Alejandro Veas  Raquel Gilar  Pablo Miñano  Juan Luis Castejón 《Educational studies》2017,43(5):533-548

The present study, based on the construct comparability approach, performs a comparative analysis of general points average for seven courses, using exploratory factor analysis (EFA) and the Partial Credit model (PCM) with a sample of 1398 student subjects (M = 12.5, SD = 0.67) from 8 schools in the province of Alicante (Spain). EFA confirmed a one-factor model which explains 74.44% of the variance. Cronbach’s alpha value for this factor was .94. The PCM supported the one-factor model, and an optimal fit was achieved in all of the courses. The analysis of differential item functioning showed no significant differences in any course. Equitable distribution was observed in the evolution of the difficulty indices along the measurement scale for each course. This type of analysis confirms the measurement of a single latent construct in the different topics analysed, despite addressing various theoretical and procedural contents.  相似文献   

On the use of extended TAM to assess students' acceptance and intent to use third‐generation learning management systems          下载免费PDF全文

Salvador Ros  Roberto Hernández  Agustín Caminero  Antonio Robles  Isabel Barbero  Araceli Maciá  Francisco Pablo Holgado 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(6):1250-1271

Service‐oriented e‐learning platforms can be considered as a third generation of learning management systems (LMSs). As opposed to the previous generations, consisting of ad hoc solutions and traditional LMS, this new technology contemplates e‐learning systems as services that can be integrated into different learning scenarios. This paper shows that the flexibility of these systems allows building personal learning environments and proposes the use of an extended technology acceptance model (TAM) to assess the acceptance and intention to use a third generation of LMS. To fit and validate the service‐oriented e‐learning platforms acceptance model, structural equation modeling and path analysis have been implemented. The results point out that the intention to use this third‐generation LMS is determined by the gadgets and container design, both of which are structural elements of this technology. Finally, it is also shown that previous experience does not determine the use intention of this technology.  相似文献   

Some challenges for educational research in Latin America     

Pablo Latapí 《Prospects》1990,20(1):51-57

Founding director of the Centro de Estudios Educativos (Centre for Educational Studies) in Mexico City and of the Revista Latinoamericana de Estudios Educativos(Latin American Journal of Educational Studies). He was in charge of the National Programme of Educational Research of the National Council for Science and Technology. He now carries out research at the Regional Centre for Adult Education and Functional Literacy for Latin America. His recent publications include: La política de alfabetización de seis países latinoamericanos, Participatory Research: A New Research Paradigm?and Elementos para una propuesta orientada a elevar la calidad: La enseñanza tutorial.  相似文献   

Mexican Educators Survey on Anatomical Sciences Education and a Review of World Tendencies     

Yolanda Salinas-Alvarez  Alejandro Quiroga-Garza  Javier Humberto Martinez-Garza  Guillermo Jacobo-Baca  Pablo Patricio Zarate-Garza  Karla Valeria Rodríguez-Alanís  Santos Guzman-Lopez  Rodrigo Enrique Elizondo-Omaña 《Anatomical sciences education》2021,14(4):471-481

Anatomical sciences curricula have been under constant reform over the years, with many countries having to reduce course hours while trying to preserve laboratory time. In Mexico, schools have historically been autonomous and unregulated, and data regarding structure and methods are still lacking. A national survey was sent by the Mexican Society of Anatomy to 110 anatomical sciences educators. The questionnaire consisted of 50 items (open and multiple choice) for gross anatomy, microscopic anatomy, neuroanatomy, and embryology courses in medical schools across Mexico. A clinical approach was the most common course approach in all disciplines. Contact course hours and laboratory hours were higher in Mexican anatomy education compared to other countries, with the highest reported contact hours for embryology (133.4 ± 44.1) and histology (125 ± 33.2). There were similar contact hours to other countries for gross anatomy (228.5 ± 60.5). Neuroanatomy course hours (43.9 ± 13.1) were less than reported by the United States and similar to Saudi Arabia and higher than the United Kingdom. Dissection and microscopy with histological slides predominate as the most common laboratory activities. Traditional methods prevail in most of the courses in Mexico and only a few educators have implemented innovative and technological tools. Implementation of new methods, approaches, and curricular changes are needed to enhance anatomical sciences education in Mexico.  相似文献   

The introduction of infinite durability to an information good and the decision to buy or rent: evidence from the film industry     

Gabriel Pablo Axarlian 《Journal of Media Economics》2017,30(3):121-142

Home entertainment markets have seen dramatic declines in revenues over the last 10 years due to the digital revolution, making new adaptation strategies of crucial importance to maintaining existing profitability. Recently, the film industry has worked with related firms to develop a standardized ecosystem for the sale and access to digital versions of their films. This system, known as UltraViolet, embodies infinite durability; the perpetual access to a purchased film across computing platforms and time. The author makes use of exogenous variation in the implementation of this system to study the effect the introduction of this new feature has had on the decision to buy or rent. His findings show that the inclusion of infinite durability creates enough value to spur increased purchasing behavior. Also, the inclusion of infinite durability creates a high degree of substitutability amongst products that include it in purchase markets. Lastly, the author found evidence that the lack of inclusion of infinite durability will spur consumers to rent rather than buy.  相似文献   

AGENDA SETTING AND COMMUNITY CONSENSUS: FIRST AND SECOND LEVEL EFFECTS     

Lopez-Escobar  Esteban; Llamas  Juan Pablo; McCombs  Maxwell 《Int. Journal of Public Opinion Research》1998,10(4):335-348

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Book reviews     

Alphons Silbermann  Michael R. Eraut  Marcel Danesi  H. S. Bhola  Pablo Latapí  Robert Balfanz  Jacques Fijalkow  Helmut Stolz  James Lynch 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1991,37(2):279-292

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On the perceptions of students and professors in the implementation of an inter-university engineering PBL experience     

Lidón Moliner  Luis Cabedo  Marta Royo  Jose Gámez-Pérez  Pablo Lopez-Crespo  Mercè Segarra 《European Journal of Engineering Education》2019,44(5):726-744

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