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Sample records for clusters estudio dinamico

  1. [Dynamic study of small metallic clusters]; Estudio Dinamico de Pequenos Agregados Metalicos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, M.J. [Valladolid Univ. (Spain). Dept. de Fisica Teorica; Jellinek, J. [Argonne National Lab., IL (United States)

    1995-12-31

    We present a brief introduction to computer simulation techniques (particularly to classical molecular dynamics) and their application to the study of the thermodynamic properties of a material system. The basic concepts are illustrated in the study of structural and energetic properties such as the liquid-solid transition and the fragmentation of small clusters of nickel. [Espanol] Presentamos una breve introducci{acute o}n de las t{acute e}cnicas de simulaci{acute o}n por ordenador (en particular de la Din{acute a}mica Molecular cl{acute a}sica) y de su aplicaci{acute o}n al estudio de las propiedades termodin{acute a}micas de un sistema material. Los conceptos b{acute a}sicos se ilustran en el estudio de las propieades estructurales y energ{acute e}ticas, as{acute i} como de la transici{acute o}n de fase s{acute o}lido-l{acute i}quido y de las fragmentaciones de peque{tilde n}os agregados de n{acute i}quel.

  2. Flow Rate Capacity Reduction Due to Temporal and Dynamic Processes in Large Pipelines. Study with Field Measurements; Efectos dinamicos y temporales en la reduccion de la capacidad de conduccion en grandes acueductos. Estudio con medidas en prototipo

    Energy Technology Data Exchange (ETDEWEB)

    Carmona Paredes, Rafael; Ortiz Nunez, Luis Alfonso; Sanchez Huerta, Alejandro [Universidad Nacional Autonoma de Mexico (Mexico)

    2002-06-01

    More than 15 years of operation have show that some water transport pressurized pipelines change their flow rate capacity faster than expected due to normal roughness increase. As explained by the tubular pinch effects, the radial migration of suspended particles in a flow can produce a high concentration close to the pipe wall. The non-uniform particle concentration leads to higher velocities at the center of the tube, equivalent to a reduced hydraulic section that increases the head losses. A model to explain field measurements at the Chapala-Guadalajara Aqueduct is proposed that suggests to hydraulic engineers to be more distrustful when using traditional head loss formulas to analyze water transport pipelines. [Spanish] La perdida de la capacidad de conduccion es un grave problema en la operacion de grandes acueductos. Mas de 15 anos de estudios y de inspeccion directa al interior de las tuberias de varios sistemas de abastecimiento de agua potable han mostrado el desarrollo de capas de material fino fuertemente adheridas a la pared de los tubos. En algunos casos, la variacion de la perdida de carga no ha podido ser explicada con los modelos tradicionales de crecimiento de la rugosidad interna, por lo que para explicar de forma adecuada las mediciones de campo realizadas en el acueducto Chapala-Guadalajara ha sido necesario incorporar de manera simultanea fenomenos dinamicos y temporales. Con base en el fecto de elongacion tubular (o tubular pinch effect), descrito por otros autores, mas observaciones directas al interior de las tuberias, en este trabajo se plantea como una posible de la disminucion de capacidad de conduccion en el acueducto Chapala-Guadalajara un cambio aparente en la seccion efectiva del flujo, originado por la migracion radial hacia la pared del tubo de las particulas suspendidas en el agua. El modelo que propone reproduce las medidas en campo con diferencias menores al 10% e invita a reflexionar sobre las practicas convencionales para

  3. Module generator of plans for dynamic processes; Modulo generdor de planes para procesos dinamicos

    Energy Technology Data Exchange (ETDEWEB)

    Reyes B, Alberto; Fernandez J, Jose L [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2002-07-01

    This work describes the generating module of plans (Geplan) as a part of the project: Development of Techniques of Intelligent Planning for Dynamic Processes, based on techniques of artificial intelligence, and that is being developed in the Gerencia de Control e Instrumentacion the Instituto de Investigaciones Electricas (IIE). The study case corresponds to the elaboration of a plan to help the plant operators in the task of taking a combined cycle central (CCC) to a stable state of operation given a specific load level. The architecture of the module generator of plans is presented and the codification of the actions allowed (ACT) is illustrated by means of rules, in addition the challenges that are due to face so that the system operates in line with the process. Also the technical aspects of the generator of plans, as well as the benefits and expectations of their use in any CCC are mentioned. [Spanish] En este trabajo se describe el modulo generador de planes (Geplan) como parte del proyecto Desarrollo de Tecnicas de Planificacion Inteligente para Procesos Dinamicos, basado en tecnicas de inteligencia Artificial, y que estan desarrollandose en la Gerencia de Control e Instrumentacion del Instituto de Investigaciones Electrica (IIE). El caso de estudio corresponde a la elaboracion de un plan para asistir a los operadores de planta en la tarea de llevar una central de ciclo combinado (CCC) a un estado estable de operacion dedo un nivel de carga especifico. Se presenta la arquitectura del modulo generador de planes y se ilustra la codificacion de las acciones permitidas (ACT) mediante reglas, ademas los retos que se deben enfrentar para que el sistema opere en linea con el proceso. Tambien se mencionan los aspectos tecnicos del generador de planes, asi como los beneficios y expectativas de su uso en cualquier CCC.

  4. Analysis of the nonlinear dynamic behavior of power systems using normal forms of superior order; Analisis del comportamiento dinamico no lineal de sistemas de potencia usando formas normales de orden superior

    Energy Technology Data Exchange (ETDEWEB)

    Marinez Carrillo, Irma

    2003-08-01

    of the generator and criteria and procedures are proposed to interpret the phenomenon of modal interaction. [Spanish] Esta tesis investiga la aplicacion de metodos de analisis de perturbacion de parametros en la teoria de sistemas dinamicos no lineales, al estudio de la estabilidad de pequena senal de sistemas electricos de potencia. El trabajo se centra en la determinacion de dos aspectos fundamentales de interes en el estudio del comportamiento dinamico no lineal del sistema: la caracterizacion y cuantificacion del grado de la interaccion no lineal entre los modos fundamentales de oscilacion del sistema y el estudio de los modos con mayor influencia en la respuesta del sistema ante perturbaciones pequenas. Con estos objetivos, se propone un modelo matematico general, basado en la aplicacion de la expansion en series de potencia del modelo no lineal del sistema de potencia y la teoria de formas normales de capos vectoriales para el estudio del comportamiento dinamico del sistema de potencia. La herramienta propuesta generalizada los metodos existentes en la literatura para considerar efectos de orden superior en el modelo dinamico del sistema de potencia. Partiendo de esta representacion, se propone una metodologia para obtener soluciones analiticas de lazo cerrado y se investiga la extension de los metodos existentes para identificar y cuantificar el grado de interaccion entre los modos fundamentales de oscilacion del sistema. La herramienta desarrollada permite, a partir de expresiones analiticas de lazos cerrado, el desarrollo de medidas analiticas para evaluar el grado de estres en el sistema, la interaccion entre los modos fundamentales de oscilacion y la determinacion de fronteras de estabilidad. El desarrollo conceptual del metodo propuesto en esta tesis ofrece, por otra parte, una gran flexibilidad para incorporar modelos detallados del sistema de potencia y la evaluacion de diversas medidas de la interaccion modal no lineal. Por ultimo, se presenta los

  5. Investigation of multi-phases dynamic systems by means of optical and electrochemical methods; Investigacion de sistemas dinamicos multifasicos mediante metodos opticos y electroquimicos

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento Martinez, Oscar

    2008-09-15

    During former investigations, the utilization of optical interferometric techniques was proposed to perform the monitoring of oxide layers growing or metallic degradation occurring in aluminum samples immersed in aqueous solutions, during initial stages of related oxidation processes without direct physical contact. Additionally a mathematical model was developed in order to obtain, from orthogonal displacements located in the metal surface during the anodic reaction, the metallic layer thickness loss or growth in the sample by interference fringes count. Here in this doctoral thesis, experimental and numerical results related to certain corrosion processes observed in different electrochemical systems using simultaneously Michelson interferometry optical monitoring and polarization curves electrochemical monitoring are presented. The qualitative and quantitative information resumed by important physical parameters related with the corrosion processes and their dynamics is analyzed, same as the alternated appearance and disappearance of interference patterns which optical visibility is lost and recovered as time goes by. On the other hand, a mathematical model for the optical-electrochemical system was developed in order to quantify metal loss or oxide layer growth in metallic samples, and also the reconstruction of conventional electrochemical dependences by using alternative experimental data obtained by interference maxima fringes counting. Lastly, and according to non-linear dynamical systems theoretical concepts, the non-linear parameters related to the existence of chaotic complex solutions are analyzed and discussed, based on experimental and numerical data obtained from the observation of corrosion processes of metals in aqueous solutions and hydrocarbons, during optical-electrochemical monitoring of our system. [Spanish] En un estudio previo, se propuso la utilizacion de tecnicas opticas interferometricas para monitorear el crecimiento de capas de oxidos o

  6. Dynamic analysis of piping with multiple damping mechanisms; Analisis dinamico de tuberias con multiples mecanismos de amortiguamiento

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Lopez, Pablo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    This paper describes a damping criterion that allows realizing in a more convenient form the dynamic analysis of piping and structures in general, subjected to independent stimulations, fabricated in different materials and/or damping devices. This criterion, named composed damping, is applicable to the method of modal superimposition. [Espanol] En este trabajo se describe un criterio de amortiguamiento que permite realizar en una forma mas conveniente el analisis dinamico de tuberias y estructuras en general, sujetas a excitaciones independientes, compuestas de diferentes materiales y/o mecanismos de amortiguamiento. Este criterio, denominado amortiguamiento compuesto, es aplicable en el metodo de superposicion modal.

  7. Dynamic analysis of piping with multiple damping mechanisms; Analisis dinamico de tuberias con multiples mecanismos de amortiguamiento

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Lopez, Pablo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    This paper describes a damping criterion that allows realizing in a more convenient form the dynamic analysis of piping and structures in general, subjected to independent stimulations, fabricated in different materials and/or damping devices. This criterion, named composed damping, is applicable to the method of modal superimposition. [Espanol] En este trabajo se describe un criterio de amortiguamiento que permite realizar en una forma mas conveniente el analisis dinamico de tuberias y estructuras en general, sujetas a excitaciones independientes, compuestas de diferentes materiales y/o mecanismos de amortiguamiento. Este criterio, denominado amortiguamiento compuesto, es aplicable en el metodo de superposicion modal.

  8. Importance of the dynamic module of soil rigidity in the analysis of the stability problems by the action of the seismic waves; Importancia del modulo dinamico de rigidez del suelo en el analisis de los problemas de estabilidad por la accion de las ondas sismicas

    Energy Technology Data Exchange (ETDEWEB)

    Zeevaert-Wiechers, L. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-09-01

    The object of the present paper is to motivate engineers interested in soil mechanics and in soil dynamics to use, apply and develop seismic-geodynamics principles in the professional practice of seismic engineering, as well as to study and investigate dynamic soil parameters. For this purpose the author presents two types of equipment that he has used with success during several decades. [Spanish] El objetivo de este trabajo es el de motivar a los ingenieros interesados en mecanica y dinamica de suelos, al uso, aplicacion y desarrollo de la sismo-geodinamica en la practica profesional de la ingenieria sismica, asi como al estudio e investigacion de los parametros dinamicos del suelo. Para este fin, el autor presenta dos equipos que ha usado durante varias decadas.

  9. Importance of the dynamic module of rigidity of the ground in the analysis of the problems of stability by the action of the seismic waves; Importancia del modulo dinamico de rigidez del suelo en el analisis de los problemas de estabilidad por la accion de las ondas sismicas

    Energy Technology Data Exchange (ETDEWEB)

    Zeevaert Wiechers, L. [Facultad de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2000-09-01

    The object of the present paper is to motivate engineers interested in soil mechanics and in soil dynamics to use, apply and develop seismic-geodynamics principles in the professional practice of seismic engineering, as well as to study and investigate dynamic soil parameters. For this purpose, the author present two types of equipment he has used with success during several decades. [Spanish] El objetivo de este trabajo es el de motivar a los ingenieros interesados en mecanica y dinamica de suelos, al uso, aplicacion y desarrollo de la sismo-geodinamica en la practica profesional de la ingenieria sismica, asi como al estudio e investigacion de los parametros dinamicos del suelo. Para este fin, el autor presenta dos equipos que ha usado con exito durante varias decadas.

  10. Development and application of the capacity to make tests of dynamic displacement in samples of oil well drilling cores; Desarrollo y aplicacion de la capacidad para realizar pruebas de desplazamiento dinamico en muestras de nucleos de perforacion de pozos petroleros

    Energy Technology Data Exchange (ETDEWEB)

    Contreras L, Enrique; Garcia M, Pablo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In the Laboratory of Deposits of the Gerencia de Geotermia of the Instituto de Investigaciones Electricas (IIE) the capacity has been developed to make tests of dynamic oil displacement by means of gas or brine injection in samples of oil well drilling cores. Also the methodologies to interpret the results of these tests in terms of dynamics and the efficiency of the oil recovery in terms of the relative permeability have been developed. These capacities represent a very important contribution towards the improvement of the insufficiency that exists in the country to make the large amount of tests of dynamic displacement that demand the different Actives of PEMEX Exploration and Production (PEP), since they satisfy their necessities of data on which the activities of design and implementation of the most suitable techniques for the hydrocarbon recovery of the oil deposits lean. In the present work these capacities are described and some examples are presented of the results that have been obtained from their application in special studies of drilling cores, which have been recently made in the Laboratory of Deposits of the IIE for diverse Actives of PEP exploitation. [Spanish] En el laboratorio de yacimientos de la Gerencia de Geotermia del Instituto de Investigaciones Electricas (IIE) se ha desarrollado la capacidad de realizar pruebas de desplazamiento dinamico de aceite mediante inyeccion de salmuera o de gases en muestras de nucleos de perforacion de pozos petroleros. Tambien se han desarrollado las metodologias para interpretar los resultados de estas pruebas en terminos de la dinamica y la eficiencia de la recuperacion de aceite y en terminos de la permeabilidades relativas. Estas capacidades representan una contribucion muy importante hacia el mejoramiento de la insuficiencia que existe en el pais para realizar la gran cantidad de pruebas de desplazamiento dinamico que demandan los diferentes activos de explotacion de PEMEX Exploracion y Produccion (PEP), ya

  11. clusters

    Indian Academy of Sciences (India)

    2017-09-27

    Sep 27, 2017 ... Author for correspondence (zh4403701@126.com). MS received 15 ... lic clusters using density functional theory (DFT)-GGA of the DMOL3 package. ... In the process of geometric optimization, con- vergence thresholds ..... and Postgraduate Research & Practice Innovation Program of. Jiangsu Province ...

