排序方式： 共有97条查询结果，搜索用时 448 毫秒
71.
The generalized sampling theorem of Kramer is derived and interpreted in the context of the theory of linear systems satisfying a generalized form of translation invariance. The results are extended to the form of expansions developed by Papoulis and by Campbell. 相似文献
72.
With the increase of the communication systems' bandwidth and with the dissemination of the information systems, the fields of information and communication technology application expanded in almost all directions. E-government in general and e-justice in particular are no exception and these areas suffered strong changes in the last decades. There is no democracy without a system of swift and transparent justice. Therefore, the introduction of information systems in the courts allows a decrease both in time and number of pending processes, boosting the efficiency of the services provided to citizens and to the society in general. 相似文献
73.
Eddie Gray Marcia Pinto Demetra Pitta David Tall 《Educational Studies in Mathematics》1999,38(1-3):111-133
This paper begins by considering the cognitive mechanisms available to individuals which enable them to operate successfully in different parts of the mathematics curriculum. We base our theoretical development on fundamental cognitive activities, namely, perception of the world, action upon it and reflection on both perception and action. We see an emphasis on one or more of these activities leading not only to different kinds of mathematics, but also to a spectrum of success and failure depending on the nature of the focus in the individual activity. For instance, geometry builds from the fundamental perception of figures and their shape, supported by action and reflection to move from practical measurement to theoretical deduction and euclidean proof. Arithmetic, on the other hand, initially focuses on the action of counting and later changes focus to the use of symbols for both the process of counting and the concept of number. The evidence that we draw together from a number of studies on children's arithmetic shows a divergence in performance. The less successful seem to focus more on perceptions of their physical activities than on the flexible use of symbol as process and concept appropriate for a conceptual development in arithmetic and algebra. Advanced mathematical thinking introduces a new feature in which concept definitions are formulated and formal concepts are constructed by deduction. We show how students cope with the transition to advanced mathematical thinking in different ways leading once more to a diverging spectrum of success.This revised version was published online in September 2005 with corrections to the Cover Date. 相似文献
74.
José Osvaldo De Sordi Wanderlei Lima de Paulo Carlos Francisco Bitencourt Jorge Daniel Barile da Silveira Jefferson Aparecido Dias Marcelo Souto de Lima 《Government Information Quarterly》2021,38(3):101592
Post-scandal effects in public management point to the occurrence of overcompliance in the work of public managers, leading to reluctance and paralysis in decision-making. This article discusses the proposition of an artifact in the form of a warning system to aid the analysis process and issuing of opinions (APIO) by public managers, providing more information and, consequently, less risk and fear. The Design Science Research method was used to exapt a scientific artifact to the context of public management. The textual structure of 178 opinions issued by public agencies was analyzed, as was the perception of 17 public managers of the characteristics of the APIO. Exaptating the artifact from a technological perspective is simple and feasible, as it involves processes with strong functional similarities. The greatest challenges to operationalize the artifact broadly and without restrictions, as occurs in scientific academia, are associated with informational behaviors. 相似文献
75.
Kelly de Jesus Helon Vicente Hultmann Ayala Leandro dos Santos Coelho João Paulo Vilas-Boas Ricardo Jorge Pinto Fernandes 《Journal of sports sciences》2019,37(13):1512-1520
We aimed to compare multilayer perceptron (MLP) neural networks, radial basis function neural networks (RBF) and linear models (LM) accuracy to predict the centre of mass (CM) horizontal speed at low-moderate, heavy and severe swimming intensities using physiological and biomechanical dataset. Ten trained male swimmers completed a 7 × 200 m front crawl protocol (0.05 m.s?1 increments and 30 s intervals) to assess expiratory gases and blood lactate concentrations. Two surface and four underwater cameras recorded independent images subsequently processed focusing a three-dimensional reconstruction of two upper limb cycles at 25 and 175 m laps. Eight physiological and 13 biomechanical variables were inputted to predict CM horizontal speed. MLP, RBF and LM were implemented with the Levenberg-Marquardt algorithm (feed forward with a six-neuron hidden layer), orthogonal least squares algorithm and decomposition of matrices. MLP revealed higher prediction error than LM at low-moderate intensity (2.43 ± 1.44 and 1.67 ± 0.60%), MLP and RBF depicted lower mean absolute percentage errors than LM at heavy intensity (2.45 ± 1.61, 1.82 ± 0.92 and 3.72 ± 1.67%) and RBF neural networks registered lower errors than MLP and LM at severe intensity (2.78 ± 0.96, 3.89 ± 1.78 and 4.47 ± 2.36%). Artificial neural networks are suitable for speed model-fit at heavy and severe swimming intensities when considering physiological and biomechanical background. 相似文献
76.
