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   

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   

Baroque Tower on a Gothic Base: A Lakatosian Reconstruction of Students' and Teachers' Understanding of Structure of the Atom     

Blanco  Rafael  Niaz  Mansoor 《Science & Education》1998,7(4):327-360

The main objective of this study is a reconstruction of students' and teachers' understanding of structure of the atom based on the following framework: a) history of science can be conceived as that of competing rival research programs; b) some of the greatest scientific research programs progressed on inconsistent foundations; c) in actual scientific practice, counter-examples would be considered as mere anomalies; d) work of Thomson, Rutherford and Bohr led to the postulation of atomic models based on competing frameworks of understanding. This study is based on 171 freshman students enrolled in General Chemistry I and 7 chemistry teachers at the Instituto Universitario de Tecnología, El Tigre, Venezuela. All the students and teachers were asked to respond to a 11 item questionnaire and explain their responses. The questionnaire was administered about a month after the students/teachers had finished the topic of atomic structure. Students' and teachers' responses were classified in the following categories: Positivist/inductivist, Transitional and Lakatosian. Results obtained show that students and teachers: a) have a very similar positivist understanding of the progress of science; b) are inconsistent in their responses by switching from a positivist response on one item to a Lakatosian on an another; c) also showed some consistent response patterns by resisting changes in some of their core beliefs by invoking "auxiliary hypotheses"; and d) consider that observable hard experimental facts give science its objective status, whereas the interpretations being subjective perhaps go beyond the fold of science.  相似文献   

An Onto-Semiotic Analysis of Combinatorial Problems and the Solving Processes by University Students     

Juan?D.?GodinoEmail author  Carmen?Batanero  Rafael?Roa 《Educational Studies in Mathematics》2005,60(1):3-36

In this paper we describe an ontological and semiotic model for mathematical knowledge, using elementary combinatorics as an example. We then apply this model to analyze the solving process of some combinatorial problems by students with high mathematical training, and show its utility in providing a semiotic explanation for the difficulty of combinatorial reasoning. We finally analyze the implications of the theoretical model and type of analysis presented for mathematics education research and practice.  相似文献   

Science Classroom Interactions and Academic Language Use with English Learners     

Tiberio Garza  Margarita Huerta  Tracy G. Spies  Rafael Lara-Alecio  Beverly J. Irby  Fuhui Tong 《International Journal of Science and Mathematics Education》2018,16(8):1499-1519

Academic language is critical for English learners (ELs) to succeed in the science classroom. This study analyzed the instructional practices centered around academic language taking place in eight, fifth-grade classrooms during a grant-funded project. Observational data collected through a classroom observation instrument were analyzed to describe and compare the instructional practices occurring in treatment and control classrooms when teachers and students used academic language. Our findings show both treatment and control classrooms using academic language during the course of the intervention study, but the instruction looked markedly different in each setting. These differences provide valuable insight for practitioners and researchers concerned with the academic language development of ELs in science classrooms.  相似文献