  12. clusters

    Indian Academy of Sciences (India)

    environmental as well as technical problems during fuel gas utilization. ... adsorption on some alloys of Pd, namely PdAu, PdAg ... ried out on small neutral and charged Au24,26,27, Cu,28 ... study of Zanti et al.29 on Pdn (n = 1–9) clusters.

  13. Measurement and calculation of dynamic coefficients in hydrodynamic bearings of gas films; Medicion y calculo de coeficientes dinamicos en cojinetes hidrodinamicos de peliculas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Rafael O.; Di Liscia, Marcelo H.; Diaz, Sergio E. [Universidad Simon Bolivar, Sartendejas, Baruta (Venezuela)

    2007-11-15

    dynamic coefficients. [Spanish] La identificacion de los coeficientes dinamicos en cojinetes de aire es fundamental para un adecuado analisis rotodinamico. El presente trabajo muestra el desarrollo de un algoritmo que permite la obtencion directa de los coeficientes dinamicos en cojinetes hidrodinamicos de aire tanto de forma numerica como experimental. El banco de pruebas utilizado consta de dos cojinetes magneticos, los cuales soportan al rotor en sus extremos y a su vez funcionan como actuadores permitiendo inducir orbitas controladas en el rotor. El cojinete de prueba se encuentra ubicado entre los cojinetes magneticos. Las fuerzas dinamicas generadas en el cojinete de aire se registran a partir de tres celdas de carga. El algoritmo fue desarrollado en un codigo comercial de programacion grafica, a traves del cual se pueden colectar, controlar y procesar las senales. El comportamiento no lineal de este tipo de cojinetes dificulta el calculo de los coeficientes dinamicos, por esta razon el procesamiento de las senales en espacio frecuencial facilita de cierta manera su manejo. Por otra parte, el modelo numerico se comparo con los resultados experimentales obteniendo aproximaciones aceptables tanto en magnitud como en comportamiento. El calculo de los coeficientes dinamicos numericos se realizo resolviendo la ecuacion diferencial de Reynolds para un fluido compresible en el espesor de la pelicula de gas, tomando en consideracion el flujo masico del fluido que se introduce, asi como la perdida de presion que sufre el mismo al pasar a traves de los orificios de alimentacion. Los metodos numericos utilizados incluyen la resolucion de la ecuacion diferencial de Reynolds por diferencias finitas, el calculo del perfil de presiones realizando iteraciones sucesivas y el calculo de las fuerzas hidrodinamicas a traves de una integracion numerica de Simpson. Los coeficientes dinamicos numericos fueron hallados aplicando una tecnica de minimos cuadrados a las fuerzas hidrodinamicas

  14. Steady state analysis and Eastern power system dynamic PDVSA EyP considering incorporating Furrial and PIGAP II generation plants; Analisis en regimen permanente y dinamico del sistema electrico de PDVSA EyP Oriente considerando la incorporacion de las plantas de generacion Furrial y PIGAP II

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, S [Universidad Nacional Experimental Politecnica, Antonio Jose de Sucre, Guayana, Bolivar (Venezuela)]. E-mail: sergiodrg200@gmail.com; Vasquez, C [Petroleos de Venezuela S.A., Maturin, Monagas (Venezuela)]. E-mail: vasquezcp@pdvsa.com

    2013-03-15

    Sector Electrico Nacional. Para el estudio de arranque de motores se determino el modelo dinamico del motor mayor mediante la estimacion de los parametros de su circuito equivalente, asi como la aplicacion del metodo de regresion no lineal para obtener el modelo de la carga partiendo de los datos caracteristicos suministrados por el fabricante.

  15. Minería de datos con técnica cluster, caso de estudio: estudiantes de Universidad Estatal Península de Santa Elena.

    Directory of Open Access Journals (Sweden)

    Mariuxi De La Cruz

    2015-10-01

    Full Text Available Este trabajo fue realizado para la Universidad Estatal Península de Santa Elena, muestra el proceso de minería de datos aplicando la técnica cluster o conglomerado, con herramientas de software libre como: PostgreSQL, apropiada para el almacenamiento de los datos y R para el análisis estadístico y la generación de los algoritmos que implica la técnica. El análisis cluster fue implementado en datos sociales, económicos y académicos de los estudiantes inscritos en la Facultad de Sistemas y Telecomunicaciones de esta institución de educación superior. El proceso es detallado en tres secciones, la primera donde se describe los conceptos  asociados a minería de datos, técnica cluster y las herramientas tecnológicas utilizadas para explotación de información. En la segunda sección  se describe el proceso de aplicación la técnica cluster con el método particional y con el método jerárquico. En la sección tres se muestra los conglomerados obtenidos al aplicar la técnica en el grupo de datos. Finalmente se presentan las conclusiones y recomendaciones de este trabajo.

  16. Studies of pyrolysis kinetics of sewage sludge obtained from dynamic experiments; Estudio cinetico de la pirolisis de fangos mediante experimentos dinamicos

    Energy Technology Data Exchange (ETDEWEB)

    Arauzo, J; Gonzalo, A; Sanchez, J L [Universidad de Zaragoza, Madrid (Spain). Inst. de Investigacion en Ingenieria de Aragon. Grupo de Procesos Termoquimicos; Resende, F L.P. [University of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering; Rocha, J D [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE); Mesa Perez, J M [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Agricola

    2004-07-01

    In this work, a pyrolysis model is presented in order to describe the pyrolysis kinetics of sewage sludge. Data were obtained from dynamic experiments, at heating rates of 5 to 20 deg C/min and in a temperature range of 40 to 900 deg C. A simple first order or near first order can predict reasonably well the final conversion reached, but, in what concerns the weight loss rate, a simple model cannot predict the peaks obtained in the weight loss rate. As it is shown, the best fit has been obtained by a model which takes into account four fractions which decompose independently following a first order kinetics. (author)

  17. Cluster-cluster clustering

    International Nuclear Information System (INIS)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.; Yale Univ., New Haven, CT; California Univ., Santa Barbara; Cambridge Univ., England; Sussex Univ., Brighton, England)

    1985-01-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales. 30 references

  18. Estudio EPIFARM

    Directory of Open Access Journals (Sweden)

    Martín Morales A

    2010-12-01

    Full Text Available INTRODUCCIÓN Los farmacéuticos comunitarios pueden ser un importante primer punto de contacto con los pacientes con disfunción eréctil (DE, pero hasta la fecha no hay ningún estudio sobre las características de los hombres que acuden a un farmacéutico solicitando consejo o tratamiento para la DE. OBJETIVO Caracterizar los perfiles de los hombres que solicitan tratamiento para la DE en la farmacia, con o sin receta de inhibidores de la fosfodiesterasa tipo 5 (iPDE5. MÉTODOS Entre septiembre y noviembre de 2008 se realizó un estudio observacional, transversal y multicéntrico en farmacias comunitarias de España. De aquellos hombres que solicitaban consejo o tratamiento para la DE, cada investigador reclutó un paciente que tenía receta médica de iPDE5 y otro que acudía sin receta médica. Los farmacéuticos del estudio completaron un cuestionario de datos demográficos, clínicos y conductuales del paciente, incluido el Cuestionario de salud sexual para varones (Sexual Health Inventory for Men. VARIABLES PRINCIPALES Características demográficas y respuestas a los cuestionarios. RESULTADOS 574 farmacéuticos seleccionaron a 1.147 pacientes, de los cuales 1.113 fueron incluidos en el análisis. No se observaron diferencias estadísticas entre los grupos en cuanto al peso, la hipertensión, la diabetes mellitus, la hipercolesterolemia, la dislipidemia, la depresión o el estrés. Tampoco se observaron diferencias estadísticas respecto a la gravedad de la DE (p = 0,7892 ni a la proporción de hombres sin DE en cada grupo (p = 0,5755. En ambos grupos, los pacientes habían presentado síntomas de DE durante una media de veintiséis meses antes de la primera consulta a un profesional sanitario. Para el 60,2% de los pacientes incluidos en el grupo sin receta, la visita a la farmacia fue la primera ocasión en la que habían hablado de su DE con un profesional sanitario, y el 50% de aquellos que habían hablado previamente de la DE lo hab

  19. TEORIA DEL FUNCIONAL DE LA DENSIDAD APLICADA AL ESTUDIO DE LA ADSORCIÓN Y DISOCIACIÓN DE HIDRÓGENO MOLECULAR SOBRE PEQUEÑOS CLUSTERS DE MOLIBDENO

    Directory of Open Access Journals (Sweden)

    Samanta M. Carrión

    2011-01-01

    Full Text Available Este trabajo presenta un estudio basado en la Teoría del Funcional de la Densidad, de la adsorción y disociación de hidrógeno molecular sobre pequeños clusters de molibdeno, desde un dímero a un hexámero. Para el mismo se utilizó el funcional de intercambio de Becke y el funcional de correlación de Lee, Yang y Parr, tal como está implementado en el programa ADF. Las funciones base utilizadas son de calidad triple zeta con funciones de polarización. Todas las estructuras fueron optimizadas para distintas multiplicidades de espín hasta encontrar la mínima energía. Se determinaron distancias interatómicas, energías de adsorción y barreras energéticas de los sistemas más estables de la serie MonH2 (n=2-6. Los resultados muestran que las estructuras más estables de los agregados son las que poseen un estado de espín singlete. Se obtuvieron barreras energéticas en todos los casos.

  20. Incorporation of a wind generator model into a dynamic power flow analysis; Incorporacion de un modelo de generador eolico al analisis de flujos dinamicos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Angeles Camacho, C.; Banuelos Ruedas, F. [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: cangelesc@iingen.unam.mx; fbanuelosr@iingen.unam.mx

    2011-07-15

    dinamicos de potencia. El modelo de la turbina toma en cuenta las velocidades del viento y la potencia reactiva consumida por el generador de induccion. El analisis de los flujos dinamicos de potencia que se presenta aqui, se realiza en funcion de los datos reales de la velocidad del viento recolectados en una estacion de monitoreo del estado de Zacatecas en intervalos de 10 minutos. La generacion inyectada en una parte de la red proporciona potencia localmente, reduciendo las perdidas globales del sistema. Sin embargo, la variacion de la potencia entregada por la central eolica causa fluctuaciones de la magnitud de voltaje y de los flujos de potencia en las lineas de transmision.

  1. Clustering of near clusters versus cluster compactness

    International Nuclear Information System (INIS)

    Yu Gao; Yipeng Jing

    1989-01-01

    The clustering properties of near Zwicky clusters are studied by using the two-point angular correlation function. The angular correlation functions for compact and medium compact clusters, for open clusters, and for all near Zwicky clusters are estimated. The results show much stronger clustering for compact and medium compact clusters than for open clusters, and that open clusters have nearly the same clustering strength as galaxies. A detailed study of the compactness-dependence of correlation function strength is worth investigating. (author)

  2. Internationalization of companies in industrial clusters: a study of medical, dental and hospital supply industries in Ribeirão Preto - SP Internacionalización de empresas en clusters industriales: un estudio aplicado en el polo médico-hospitalar-odontológico de Ribeirão Preto - SP Internacionalização de empresas em clusters industriais: um estudo aplicado no polo médico-hospitalar-odontológioco de Ribeirão Preto - SP

    Directory of Open Access Journals (Sweden)

    Gustavo Barbieri Lima

    2011-03-01

    Full Text Available A trend, both national and international, has been identified in academic research, as well as in business and government. Micro, small and medium sized companies have sought to organize strategic networks of inter-organizational cooperation to be more competitive in their markets or even ensure survival in face of fierce competition arising from globalization. This research investigated relations of the internationalization process that allow these companies to cooperate in industrial clusters and local productive arrangements as opposed to penetration of individual companies in international markets. The method of case study was used to carry out this research. Results show that these companies are very much in favor of the internationalization process, and that this center may now be characterized as an exporter. Inter-organizational cooperation was cited by SEBRAE-SP as extremely important not only for survival of companies monitored, but also for their entry into international markets and increased exportsUna tendencia, tanto en el ámbito nacional como en el internacional, ha sido evidente en investigaciones académicas, como también en los medios empresariales y gubernamentales: la de empresas, especialmente micro, pequeñas y medianas, que buscan organizarse en redes estratégicas de cooperación ínter organizacionales, para mantenerse competitivas en los mercados donde actúan o, precisamente, para asegurar su sobrevivencia delante de la instigada competición proveniente del proceso denominado globalización de mercados. El objetivo general del presente estudio es investigar las interconexiones del proceso de internacionalización que les permite a las micro y pequeñas empresas cooperar en clusters industriales o arreglos productivos locales, en contrapunto a la inserción individual de las empresas en los mercados internacionales. Se utilizó el método de estudio de caso para la realización de la presente investigación. Como

  3. de estudios observacionales

    Directory of Open Access Journals (Sweden)

    Erik von Elm

    2008-01-01

    un documento de explicación y elaboración al que puede accederse libremente en los sitios web de PLoS Medicine, Annals of Internal Medicine y Epidemiology. Esperamos que la declaración STROBE contribuya a mejorar la calidad de la publicación de los estudios observacionales.

  4. Dynamic analysis of the condensate and of the feed water in the Laguna Verde nuclear power station; Analisis dinamico del sistema de condensado y agua de alimentacion de la nucleoelectrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Muth, Javier; Sandoval Pena, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This article shows a non-lineal mathematical model for the condensate, and feed water systems and for feed water heater drains at the Laguna Verde Nuclear Power Station for its simulation in real time. The model allows the calculation of flows and pressures in all the piping system and equipment that integrate the systems. It was obtained by using the force unbalance in the fluid concept and is capable of reproducing its dynamic behavior through variations induced by the different operation modes and more common failures. The final model objective is to form part of the Laguna Verde simulator that will be used for operator training of this Nuclear Power Plant. [Espanol] En este articulo se muestra un modelo matematico no lineal de los sistemas de condensado, agua de alimentacion y drenes de calentadores de la central nuclear de Laguna Verde para su simulacion en tiempo real. El modelo permite calcular los flujos y las presiones en toda la red de tuberias y equipos que integran los sistemas. Se obtuvo utilizando el concepto de desbalance de fuerzas en el fluido, y es capaz de reproducir su comportamiento dinamico ante variaciones inducidas por los diversos modos de operacion y fallas mas comunes. El objetivo final del modelo es formar parte del simulador de Laguna Verde que se empleara para el adiestramiento de los operadores de dicha central nuclear.

  5. Estudio de validez predictiva

    OpenAIRE

    Barquero-Segura, José Antonio

    2003-01-01

    Proyecto de investigación Este documento es un informe ejecutivo de la información obtenida de los estudios sobre la validez predictiva de los parámetros de selección de estudiantes y su relación con el rendimiento académico. En él se presenta una síntesis de información más relevante obtenida en los últimos 17 años.

