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Ruud van der Pol 《Information Retrieval》2003,6(1):21-47
The paper reports the development of Dipe-D, a knowledge-based procedure for the formulation of Boolean queries in information retrieval. Dipe-D creates a query in two steps: (1) the user's information need is developed interactively, while identifying the concepts of the information need, and subsequently (2) the collection of concepts identified is automatically transformed into a Boolean query. In the first step, the subject area—as represented in a knowledge base—is explored by the user. He does this by means of specifying the (concepts that meet his) information need in an artificial language and looking through the solution as provided by the computer. The specification language allows one to specify concepts by their features, both in precise terms as well as vaguely. By repeating the process of specifying the information need and exploring the resulting concepts, the user may precisely single out the concepts that describe his information need. In the second step, the program provides the designations (and variants) for the concepts identified, and connects them by appropriate operators. Dipe-D is meant to improve on existing procedures that identify the concepts less systematically, create a query manually, and then sometimes expand that query. Experiments are reported on each of the two steps; they indicate that the first step identifies only but not all the relevant concepts, and the second step performs (at least) as good as human beings do. 相似文献
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Wouter P.C. BoonAuthor Vitae Ellen H.M. Moors Author VitaeStefan Kuhlmann Author Vitae Ruud E.H.M. Smits Author Vitae 《Research Policy》2011,40(2):242-252
User involvement is assumed to be beneficial to innovation processes. Intermediary user organisations contribute to articulating societal demands for innovations. However, the learning processes inside these organisations are still not understood well. Therefore, this paper empirically investigates intermediaries using an event history approach. It yields characteristic learning mechanisms, e.g. concerning the management of expectations or actively building a case. If intermediaries overcome challenges regarding positioning, representation and the level of proactivity, they can play a precarious role in demand articulation in the context of new technologies. 相似文献
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Koning RH 《Journal of sports sciences》2011,29(1):19-27
Home advantage is a pervasive phenomenon in sport. It has been established in team sports such as basketball, baseball, American football, and European soccer. Attention to home advantage in individual sports has so far been limited. The aim of this study was to examine home advantage in professional tennis. Match-level data are used to measure home advantage. The test used is based on logit models, and consistent specification is addressed explicitly. Depending on the interpretation of home advantage, restrictions on the specification of the model need to be imposed. We find that although significant home advantage exists for men, the performance of women tennis players appears to be unaffected by home advantage. 相似文献
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Kathleen Custers Elizabeth Dorrance Hall Staci Bushnell Smith Jenna McNallie 《Mass Communication and Society》2017,20(5):637-662
Persistent fear of crime can have serious consequences for one’s social behavior. Previous research has shown that people who fear crime are more likely to engage in self-protective behavior. Although a substantial amount of research has examined the relationship between television exposure and fear of crime, research on the association between television exposure and self-protective behavior is scarce. Based on cultivation theory and the mediated fear model, the current study aimed to examine whether news and crime drama television viewing are indirectly related to self-protective behavior via fear of crime. Structural equation modeling of data from 392 undergraduate students showed that news viewing and crime drama viewing is indirectly associated with self-protective behavior. The current study provided evidence for the importance of accounting for gender when investigating the complex issue of media effects on fear of crime and self-protective behavior. 相似文献
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Ruud H Koning 《Journal of sports sciences》2013,31(4):417-427
Home advantage is a well-documented phenomenon in many sports. Home advantage has been shown to exist for team sports (soccer, hockey, football, baseball, basketball) and for countries organizing sports tournaments like the Olympics and World Cup Soccer. There is also some evidence for home advantage in some individual sports, but there is a much more limited literature. This paper addresses the issue of home advantage in speed skating. From a methodological point of view, it is difficult to identify home advantage, because skaters vary in their abilities and the conditions of tournaments vary. There is a small but significant home advantage using a generalized linear mixed model, with random effects for skaters and fixed effects for skating rinks and seasons. Even though the home advantage effect exists, it is very small when compared to variation in skating times due to differences of rinks and individual abilities. 相似文献
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Abstract In tournaments in various sports that feature one–on–one competition, the trophy is sometimes prominently displayed near the athletes during the final. Based on recent research on subtle reward cues, we propose that such trophies have the potential to induce choking under pressure in the match favourites, who are known to be most at risk. To test this idea, we analysed real-life tennis performance data (service performance and rally performance) from professional tournaments. While favourites generally outperformed underdogs during rallies, they did not do so in finals in which (a) large amounts of money were at stake and (b) a trophy was on display near the court. These findings support the idea that tournament trophies may distract favourites by continuously reminding them of what is at stake, and via that route may severely thwart their performance. 相似文献
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Janet Moeijes Jooske T. Van Busschbach Krista L. Lockhart Ruud J. Bosscher Jos W. R. Twisk 《European Journal of Sport Science》2019,19(3):365-374
Several studies suggest that sports participation is beneficial for psychosocial health. There is, however, only a limited number of studies about the relationship of specific characteristics of sports participation with psychosocial health. The present study investigated associations between characteristics of sports participation and three aspects of psychosocial health, i.e. internalising problems, externalising problems and prosocial behaviour. The examined characteristics of sports participation pertained to individual versus team sports, indoor versus outdoor sports, involvement in competition or not, and contact sports versus non-contact sports. Cross-sectional data were collected from 1768 Dutch children aged 10–12 years who were member of a sports club. These children completed the Movement and Sports Monitor Questionnaire Youth aged 8–12 years (MSMQ) and the Strength and Difficulties Questionnaire (SDQ). Linear multilevel analyses and logistic generalised estimating equation were conducted. Children participating in team sports, outdoor sports, or competition showed fewer internalising problems than children engaged in individual sports, indoor sports, or only training. The associations with internalising problems were stronger for boys than for girls. Children participating in non-contact sports showed fewer externalising problems than children performing non-contact sports as well as contact sports. Children practising indoor sports or non-contact sports showed better prosocial behaviour than children doing outdoor or contact sports. In conclusion, the form of sports participation seemed to matter highly with respect to internalising problems, especially for boys, and, to a lesser extent, with respect to externalising problems and prosocial behaviour. This offers starting points for developing tailor-made sports programmes for children. 相似文献
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