Topic discovery based on text mining techniques     

Aurora Pons-Porrata  Rafael Berlanga-Llavori  José Ruiz-Shulcloper 《Information processing & management》2007

In this paper, we present a topic discovery system aimed to reveal the implicit knowledge present in news streams. This knowledge is expressed as a hierarchy of topic/subtopics, where each topic contains the set of documents that are related to it and a summary extracted from these documents. Summaries so built are useful to browse and select topics of interest from the generated hierarchies. Our proposal consists of a new incremental hierarchical clustering algorithm, which combines both partitional and agglomerative approaches, taking the main benefits from them. Finally, a new summarization method based on Testor Theory has been proposed to build the topic summaries. Experimental results in the TDT2 collection demonstrate its usefulness and effectiveness not only as a topic detection system, but also as a classification and summarization tool.  相似文献   

State of the library and information science blogosphere after social networks boom: A metric approach     

Daniel Torres-Salinas  lvaro Cabezas-Clavijo  Rafael Ruiz-Prez  Emilio Delgado Lpez-Czar 《Library & information science research》2011,33(2):168-174

A metric analysis of blogs on library and information science (LIS) between November 2006 and June 2009 indexed on the Libworm search engine characterizes the community's behavior quantitatively. An analysis of 1108 personal and corporate blogs with a total of 275,103 posts is used to calculate survival rate, production (number of posts published), and visibility via such indicators as links received, Technorati authority, and Google's PagePank. Over the study period, there was a 52% decrease in the number of active blogs. Despite the drop in production over this period, the average number of posts per blog remained constant (14 per month). The most representative blogs in the discipline are identified. The emergence of such platforms as Facebook and Twitter seems to have meant that both personal and corporate blogs have lost some of their prominence.  相似文献   

Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis     

Salmanzadeh A  Kittur H  Sano MB  C Roberts P  Schmelz EM  Davalos RV 《Biomicrofluidics》2012,6(2):24104-2410413

Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool.  相似文献   

Web technologies applied to virtual heritage: An example of an Iberian Art Museum     

María Dolores Robles-Ortega  Francisco R. Feito  Juan J. Jiménez  Rafael J. Segura 《Journal of Cultural Heritage》2012,13(3):326-331

Nowadays, some virtual museums include 3D room scenes to show the models of its pieces, just like in real museums. Nevertheless, the generation and maintenance of this kind of scenes is generally difficult and should be done by an expert. For example, any change such as including a new piece or modifying the position of an existing fragment usually requires a different design and the creation of a new scene. In this paper we present a case study on the development of a web-based application to automatize this process. To this end, a database to store both graphic and non-graphic information about the pieces, and some 3D rooms to show them has been created. The designed scenes only contain some pieces of furniture to exhibit the fragments, which will be subsequently included. Thus, when a room is loaded in the web page, its associated pieces are obtained through a query in the database and its models are dynamically included in the original scene. Therefore, the position changes or the inclusion of new pieces are not performed in the 3D model, but in the database. Our application makes the transmission of the knowledge to the general public easier because any new discovered piece can be included in a existing museum effortlessly.  相似文献   

Quantitative and qualitative evaluation of linguistic input support to a prelingually deaf child with cued speech: A case study     

Torres S  Moreno-Torres I  Santana R 《Journal of deaf studies and deaf education》2006,11(4):438-448

This paper studies the linguistic input attended by a deaf child exposed to cued speech (CS) in the final part of her prelinguistic period (18-24 months). Subjects are the child, her mother, and her therapist. Analyses have provided data about the quantity of input directed to the child (oral input, more than 1,000 words per half-an-hour session; cued ratio, more than 60% of oral input; and attended ratio, more than 55% of oral input), its linguistic quality (lexical variety, grammatical complexity, etc.), and other properties of interaction (child attention and use of spontaneous gestures). Results show that both adults provided a rich linguistic input to the child and that the child attended most of the input that the adults cued. These results might explain the positive linguistic development of children exposed early to CS.  相似文献   

Agents control in intelligent learning systems: The case of reactive characteristics     

Ana Lilia Laureano-Cruces  Javier Ramírez-Rodríguez  Fernando de Arriaga  Rafael Escarela-Pérez 《Interactive Learning Environments》2013,21(2):95-118

Intelligent learning systems (ILSs) have evolved in the last few years basically because of influences received from multi-agent architectures (MAs). Conflict resolution among agents has been a very important problem for multi-agent systems, with specific features in the case of ILSs. The literature shows that ILSs with cognitive or pedagogical agents are prone to arbitration methods, where as ILSs with reactive agents are much in favor of control mechanisms. For these kind of systems, different control types are proposed based on the different stimuli that these agents will receive. These stimuli are aspects to be evaluated during the teaching/learning process such as: (1) error analysis, (2) learning styles, (3) analogies, (4) social aspects, etc.