  6. un estudio comparativo

    Directory of Open Access Journals (Sweden)

    Federico Varona

    2007-01-01

    Full Text Available La comunicación efectiva es uno de los mayores retos que tienen hoy las organizaciones y empresas tanto a nivel nacional como internacional (global. Este artículo presenta los resultados de la investigación realizada por un equipo internacional de investigadores interesados en descubrir y comparar las conductas comunicativas o estilos de comunicación de los empleados finlandeses y mexicanos cuando interactúan con sus superiores. Para ello presentamos: primero, un breve marco teórico del estudio; segundo, la metodología; tercero, los resultados del análisis estadístico comparativo entre los empleados de Finlandia y México; cuarto, las conclusiones generales y su explicación cultural; y quinto, las implicaciones teóricas y prácticas de este estudio con respecto a las competencias comunicativas necesarias para la comunicación efectiva entre empleados y superiores tanto en organizaciones nacionales como internacionales (globales.

  7. Cluster headache

    Science.gov (United States)

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... Doctors do not know exactly what causes cluster headaches. They ... (chemical in the body released during an allergic response) or ...

  8. Dos estudios de casos

    Directory of Open Access Journals (Sweden)

    Hernán Guillermo Salazar Morales

    1989-04-01

    Full Text Available RESUMEN A continuación se presenta dos casos de estudio en donde se puede apreciar a la forma  como se establecen  las relaciones en una organización y lo que una DECISION  puede llegar a incidir en el desarrollo de las operaciones de una empresa. Decisiones basadas en la intuición, o en corazonadas, frecuentemente conducen en dirección equivocada, ocasionando pérdidas en tiempo, personal y dinero. El proceso de toma de decisiones deben ser TAREAS ESTRUCTURADAS que se sustenten con hechos. Su ejecución debe hacerse secuencialmente y cumplir con cada uno de sus pasos. El diseño de los  casos está orientado para que  sirvan como material de aplicación en la asignatura de  taller de planeación.

  9. DE AGUA. ESTUDIO PRELIMINAR

    Directory of Open Access Journals (Sweden)

    Esther E. Pellizzari

    2015-01-01

    Full Text Available El objetivo del presente estudio fue investigar la resistencia al arsénico en cultivos puros de Pseudomonas aeruginosa , aislada de aguas subterráneas de Presidencia Roque Sáenz Peña, provincia de Chaco y evaluar la posibilidad de su uso para la remoción de este contaminante presente en las aguas subterráneas. Las cepas fueron inmovilizadas en piedra natural y se cu ltivaron en caldo de sales y 1 mgAs/L . Se observó la resistencia al arsénico y la formación de biofilm , logrando la interacción entre la s células, roca y arsénico . L a remoción de arsénico se evaluó durante 3 meses y el porcentaje de eliminación de arsénico al final del experimento fue 60%.

  10. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  11. Application of the identification methods from Hilbert and Prony to the study of oscillatory phenomena in electrical power systems; Aplicacion de los metodos de identificacion de Hilbert y Prony al estudio de fenomenos oscilatorios en sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Soto, Manuel Antonio

    2002-10-15

    In the present thesis work the application of identification techniques is investigated based on methods of spectral analysis to the study of the instantaneous characteristics of signals obtained by means of digital simulation of the dynamic behavior of the power system. The study focuses on the perspectives developed from two different approaches of analysis: the use of lineal methods of spectral analysis and the use of methods of non-lineal analysis, based on the concept of an analytical signal. The developed tools are applied to the study of two phenomena of electromechanical origin of different characteristics in complex power systems. A comparison between the results obtained is performed for these techniques and the possibility of its application is discussed for the problem of on-line identification in power systems. [Spanish] En el presente trabajo de tesis se investiga la aplicacion de tecnicas de identificacion basadas en metodos de analisis espectral al estudio de las caracteristicas instantaneas de senales obtenidas mediante simulacion digital del comportamiento dinamico del sistema de potencia. El estudio se centra en las aproximaciones desarrolladas desde dos enfoques distintos de analisis: la utilizacion de metodos lineales de analisis espectral y la utilizacion de metodos de analisis no lineal, basados en el concepto de una senal analitica. Las herramientas desarrolladas se aplican al estudio de dos fenomenos de origen electromecanico de caracteristicas distintas en sistemas complejos de potencia. Se hace una comparacion entre los resultados obtenidos por estas tecnicas y se discute la posibilidad de su aplicacion al problema de identificacion en linea en sistemas de potencia.

  12. Cluster management.

    Science.gov (United States)

    Katz, R

    1992-11-01

    Cluster management is a management model that fosters decentralization of management, develops leadership potential of staff, and creates ownership of unit-based goals. Unlike shared governance models, there is no formal structure created by committees and it is less threatening for managers. There are two parts to the cluster management model. One is the formation of cluster groups, consisting of all staff and facilitated by a cluster leader. The cluster groups function for communication and problem-solving. The second part of the cluster management model is the creation of task forces. These task forces are designed to work on short-term goals, usually in response to solving one of the unit's goals. Sometimes the task forces are used for quality improvement or system problems. Clusters are groups of not more than five or six staff members, facilitated by a cluster leader. A cluster is made up of individuals who work the same shift. For example, people with job titles who work days would be in a cluster. There would be registered nurses, licensed practical nurses, nursing assistants, and unit clerks in the cluster. The cluster leader is chosen by the manager based on certain criteria and is trained for this specialized role. The concept of cluster management, criteria for choosing leaders, training for leaders, using cluster groups to solve quality improvement issues, and the learning process necessary for manager support are described.

  13. MEXCODE* CASO DE ESTUDIO

    Directory of Open Access Journals (Sweden)

    Gabriel Arturo García Gómez

    2000-01-01

    Full Text Available El caso plantea la reactivación de un proyecto que se presentó en el año 1995 como alternativa para el desarrollo del centro del Valle y mejora de la eficiencia en el manejo del comercio exterior de la Cuenca Pacífica. El proyecto se revivió a raíz de la necesidad de la compañía patrocinadora de mejorar sus flujos de caja proyectados y la reciente autorización para su funcionamiento. El proyecto es el popularmente denominado “Puerto Seco” de la ciudad de Guadalajara de Buga, internamente nombrado Mexcode. Los estudios iniciales estaban encaminados a que el proyecto fuera manejado por el municipio de Buga, sin embargo, posteriormente se vio la necesidad de buscar que pasara a manos de la empresa privada. El municipio, después de analizar las propuestas de varios inversionistas de la región en las cuales se evaluaba la ubicación dentro de la zona de los predios de sus empresas, su área, proximidad a la línea férrea y a la doble calzada Buga-Tuluá (sitio de paso del 80% de la carga de importación y exportación por Buenaventura y evaluar aspectos relativos a su trayectoria empresarial y compromiso con el desarrollo de la región, decidió otorgarle el proyecto al Grupo Empresarial Agri-Supplies S.A.

  14. Estudio del CH interestelar

    Science.gov (United States)

    Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.

    El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.

  15. Isotopic clusters

    International Nuclear Information System (INIS)

    Geraedts, J.M.P.

    1983-01-01

    Spectra of isotopically mixed clusters (dimers of SF 6 ) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  16. Cluster Headache

    Science.gov (United States)

    ... a role. Unlike migraine and tension headache, cluster headache generally isn't associated with triggers, such as foods, hormonal changes or stress. Once a cluster period begins, however, drinking alcohol ...

  17. Cluster Headache

    OpenAIRE

    Pearce, Iris

    1985-01-01

    Cluster headache is the most severe primary headache with recurrent pain attacks described as worse than giving birth. The aim of this paper was to make an overview of current knowledge on cluster headache with a focus on pathophysiology and treatment. This paper presents hypotheses of cluster headache pathophysiology, current treatment options and possible future therapy approaches. For years, the hypothalamus was regarded as the key structure in cluster headache, but is now thought to be pa...

  18. Categorias Cluster

    OpenAIRE

    Queiroz, Dayane Andrade

    2015-01-01

    Neste trabalho apresentamos as categorias cluster, que foram introduzidas por Aslak Bakke Buan, Robert Marsh, Markus Reineke, Idun Reiten e Gordana Todorov, com o objetivo de categoriíicar as algebras cluster criadas em 2002 por Sergey Fomin e Andrei Zelevinsky. Os autores acima, em [4], mostraram que existe uma estreita relação entre algebras cluster e categorias cluster para quivers cujo grafo subjacente é um diagrama de Dynkin. Para isto desenvolveram uma teoria tilting na estrutura triang...

  19. Meaningful Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2004-05-26

    We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.

  20. Horticultural cluster

    OpenAIRE

    SHERSTIUK S.V.; POSYLAYEVA K.I.

    2013-01-01

    In the article there are the theoretical and methodological approaches to the nature and existence of the cluster. The cluster differences from other kinds of cooperative and integration associations. Was develop by scientific-practical recommendations for forming a competitive horticultur cluster.

  1. Estenosis traqueal: Estudio preliminar

    Directory of Open Access Journals (Sweden)

    Rafael Pinilla González

    2000-12-01

    Full Text Available Se realizó un estudio retrospectivo y descriptivo con la utilización de los expedientes clínicos de 5 pacientes con estenosis traqueal, mayoritariamente como consecuencia de intubación prolongada, y en el que se tuvo en cuenta aspectos relacionados con el diagnóstico, el tratamiento y las complicaciones. Existió un predominio del sexo femenino y edad media de 44,6 años. La intubación prolongada de origen diverso fue la causa de la estenosis en 4 de los 5 pacientes y en 1 fue posterior a la reparación de lesión traqueal yatrógena. La instalación de la estenosis tuvo lugar entre 8 días y 3 meses. La tomografía lineal en 3 pacientes y en 2 la radiografía simple de tráquea anteroposterior y lateral verificaron el diagnóstico. La endoscopia traqueobronquial preoperatoria fue de utilidad en la caracterización de la estenosis. En todos los pacientes se realizó tratamiento quirúrgico al resecar el área estenótica con posterior anastomosis terminoterminal y fijación del cuello en flexión durante 8 días como promedio. Dos pacientes mostraron granulomas en el nivel de la línea de sutura, los cuales fueron tratados por vacuolización con láser. No se reportó mortalidad en la muestra estudiadaA retrospective and descriptive study was conducted by using the medical histories of 5 patients with tracheal stenosis, mostly as a result of prolongued intubation. Aspects connected with the diagnosis, treatment and complications were taken into account. It was observed a predominance of females and an average age of 44.6. Prolongued intubation of different origin was the cause of stenosis in 4 of the 5 patients, whereas in the other it occurred after the reparation of the tracheal and athrogenous lesion. The installation of stenosis took place between 8 days and 3 months. Lineal tomography in 3 patients and anteroposterior and lateral simple X-ray of the trachea in 2 confirmed the diagnosis. Preoperative tracheobronchial endoscopy was

  2. Cluster Matters

    DEFF Research Database (Denmark)

    Gulati, Mukesh; Lund-Thomsen, Peter; Suresh, Sangeetha

    2018-01-01

    sell their products successfully in international markets, but there is also an increasingly large consumer base within India. Indeed, Indian industrial clusters have contributed to a substantial part of this growth process, and there are several hundred registered clusters within the country...... of this handbook, which focuses on the role of CSR in MSMEs. Hence we contribute to the literature on CSR in industrial clusters and specifically CSR in Indian industrial clusters by investigating the drivers of CSR in India’s industrial clusters....

  3. Competitive and innovation factors in wine tourism clusters: A comparative study between consolidated and emerging regions in Brazil and Uruguay / Factores de competitividad e innovación en clusters enoturísticos: Un estudio comparativo entre las regiones consolidadas y emergentes en Brasil y Uruguay

    Directory of Open Access Journals (Sweden)

    Flores Shana Sabbado

    2016-01-01

    Full Text Available The purpose of this article is to establish a cross-country analysis of the structure and organization of wine tourism clusters in consolidated and emerging wine regions in Brazil and Uruguay, looking for identifying the key factors for competitiveness and innovation. The regions chosen for analysis are: Vale dos Vinhedos, Campanha and Vale do São Francisco, in Brazil, and sites on Montevideo and Canelones, in Uruguay. The study analyze competitive factors in each region, including: the structure and density, support institutions at national and regional level, educational and research institutions, organization process for the geographical indication and the relationship between wine tourism and the promotion of wine and region. Further than comparing the two countries, the research also puts stop regions according to their stage of development in each assessed factor. Thus, the study suggests strategies that can be adopted at regional level or in cooperation between regions (in the country or bi-national cooperation to strengthen and develop the tourist areas of the wine as a whole.

  4. Estudios Experimentales 2 Parte: Estudios Cuasi-Experimentales

    OpenAIRE

    Manterola, Carlos; Otzen, Tamara

    2015-01-01

    Los estudios experimentales, se caracterizan por la valoración del efecto de una o más intervenciones, habitualmente de forma comparativa con otra intervención, o un placebo; y el carácter prospectivo, de la recolección de datos y seguimiento. Agrupados bajo esta denominación, existe una diversidad de diseños, entre los que se encuentran los estudios cuasi-experimentales (ECE), que se caracterizan especialmente por la ausencia de asignación aleatoria. El objetivo de este manuscrito, es report...

  5. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    On obtaining a new data set, the researcher is immediately faced with the challenge of obtaining a high-level understanding from the observations. What does a typical item look like? What are the dominant trends? How many distinct groups are included in the data set, and how is each one characterized? Which observable values are common, and which rarely occur? Which items stand out as anomalies or outliers from the rest of the data? This challenge is exacerbated by the steady growth in data set size [11] as new instruments push into new frontiers of parameter space, via improvements in temporal, spatial, and spectral resolution, or by the desire to "fuse" observations from different modalities and instruments into a larger-picture understanding of the same underlying phenomenon. Data clustering algorithms provide a variety of solutions for this task. They can generate summaries, locate outliers, compress data, identify dense or sparse regions of feature space, and build data models. It is useful to note up front that "clusters" in this context refer to groups of items within some descriptive feature space, not (necessarily) to "galaxy clusters" which are dense regions in physical space. The goal of this chapter is to survey a variety of data clustering methods, with an eye toward their applicability to astronomical data analysis. In addition to improving the individual researcher’s understanding of a given data set, clustering has led directly to scientific advances, such as the discovery of new subclasses of stars [14] and gamma-ray bursts (GRBs) [38]. All clustering algorithms seek to identify groups within a data set that reflect some observed, quantifiable structure. Clustering is traditionally an unsupervised approach to data analysis, in the sense that it operates without any direct guidance about which items should be assigned to which clusters. There has been a recent trend in the clustering literature toward supporting semisupervised or constrained

  6. Cluster evolution

    International Nuclear Information System (INIS)

    Schaeffer, R.

