Application of symbolic dynamics to characterize coordinated activity in the context of biological neural networks     

David Arroyo  Roberto Latorre  Pablo Varona  Francisco B. Rodríguez 《Journal of The Franklin Institute》2013,350(10):2967-2981

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Relevance-based language modelling for recommender systems     

Javier Parapar  Alejandro Bellogín  Pablo Castells  Álvaro Barreiro 《Information processing & management》2013

Relevance-Based Language Models, commonly known as Relevance Models, are successful approaches to explicitly introduce the concept of relevance in the statistical Language Modelling framework of Information Retrieval. These models achieve state-of-the-art retrieval performance in the pseudo relevance feedback task. On the other hand, the field of recommender systems is a fertile research area where users are provided with personalised recommendations in several applications. In this paper, we propose an adaptation of the Relevance Modelling framework to effectively suggest recommendations to a user. We also propose a probabilistic clustering technique to perform the neighbour selection process as a way to achieve a better approximation of the set of relevant items in the pseudo relevance feedback process. These techniques, although well known in the Information Retrieval field, have not been applied yet to recommender systems, and, as the empirical evaluation results show, both proposals outperform individually several baseline methods. Furthermore, by combining both approaches even larger effectiveness improvements are achieved.  相似文献   

Determining the minimum number of passive stretches necessary to alter musculotendinous stiffness     

Eric D. Ryan  Trent J. Herda  Pablo B. Costa  Jason M. Defreitas  Travis W. Beck  Jeffrey Stout 《Journal of sports sciences》2013,31(9):957-961

Abstract

In this study, we examined the minimum number of constant-torque passive stretches necessary to reduce musculotendinous stiffness. Thirteen healthy individuals (mean age 22 years, s = 3; stature 1.67 m, s = 0.1; mass 66 kg, s = 13 kg) volunteered to participate in the investigation and underwent four 30-s constant-torque passive stretches of the plantar flexor muscles. Musculotendinous stiffness was examined from the angle–torque curves generated prior to the passive stretches, at the beginning of each 30-s stretch, and immediately following the four 30-s passive stretches. The results indicated that musculotendinous stiffness of the plantar flexors was reduced following two 30-s constant-torque passive stretches (P < 0.05) compared with the pre- musculotendinous stiffness assessment. Musculotendinous stiffness remained depressed following the third and fourth stretches, but did not decrease further. These findings suggest that two 30-s bouts of constant-torque passive stretching may be necessary to cause a significant decrease in musculotendinous stiffness of the plantar flexor muscles.  相似文献   

Machismo and higher education: Examining the relation between caballerismo and ethnic identity,support seeking,and sense of connectedness among college Latinos     

Fernando Estrada  Paul Jimenez 《Journal of Latinos & Education》2018,17(3):215-224

Latino men, part of the nation’s largest and fastest-growing minority group, stand to benefit from new knowledge related to factors that positively influence college persistence. In this study, the investigators examined whether machismo—a multidimensional and gendered social construct—was directly and indirectly associated with three outcomes associated with postsecondary success: connectedness at school, ethnic identity, and support-seeking behavior. Hierarchical moderated regression analysis on data from 140 mainly Mexican American undergraduates partially supported the hypotheses. Implications for college counselors and program coordinators are discussed, along with limitations of the study and areas for future scholarship.  相似文献   

Sliding mode optimal control for linear systems     

Michael Basin  Pablo Rodriguez-Ramirez  Antonella Ferrara  Dario Calderon-Alvarez 《Journal of The Franklin Institute》2012,349(4):1350-1363

This paper addresses the optimal control problem for a linear system with respect to a Bolza–Meyer criterion with a non-quadratic non-integral term. The optimal solution is obtained as a sliding mode control, whereas the conventional linear feedback control fails to provide a causal solution. Performance of the obtained optimal controller is verified in the illustrative example against the conventional LQ regulator that is optimal for the quadratic Bolza–Meyer criterion. The simulation results confirm an advantage in favor of the designed sliding mode control.  相似文献   

Building user profiles based on sequences for content and collaborative filtering     

Pablo Sánchez  Alejandro Bellogín 《Information processing & management》2019,56(1):192-211

Modeling user profiles is a necessary step for most information filtering systems – such as recommender systems – to provide personalized recommendations. However, most of them work with users or items as vectors, by applying different types of mathematical operations between them and neglecting sequential or content-based information. Hence, in this paper we study how to propose an adaptive mechanism to obtain user sequences using different sources of information, allowing the generation of hybrid recommendations as a seamless, transparent technique from the system viewpoint. As a proof of concept, we develop the Longest Common Subsequence (LCS) algorithm as a similarity metric to compare the user sequences, where, in the process of adapting this algorithm to recommendation, we include different parameters to control the efficiency by reducing the information used in the algorithm (preference filter), to decide when a neighbor is considered useful enough to be included in the process (confidence filter), to identify whether two interactions are equivalent (δ-matching threshold), and to normalize the length of the LCS in a bounded interval (normalization functions). These parameters can be extended to work with any type of sequential algorithm.We evaluate our approach with several state-of-the-art recommendation algorithms using different evaluation metrics measuring the accuracy, diversity, and novelty of the recommendations, and analyze the impact of the proposed parameters. We have found that our approach offers a competitive performance, outperforming content, collaborative, and hybrid baselines, and producing positive results when either content- or rating-based information is exploited.  相似文献   