This study sheds light on polycentric forms of organizing and corresponding performance implications. Organizations with a polycentric architecture supplement their internal hierarchical decision-making structures with egalitarian, local structures in order to encourage collaboration with legally independent stakeholders. We ground our study on the planning stage for four capital-intensive infrastructure development projects (megaprojects) in the UK. We first establish that megaproject planning is carried on by polycentric organizations. We show that in this form of organizing the promoter has decision-making authority over the high-order choices, but shares the authority over the local choices with groups of autonomous stakeholders. We also show how this organizational architecture addresses local disputes and pressures to relax performance targets. Our main contribution is a contingency model that proposes four conditions linking performance to polycentric organizing, whether or not: i) the institutional environment empowers an ‘umpire’ to referee disputes; and ii) the system leader can mobilize substantial slack resources to reconcile conflicting interests. We argue that the four conditions reveal very different classes of managerial problems, and draw implications for practice and policy including but not limited to megaprojects. 相似文献
77.
This article charts the emergence of the births, deaths and marriages column in the colonial Australian press. Using Australia’s oldest continuing newspaper the Sydney Morning Herald as a case study, this article examines the evolution of the notices over a 25-year period from the newspaper’s first publication (as the Sydney Herald) in 1831. We argue that the births, deaths and marriages notices in the Herald were part of early attempts by colonists to reinforce their respectability before becoming a practice with widespread appeal that both announced key life events and marked people’s connection to place. Drawing on the scholarship of Pierre Bourdieu, our analysis pinpoints the moment these notices were ‘legitimised’ by the journalistic field and marked the birth of a media ritual in colonial Australian society. We provide historical insight into the ways in which the news media establish legitimacy in the social spaces they serve. 相似文献
78.
Carla Luguetti Kimberly L. Oliver Luiz Eduardo Pinto Basto Tourinho Dantas David Kirk 《Research quarterly for exercise and sport》2017,88(1):60-71
Purpose: This study was a 2-phase activist research project aimed at co-creating a prototype pedagogical model for working with youth from socially vulnerable backgrounds in a sport context. This article addresses the learning aspirations (learning outcomes) that emerged when we created spaces for youth to develop strategies to manage the risks they face in their community. Method: This study took place in a socially and economically disadvantaged neighborhood in a Brazilian city where we worked with a group of 17 boys aged 13 to 15 years old, 4 coaches, a pedagogic coordinator, and a social worker. During a 6-month period, we collected multiple sources of data including field journal entries/observations (38) and audio records of youth work sessions (18), coaches' work sessions (16), combined coaches and youth work sessions (3), and meetings between the lead and the 2nd author for debriefing and planning sessions (36). Results: By using an activist approach, 4 learning aspirations emerged: becoming responsible/committed, learning from mistakes, valuing each other's knowledge, and communicating with others. Conclusion: Findings suggest there is a need for more sports programs that start from young people's concrete needs and life situations and look to create places for youth to see alternative possibilities and take action. 相似文献
79.
The aim of this study was to evaluate and compare acute effects of a reciprocal action protocol and a super-set protocol on knee extensor performance during concentric isokinetic exercise. Fourteen men aged 29.4 ± 6.1 years were tested on three different protocols, with 1 min of rest between sets: control (3 sets of 10 isokinetic knee extension repetitions), reciprocal action protocol (3 sets of 10 repetitions of reciprocal isokinetic concentric knee flexion and knee extension repetitions), and super-set protocol (3 sets of a combination of 10 repetitions of knee flexion immediately followed by 10 repetitions of knee extension repetitions). Tests were performed at 60° · s(-1) and 180° · s(-1), randomized across 3 days and separated by at least 72 h. There were no significant differences between protocols for peak torque at 60° · s(-1) or 180° · s(-1). Total work was significantly higher during the reciprocal action protocol compared with the super-set protocol at 60° · s(-1). There was a significant decline in peak torque (from 240.6 to 212.9 N · m) and total work (from 2294 to 1899 J) for the control condition at 60° · s(-1). Also, total work declined significantly across sets for the super-set protocol at 60° · s(-1) (from 2157 to 1707 J). Results indicate that a reciprocal action protocol provides torque maintenance during multiple sets of isokinetic training, both at slow and high velocities. 相似文献
80.
Preschool process quality and activity setting are considered important aspects influencing child engagement. As such, it is important to understand how educational settings can promote engagement, particularly for children with disabilities and/or at risk. This observational study describes process quality and activity setting in inclusive preschools, analyzing its predictive role for child engagement. Participants were 184 children attending 39 preschools. Three groups of children, nested within classrooms, were considered: with disabilities (n = 45), at risk (n = 59), typically developing (n = 80). Child Observation in Preschool assessed engagement and activity setting; Classroom Assessment Scoring System assessed quality of teacher–child interactions. Research Findings: Results from multilevel regressions show that classroom emotional support and organization and more time in free play were positively predicting child engagement, whereas more time in whole group was a negative predictor of engagement. Besides these main effects, an interaction effect between child developmental functioning and activity settings was found. For at-risk children, more time in whole-group activities had greater negative effects on child engagement. For children with disabilities, more time in free-play had greater positive effects on child engagement. Practice or Policy: Results contribute to inform teachers regarding the importance of individualizing interactions and planning activity settings to promote engagement and participation in inclusive preschools. 相似文献