    1987-01-01

    The galaxy and cluster luminosity functions are constructed from a model of the mass distribution based on hierarchical clustering at an epoch where the matter distribution is non-linear. These luminosity functions are seen to reproduce the present distribution of objects as can be inferred from the observations. They can be used to deduce the redshift dependence of the cluster distribution and to extrapolate the observations towards the past. The predicted evolution of the cluster distribution is quite strong, although somewhat less rapid than predicted by the linear theory

  7. Clustering Dycom

    KAUST Repository

    Minku, Leandro L.

    2017-10-06

    Background: Software Effort Estimation (SEE) can be formulated as an online learning problem, where new projects are completed over time and may become available for training. In this scenario, a Cross-Company (CC) SEE approach called Dycom can drastically reduce the number of Within-Company (WC) projects needed for training, saving the high cost of collecting such training projects. However, Dycom relies on splitting CC projects into different subsets in order to create its CC models. Such splitting can have a significant impact on Dycom\\'s predictive performance. Aims: This paper investigates whether clustering methods can be used to help finding good CC splits for Dycom. Method: Dycom is extended to use clustering methods for creating the CC subsets. Three different clustering methods are investigated, namely Hierarchical Clustering, K-Means, and Expectation-Maximisation. Clustering Dycom is compared against the original Dycom with CC subsets of different sizes, based on four SEE databases. A baseline WC model is also included in the analysis. Results: Clustering Dycom with K-Means can potentially help to split the CC projects, managing to achieve similar or better predictive performance than Dycom. However, K-Means still requires the number of CC subsets to be pre-defined, and a poor choice can negatively affect predictive performance. EM enables Dycom to automatically set the number of CC subsets while still maintaining or improving predictive performance with respect to the baseline WC model. Clustering Dycom with Hierarchical Clustering did not offer significant advantage in terms of predictive performance. Conclusion: Clustering methods can be an effective way to automatically generate Dycom\\'s CC subsets.

  8. Clustering analysis

    International Nuclear Information System (INIS)

    Romli

    1997-01-01

    Cluster analysis is the name of group of multivariate techniques whose principal purpose is to distinguish similar entities from the characteristics they process.To study this analysis, there are several algorithms that can be used. Therefore, this topic focuses to discuss the algorithms, such as, similarity measures, and hierarchical clustering which includes single linkage, complete linkage and average linkage method. also, non-hierarchical clustering method, which is popular name K -mean method ' will be discussed. Finally, this paper will be described the advantages and disadvantages of every methods

  9. Cluster analysis

    CERN Document Server

    Everitt, Brian S; Leese, Morven; Stahl, Daniel

    2011-01-01

    Cluster analysis comprises a range of methods for classifying multivariate data into subgroups. By organizing multivariate data into such subgroups, clustering can help reveal the characteristics of any structure or patterns present. These techniques have proven useful in a wide range of areas such as medicine, psychology, market research and bioinformatics.This fifth edition of the highly successful Cluster Analysis includes coverage of the latest developments in the field and a new chapter dealing with finite mixture models for structured data.Real life examples are used throughout to demons

  10. Cluster editing

    DEFF Research Database (Denmark)

    Böcker, S.; Baumbach, Jan

    2013-01-01

    . The problem has been the inspiration for numerous algorithms in bioinformatics, aiming at clustering entities such as genes, proteins, phenotypes, or patients. In this paper, we review exact and heuristic methods that have been proposed for the Cluster Editing problem, and also applications......The Cluster Editing problem asks to transform a graph into a disjoint union of cliques using a minimum number of edge modifications. Although the problem has been proven NP-complete several times, it has nevertheless attracted much research both from the theoretical and the applied side...

  11. Occupational Clusters.

    Science.gov (United States)

    Pottawattamie County School System, Council Bluffs, IA.

    The 15 occupational clusters (transportation, fine arts and humanities, communications and media, personal service occupations, construction, hospitality and recreation, health occupations, marine science occupations, consumer and homemaking-related occupations, agribusiness and natural resources, environment, public service, business and office…

  12. Fuzzy Clustering

    DEFF Research Database (Denmark)

    Berks, G.; Keyserlingk, Diedrich Graf von; Jantzen, Jan

    2000-01-01

    A symptom is a condition indicating the presence of a disease, especially, when regarded as an aid in diagnosis.Symptoms are the smallest units indicating the existence of a disease. A syndrome on the other hand is an aggregate, set or cluster of concurrent symptoms which together indicate...... and clustering are the basic concerns in medicine. Classification depends on definitions of the classes and their required degree of participant of the elements in the cases' symptoms. In medicine imprecise conditions are the rule and therefore fuzzy methods are much more suitable than crisp ones. Fuzzy c......-mean clustering is an easy and well improved tool, which has been applied in many medical fields. We used c-mean fuzzy clustering after feature extraction from an aphasia database. Factor analysis was applied on a correlation matrix of 26 symptoms of language disorders and led to five factors. The factors...

  13. Cluster generator

    Science.gov (United States)

    Donchev, Todor I [Urbana, IL; Petrov, Ivan G [Champaign, IL

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  14. Cluster Bulleticity

    OpenAIRE

    Massey, Richard; Kitching, Thomas; Nagai, Daisuke

    2010-01-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, such as the bullet cluster (1E 0657−56) and baby bullet (MACS J0025−12). These systems provide evidence for an additional, invisible mass in the separation between the distributions of their total mass, measured via gravitational lensing, and their ordinary ‘baryonic’ matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by their rarity. C...

  15. Cluster headache

    OpenAIRE

    Leroux, Elizabeth; Ducros, Anne

    2008-01-01

    Abstract Cluster headache (CH) is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes) of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye). It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name) in bouts that can occur ...

  16. Estudios sobre plantas andinas,- V

    Directory of Open Access Journals (Sweden)

    Cuatrecasas José

    1943-12-01

    Full Text Available Desde hace diez años, he venido interesándome por el conocimiento y clasificación del género Diplostephium, distribuido abundantemente en las zonas frías de los Andes, desde Venezuela al norte de Chile con un enclave en Costa Rica. Las excursiones realizadas en 1932 me permitieron descubrir dos nuevas especies colombianas (1 y el estudio de la colección Isern me dio oportunidad de conocer otras especies ecuatorianas y peruanas (2. A raíz del abundante material recogido en mis excursiones por Colombia desde el año 1938, decidí llevar a cabo el estudio monográfico del género; para ella diversos centros de los Estados Unidos pusieron a mi disposición sus coIecciones: Smithsonian Institution (United States National Herbarium, Field Museum of Natural History de Chicago y New York Botanical Garden, los cuales me remitieron el material para este fin al Instituto de Ciencias Naturales de Bogotá; el trabajo fue iniciado en este centro, pero al trasladarme a la Escuela Superior de Agricultura Tropical de Cali, la dirección del Instituto me permitió llevar para el Valle todos los ejemplares, incluso los del Herbario Nacional Colombiano, y así pude concluir el estudio provisional, en mi nuevo lugar de trabajo.

  17. Estudios sobre Plantas Andinas, X

    Directory of Open Access Journals (Sweden)

    Cuatrecasas José

    1967-09-01

    Full Text Available Durante la preparación del género Baccharis para Prima Flora Colombiana tuve que estudiar gran número de especies andinas, tropicales y extratropicales de fuera de Colombia; el objeto principal de tales estudios fue el de tipificar las especies íntimamente relacionadas con las colombianas y establecer su diferenciación taxonómica. La consulta de los tipos específicos y la identificación de gran número de colecciones procedentes de las regiones andinas hasta el sur del continente americano permitió precisar el concepto de bastantes especies y de su área geográfica, al mismo tiempo que el establecimiento de numerosas sinonimias.  La mayor parte de las novedades taxonómicas y de los comentarios derivados de tal estudio va incluída en el texto de las Astereae de Colombia a publicar en breve. El objeto de este artículo es dar a conocer otra parte de las novedades relativas a especies andinas de los países vecinos y describir varias entidades taxonómicas deficientemente conocidas, incorporando a su conocimiento los resultados de muchas disecciones llevadas a cabo en los mencionados estudios.  El trabajo basico para estas notas fue hecho en la Smithsonian Institution; se consultaron también las colecciones de los herbarios europeos de Londres, París, Florencia, Ginebra y Madrid en viaje hecho en otoño de 1963. National Science Foundation de Washington D.C. subvencionó los trabajos.

  18. LOS ESTUDIOS DE POBREZA URBANA

    Directory of Open Access Journals (Sweden)

    Rina De León Herrera

    2007-08-01

    Full Text Available En este artículo se intenta mostrar en forma sucinta la evolución de los estudios de pobreza urbana; se retoma para ello la producción escritural de investigadores que han hecho aportes valiosos sobre la temática en diferentes épocas y espacios geográficos. La información se ha organizado en dos unidades de análisis: la producción escritural en los países desarrollados y en los países en desarrollo.

  19. Esclavizada en los Estudios Poscoloniales

    Directory of Open Access Journals (Sweden)

    Nellys Montenegro De la Hoz

    2014-01-01

    Full Text Available Este ensayo va a centrarse en el análisis de las formas de resis - tencia e identidad esclavizada presentes en Changó, el gran putas de Manuel Zapata Olivella, a través del análisis de los discur - sos hegemónicos y subalternos que hacían parte del sistema de poder, y la intervención de las teorías o estudios poscoloniales que cuestionan dichas perspectivas para redefinir las diferencias de las identidades contradictorias y desarrollar de esta manera literaturas deslindadas de las estructuras ideológicas y hegemónicas.

  20. Clustering Dycom

    KAUST Repository

    Minku, Leandro L.; Hou, Siqing

    2017-01-01

    baseline WC model is also included in the analysis. Results: Clustering Dycom with K-Means can potentially help to split the CC projects, managing to achieve similar or better predictive performance than Dycom. However, K-Means still requires the number

  1. Cluster forcing

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    The cluster theory attributed to Michael Porter has significantly influenced industrial policies in countries across Europe and North America since the beginning of the 1990s. Institutions such as the EU, OECD and the World Bank and governments in countries such as the UK, France, The Netherlands...... or management. Both the Accelerate Wales and the Accelerate Cluster programmes target this issue by trying to establish networks between companies that can be used to supply knowledge from research institutions to manufacturing companies. The paper concludes that public sector interventions can make...... businesses. The universities were not considered by the participating companies to be important parts of the local business environment and inputs from universities did not appear to be an important source to access knowledge about new product development or new techniques in production, distribution...

  2. Regional Innovation Clusters

    Data.gov (United States)

    Small Business Administration — The Regional Innovation Clusters serve a diverse group of sectors and geographies. Three of the initial pilot clusters, termed Advanced Defense Technology clusters,...

  3. Cluster analysis

    OpenAIRE

    Mucha, Hans-Joachim; Sofyan, Hizir

    2000-01-01

    As an explorative technique, duster analysis provides a description or a reduction in the dimension of the data. It classifies a set of observations into two or more mutually exclusive unknown groups based on combinations of many variables. Its aim is to construct groups in such a way that the profiles of objects in the same groups are relatively homogenous whereas the profiles of objects in different groups are relatively heterogeneous. Clustering is distinct from classification techniques, ...

  4. Nuclear clustering - a cluster core model study

    International Nuclear Information System (INIS)

    Paul Selvi, G.; Nandhini, N.; Balasubramaniam, M.

    2015-01-01

    Nuclear clustering, similar to other clustering phenomenon in nature is a much warranted study, since it would help us in understanding the nature of binding of the nucleons inside the nucleus, closed shell behaviour when the system is highly deformed, dynamics and structure at extremes. Several models account for the clustering phenomenon of nuclei. We present in this work, a cluster core model study of nuclear clustering in light mass nuclei

  5. Perdurabilidad empresarial: concepto, estudios, hallazgos

    Directory of Open Access Journals (Sweden)

    Hugo Alberto Rivera Rodríguez

    2012-06-01

    Full Text Available La literatura en dirección de empresas durante los últimos 20 años ha analizado diferentes aspectos de la perdurabilidad empresarial, sobre todo lo relacionado con el papel del líder, la asociación con la rentabilidad, y los efectos que genera en el tejido empresarial. Sin embargo, aún existen muchos aspectos en los cuales se debe profundizar. El primero de ellos es dar solución a la diversidad terminológica existente. Al no tener un consenso sobre el concepto, se utilizan de manera indiscriminada términos como longevidad, sostenibilidad, éxito, supervivencia, duración, etc., los cuales en lugar de aclarar, generan confusión. Por otro lado, tampoco hay evidencia suficiente para sugerir alternativas que permitan a las empresas lograr ser perdurables. El artículo que se presenta se fundamenta en una revisión exhaustiva del concepto de perdurabilidad empresarial, y hace una relación de los principales hallazgos encontrados en la literatura sobre las condiciones que pueden facilitar la perdurabilidad empresarial. Con ello se pretende de avanzar en el estudio de la relación entre la perdurabilidad, el comportamiento estratégico de las empresas y desempeño financiero.

  6. Funciones profesorales: un estudio factorial

    Directory of Open Access Journals (Sweden)

    Pedro S. de VICENTE RODRÍGUEZ

    2009-11-01

    Full Text Available La preocupación por la «cantidad» ha privado durante mucho tiempo en el ámbito educativo; ha sido considerado esencial por los gobiernos la consecución de una «educación para todos». Sin embargo, el aumento de los costos no ha conllevado una mejora sustancial, una disminución efectiva de la ineficacia de los sistemas tradicionales de enseñanza; de ello dan fe las tasas de abandonos y repeticiones de curso. Esto conduce a considerar que la falta de correspondencia entre el aumento de los recursos destinados a educación y el rendimiento de las instituciones educativas sea un problema de «calidad» más que de «cantidad». De ahí que se hable hoy insistentemente de la mejora de la calidad de la educación. Al tema de la «calidad de la educación» se dedicó en 1981 un seminario organizado por la Escuela Asturiana de estudios Hispánicos. En él, Víctor García Hoz definía la calidad educativa «como el modo de ser de la educación que reúne las características de integridad, coherencia y eficacia»1, entendiendo la eficacia como la denotación de que el fin perseguido ha sido alcanzado, más que como producción de algo material, con lo que es posible hablar en términos de eficacia refiriéndose tanto a lo cuantitativo como a lo cualitativo.

