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Academic genealogy aims to structure and analyze the mentoring relationships between advisor and advisee. The representation of this structure results in academic genealogy graphs. For the analysis and characterization of these graphs, we present a set of metrics and their corresponding mirror metrics that capture the characteristics of its topological structure and represent them as quantitative attributes. The metrics of fecundity, fertility, descendants, cousins, generations, and relationships consider the descendants of the academics represented in the graph. The mirror metric of these topological metrics considers the ascendancy of academics. Individually, the metrics have strong semantic intuition and define characteristics regarding the performance in the mentoring of an academic. Together, the metrics are useful for the identification, characterization, and classification of communities and their members. The genealogical data available through the platforms of the Mathematics Genealogy Project and the Academic Family Tree were used as case studies. Two hundred thirteen thousand and 675,000 academic records were obtained for each project. We analyze the capacity of characterization of the metrics using the structuring of a similarity graph and through the distribution of the nodes in principal components. We observed that the set of metrics is capable of capturing the configuration pattern existing in genealogy graphs independently of its scale.  相似文献   
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Information Retrieval Journal - On the quest of providing a more natural interaction between users and search systems, open-domain conversational search assistants have emerged, by assisting users...  相似文献   
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A connectionist method for autotuning the free parameter of a fractional-order hold (FROH) circuit in order to improve the performance of the digitally controlled systems is proposed. Such a technique employs multilayer perceptrons to approximate the mapping between the sampling period/continuous-time parameters of the estimated plant and the optimal value of the FROH adjustable gain. In this way, adaptive discretization systems to improve the stability properties of the resulting discrete-time zeros are implemented. Simulation results are presented in order to illustrate the properties of the complete system applied to two actual digitally controlled printing devices (HP 7090A and low-cost computer printer).  相似文献   
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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   
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The objective of the present study was to investigate the effects of different sports on stress fractures among adolescents during a 9-month follow-up period. The sample was composed of 184 adolescents divided into three groups (impact sports [n = 102]; swimming [n = 35]; non-sports [n = 47]). The occurrence of stress fracture was reported by participants and coaches. As potential confounders we considered age, sex, resistance training, body composition variables and age at peak of height velocity. There were 13 adolescents who reported fractures during the 9-month period. Bone mineral density values were higher in adolescents engaged in impact sports (P-value = 0.002). Independently of confounders, the risk of stress fracture was lower in adolescents engaged in impact sports than in non-active adolescents (hazard ratio [HR] = 0.23 [95% confidence interval (CI) = 0.05 to 0.98]), while swimming practice was not associated to lower risk of fracture (HR = 0.49 [95% CI = 0.09 to 2.55]). In conclusion, the findings from this study indicate the importance of sports participation among adolescents in the reduction of stress fracture risk, especially with impact sports. More importantly, these results could be relevant for recognising adolescents in danger of not reaching their potential for peak bone mass and later an increased risk of fractures.  相似文献   
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Determinants of possession of the ball in soccer   总被引:1,自引:0,他引:1  
In research on the importance of the possession of the ball in soccer, little attention has been paid to its determinants. Using data from 170 matches of the 2003 - 2004 Spanish Soccer League, we explain why differences in the possession of the ball among teams are so great. In particular, four variables are examined: evolving match status (i.e. whether the team is winning, losing or drawing), venue (i.e. playing at home or away), and the identities of the team and the opponent in each match. Results of linear regression analysis show that these four variables are statistically significant and together explain most of the variance in possession. In short, home teams have more possession than away teams, teams have more possession when they are losing matches than when winning or drawing, and the identity of the opponent matters - the worse the opponent, the greater the possession of the ball. Combinations of these variables could be used to develop a model that predicts possession in soccer.  相似文献   
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International short‐term study tours are a fast‐growing format for outbound education and provide exciting experiential learning opportunities for students in the creative industries disciplines. This success has encouraged researchers to seek a comprehensive view of the various concrete experiences that contribute to student learning during study tours. To that end, this article presents evidence from a qualitative online post‐tour questionnaire administered with students studying various art and design disciplines who participated in short‐term international study tours at a large Australian university in 2015. Using Kolb's Experiential Learning Theory as a framework, data collected explored student perceptions of which concrete experiences on a study tour are most impactful and which may actually hinder learning. Findings revealed: experiencing key industry venues are the most significant aspects of a study tour, rather than networking or personal growth; poor itinerary planning and travel issues are the least liked aspects of a tour, yet are often the most easily addressed with better tour management and planning; and students were positively impacted by unexpected gains in knowledge about their creative industries discipline. This study, therefore, provides unique insights into which concrete experiences may be most impactful as part of the experiential learning cycle within an international study tour for creative industries students.  相似文献   
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