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81.
This paper solves a data-driven control problem for a flow-based distribution network with two objectives: a resource allocation and a fair distribution of costs. These objectives represent both cooperation and competition directions. It is proposed a solution that combines either a centralized or distributed cooperative game approach using the Shapley value to determine a proper partitioning of the system and a fair communication cost distribution. On the other hand, a decentralized non-cooperative game approach computing the Nash equilibrium is used to achieve the control objective of the resource allocation under a non-complete information topology. Furthermore, an invariant-set property is presented and the closed-loop system stability is analyzed for the non-cooperative game approach. Another contribution regarding the cooperative game approach is an alternative way to compute the Shapley value for the proposed specific characteristic function. Unlike the classical cooperative-games approach, which has a limited application due to the combinatorial explosion issues, the alternative method allows calculating the Shapley value in polynomial time and hence can be applied to large-scale problems.  相似文献   
82.
Governmental initiatives around scientific policy have progressively raised collaboration to priority status. In this context, a need has arisen to broaden the traditional approach to the analysis and study of research results by descending to the group or even the individual scale and supplementing the output-, productivity-, visibility- and impact-based focus with new measures that emphasize collaboration from the vantage of structural analysis. To this end, the present paper proposes new hybrid indicators for the analysis and evaluation of individual research results, popularity and prestige, that combine bibliometric and structural aspects. A case study was conducted of the nine most productive departments in Carlos III University of Madrid. The findings showed hybridization to be a tool sensitive to traditional indicators, but also to the new demands of modern science as a self-organized system of interaction among individuals, furnishing information on researchers’ environments and the behaviour and attitudes adopted within those environments.  相似文献   
83.
Using data from a nation-wide survey on Spanish workers, this paper examines two issues: the determinants of school choice (distinguishing between public and private schools) and the influence of school type on the individual’s educational attainment. For that, bivariate probit models are estimated. The analysis is carried out separately by gender and birth cohort. We find that individuals who have attended a private school come from households with higher socio-cultural level and that having attended a private school does not raise the probability of reaching a higher degree, once potential endogeneity of school choice and educational outcomes are taken into account. However, the latter result depends on the instrumental variable used for observed school type in models of demand for higher education.  相似文献   
84.
Isokinetic hamstring-to-quadriceps (H:Q) ratios are frequently used to assess knee muscle strength imbalances and risk of injuries/re-injuries. The use of peak torque (PT) or total work (TW) to estimate joint stability may lead to different results because of the differences between these two neuromuscular variables. Thus, the current study aimed to compare the conventional and functional H:Q ratios calculated by PT and TW. Ninety-three male professional soccer players from Brazilian first division teams performed isokinetic concentric and eccentric contractions of the quadriceps and the hamstrings at 60°/s. Muscle strength balance was calculated using the conventional torque ratio (CTR) and conventional work ratio (CWR), functional torque ratio (FTR) and functional work ratio (FWR) were highly and moderately correlated between them (r?=?0.83 and r?=?0.73, respectively). The Wilcoxon statistical test revealed significant differences between CTR and CWR, as well as FTR and FWR (p?T-test demonstrated significant differences in mean CTR–CWR and FTR–FWR, whereas Bland–Altman plots showed non-consistent bias. In addition, the chi-square test demonstrated significant differences between players below the conventional reference values and functional reference values (p?相似文献   
85.
This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.  相似文献   
86.
The counterpart to the open access to information facilitated by the Internet is the problem of the over-saturation of data and sources. A collaborative model of hypermedia is proposed as a pedagogical approach to the teaching of urban planning in which students organize and construct information from the possibilities provided by hypertext language. The methodology is structured in three phases: organization when searching for information; presentation of information using hypermedia; and assessment of the work. The results show that organization of information in the form of websites obtained the highest scores, although collaborative assessment should be restricted to subjective aspects of communication, while objective aspects should be assessed by the teacher and by groups of experts.  相似文献   
87.
This article presents one analytical theme emerging from a bibliometric and content analysis of an annotated bibliography, compiled by the first author, comprising 1564 Asian martial arts monographs published in Spain between 1906 and 2009. The analysis reveals that the use of Asian martial arts and religio-spiritual self-cultivation practices, while very old in their indigenous South East Asian context, only appeared in published texts in Spain from the 1960s and this theme has been increasingly written about in the last two decades. In our analytical discussion, we contextualise this shift from a socio-historical perspective, focusing on three aspects: first and second, how this shift in focus in Asian Martial Art publishing fits with the patterns of societal secularisation in Spain, the rise of the New Age movement and counter-cultural spiritualities across Western culture; third, we comment on how, from this broader socio-historical context, Asian martial arts were well placed to fill ‘cultural spaces’ created by these changes.  相似文献   
88.
89.
Automatic evaluation is a challenging field that has been addressed by the academic community in order to reduce the assessment workload. In this work we present a new element for the authoring tool Easy Java Simulations (EJS). This element, which is named automatic evaluation element (AEE), provides automatic evaluation to virtual and remote laboratories built with EJS by using the server application Goodle grading management system (GMS). The integration of both tools entitles a professor to create interactive virtual and remote laboratories and automatically evaluate the work of their students. As a test bed two case studies are presented; a non-linear controller design virtual laboratory used in an advanced control master course and a servomechanism virtual laboratory used in an undergraduate basic control course.  相似文献   
90.
The coupling of the traditional classroom instruction and a virtual learning environment (VLE) in an engineering course is critical to stimulating the learning process and to encouraging students to develop competencies outside of the classroom. This can be achieved through planned activities and the use of information and communication technologies (ICTs), resources designed to complement students’ autonomous learning needs. A quantitative analysis of students’ academic performance using final course grades was performed for a fundamentals of electronics course and we examine students’ perception of their autonomy using surveys. The students’ progress and attitudes were monitored over four consecutive semesters. The first began with the design of the intervention and the following three consisted in the implementation. The strategy was focused on the development of course competencies through autonomous learning with ICT tools presented in the VLE. Findings indicate that the students who did the activities in the VLE showed an increase in performance scores in comparison with students who did not do them. The strategy used in this study, which enhanced perceived autonomy, was associated with a positive effect on their learning process. This research shows that a technology-enhanced course supported by ICT activities can both improve academic performance and foster autonomy in students.  相似文献   
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