  7. Cluster headache

    Directory of Open Access Journals (Sweden)

    Ducros Anne

    2008-07-01

    Full Text Available Abstract Cluster headache (CH is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye. It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name in bouts that can occur during specific months of the year. Alcohol is the only dietary trigger of CH, strong odors (mainly solvents and cigarette smoke and napping may also trigger CH attacks. During bouts, attacks may happen at precise hours, especially during the night. During the attacks, patients tend to be restless. CH may be episodic or chronic, depending on the presence of remission periods. CH is associated with trigeminovascular activation and neuroendocrine and vegetative disturbances, however, the precise cautive mechanisms remain unknown. Involvement of the hypothalamus (a structure regulating endocrine function and sleep-wake rhythms has been confirmed, explaining, at least in part, the cyclic aspects of CH. The disease is familial in about 10% of cases. Genetic factors play a role in CH susceptibility, and a causative role has been suggested for the hypocretin receptor gene. Diagnosis is clinical. Differential diagnoses include other primary headache diseases such as migraine, paroxysmal hemicrania and SUNCT syndrome. At present, there is no curative treatment. There are efficient treatments to shorten the painful attacks (acute treatments and to reduce the number of daily attacks (prophylactic treatments. Acute treatment is based on subcutaneous administration of sumatriptan and high-flow oxygen. Verapamil, lithium, methysergide, prednisone, greater occipital nerve blocks and topiramate may be used for prophylaxis. In refractory cases, deep-brain stimulation of the

  8. Brightest Cluster Galaxies in REXCESS Clusters

    Science.gov (United States)

    Haarsma, Deborah B.; Leisman, L.; Bruch, S.; Donahue, M.

    2009-01-01

    Most galaxy clusters contain a Brightest Cluster Galaxy (BCG) which is larger than the other cluster ellipticals and has a more extended profile. In the hierarchical model, the BCG forms through many galaxy mergers in the crowded center of the cluster, and thus its properties give insight into the assembly of the cluster as a whole. In this project, we are working with the Representative XMM-Newton Cluster Structure Survey (REXCESS) team (Boehringer et al 2007) to study BCGs in 33 X-ray luminous galaxy clusters, 0.055 < z < 0.183. We are imaging the BCGs in R band at the Southern Observatory for Astrophysical Research (SOAR) in Chile. In this poster, we discuss our methods and give preliminary measurements of the BCG magnitudes, morphology, and stellar mass. We compare these BCG properties with the properties of their host clusters, particularly of the X-ray emitting gas.

  9. Partitional clustering algorithms

    CERN Document Server

    2015-01-01

    This book summarizes the state-of-the-art in partitional clustering. Clustering, the unsupervised classification of patterns into groups, is one of the most important tasks in exploratory data analysis. Primary goals of clustering include gaining insight into, classifying, and compressing data. Clustering has a long and rich history that spans a variety of scientific disciplines including anthropology, biology, medicine, psychology, statistics, mathematics, engineering, and computer science. As a result, numerous clustering algorithms have been proposed since the early 1950s. Among these algorithms, partitional (nonhierarchical) ones have found many applications, especially in engineering and computer science. This book provides coverage of consensus clustering, constrained clustering, large scale and/or high dimensional clustering, cluster validity, cluster visualization, and applications of clustering. Examines clustering as it applies to large and/or high-dimensional data sets commonly encountered in reali...

  10. Diversity among galaxy clusters

    International Nuclear Information System (INIS)

    Struble, M.F.; Rood, H.J.

    1988-01-01

    The classification of galaxy clusters is discussed. Consideration is given to the classification scheme of Abell (1950's), Zwicky (1950's), Morgan, Matthews, and Schmidt (1964), and Morgan-Bautz (1970). Galaxies can be classified based on morphology, chemical composition, spatial distribution, and motion. The correlation between a galaxy's environment and morphology is examined. The classification scheme of Rood-Sastry (1971), which is based on clusters's morphology and galaxy population, is described. The six types of clusters they define include: (1) a cD-cluster dominated by a single large galaxy, (2) a cluster dominated by a binary, (3) a core-halo cluster, (4) a cluster dominated by several bright galaxies, (5) a cluster appearing flattened, and (6) an irregularly shaped cluster. Attention is also given to the evolution of cluster structures, which is related to initial density and cluster motion

  11. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    Science.gov (United States)

    Martinez Mateo, Isidoro Jose

    fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  12. What Makes Clusters Decline?

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    2015-01-01

    Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark. The longit...... but being quick to withdraw in times of crisis....

  13. Clustering of correlated networks

    OpenAIRE

    Dorogovtsev, S. N.

    2003-01-01

    We obtain the clustering coefficient, the degree-dependent local clustering, and the mean clustering of networks with arbitrary correlations between the degrees of the nearest-neighbor vertices. The resulting formulas allow one to determine the nature of the clustering of a network.

  14. Relevant Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan

    2009-01-01

    Subspace clustering aims at detecting clusters in any subspace projection of a high dimensional space. As the number of possible subspace projections is exponential in the number of dimensions, the result is often tremendously large. Recent approaches fail to reduce results to relevant subspace...... clusters. Their results are typically highly redundant, i.e. many clusters are detected multiple times in several projections. In this work, we propose a novel model for relevant subspace clustering (RESCU). We present a global optimization which detects the most interesting non-redundant subspace clusters...... achieves top clustering quality while competing approaches show greatly varying performance....

  15. Cluster ion beam facilities

    International Nuclear Information System (INIS)

    Popok, V.N.; Prasalovich, S.V.; Odzhaev, V.B.; Campbell, E.E.B.

    2001-01-01

    A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion beams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

  16. PREFACE: Nuclear Cluster Conference; Cluster'07

    Science.gov (United States)

    Freer, Martin

    2008-05-01

    The Cluster Conference is a long-running conference series dating back to the 1960's, the first being initiated by Wildermuth in Bochum, Germany, in 1969. The most recent meeting was held in Nara, Japan, in 2003, and in 2007 the 9th Cluster Conference was held in Stratford-upon-Avon, UK. As the name suggests the town of Stratford lies upon the River Avon, and shortly before the conference, due to unprecedented rainfall in the area (approximately 10 cm within half a day), lay in the River Avon! Stratford is the birthplace of the `Bard of Avon' William Shakespeare, and this formed an intriguing conference backdrop. The meeting was attended by some 90 delegates and the programme contained 65 70 oral presentations, and was opened by a historical perspective presented by Professor Brink (Oxford) and closed by Professor Horiuchi (RCNP) with an overview of the conference and future perspectives. In between, the conference covered aspects of clustering in exotic nuclei (both neutron and proton-rich), molecular structures in which valence neutrons are exchanged between cluster cores, condensates in nuclei, neutron-clusters, superheavy nuclei, clusters in nuclear astrophysical processes and exotic cluster decays such as 2p and ternary cluster decay. The field of nuclear clustering has become strongly influenced by the physics of radioactive beam facilities (reflected in the programme), and by the excitement that clustering may have an important impact on the structure of nuclei at the neutron drip-line. It was clear that since Nara the field had progressed substantially and that new themes had emerged and others had crystallized. Two particular topics resonated strongly condensates and nuclear molecules. These topics are thus likely to be central in the next cluster conference which will be held in 2011 in the Hungarian city of Debrechen. Martin Freer Participants and Cluster'07

  17. A theoretical quantum study on the distribution of electrophilic and nucleophilic active sites on Cu(100) surfaces modeled as finite clusters; Un estudio teorico cuantico sobre la distribucion de sitios activos electrofilicos y nucleofilicos sobre superficies de Cu(100) modeladas como cumulos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Rios R, C.H.; Romero R, M. [Universidad Autonoma Metropolitana-Azcapotzalco, Departamento de Materiales, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200 Mexico D.F. (Mexico); Ponce R, A.; Mendoza H, L.H. [Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Quimicas, Carretera Pachuca-Tulancingo km. 4.5, 42181 Pachuca, Hidalgo (Mexico)]. e-mail: clara_hrr@yahoo.es

    2008-07-01

    In this work, it is shown a theoretical quantum study of the active sites distribution on a monocrystalline surface of Cu(100). The copper surface was modeled as finite clusters of 14, 23, 38 and 53 atoms. We performed Hartree-Fock and Density Functional Theory (B3LYP) ab initio calculations employing the pseudopotentials of Hay and Wadt (LANLlMB y LANL2DZ). From calculations, we found a work function value of 4.1 eV. The mapping of the HOMO and LUMO in the frozen core approximation, allowed us finding the electrophilic and nucleophilic active sites distribution, respectively. The results indicated that electrophilic sites on the Cu(100) surface were located on hollow position and its numerical density was 8.6 x 10{sup 16} sites cm{sup -2}. From the nucleophilic local softness study, it was found that the nucleophilic sites were formed by a group of atoms and it had a numerical density of 2.4x 10{sup 16} sitescm{sup -2} . Last results indicated that adsorptions with 2 x 2 and 3 x 3 distributions can be favored onto a Cu(100) surface for the electrophilic and nucleophilic cases, respectively. (Author)

  18. El creciente campo de los Estudios Sensoriales

    Directory of Open Access Journals (Sweden)

    David Howes

    2014-09-01

    Full Text Available Este ensayo presenta una breve descripción acerca del giro sensorial en la investigación contemporánea, y propone algunas perspectivas de trabajo para futuras investigaciones. Esta labor no pretende ser exhaustiva y, más bien, busca indicar las principales tendencias en este campo. El ensayo, en su primera parte, ofrece una mirada general sobre la aparición y el desarrollo de la historia y la antropología de los sentidos. En la segunda parte, la atención se concentra en cómo el campo de los estudios sensoriales puede ser, de otro lado, conceptualizado como compuesto de cultura visual, cultura auditiva (o estudios del sonido, cultura del olfato, cultura del gusto y cultura del tacto. Se ofrece una explicación acerca de la génesis de estas divisiones. Posteriormente, se presenta una visión general de algunas cuestiones claves en los estudios sensoriales, como la pregunta por el número de los sentidos y la relación entre orden sensorial y orden social. El ensayo concluye con ocho proposiciones para los estudios sensoriales.

  19. El creciente campo de los Estudios Sensoriales

    Directory of Open Access Journals (Sweden)

    David Howes

    2014-08-01

    Full Text Available Este ensayo presenta una breve descripción acerca del giro sensorial en la investigación contemporánea, y propone algunas perspectivas de trabajo para futurasinvestigaciones. Esta labor no pretende ser exhaustiva y, más bien, busca indicar las principales tendencias en este campo. El ensayo, en su primera parte, ofrece una mirada general sobre la aparición y el desarrollo de la historia y la antropología de los sentidos. En la segunda parte, la atención se concentra en cómo el campo de los estudios sensoriales puede ser, de otro lado, conceptualizado como compuesto de cultura visual, cultura auditiva (o estudios del sonido, cultura del olfato, cultura del gusto y cultura del tacto. Se ofrece una explicación acerca de la génesis de estas divisiones. Posteriormente,se presenta una visión general de algunas cuestiones claves en los estudios sensoriales, como la pregunta por el número de los sentidos y la relación entre orden sensorial y orden social. El ensayo concluye con ocho proposiciones para los estudios sensoriales.

  20. Management of cluster headache

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer C; Jensen, Rigmor H

    2012-01-01

    The prevalence of cluster headache is 0.1% and cluster headache is often not diagnosed or misdiagnosed as migraine or sinusitis. In cluster headache there is often a considerable diagnostic delay - an average of 7 years in a population-based survey. Cluster headache is characterized by very severe...... or severe orbital or periorbital pain with a duration of 15-180 minutes. The cluster headache attacks are accompanied by characteristic associated unilateral symptoms such as tearing, nasal congestion and/or rhinorrhoea, eyelid oedema, miosis and/or ptosis. In addition, there is a sense of restlessness...... and agitation. Patients may have up to eight attacks per day. Episodic cluster headache (ECH) occurs in clusters of weeks to months duration, whereas chronic cluster headache (CCH) attacks occur for more than 1 year without remissions. Management of cluster headache is divided into acute attack treatment...

  1. Symmetries of cluster configurations

    International Nuclear Information System (INIS)

    Kramer, P.

    1975-01-01

    A deeper understanding of clustering phenomena in nuclei must encompass at least two interrelated aspects of the subject: (A) Given a system of A nucleons with two-body interactions, what are the relevant and persistent modes of clustering involved. What is the nature of the correlated nucleon groups which form the clusters, and what is their mutual interaction. (B) Given the cluster modes and their interaction, what systematic patterns of nuclear structure and reactions emerge from it. Are there, for example, families of states which share the same ''cluster parents''. Which cluster modes are compatible or exclude each other. What quantum numbers could characterize cluster configurations. There is no doubt that we can learn a good deal from the experimentalists who have discovered many of the features relevant to aspect (B). Symmetries specific to cluster configurations which can throw some light on both aspects of clustering are discussed

  2. Patrones arquitectónicos, clusters constructivos homogéneos y variabilidad en el estudio de edificios históricos. Aspectos técnico-formales de la vivienda rural en la provincia de La Rioja (Argentina durante el período republicano

    Directory of Open Access Journals (Sweden)

    Rolón, Guillermo

    2014-12-01

    Full Text Available The paper presents the methodological procedure by which the characteristics of the traditional architecture in rural areas in La Rioja province (Argentina of the Republican Period (from 19>th century until nowadays were analyzed. The comprehensive application of stratigraphic and typological analysis along with multivariate analytical techniques allowed the identification and characterization of the developed architectural patterns. The concept of architectural pattern was used within the methodological design, as an alternative to the building type, in order to consider and evaluate not only the stable aspects (the constructive and homogeneous “cluster” as internal structure of the pattern, but also those variable characteristics that were observed in the construction of the dwellings considered.El artículo presenta el procedimiento metodológico con el cual se analizaron las características de la arquitectura popular del ámbito rural en la provincia de La Rioja (Argentina del período republicano (s. XIX a la actualidad. La aplicación integral de análisis estratigráficos y tipológicos, y el auxilio de técnicas analíticas multivariantes, permitió identificar y caracterizar los patrones arquitectónicos desarrollados. Se utilizó el concepto de patrón arquitectónico en el diseño metodológico, como alternativa al de tipo edilicio, para considerar y evaluar no sólo los aspectos estables (el cluster constructivo homogéneo o estructura interna del patrón, sino también aquellas características variables que se observaron en la edificación de las unidades domésticas consideradas.

  3. Cluster Decline and Resilience

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark, 1963......-2011. Our longitudinal study reveals that technological lock-in and exit of key firms have contributed to impairment of the cluster’s resilience in adapting to disruptions. Entrepreneurship has a positive effect on cluster resilience, while multinational companies have contradicting effects by bringing...... in new resources to the cluster but being quick to withdraw in times of crisis....

