Distributed Correlation-Based Feature Selection in Spark

CFS (Correlation-Based Feature Selection) is an FS algorithm that has been successfully applied to classification problems in many domains. We describe Distributed CFS (DiCFS) as a completely redesigned, scalable, parallel and distributed version of the CFS algorithm, capable of dealing with the large volumes of data typical of big data applications. Two versions of the algorithm were implemented and compared using the Apache Spark cluster computing model, currently gaining popularity due to its much faster processing times than Hadoop's MapReduce model. We tested our algorithms on four publicly available datasets, each consisting of a large number of instances and two also consisting of a large number of features. The results show that our algorithms were superior in terms of both time-efficiency and scalability. In leveraging a computer cluster, they were able to handle larger datasets than the non-distributed WEKA version while maintaining the quality of the results, i.e., exactly the same features were returned by our algorithms when compared to the original algorithm available in WEKA.Comment: 25 pages, 5 figure

Dynamic Properties of a Granular Soil

The variation of the Dynamic Shear Modulus, G, and Damping Ratio, D, in a coarse grained alluvial soil from the Santiago area, Chile, is analyzed when changes occur in its grain size distribution, degree of compaction, confining pressure, magnitude of the cyclic deviator stress, and number of applied loading loops. Using statistical techniques it was possible to determine the degree of influence of each one of such factors in the magnitude of G and D. Further, the experimental error derived from laboratory tests measurements could be evaluated. The Hyperbolic Model shows a better performance than the Ramber-Osgood Model when theoretical results are adjusted to experimental shear stress-strain laws

Carbon storage in the soil under different land uses in the south of Portugal

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Identities for subspaces of the Weyl algebra

In this note we described the polynomial identities of degree 4 for the certain subspace of the Weyl algerbra A_1 over an infinite field of arbitrary characteristic.Comment: 9 page

Evaluación de la estructura de la mediana empresa Transportes Soza del departamento de Matagalpa para la adopción de NIIF para PYMES en el I semestre del 2012

En la presente investigación, se realizó un estudio basado en la capacidad de adopción de las Normas Internacionales de Información Financiera para Pequeñas y Medianas Empresas en Matagalpa y Jinotega en el 2012, con el propósito de Evaluar la estructura que presenta la mediana empresa Transportes Soza de acuerdo a lo establecido en dichas Normas de Información Financiera. Esta temática es de suma importancia para la empresa Transportes Soza porque, la adopción de estas Normas tiene como objetivo la implementación de un único conjunto de normas contables de carácter global que sean de alta calidad, comprensibles, que requieran información de alta calidad, transparente y comparable en los estados financieros que ayuden a participar a las empresas en los mercados de capitales de todo el mundo y a tomar decisiones económicas eficientes. Actualmente la empresa Transportes Soza no tiene conocimiento sobre el marco de referencia conceptual y legal que aborda el tema. Cuenta con una estructura organizativa que le permite una mayor eficiencia y eficacia en el desarrollo de sus funciones operativas, así como también cuenta con los recursos necesarios y la disposición para la implementación de estas Normas Financiera. La empresa se encuentra en una etapa de actualización y formalización de su sistema contable con el propósito de que la información generada sea confiable, oportuna y precisa para la toma de decisiones. Esta información generada por su sistema contable es presentada en forma de estados financieros a los cuales va dirigido la NIIF para PYME

Semantic based P2P System for local e-Government

The Electronic Government is an emerging field of applications for the Semantic Web where ontologies are becoming an important research technology. The e-Government faces considerable challenges to achieve interoperability given the semantic differences of interpretation, omplexity and width of scope. This paper addresses the importance of providing an infrastructure capable of dealing with issues such as: communications between public administrations across government and retrieval of official and non official documents in a timely, secure and accurate way at the back office. A semantic peer-to-peer approach is proposed to enhance the information management at the e-Government domain; this approach is integrated with a Government Information Retrieval system and it reuses the EGO Model which can be deployed within the e-Government context

EgoIR: ontology-based information retrieval intended for eGovernment

The eGovernment is a field of applications for the Semantic Web. The eGovernment also is becoming an important research area and faces considerable challenges to achieve interoperability because of the semantic differences of interpretation, complexity and width of scope. It is however an open question how to apply these techniques fruitfully in the eGovernment domain. This paper addresses the importance of providing a semantic application that, within the eGovernment domain, is capable of dealing with the issue of the retrieval of government documentation in a timely and accurate way. In this paper, we present an approach ontology-based for retrieving government information

Comparative Evaluation of Monocular Augmented-Reality Display for Surgical Microscopes

Abstract-Medical augmented reality has undergone much development recently. However, there is a lack of studies quantitatively comparing the different display options available. This paper compares the effects of different graphical overlay systems in a simple micromanipulation task with "soft" visual servoing. We compared positioning accuracy in a real-time visually-guided task using Micron, an active handheld tremor-canceling microsurgical instrument, using three different displays: 2D screen, 3D screen, and microscope with monocular image injection. Tested with novices and an experienced vitreoretinal surgeon, display of virtual cues in the microscope via an augmented reality injection system significantly decreased 3D error (p < 0.05) compared to the 2D and 3D monitors when confounding factors such as magnification level were normalized

Síntesis y estructura de espiro [pirrolidin-2,4'-piperidinas]

RESUMENSe estudió la formación de r,2',5'-trimetilespiro[pirrolidin-2,4'-piperidinasJ a partir de sus correspondientes l,2,5-trimetil-4-alil-4-aminopiperidinas en condiciones de la reacción de aminomercuración. Los productos formados se aislaron por cromatografía en columna sobre alúmina (ALO,) y sus estructuras se establecieron por medio del análisis espectroscópico ( IR, RMN 'H y espectrometría de masas). _________________________________________________________________________________ ABSTRACTThe synthesis of 1,2,5-trimethylspiro[piper¡dine-4,2'-pirrolidines] from their respectives 1,2,5-trimethyl-4-allyl-4-aminopipcridines were carried out under the conditions of amino-mercuration reaction. The obtained producís were isoiated by column chromatography on alumine (ALO,) and their structures were determinated by spectroscopic analysis( IR, 'H NMR and mass spectrometry)