Ontology refinement for improved information retrieval     

Antonio Jimeno-Yepes  Rafael Berlanga-Llavori  Dietrich Rebholz-Schuhmann 《Information processing & management》2010

Ontologies are frequently used in information retrieval being their main applications the expansion of queries, semantic indexing of documents and the organization of search results. Ontologies provide lexical items, allow conceptual normalization and provide different types of relations. However, the optimization of an ontology to perform information retrieval tasks is still unclear. In this paper, we use an ontology query model to analyze the usefulness of ontologies in effectively performing document searches. Moreover, we propose an algorithm to refine ontologies for information retrieval tasks with preliminary positive results.  相似文献   

Synthetic hybrid indicators based on scientific collaboration to quantify and evaluate individual research results     

Antonio Perianes-Rodríguez  Zaida Chinchilla-Rodríguez  Benjamín Vargas-Quesada  Carlos Olmeda Gómez  Félix Moya-Anegón 《Journal of Informetrics》2009,3(2):91-101

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   

Online learning: Learner characteristics and their approaches to managing learning   总被引：1，自引：0，他引：1  

Rodrigo del Valle  Thomas M. Duffy 《Instructional Science》2009,37(2):129-149

Using cluster analysis this study investigated the characteristics of learning strategies learners use in online courses with one-on-one mentoring. Three distinct approaches were identified: “Mastery oriented”, “Task focused” and “Minimalist in effort”. Despite the widespread concern that students will have difficulty managing their time in online courses with high level of student freedom, this study found that the vast majority of learners were very effective in their learning strategies. The findings speak well for the potential of distance education environments to provide high quality self-paced learning, accommodating different learning strategies, which is difficult to do in group-paced courses. We further explored how these approaches relate to and interact with, participants’ background and their levels of satisfaction and self reported learning.  相似文献   

Visualizing and monitoring effective interactions in online collaborative groups   总被引：1，自引：0，他引：1  

Antonio Calvani  Antonio Fini  Marcello Molino  Maria Ranieri 《British journal of educational technology : journal of the Council for Educational Technology》2010,41(2):213-226

Online education based on small self‐managing groups, with slight supervision by a professional tutor, is a strategically interesting methodology for lifelong learning. This solution may combine aspects of cost‐effectiveness (reducing tutors' work) with the demands for active and engaging learning methods based on the exchange and sharing of experiences. In such a context, how can information on collaborative attitudes and behaviour be gathered? A typical tool for online learning activities is the threaded web forum. This study proposes a methodology for assessing effective collaborative interactions within the add‐on module, Forum Plus, for the Moodle learning management system (LMS). The methodology here presented is able to supply an early overview of the level of effectiveness of the collaborative group and therefore it may provide a useful instrument to guide further qualitative observations conducted directly in the web forum.  相似文献   

Effect of different velocity loss thresholds during a power-oriented resistance training program on the mechanical capacities of lower-body muscles     

Alejandro Pérez-Castilla  Paulino Padial  Antonio J. Morales-Artacho  Belén Feriche 《Journal of sports sciences》2018,36(12):1331-1339

This study compared the effects of two velocity loss thresholds during a power-oriented resistance training program on the mechanical capacities of lower-body muscles. Twenty men were counterbalanced in two groups (VL10 and VL20) based on their maximum power capacity. Both groups used the same exercises, relative intensity and repetition volume, only differing in the velocity loss threshold of each set (VL10: 10% vs. VL20: 20%). Pre- and post-training assessments included an incremental loading test and a 15-m linear sprint to assess the force- and load-velocity relationships and athletic performance variables, respectively. No significant between-group differences (P > 0.05) were observed for the force-velocity relationship parameters (ES range = 0.15–0.42), the MPV attained against different external loads (ES range = 0.02–0.18) or the 15-m sprint time (ES = 0.09). A high between-participants variability was reported for the number of repetitions completed in each training set (CV = 30.3% for VL10 and 29.4% for VL20). These results suggest that both velocity loss thresholds induce similar changes on the lower-body function. The high and variable number of repetitions completed may compromise the velocity-based approach for prescribing and monitoring the repetition volume during a power-oriented resistance training program conducted with the countermovement jump exercise.  相似文献   

A noise-filtering event generator for PIDPlus controllers     

Luca Merigo  Manuel Beschi  Fabrizio Padula  Antonio Visioli 《Journal of The Franklin Institute》2018,355(2):774-802

In this paper we propose a new event generator, which has strong noise-filtering capabilities, to be used in event-based control systems with a PIDPlus controller. An approximate frequency analysis is performed in order to characterize the event generator system and tuning guidelines are provided for its design parameter. Simulation and experimental results obtained with a laboratory setup demonstrate the effectiveness of the methodology in providing a satisfactory performance related to set-point and load disturbance step responses with a total variation that is significantly reduced with respect to the standard cases.  相似文献   