  4. Comprehensive cluster analysis with Transitivity Clustering.

    Science.gov (United States)

    Wittkop, Tobias; Emig, Dorothea; Truss, Anke; Albrecht, Mario; Böcker, Sebastian; Baumbach, Jan

    2011-03-01

    Transitivity Clustering is a method for the partitioning of biological data into groups of similar objects, such as genes, for instance. It provides integrated access to various functions addressing each step of a typical cluster analysis. To facilitate this, Transitivity Clustering is accessible online and offers three user-friendly interfaces: a powerful stand-alone version, a web interface, and a collection of Cytoscape plug-ins. In this paper, we describe three major workflows: (i) protein (super)family detection with Cytoscape, (ii) protein homology detection with incomplete gold standards and (iii) clustering of gene expression data. This protocol guides the user through the most important features of Transitivity Clustering and takes ∼1 h to complete.

  5. Casos de Estudio de Distribuciones de Probabilidad para Turismo

    OpenAIRE

    Fernández Morales, Antonio

    2016-01-01

    Este trabajo propone diversos casos de estudio para el estudio de las distribuciones de probabilidad aplicadas a la investigación y la práctica profesional en el ámbito del turismo. Se afronta el estudio de distribuciones de probabilidad, tanto de variables aleatorias discretas como continuas.

  6. LMC clusters: young

    International Nuclear Information System (INIS)

    Freeman, K.C.

    1980-01-01

    The young globular clusters of the LMC have ages of 10 7 -10 8 y. Their masses and structure are similar to those of the smaller galactic globular clusters. Their stellar mass functions (in the mass range 6 solar masses to 1.2 solar masses) vary greatly from cluster to cluster, although the clusters are similar in total mass, age, structure and chemical composition. It would be very interesting to know why these clusters are forming now in the LMC and not in the Galaxy. The author considers the 'young globular' or 'blue populous' clusters of the LMC. The ages of these objects are 10 7 to 10 8 y, and their masses are 10 4 to 10 5 solar masses, so they are populous enough to be really useful for studying the evolution of massive stars. The author concentrates on the structure and stellar content of these young clusters. (Auth.)

  7. Star clusters and associations

    International Nuclear Information System (INIS)

    Ruprecht, J.; Palous, J.

    1983-01-01

    All 33 papers presented at the symposium were inputted to INIS. They dealt with open clusters, globular clusters, stellar associations and moving groups, and local kinematics and galactic structures. (E.S.)

  8. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1978-01-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  9. Clustering at high redshifts

    International Nuclear Information System (INIS)

    Shaver, P.A.

    1986-01-01

    Evidence for clustering of and with high-redshift QSOs is discussed. QSOs of different redshifts show no clustering, but QSOs of similar redshifts appear to be clustered on a scale comparable to that of galaxies at the present epoch. In addition, spectroscopic studies of close pairs of QSOs indicate that QSOs are surrounded by a relatively high density of absorbing matter, possibly clusters of galaxies

  10. Cluster Physics with Merging Galaxy Clusters

    Directory of Open Access Journals (Sweden)

    Sandor M. Molnar

    2016-02-01

    Full Text Available Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space which cannot be explored in our laboratories on Earth. In the standard LCDM model, where the total density is dominated by the cosmological constant ($Lambda$ and the matter density by cold dark matter (CDM, structure formation is hierarchical, and clusters grow mostly by merging.Mergers of two massive clusters are the most energetic events in the universe after the Big Bang,hence they provide a unique laboratory to study cluster physics.The two main mass components in clusters behave differently during collisions:the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulenceare developed during collisions. In the present contribution we review the different methods used to derive the physical properties of merging clusters. Different physical processes leave their signatures on different wavelengths, thusour review is based on a multifrequency analysis. In principle, the best way to analyze multifrequency observations of merging clustersis to model them using N-body/HYDRO numerical simulations. We discuss the results of such detailed analyses.New high spatial and spectral resolution ground and space based telescopeswill come online in the near future. Motivated by these new opportunities,we briefly discuss methods which will be feasible in the near future in studying merging clusters.

  11. Size selected metal clusters

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. The Optical Absorption Spectra of Small Silver Clusters (5-11) ... Soft Landing and Fragmentation of Small Clusters Deposited in Noble-Gas Films. Harbich, W.; Fedrigo, S.; Buttet, J. Phys. Rev. B 1998, 58, 7428. CO combustion on supported gold clusters. Arenz M ...

  12. The Durban Auto Cluster

    DEFF Research Database (Denmark)

    Lorentzen, Jochen; Robbins, Glen; Barnes, Justin

    2004-01-01

    The paper describes the formation of the Durban Auto Cluster in the context of trade liberalization. It argues that the improvement of operational competitiveness of firms in the cluster is prominently due to joint action. It tests this proposition by comparing the gains from cluster activities...

  13. Marketing research cluster analysis

    Directory of Open Access Journals (Sweden)

    Marić Nebojša

    2002-01-01

    Full Text Available One area of applications of cluster analysis in marketing is identification of groups of cities and towns with similar demographic profiles. This paper considers main aspects of cluster analysis by an example of clustering 12 cities with the use of Minitab software.

  14. Marketing research cluster analysis

    OpenAIRE

    Marić Nebojša

    2002-01-01

    One area of applications of cluster analysis in marketing is identification of groups of cities and towns with similar demographic profiles. This paper considers main aspects of cluster analysis by an example of clustering 12 cities with the use of Minitab software.

  15. Minimalist's linux cluster

    International Nuclear Information System (INIS)

    Choi, Chang-Yeong; Kim, Jeong-Hyun; Kim, Seyong

    2004-01-01

    Using barebone PC components and NIC's, we construct a linux cluster which has 2-dimensional mesh structure. This cluster has smaller footprint, is less expensive, and use less power compared to conventional linux cluster. Here, we report our experience in building such a machine and discuss our current lattice project on the machine

  16. Range-clustering queries

    NARCIS (Netherlands)

    Abrahamsen, M.; de Berg, M.T.; Buchin, K.A.; Mehr, M.; Mehrabi, A.D.

    2017-01-01

    In a geometric k -clustering problem the goal is to partition a set of points in R d into k subsets such that a certain cost function of the clustering is minimized. We present data structures for orthogonal range-clustering queries on a point set S : given a query box Q and an integer k>2 , compute

  17. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Abstract. Surveys of clusters of galaxies provide us with a powerful probe of the den- sity and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameter w. Upcoming Sunyaev–. Zel'dovich (SZ) surveys would provide us large yields of clusters to ...

  18. Estudios de competitividad en sistemas urbano - territoriales

    Directory of Open Access Journals (Sweden)

    Esteban Soms García

    2007-05-01

    El Ministerio de Planificación y Cooperación de Chile, ha desarrollado varios estudios relacionados con la competitividad regional, destinados a pronosticar y evaluar los impactos positivos y negativos que podrían derivarse de los recientes Acuerdos de Libre Comercio suscritos por Chile con la Comunidad Europea, Estados Unidos y Corea, más los acuerdos ad portas con los Países de la APEC. En lo referente a competitividad urbana, destacan algunos estudios y proyectos relacionados con el programa gubernamental "Ciudades para el Bicentenario", impulsado el Ministerio de Vivienda y Urbanismo y los Gobiernos Regionales de Antofagasta, Bio Bio, Valparaíso y Santiago.

  19. Estrategia organizacional: una propuesta de estudio

    Directory of Open Access Journals (Sweden)

    Ángela Lucía Noguera Hidalgo

    2014-01-01

    Full Text Available El concepto de estrategia en el contexto de las organizaciones empresariales es uno de los temas que genera gran interés en los asuntos del management. Sin embargo, la proposición de nuevos enfoques no ha aportado significativamente al avance en el estudio de este concepto. El estancamiento se hace evidente, razón por la cual el presente documento esboza una propuesta que reúne algunos de los retos para el estudio de la estrategia. En él se presenta una revisión que deja por sentados los posibles caminos a seguir, los cuales contribuyen a la perdurabilidad de las organizaciones.

  20. ESTUDIOS (INTERCULTURALES EN CLAVE DE-COLONIAL

    Directory of Open Access Journals (Sweden)

    Catherine Walsh

    2010-01-01

    Full Text Available Los «estudios culturales» en América Latina forman parte de una política de nombrar inscrita en legados y cartografiados frecuentemente como totalidad, ocultando o dejando pasar por alto las diferencias a su interior. Este articula examina desde dónde nacen los estudios culturales en América Latina en general y en la Universidad Andina Simón Bolívar en Quito en particular, con qué política de nombramiento, qué proyecto(s y qué bases y perspectivas de conocimiento. Considera qué implica concebir y construir los estudios culturales como proyecto político-intelectual, inter-cultural, inter-epistémico y de orientación de-colonial y los desafíos y obstáculos al respecto, incluyendo dentro de la problemática misma de la «uni»-versidad.

  1. Cluster analysis for applications

    CERN Document Server

    Anderberg, Michael R

    1973-01-01

    Cluster Analysis for Applications deals with methods and various applications of cluster analysis. Topics covered range from variables and scales to measures of association among variables and among data units. Conceptual problems in cluster analysis are discussed, along with hierarchical and non-hierarchical clustering methods. The necessary elements of data analysis, statistics, cluster analysis, and computer implementation are integrated vertically to cover the complete path from raw data to a finished analysis.Comprised of 10 chapters, this book begins with an introduction to the subject o

  2. Clusters in nuclei

    CERN Document Server

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This third volume follows the successful Lect. Notes Phys. 818 (Vol. 1) and 848 (Vol. 2), and comprises six extensive lectures covering the following topics:  - Gamma Rays and Molecular Structure - Faddeev Equation Approach for Three Cluster Nuclear Reactions - Tomography of the Cluster Structure of Light Nuclei Via Relativistic Dissociation - Clustering Effects Within the Dinuclear Model : From Light to Hyper-heavy Molecules in Dynamical Mean-field Approach - Clusterization in Ternary Fission - Clusters in Light N...

  3. Spatial cluster modelling

    CERN Document Server

    Lawson, Andrew B

    2002-01-01

    Research has generated a number of advances in methods for spatial cluster modelling in recent years, particularly in the area of Bayesian cluster modelling. Along with these advances has come an explosion of interest in the potential applications of this work, especially in epidemiology and genome research. In one integrated volume, this book reviews the state-of-the-art in spatial clustering and spatial cluster modelling, bringing together research and applications previously scattered throughout the literature. It begins with an overview of the field, then presents a series of chapters that illuminate the nature and purpose of cluster modelling within different application areas, including astrophysics, epidemiology, ecology, and imaging. The focus then shifts to methods, with discussions on point and object process modelling, perfect sampling of cluster processes, partitioning in space and space-time, spatial and spatio-temporal process modelling, nonparametric methods for clustering, and spatio-temporal ...

  4. Clusters and how to make it work : Cluster Strategy Toolkit

    NARCIS (Netherlands)

    Manickam, Anu; van Berkel, Karel

    2014-01-01

    Clusters are the magic answer to regional economic development. Firms in clusters are more innovative; cluster policy dominates EU policy; ‘top-sectors’ and excellence are the choice of national policy makers; clusters are ‘in’. But, clusters are complex, clusters are ‘messy’; there is no clear

  5. ESTUDIOS TRANSCULTURALES DEL BURNOUT: LOS ESTUDIOS TRANSCULTURALES BRASIL-ESPAÑA

    Directory of Open Access Journals (Sweden)

    Macarena Gálvez Herrer

    2003-07-01

    Full Text Available Los estudios transculturales no son un ejercicio secundario y complementario en el estudio de la psicología; un modelo antropológico de la conducta humana obliga a plantear que las variables culturales no son secundarias sino primarias. Por estas razones el estudio del “burnout†o desgaste profesional puede profundizarse mediante la utilización de los métodos transculturales. No es suficiente con la simple comparación de resultados, sino que es necesario buscar instrumentos propios de cada cultura y establecer la comparación no sólo del síndrome de desgaste profesional sino de todos los diferentes elementos del proceso. El trabajo presentado establece las bases teóricas de este planteamiento, y expone, mediante un ejemplo, algunas de las vías posibles para una psicología transcultural del burnout.

  6. Estudios transculturales del burnout: Los estudios transculturales Brasil-España

    Directory of Open Access Journals (Sweden)

    Bernardo Moreno Jiménez

    2003-01-01

    Full Text Available Los estudios transculturales no son un ejercicio secundario y complementario en el estudio de la psicología; un modelo antropológico de la conducta humana obliga a plantear que las variables culturales no son secundarias sino primarias. Por estas razones el estudio del “burnout” o desgaste profesional puede profundizarse mediante la utilización de los métodos transculturales. No es suficiente con la simple comparación de resultados, sino que es necesario buscar instrumentos propios de cada cultura y establecer la comparación no sólo del síndrome de desgaste profesional sino de todos los diferentes elementos del proceso. El trabajo presentado establece las bases teóricas de este planteamiento, y expone, mediante un ejemplo, algunas de las vías posibles para una psicología transcultural del burnout

  7. Agricultural Clusters in the Netherlands

    NARCIS (Netherlands)

    Schouten, M.A.; Heijman, W.J.M.

    2012-01-01

    Michael Porter was the first to use the term cluster in an economic context. He introduced the term in The Competitive Advantage of Nations (1990). The term cluster is also known as business cluster, industry cluster, competitive cluster or Porterian cluster. This article aims at determining and

  8. Open source clustering software.

    Science.gov (United States)

    de Hoon, M J L; Imoto, S; Nolan, J; Miyano, S

    2004-06-12

    We have implemented k-means clustering, hierarchical clustering and self-organizing maps in a single multipurpose open-source library of C routines, callable from other C and C++ programs. Using this library, we have created an improved version of Michael Eisen's well-known Cluster program for Windows, Mac OS X and Linux/Unix. In addition, we generated a Python and a Perl interface to the C Clustering Library, thereby combining the flexibility of a scripting language with the speed of C. The C Clustering Library and the corresponding Python C extension module Pycluster were released under the Python License, while the Perl module Algorithm::Cluster was released under the Artistic License. The GUI code Cluster 3.0 for Windows, Macintosh and Linux/Unix, as well as the corresponding command-line program, were released under the same license as the original Cluster code. The complete source code is available at http://bonsai.ims.u-tokyo.ac.jp/mdehoon/software/cluster. Alternatively, Algorithm::Cluster can be downloaded from CPAN, while Pycluster is also available as part of the Biopython distribution.