Some numerical tests for an alternative approach to optimal feedback control     

Roberto Font  Pablo Pedregal 《Journal of The Franklin Institute》2018,355(15):7011-7026

We test a recently proposed approach to optimal feedback control of nonlinear systems leading to an iterative descending strategy [24]. We start by discussing the numerical implementation of this strategy, and propose a number of improvements that can speed up the computation process by up to two orders of magnitude. The resulting algorithm is then applied to a series of test problems of increasing complexity. Results seem to show that this can be a promising strategy to bear in mind for more realistic situations.  相似文献   

Risk markers for disappearance of pediatric Web resources.     

Angel A Hernández-Borges  Alejandro Jiménez-Sosa  Maria L Torres-Alvarez de Arcaya  Pablo Macías-Cervi  Maria A Gaspar-Guardado  Ana Ruíz-Rabaza 《Journal of the Medical Library Association》2005,93(3):374-380

OBJECTIVES: The authors sought to find out whether certain Webometric indexes of a sample of pediatric Web resources, and some tests based on them, could be helpful predictors of their disappearance. METHODS: The authors performed a retrospective study of a sample of 363 pediatric Websites and pages they had followed for 4 years. Main measurements included: number of resources that disappeared, number of inbound links and their annual increment, average daily visits to the resources in the sample, sample compliance with the quality criteria of 3 international organizations, and online time of the Web resources. RESULTS: On average, 11% of the sample disappeared annually. However, 13% of these were available again at the end of follow up. Disappearing and surviving Websites did not show differences in the variables studied. However, surviving Web pages had a higher number of inbound links and higher annual increment in inbound links. Similarly, Web pages that survived showed higher compliance with recognized sets of quality criteria than those that disappeared. A subset of 14 quality criteria whose compliance accounted for 90% of the probability of online permanence was identified. Finally, a progressive increment of inbound links was found to be a marker of good prognosis, showing high specificity and positive predictive value (88% and 94%, respectively). CONCLUSIONS: The number of inbound links and annual increment of inbound links could be useful markers of the permanence probability for pediatric Web pages. Strategies that assure the Web editors' awareness of their Web resources' popularity could stimulate them to improve the quality of their Websites.  相似文献   

Comparative analysis of academic grades in compulsory secondary education in Spain using statistical techniques     

Alejandro Veas  Raquel Gilar  Pablo Miñano  Juan Luis Castejón 《Educational studies》2017,43(5):533-548

The present study, based on the construct comparability approach, performs a comparative analysis of general points average for seven courses, using exploratory factor analysis (EFA) and the Partial Credit model (PCM) with a sample of 1398 student subjects (M = 12.5, SD = 0.67) from 8 schools in the province of Alicante (Spain). EFA confirmed a one-factor model which explains 74.44% of the variance. Cronbach’s alpha value for this factor was .94. The PCM supported the one-factor model, and an optimal fit was achieved in all of the courses. The analysis of differential item functioning showed no significant differences in any course. Equitable distribution was observed in the evolution of the difficulty indices along the measurement scale for each course. This type of analysis confirms the measurement of a single latent construct in the different topics analysed, despite addressing various theoretical and procedural contents.  相似文献   

A comparison of the nurse–patient interaction criteria among geriatric clients in home health care and community settings: a trade-off analysis     

Allan B. de Guzman  Kinz Alyssa M. Jaurigue  Aldrich Azydee B. Jimenez 《Educational gerontology》2019,45(3):176-190

While the nurse–patient relationship plays a vital role in enhancing a client’s well-being, in this study, it was observed that most nurses only communicate with their clients when dealing with administrative or functional activities. Although previous studies had been conducted involving the nature of nurse–patient interaction, none has yet investigated the potential of conjoint or trade-off analysis in understanding elderly patients’ preferences in home care and community settings. This study contributes to the gap in such knowledge about the nurse–patient relationship. A total of 238 Filipino elderly patients were recruited from home health care and community settings to participate in the research. A set of 36 choice bundles with 4 holdouts were extracted from a pool 144 orthogonal array. In this quantitative study, respondents were asked to sort and rank each card based on its importance and utility value. All data gathered were analyzed using SPSS version 20. Notably, the analysis found that the most important factor for elderly clients in home health care is non-verbal communication followed by verbal, gender and type of care provider while for elderly clients in community settings, gender is the most important consideration in nurse–patient interaction and this was followed by non-verbal cues, care provider and verbal cues. Findings of the study provide valuable inputs that could inform guidelines in implementing nurse professional development programs specifically in matters that relate to the effective communication between the nurse and patient in all health-care settings.  相似文献