The paper reviews several ILSs, related to our work; different control mechanisms are proposed to solve the agents' intervention conflicts. Finally, the use of several mechanisms is exemplified by the results of a specific ILS.  相似文献   

Human capital and innovation: the importance of the optimal organizational task structure     

Tiago Fonseca  Pedro de Faria  Francisco Lima 《Research Policy》2019,48(3):616-627

Management literature has identified high-skilled human capital as a crucial dimension of innovation processes at the firm level. In this study, we introduce an alternative view of human capital based on the tasks that firms’ workers perform. We propose a measure of cognitive analytical and interpersonal tasks: the degree of abstractism. We argue that the level of abstractism of a firm has an effect on a firm's propensity to innovate and on its product innovation performance. We hypothesize that while the degree of abstractism has a linear positive relationship with the propensity to innovate, the relationship between abstractism and product innovation performance follows an inverted u-shaped relationship. We find partial support to our hypotheses using data from more than six thousand Portuguese firms. We discuss how these results change our understanding of the relationship between human capital and innovation at the firm level.  相似文献   

Trajectories of Adjustment in a Brazilian Sample of Street-Involved Youth     

Rebeca Fernandes Ferreira Lima  Marcela Raffaelli  Normanda Araujo de Morais  Juliana P. Santana  Carlos J. Nieto  Silvia H. Koller 《Child development》2020,91(4):1237-1253

Trajectories of adjustment were examined in a sample of street-involved youth across a 1-year period. Participants (N = 113; M_age = 14.18 years; 80.5% male, 91% non-White) were recruited in three Brazilian cities. Interviews conducted at three time points included six measures of physical and psychological adjustment. Unconditional growth models revealed linear declines over time (i.e., improved adjustment) on three indicators: health symptoms, sexual risk behaviors, and negative affect. There were no linear changes in drug use, positive affect, or life satisfaction. Conditional growth models revealed few significant effects for age or gender, but ratings of stressful life events moderated longitudinal changes in health symptoms, drug use, and negative affect. Implications for practice, policy, and theory are discussed.  相似文献   

Evaluation of soccer players under the Moneyball concept     

Luiz Octávio Gavião  Annibal Parracho Sant’Anna  Gilson Brito Alves Lima  Pauli Adriano de Almada Garcia 《Journal of sports sciences》2020,38(11-12):1221-1247

ABSTRACT

The recruitment of athletes with limited resources is a global problem in professional sports. In US Major League Baseball, the experience of the Oakland Athletics’ general manager in the last decade turned his “Moneyball” model into a synonym of quantitative analysis in the transfer market of baseball players. His strategy focused on hiring players with outstanding technical skills but relatively low market value. This study adapted this model to the framework of a multiple criteria decision aid (MCDA), by selecting undervalued players who have complementary abilities. The novelty here refers to the joint use of four algorithms explored by the composition of probabilistic preferences (CPP) (i.e., ranking, classification, dynamic evaluation and regularity analysis) and their application to soccer player performance evaluation. The new model analysed the recent transfer of a left-back soccer player to Europe. The results indicated 12 opportunities for better investment, among 32 left and right-back players considered. Two years later, the value of the same player was considerably lower. He played only five matches in the 2018–2019 season, without scoring or providing any assists. On the other hand, the players better classified by the CPP-MB model presented higher performances and market values.  相似文献   

Correlation analysis of performance measures for multi-label classification     

Rafael B. Pereira  Alexandre Plastino  Bianca Zadrozny  Luiz H.C. Merschmann 《Information processing & management》2018,54(3):359-369

In many important application domains, such as text categorization, scene classification, biomolecular analysis and medical diagnosis, examples are naturally associated with more than one class label, giving rise to multi-label classification problems. This fact has led, in recent years, to a substantial amount of research in multi-label classification. In order to evaluate and compare multi-label classifiers, researchers have adapted evaluation measures from the single-label paradigm, like Precision and Recall; and also have developed many different measures specifically for the multi-label paradigm, like Hamming Loss and Subset Accuracy. However, these evaluation measures have been used arbitrarily in multi-label classification experiments, without an objective analysis of correlation or bias. This can lead to misleading conclusions, as the experimental results may appear to favor a specific behavior depending on the subset of measures chosen. Also, as different papers in the area currently employ distinct subsets of measures, it is difficult to compare results across papers. In this work, we provide a thorough analysis of multi-label evaluation measures, and we give concrete suggestions for researchers to make an informed decision when choosing evaluation measures for multi-label classification.  相似文献