Fast distributed algebraic connectivity estimation in large scale networks     

Eduardo Montijano  Juan I. Montijano  Carlos Sagues 《Journal of The Franklin Institute》2017,354(13):5421-5442

This paper presents a distributed method to estimate the algebraic connectivity of fixed undirected communication graphs. The proposed algorithm uses bisection to estimate the second smallest eigenvalue of the Laplacian matrix associated to the graph. In order to decide the sub-interval in which the eigenvalue is contained, a distributed averaging algorithm based on Chebyshev polynomials is considered together with a max consensus algorithm. The information exchanged by neighbors in the graph each communication round is constant and independent of the size of the network, making it scalable to large networks. Besides, exploiting the convergence properties of Chebyshev polynomials we provide a direct estimation of the algebraic connectivity so that, instead of the midpoint of the bisection interval, the new approximation can be used. Finally, our algorithm also provides upper and lower bounds on the algebraic connectivity and an estimation of the Fiedler eigenvector associated to it. Simulations in large networks demonstrate the scalability and accuracy of the algorithm.  相似文献   

A school-based motivational intervention to promote physical activity from a self-determination theory perspective     

David González-Cutre  Ana C. Sierra  Vicente J. Beltrán-Carrillo  Manuel Peláez-Pérez  Eduardo Cervelló 《The Journal of educational research》2018,111(3):320-330

The authors analyzed the effects of a multidimensional intervention to promote physical activity (PA) in school, based on self-determination theory. The study involved 88 students, between 14 and 17 years old, who were divided into a control group (n = 59) and an experimental group (n = 29). In the experimental group, a 6-month intervention was conducted, applying a teaching unit of fitness and health in physical education (PE) classes, an extracurricular program of healthy PA, and meetings with families. Questionnaires were administered to measure different motivational variables and PA levels at four time points. Significant differences were found in favor of the experimental group in parental and peer autonomy support; integrated regulation in PE; autonomy, intrinsic, and identified regulation in leisure-time PA; moderate, hard, and very hard PA; and physical self-worth. Motivational effects were maintained over time but the effects on PA levels disappeared at 6 months.  相似文献   

Memory for recent actions in the bottlenosed dolphin (Tursiops truncatus): Repetition of arbitrary behaviors using an abstract rule     

Eduardo Mercado  Scott O. Murray  Robert K. Uyeyama  Adam A. Pack  Louis M. Herman 《Learning & behavior》1998,26(2):210-218

Little is known about how animals represent their own actions in working memory. We investigated whether bottlenosed dolphins could recall actions they had recently performed and reveal those recollections using an abstract rule. Two dolphins were trained to respond to a specific gestural command by repeating the last behavior performed. Both dolphins proved to be able to repeat a wide variety of behaviors on command and were able to generalize the repeating rule to novel behaviors and situations. One dolphin was able to repeat all 36 behaviors she was tested on, including behaviors involving multiple simultaneous actions and self-selected behaviors. These results suggest that dolphins can flexibly access memories of their recent actions and that these memories are of sufficient detail to allow for reenactments. The repeating task can potentially be used to investigate short-term action and event representations in a variety of species.  相似文献   

肝片吸虫感染对山羊机体无机盐含量的影响     

顾有方  朱道仙  毛鑫智  沈永林  J.Gonzalez-Gallego 《安徽科技学院学报》2001,(4)

选择 9只 6 - 10月龄的健康雄性白山羊 ,经粪便检查和DotBLISA检测 ,确认无肝片吸虫感染 ,随机分成感染组 (n =5 )和对照组 (n =4 ) ,试验组每只一次口服接种 15 0个肝片吸虫囊蚴。每周定时从颈静脉采集感染前 0周和感染后 14周血液一次 ,分离血清 ,测定血清中的钾、钙、钠、镁、磷、氯等无机盐的含量 ,旨在研究感染肝片吸虫对山羊机体无机盐含量的影响。结果表明感染后山羊血清中的钾、钠、钙、镁、磷、氯的含量均成波动变化 ,说明肝片吸虫感染后机体无机盐含量发生了不同程度的变化 ,这与虫体感染后机体的代谢发生改变有关。  相似文献   