  9. ESTUDIO DE FRACCIONES EN CONTEXTOS SONOROS

    Directory of Open Access Journals (Sweden)

    Alexander Conde

    2016-01-01

    Full Text Available En este ensayo resaltamos los vínculos cognitivos entre las matemáticas y la música, que pueden favorecer procesos de enseñanza y aprendizaje de las fracciones en la matemática escolar. Las actividades exhibidas provienen de una investigación que promueve experiencias sensoriales en el campo rítmico para favorecer la construcción de nociones matemáticas. Dichas actividades posibilitan un engranaje armónico entre las matemáticas y la música convergentes en el tiempo y el sonido como los objetos de estudio común entre éstas disciplinas. El análisis de la investigación que aquí reportamos es producto de la aplicación de las actividades en diferentes programas de formación de profesorado de México y Francia, alrededor de la enseñanza y aprendizaje de las matemáticas en contextos interdisciplinarios. Este análisis se desarrolló desde tres categorías referentes a las nociones de unidad relativa, relación parte-parte y equipartición, las cuales son nociones fundamentales para el estudio de las fracciones en la matemática escolar. Encontramos que la enseñanza con enfoque integrador requiere no solo conocimientos especializados, sino un cambio de creencias en torno a las opiniones del profesorado sobre la organización del currículo, su enseñanza y la manera en que aprende la población estudiantil. Un aporte de esta experiencia es ofrecer a docentes elementos teóricos y didácticos para el estudio de las fracciones en contextos interdisciplinarios.

  10. Electron: Cluster interactions

    International Nuclear Information System (INIS)

    Scheidemann, A.A.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E ∼ 0.1 to E ∼ 6 eV. The investigation focused on the closed shell clusters Na 8 , Na 20 , Na 40 . The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size

  11. Clustering high dimensional data

    DEFF Research Database (Denmark)

    Assent, Ira

    2012-01-01

    High-dimensional data, i.e., data described by a large number of attributes, pose specific challenges to clustering. The so-called ‘curse of dimensionality’, coined originally to describe the general increase in complexity of various computational problems as dimensionality increases, is known...... to render traditional clustering algorithms ineffective. The curse of dimensionality, among other effects, means that with increasing number of dimensions, a loss of meaningful differentiation between similar and dissimilar objects is observed. As high-dimensional objects appear almost alike, new approaches...... for clustering are required. Consequently, recent research has focused on developing techniques and clustering algorithms specifically for high-dimensional data. Still, open research issues remain. Clustering is a data mining task devoted to the automatic grouping of data based on mutual similarity. Each cluster...

  12. Estudio de un caso de control interno

    OpenAIRE

    Alfonso Pirela

    2005-01-01

    El estudio se efectuó con el objetivo de analizar el control interno en el Almacén de la Facultad de ciencias Económicas y Sociales de la Universidad del Zulia. La metodología fue descriptiva. Se utilizó como población a todo el personal del almacén. Los resultados arrojaron que el control del almacén no cuenta con un sistema de control interno integrado que le permita llevar con efectividad las actividades de recepción, almacenamiento y despacho de la mercancía.

  13. Estudio de un caso de control interno

    Directory of Open Access Journals (Sweden)

    Alfonso Pirela

    2005-09-01

    Full Text Available El estudio se efectuó con el objetivo de analizar el control interno en el Almacén de la Facultad de ciencias Económicas y Sociales de la Universidad del Zulia. La metodología fue descriptiva. Se utilizó como población a todo el personal del almacén. Los resultados arrojaron que el control del almacén no cuenta con un sistema de control interno integrado que le permita llevar con efectividad las actividades de recepción, almacenamiento y despacho de la mercancía.

  14. Estudio sobre redes sociales y estudiantes

    OpenAIRE

    Toledo Morales, Purificación; Sánchez García, José Manuel

    2012-01-01

    En este estudio pretendemos analizar cómo una muestra de 150 estudiantes utiliza las redes sociales, y explorar el impacto de estas en el rendimiento académico de los mismos. Los datos recogidos de la aplicación y análisis de una escala de opinión revelaron que mas de la mitad de los estudiantes encuestados utilizan internet con una finalidad puramente recreativa, y las redes sociales para estar en contacto con los amigos. La mayoría de los encuestados rechazan las solicitudes de amistad de d...

  15. Amplificadores con transistores. Estudio y dimensionado

    OpenAIRE

    Lubiano García, Adrián

    2017-01-01

    Este trabajo es un estudio de las distintas configuraciones de los amplificadores con transistores vistos en la asignatura de Electrónica Analógica del tercer curso del Grado en Ingeniería en Electrónica Industrial y Automática de la Escuela de Ingenierías Industriales de la Universidad de Valladolid. En este trabajo se mostrarán los pasos seguidos en la creación de una aplicación con Visual Basic para la realización de los ejercicios de las distintas configuraciones, así...

  16. Estudio del álbum sin palabras

    OpenAIRE

    Bosch Andreu, Emma

    2015-01-01

    [spa] Estudio del Álbum Sin Palabras tiene como objetivo principal definir, analizar y categorizar los álbumes sin palabras destinados principalmente al público infantil y juvenil dando a conocer sus características, peculiariades y diversidad tipológica, para facilitar las tareas de análisis y de mediación de investigadores, educadores, bibliotecarios y cualquier persona interesada en los libros con imágenes. En el capítulo titulado «Un nuevo mapa para los Libros Sin Palabras» situamos e...

  17. Anorexia nervosa: un estudio de casos

    OpenAIRE

    Zusman, Lillyana

    2013-01-01

    La Anorexia Nervosa es un trastorno de alimentación que se define (etimológicamente) como una "pérdida nerviosa del apetito". Se caracteriza por la actitud consciente, voluntaria y rotunda de los sujetos  de tener un exceso de peso que intentan modificar por vía de la inanición. A partir del estudio de casos, se propone la distinción entre una Anorexia Nervosa Estructural -aquella en la que predomina el conflicto intrapsíquico primario y arcaico, y que manifiesta una conducta aislada y retraí...

  18. Substructure in clusters of galaxies

    International Nuclear Information System (INIS)

    Fitchett, M.J.

    1988-01-01

    Optical observations suggesting the existence of substructure in clusters of galaxies are examined. Models of cluster formation and methods used to detect substructure in clusters are reviewed. Consideration is given to classification schemes based on a departure of bright cluster galaxies from a spherically symmetric distribution, evidence for statistically significant substructure, and various types of substructure, including velocity, spatial, and spatial-velocity substructure. The substructure observed in the galaxy distribution in clusters is discussed, focusing on observations from general cluster samples, the Virgo cluster, the Hydra cluster, Centaurus, the Coma cluster, and the Cancer cluster. 88 refs

  19. Estudio osteométrico y selección de variables relevantes para clasificación de rostros en estudios de antropología forense

    Directory of Open Access Journals (Sweden)

    Soncini, Julieta A.

    2001-01-01

    Full Text Available Se espera que este estudio contribuya a los análisis de identificación de restos óseos humanos, al proponer esta nueva vía de reducción del universo de búsqueda en la comparación de fotografías de personas en vida/ fichas pre - mortem y restos óseos N.N. En la presente investigación se han establecido un número mínimo de quince variables craneométricas para la clasificación de cráneos y la determinación de aquellas más relevantes para la diferenciación morfológica facial. La base de datos utilizada consta de una muestra de 159 cráneos y 31 variables craneométricas. Algunos de los análisis que hemos realizado con los datos obtenidos incluyen Técnicas Geométricas, Clasificaciones No Supervisadas, Clustering (Agrupamientos, Medidas de Similitud, Criterios de Clustering, Algoritmos Simples de Búsqueda de Clusters, Clasificadores de Mínima Distancia por Funciones Discriminantes - Lineales y el Algoritmo k-Medias.

  20. Nuclear cluster states

    International Nuclear Information System (INIS)

    Rae, W.D.M.; Merchant, A.C.

    1993-01-01

    We review clustering in light nuclei including molecular resonances in heavy ion reactions. In particular we study the systematics, paying special attention to the relationships between cluster states and superdeformed configurations. We emphasise the selection rules which govern the formation and decay of cluster states. We review some recent experimental results from Daresbury and elsewhere. In particular we report on the evidence for a 7-α chain state in 28 Si in experiments recently performed at the NSF, Daresbury. Finally we begin to address theoretically the important question of the lifetimes of cluster states as deduced from the experimental energy widths of the resonances. (Author)

  1. 15th Cluster workshop

    CERN Document Server

    Laakso, Harri; Escoubet, C. Philippe; The Cluster Active Archive : Studying the Earth’s Space Plasma Environment

    2010-01-01

    Since the year 2000 the ESA Cluster mission has been investigating the small-scale structures and processes of the Earth's plasma environment, such as those involved in the interaction between the solar wind and the magnetospheric plasma, in global magnetotail dynamics, in cross-tail currents, and in the formation and dynamics of the neutral line and of plasmoids. This book contains presentations made at the 15th Cluster workshop held in March 2008. It also presents several articles about the Cluster Active Archive and its datasets, a few overview papers on the Cluster mission, and articles reporting on scientific findings on the solar wind, the magnetosheath, the magnetopause and the magnetotail.

  2. Clusters in simple fluids

    International Nuclear Information System (INIS)

    Sator, N.

    2003-01-01

    This article concerns the correspondence between thermodynamics and the morphology of simple fluids in terms of clusters. Definitions of clusters providing a geometric interpretation of the liquid-gas phase transition are reviewed with an eye to establishing their physical relevance. The author emphasizes their main features and basic hypotheses, and shows how these definitions lead to a recent approach based on self-bound clusters. Although theoretical, this tutorial review is also addressed to readers interested in experimental aspects of clustering in simple fluids

  3. Estudio sobre encofrados de madera modernos

    Directory of Open Access Journals (Sweden)

    de la Peña Aznar, Juan M.

    1980-11-01

    Full Text Available The author continues the development of the subject «Modern Timber Formwork», by summing up the comparative examination —already carried out in Part III of this Study— of the different types of glued timber existing on the market. In addition, the loads and stresses allowable for coniferous timber and the proposal for establishing Regulations for the Timber Section of the Research and Experimental Forestry Institute of Spain are given. In part V of the author's Study, published in this article, the important subject of the glues used for joining timber, a truly vital point in order to obtain louvered timber beams which are simply glued together, is approached.

    El autor continúa el desarrollo del tema sobre «Encofrados de madera modernos», resumiendo el estudio comparativo —ya hecho en la Parte III de este Estudio— de las diferentes vigas de madera encolada existentes en el mercado dando, además, las cargas y tensiones admisibles para maderas coníferas y la propuesta de Reglamentación de la Sección de Maderas del Instituto Forestal de Investigaciones y Experiencias de España. En la parte V del Estudio del autor, publicada en este articulo, se aborda el importante tema de las colas empleadas para las uniones de madera, algo realmente vital para la obtención de vigas de madera en celosía simplemente encoladas.

  4. Lifting to cluster-tilting objects in higher cluster categories

    OpenAIRE

    Liu, Pin

    2008-01-01

    In this note, we consider the $d$-cluster-tilted algebras, the endomorphism algebras of $d$-cluster-tilting objects in $d$-cluster categories. We show that a tilting module over such an algebra lifts to a $d$-cluster-tilting object in this $d$-cluster category.

  5. Estudios Experimentales 1 Parte: El Ensayo Clínico

    OpenAIRE

    Manterola, Carlos; Otzen, Tamara

    2015-01-01

    Los estudios experimentales, se caracterizan por la valoración del efecto de una o más intervenciones, habitualmente de forma comparativa con otra intervención, o un placebo; y el carácter prospectivo, de la recolección de los datos y el seguimiento de los grupos en estudio. Bajo la denominación de estudios experimentales, existe una diversidad de diseños, desde los ensayos clínicos (EC) y sus variantes, hasta los estudios cuasi-experimentales y los experientos naturales. El objetivo de este ...

  6. Neurostimulation in cluster headache

    DEFF Research Database (Denmark)

    Pedersen, Jeppe L; Barloese, Mads; Jensen, Rigmor H

    2013-01-01

    PURPOSE OF REVIEW: Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide...... effective strategy must be preferred as first-line therapy for intractable chronic cluster headache....

  7. Cauchy cluster process

    DEFF Research Database (Denmark)

    Ghorbani, Mohammad

    2013-01-01

    In this paper we introduce an instance of the well-know Neyman–Scott cluster process model with clusters having a long tail behaviour. In our model the offspring points are distributed around the parent points according to a circular Cauchy distribution. Using a modified Cramér-von Misses test...

  8. When Clusters become Networks

    NARCIS (Netherlands)

    S.M.W. Phlippen (Sandra); G.A. van der Knaap (Bert)

    2007-01-01

    textabstractPolicy makers spend large amounts of public resources on the foundation of science parks and other forms of geographically clustered business activities, in order to stimulate regional innovation. Underlying the relation between clusters and innovation is the assumption that co-located

  9. Mixed-Initiative Clustering

    Science.gov (United States)

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  10. Coma cluster of galaxies

    Science.gov (United States)

    1999-01-01

    Atlas Image mosaic, covering 34' x 34' on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies (over 1000 members), most prominently the two giant ellipticals, NGC 4874 (right) and NGC 4889 (left). The remaining members are mostly smaller ellipticals, but spiral galaxies are also evident in the 2MASS image. The cluster is seen toward the constellation Coma Berenices, but is actually at a distance of about 100 Mpc (330 million light years, or a redshift of 0.023) from us. At this distance, the cluster is in what is known as the 'Hubble flow,' or the overall expansion of the Universe. As such, astronomers can measure the Hubble Constant, or the universal expansion rate, based on the distance to this cluster. Large, rich clusters, such as Coma, allow astronomers to measure the 'missing mass,' i.e., the matter in the cluster that we cannot see, since it gravitationally influences the motions of the member galaxies within the cluster. The near-infrared maps the overall luminous mass content of the member galaxies, since the light at these wavelengths is dominated by the more numerous older stellar populations. Galaxies, as seen by 2MASS, look fairly smooth and homogeneous, as can be seen from the Hubble 'tuning fork' diagram of near-infrared galaxy morphology. Image mosaic by S. Van Dyk (IPAC).

  11. Cluster growth kinetics

    International Nuclear Information System (INIS)

    Dubovik, V.M.; Gal'perin, A.G.; Rikhvitskij, V.S.; Lushnikov, A.A.

    2000-01-01

    Processes of some traffic blocking coming into existence are considered as probabilistic ones. We study analytic solutions for models for the dynamics of both cluster growth and cluster growth with fragmentation in the systems of finite number of objects. Assuming rates constancy of both coalescence and fragmentation, the models under consideration are linear on the probability functions

  12. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  13. Negotiating Cluster Boundaries

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    2017-01-01

    Palm oil was introduced to Malay(si)a as an alternative to natural rubber, inheriting its cluster organizational structure. In the late 1960s, Malaysia became the world’s largest palm oil exporter. Based on archival material from British colonial institutions and agency houses, this paper focuses...... on the governance dynamics that drove institutional change within this cluster during decolonization. The analysis presents three main findings: (i) cluster boundaries are defined by continuous tug-of-war style negotiations between public and private actors; (ii) this interaction produces institutional change...... within the cluster, in the form of cumulative ‘institutional rounds’ – the correction or disruption of existing institutions or the creation of new ones; and (iii) this process leads to a broader inclusion of local actors in the original cluster configuration. The paper challenges the prevalent argument...