Sailing in all winds: Technological search over the business cycle     

Daniela Silvestri  Massimo Riccaboni  Antonio Della Malva 《Research Policy》2018,47(10):1933-1944

Business cycles modify firms’ incentives to innovate and the direction of innovation. By introducing a new measure of patent unconventionality this paper explores the impact of the business cycle on firms’ technological search strategies. We find that during upturns firms generate inventions characterized by a higher level of technological unconventionality. We also find that financially resilient and diversified firms produce more unconventional patents. While patent unconventionality is associated with technological impact and market value, firms extract more value by investing in unconventional inventions in downturns.  相似文献   

Protective effects of photobiomodulation against resistance exercise-induced muscle damage and inflammation in rats     

Helenita Antonia de Oliveira  Ednei Luiz Antonio  Flávio André Silva  Paulo de Tarso Camillo de Carvalho  Regiane Feliciano  Amanda Yoshizaki 《Journal of sports sciences》2018,36(20):2349-2357

We investigated whether low-level laser therapy (LLLT) prior to or post resistance exercise could attenuate muscle damage and inflammation. Female Wistar rats were assigned to non-LLLT or LLLT groups. An 830-nm DMC Laser Photon III was used to irradiate their hind legs with 2J, 4J, and 8J doses. Irradiations were performed prior to or post (4J) resistance exercise bouts. Resistance exercise consisted of four maximum load climbs. The load work during a resistance exercise bout was similar between Control (non-LLLT, 225 ± 10 g), 2J (215 ± 8 g), 4J (210 ± 9 g), and 8J (226 ± 9 g) groups. Prior LLLT did not induce climbing performance improvement, but exposure to 4J irradiation resulted in lower blood lactate levels post-exercise. The 4J dose decreased creatine kinase and lactic dehydrogenase levels post-exercise regardless of the time of application. Moreover, 4-J irradiation exposure significantly attenuated tumor necrosis factor alpha, interleukin-6, interleukin-1β, cytokine-induced neutrophil chemoattractant-1, and monocyte chemoattractant protein-1. There was minor macrophage muscle infiltration in 4J-exposed rats. These data indicate that LLLT prior to or post resistance exercise can reduce muscle damage and inflammation, resulting in muscle recovery improvement. We attempted to determine an ideal LLLT dose for suitable results, wherein 4J irradiation exposure showed a significant protective role.  相似文献   

Effects of an unsupervised pedometer-based physical activity program on daily steps of adults with moderate to severe asthma: a randomized controlled trial     

Cristina Martins Coelho  Maycon Moura Reboredo  Felipe Martins Valle  Carla Malaguti  Larissa Almeida Campos  Lucas Mendes Nascimento 《Journal of sports sciences》2018,36(10):1186-1193

Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.  相似文献   

Effect of contact and no-contact small-sided games on elite handball players     

Antonio Dello Iacono  Domenico Martone  Alessandro Moura Zagatto  Yoav Meckel  Mahmood Sindiani  Mirjana Milic 《Journal of sports sciences》2018,36(1):14-22

This study aimed to investigate the effect of contact (C-SSG) and no-contact (NC-SSG) handball small-sided games (SSGs) on motion patterns and physiological responses of elite handball players. Twelve male handball players performed 10 C-SSG and 10 NC-SSG while being monitored through the heart rate (HR) and rate of perceived exertion (RPE) as physiological responses and time-motion activities profile using video-match analysis. Both game conditions resulted in similar HR responses (P > 0.05), but the NC-SSG led to a higher RPE scores. The time-motion activity analysis featured NC-SSG with a greater amount of walking (855.6 ± 25.1 vs. 690.6 ± 35.2 m) and backward movements (187.5 ± 12.3 vs. 142.5 ± 8.7 m) combined with fast running (232.3 ± 8.5 vs. 159.7 ± 5.7 m) and sprinting (79.5 ± 4.7 vs. 39.7 ± 3.7 m) activities (P < 0.001). Conversely, C-SSG had a higher percentage of jogging and sideway movements associated with greater frequency of jumping (0.87 ± 0.09 vs. 0.31 ± 0.06 nr) and physical contact (1.82 ± 0.55 vs. 0.25 ± 0.03 nr) events (P < 0.001). No between-regimen differences were found for the number of throws (P = 0.745). In addition, the RPE was significantly correlated with fast running relative distances (r = 0.909, P < 0.001) and sprinting relative distances (r = 0.939, P < 0.001). In conclusion, this investigation showed that both C-SSG and NC-SSG in team handball can effectively represent specifically oriented exercises, according to the sport-task and the performance demands.  相似文献