X. DEVELOPMENTAL TRAJECTORIES OF CHILDREN'S SLEEP PROBLEMS AFTER THE BIRTH OF A SIBLING     

Paige Safyer  Matthew M. Stevenson  Richard Gonzalez  Brenda L. Volling  Wonjung Oh  Tianyi Yu 《Monographs of the Society for Research in Child Development》2017,82(3):130-141

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The adjustment of goldfish to reduction in magnitude of reward in massed trials     

R. C. Gonzalez  Marjorie Ferry  Alice S. Powers 《Learning & behavior》1974,2(1):23-26

For a group of goldfish trained in a runway under conditions of highly massed practice, reduction in magnitude of reward produced a gradual decline in performance to the level of a small-reward control group but no suggestion of negative successive contrast. These results are consistent with the suggestion that reward plays a somewhat different role in the learning of fish and rats. They also serve to extend the range of conditions under which the stimulus aftereffects of reward come to control the instrumental behavior of fish.  相似文献   

The relationship between leadership preparation and the level of teachers’ interest in assuming a principalship in Chile     

Sergio Galdames  Alvaro Gonzalez 《School Leadership & Management》2016,36(4):435-451

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Spanish and English Early Literacy Profiles of Preschool Latino English Language Learner Children     

Jorge Gonzalez  Sharolyn Pollard-Durodola  Laura Saenz  Denise Soares  Heather Davis  Nora Resendez 《Early education and development》2016,27(4):513-531

Research Findings: The purpose of this study was to examine within-group individual differences in the code-related and oral language abilities of an economically stressed Spanish-speaking English language learner (ELL) preschool sample and to evaluate the predictive relationship of these differences to later listening comprehension. Latent class analysis was used to identify similarities in both the latent and outcome variables to form classes of students with similar profiles on the measured variables. Our 1st finding confirmed the existence of 4 distinct psychometrically validated profiles: (a) Low English Language, Average Spanish Language, Mixed Spanish Code-Related (prevalence 19.4%); (b) Average English Language, Strengths in Spanish Language and Spanish Code-Related (24.2%); (c) Mixed English and Spanish Language, Low Spanish Code-Related (prevalence 34%); and (d) High English Language, Average Spanish Language, Mixed Spanish Code-Related (prevalence 22%). The resulting profiles demonstrated that English and Spanish code- and language-related domains of emergent literacy developed unevenly across the Spanish-speaking ELL preschoolers. Relative strengths and weaknesses in code- and language-related skills were also found to be meaningfully related to end-of-year listening comprehension—a precursor to reading comprehension. Finally, profiles yielded meaningful variability along sociodemographic variables. Practice or Policy: Implications, limitations, and directions for future research are discussed.  相似文献   

VII. DEVELOPMENTAL TRAJECTORIES OF CHILDREN'S EMOTIONAL REACTIVITY AFTER THE BIRTH OF A SIBLING     

Patty X. Kuo  Brenda L. Volling  Richard Gonzalez  Wonjung Oh  Tianyi Yu 《Monographs of the Society for Research in Child Development》2017,82(3):93-105

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The relationship of teachers' conceptions of mathematics and mathematics teaching to instructional practice   总被引：4，自引：0，他引：4  

Alba Gonzalez Thompson 《Educational Studies in Mathematics》1984,15(2):105-127

Case studies were conducted to investigate the conceptions of mathematics and mathematics teaching held by three junior high school teachers. Examination of the relationship between conceptions and practice showed that the teachers' beliefs, views, and preferences about mathematics and its teaching played a significant, albeit subtle, role in shaping their instructional behavior. Differences among the teachers in their conceptions and practices are explained followed by a discussion of properties of their conceptual systems.This paper is based on the author's doctoral dissertation which was directed by Professor Thomas J. Cooney of the University of Georgia and was partly supported by a grant from San Diego State University. I wish to express my appreciation to the teachers who participated in the study and their administrators.  相似文献