  14. Mathematical classification and clustering

    CERN Document Server

    Mirkin, Boris

    1996-01-01

    I am very happy to have this opportunity to present the work of Boris Mirkin, a distinguished Russian scholar in the areas of data analysis and decision making methodologies. The monograph is devoted entirely to clustering, a discipline dispersed through many theoretical and application areas, from mathematical statistics and combina­ torial optimization to biology, sociology and organizational structures. It compiles an immense amount of research done to date, including many original Russian de­ velopments never presented to the international community before (for instance, cluster-by-cluster versions of the K-Means method in Chapter 4 or uniform par­ titioning in Chapter 5). The author's approach, approximation clustering, allows him both to systematize a great part of the discipline and to develop many in­ novative methods in the framework of optimization problems. The optimization methods considered are proved to be meaningful in the contexts of data analysis and clustering. The material presented in ...

  15. Neutrosophic Hierarchical Clustering Algoritms

    Directory of Open Access Journals (Sweden)

    Rıdvan Şahin

    2014-03-01

    Full Text Available Interval neutrosophic set (INS is a generalization of interval valued intuitionistic fuzzy set (IVIFS, whose the membership and non-membership values of elements consist of fuzzy range, while single valued neutrosophic set (SVNS is regarded as extension of intuitionistic fuzzy set (IFS. In this paper, we extend the hierarchical clustering techniques proposed for IFSs and IVIFSs to SVNSs and INSs respectively. Based on the traditional hierarchical clustering procedure, the single valued neutrosophic aggregation operator, and the basic distance measures between SVNSs, we define a single valued neutrosophic hierarchical clustering algorithm for clustering SVNSs. Then we extend the algorithm to classify an interval neutrosophic data. Finally, we present some numerical examples in order to show the effectiveness and availability of the developed clustering algorithms.

  16. Estudio “Cumple con SAM”

    Directory of Open Access Journals (Sweden)

    Escribá MP

    2009-06-01

    Full Text Available INTRODUCCIÓN Existen estudios que demuestran los beneficios de los sistemas personalizados de dosificación para aumentar la adherencia al tratamiento en pacientes polimedicados. Recientemente se puso en el mercado un sistema de administración de medicamentos (SAM, portable y de pequeño tamaño, que combina un reloj con alarmas programables y varios compartimentos en donde colocar las formas farmacéuticas de los medicamentos. Para la valoración de su utilidad se ha realizado un estudio piloto de satisfacción sobre el SAM entre los pacientes diana de estos dispositivos, solicitando, tras un breve período de uso, su opinión sobre las características del mismo. Se ha evaluando también la mejora del cumplimiento. MATERIAL Y MÉTODOS 43 farmacéuticos comunitarios voluntarios de 26 oficinas de farmacia ubicadas en 5 provincias reclutaron sobre la base de unos criterios de inclusión y exclusión 302 pacientes incumplidores para que utilizasen durante al menos 15 días el SAM y, posteriormente, rellenasen una encuesta de opinión sobre éste. RESULTADOS La opinión del 91% de los pacientes participantes en el estudio es que el SAM es útil, muy útil o imprescindible como sistema de administración de medicamentos. El incumplimiento autocomunicado pasa del 87% al 23% de pacientes. El SAM puede ser útil para los pacientes como sistema de administración de medicamentos en la mejora de la adherencia a su tratamiento farmacológico en la medida en que disminuye los olvidos. Sin embargo, también ponen de manifiesto algunos problemas de diseño mejorables como son el excesivo tamaño, dificultad de apertura e intensidad del sonido. Estos dos últimos problemas dificultan su uso entre la población de mayor edad.

  17. Herd Clustering: A synergistic data clustering approach using collective intelligence

    KAUST Repository

    Wong, Kachun; Peng, Chengbin; Li, Yue; Chan, Takming

    2014-01-01

    , this principle is used to develop a new clustering algorithm. Inspired by herd behavior, the clustering method is a synergistic approach using collective intelligence called Herd Clustering (HC). The novel part is laid in its first stage where data instances

  18. Un estudio sobre el rendimiento universitario

    Directory of Open Access Journals (Sweden)

    Albaladejo Pina, I. P.

    1999-01-01

    Full Text Available El objetivo del presente trabajo es contrastar los rendimientos académicos de alumnos de dos cursos de la Facultad de Ciencias Económicas y Empresariales de la Universidad de Murcia, uno con el antiguo plan de estudios y otro con el actualmente en vigor. Analizamos el éxito y el fracaso para los estudiantes de cada uno de estos cursos, así como las variables socioeconómicas y educacionales que pueden influir en su rendimiento. Comprobamos, mediante unas estimaciones logit, que tanto unas como otras variables son factores condicionantes de este rendimiento. En particular, destacamos la influencia de haber cursado la opción C de COU en cuanto a fracasar o no en su primer curso universitario.

  19. Estudio sobre encofrados de madera modernos

    Directory of Open Access Journals (Sweden)

    de la Peña Aznar, Juan M.

    1980-12-01

    Full Text Available The author continues the development of the subject «Modern Timber Formwork», by summing up the comparative examination —already carried out in Part III of this Study— of the different types of glued timber existing on the market. In addition, the loads and stresses allovk/able for coniferous timber and the proposal for establishing Regulations for the Timber Section of the Research and Experimental Forestry Institute of Spain are given. In part V of the author's Study, published in this article, the important subject of the glues used for joining timber, a truly vital point in order to obtain louvered timber beams which are simply glued together, is approached.

    El autor continúa el desarrollo del tema sobre «Encofrados de madera modernos», resumiendo el estudio comparativo —ya hecho en la Parte III de este Estudio— de las diferentes vigas de madera encolada existentes en el mercado dando, además, las cargas y tensiones admisibles para maderas coníferas y la propuesta de Reglamentación de la Sección de Maderas del Instituto Forestal de Investigaciones y Experiencias de España. En la parte V del Estudio del autor, publicada en este artículo, se aborda el importante tema de las colas empleadas para las uniones de madera, algo realmente vital para la obtención de vigas de madera en celosía simplemente encoladas.

  20. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    Science.gov (United States)

    Sanfilippo, Antonio [Richland, WA; Calapristi, Augustin J [West Richland, WA; Crow, Vernon L [Richland, WA; Hetzler, Elizabeth G [Kennewick, WA; Turner, Alan E [Kennewick, WA

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset of the documents of the document set, using a plurality of terms of the documents, providing a cluster label indicative of subject matter content of the documents of the cluster, wherein the cluster label comprises a plurality of word senses, and selecting one of the word senses of the cluster label.

  1. Cluster-cluster correlations and constraints on the correlation hierarchy

    Science.gov (United States)

    Hamilton, A. J. S.; Gott, J. R., III

    1988-01-01

    The hypothesis that galaxies cluster around clusters at least as strongly as they cluster around galaxies imposes constraints on the hierarchy of correlation amplitudes in hierachical clustering models. The distributions which saturate these constraints are the Rayleigh-Levy random walk fractals proposed by Mandelbrot; for these fractal distributions cluster-cluster correlations are all identically equal to galaxy-galaxy correlations. If correlation amplitudes exceed the constraints, as is observed, then cluster-cluster correlations must exceed galaxy-galaxy correlations, as is observed.

  2. Formation of stable products from cluster-cluster collisions

    International Nuclear Information System (INIS)

    Alamanova, Denitsa; Grigoryan, Valeri G; Springborg, Michael

    2007-01-01

    The formation of stable products from copper cluster-cluster collisions is investigated by using classical molecular-dynamics simulations in combination with an embedded-atom potential. The dependence of the product clusters on impact energy, relative orientation of the clusters, and size of the clusters is studied. The structures and total energies of the product clusters are analysed and compared with those of the colliding clusters before impact. These results, together with the internal temperature, are used in obtaining an increased understanding of cluster fusion processes

  3. La auditoria sociolaboral y los estudios de relaciones laborales

    OpenAIRE

    Benito Bermejo, José Luis

    2016-01-01

    Se analizan los estudios de Relaciones Laborales en relación al perfil profesional de auditor sociolaboral, haciendo un repaso de la historia de ambos, así como comparando la titulación con otras titulaciones. Se concluye con una propuesta de futuro para los estudios de Relaciones Laborales. Grado en Relaciones Laborales y Recursos Humanos (Segovia)

  4. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    Brown clustering, an unsupervised hierarchical clustering technique based on ngram mutual information, has proven useful in many NLP applications. However, most uses of Brown clustering employ the same default configuration; the appropriateness of this configuration has gone predominantly...

  5. Cluster Management Institutionalization

    DEFF Research Database (Denmark)

    Normann, Leo; Agger Nielsen, Jeppe

    2015-01-01

    of how it was legitimized as a “ready-to-use” management model. Further, our account reveals how cluster management translated into considerably different local variants as it travelled into specific organizations. However, these processes have not occurred sequentially with cluster management first...... legitimized at the field level, then spread, and finally translated into action in the adopting organizations. Instead, we observed entangled field and organizational-level processes. Accordingly, we argue that cluster management institutionalization is most readily understood by simultaneously investigating...

  6. The concept of cluster

    DEFF Research Database (Denmark)

    Laursen, Lea Louise Holst; Møller, Jørgen

    2013-01-01

    villages in order to secure their future. This paper will address the concept of cluster-villages as a possible approach to strengthen the conditions of contemporary Danish villages. Cluster-villages is a concept that gather a number of villages in a network-structure where the villages both work together...... to forskellige positioner ser vi en ny mulighed for landsbyudvikling, som vi kalder Clustervillages. In order to investigate the potentials and possibilities of the cluster-village concept the paper will seek to unfold the concept strategically; looking into the benefits of such concept. Further, the paper seeks...

  7. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K

    2013-01-01

    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  8. Introduction to cluster dynamics

    CERN Document Server

    Reinhard, Paul-Gerhard

    2008-01-01

    Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a ""small"" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy. Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subje

  9. Contextualizing the Cluster

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    This dissertation examines the case of the palm oil cluster in Malaysia and Indonesia, today one of the largest agricultural clusters in the world. My analysis focuses on the evolution of the cluster from the 1880s to the 1970s in order to understand how it helped these two countries to integrate...... into the global economy in both colonial and post-colonial times. The study is based on empirical material drawn from five UK archives and background research using secondary sources, interviews, and archive visits to Malaysia and Singapore. The dissertation comprises three articles, each discussing a major under...

  10. Atomic cluster collisions

    Science.gov (United States)

    Korol, Andrey V.; Solov'yov, Andrey

    2013-01-01

    Atomic cluster collisions are a field of rapidly emerging research interest by both experimentalists and theorists. The international symposium on atomic cluster collisions (ISSAC) is the premier forum to present cutting-edge research in this field. It was established in 2003 and the most recent conference was held in Berlin, Germany in July of 2011. This Topical Issue presents original research results from some of the participants, who attended this conference. This issues specifically focuses on two research areas, namely Clusters and Fullerenes in External Fields and Nanoscale Insights in Radiation Biodamage.

  11. Combining cluster number counts and galaxy clustering

    Energy Technology Data Exchange (ETDEWEB)

    Lacasa, Fabien; Rosenfeld, Rogerio, E-mail: fabien@ift.unesp.br, E-mail: rosenfel@ift.unesp.br [ICTP South American Institute for Fundamental Research, Instituto de Física Teórica, Universidade Estadual Paulista, São Paulo (Brazil)

    2016-08-01

    The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for the fact that they are not independent quantities, since they probe the same density field. It is important to develop a good understanding of their correlation in order to extract parameter constraints. We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. We employ the framework of the halo model complemented by a Halo Occupation Distribution model (HOD). We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions. Indeed, we show that the non-Gaussian covariance becomes dominant at small scales, low redshifts or high cluster masses. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias. We demonstrate that the SSC obeys mathematical inequalities and positivity. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeably better constraints, with improvements of order 20% on cosmological parameters compared to the best single probe, and even greater improvement on HOD parameters, with reduction of error bars by a factor 1.4-4.8. This happens in particular because the cross-covariance introduces a synergy between the probes on small scales. We conclude that accounting for non-Gaussian effects is required for the joint analysis of these observables in galaxy surveys.

  12. Estudios sobre postmodernidad y estudios culturales: ¿sinónimos?

    Directory of Open Access Journals (Sweden)

    Dr. Roberto A. Follari

    2000-01-01

    Full Text Available La postmodernidad exige para ser comprendida una dimensión sociohistórica y otra filosófica que le resulta irrenunciables. También hay una serie de fenómenos propiamente culturales, que son los que los denominados "estudios culturales" (G. Canclini. M. Barbero, etc. han asumido en Latinoamérica. Tales estudios han aportado una descripción de fenómenos nuevos, que no son analizados por ningún otro discurso teórico (tribus urbanas, identidades lábiles, influencia de los medios en los nuevos estilos de consumo, etc.. Con ello se da cuenta de parte de la cuestión postmodernidad, pero sin dudase deja fuera otras: lo filosófico y aún lo social y lo político quedan fuera de esa especie de antropología del presente. Por lo tanto, un enfoque integral de lo postmoderno incluye los estudios culturales, pero está lejos de limitarse a ellos.

  13. Escala de Metas de Estudio para Estudiantes Universitarios

    Directory of Open Access Journals (Sweden)

    María Victoria Pérez Villalobos

    2009-01-01

    Full Text Available Actualmente disponemos de gran cantidad de trabajos que muestran la implicación de las metas de estudio en la motivación por estudiar y aprender. Este trabajo analiza la motivación académica y, especialmente, la variable "metas de estudio". El principal propósito de esta investigación es conocer las características psicométricas de la adaptación de la Escala de Metas de Estudio a la población universitaria chilena. Los participantes son 542 estudiantes chilenos, de distintas facultades universitarias. Los resultados del análisis factorial y de consistencia interna son aceptables en las tres subescalas. Estos resultados fundamentan el uso de la Escala de Metas de Estudio para evaluar la motivación al estudio de alumnas y alumnos universitarios en Chile (CL.

  14. Metal cluster compounds - chemistry and importance; clusters containing isolated main group element atoms, large metal cluster compounds, cluster fluxionality

    International Nuclear Information System (INIS)

    Walther, B.

    1988-01-01

    This part of the review on metal cluster compounds deals with clusters containing isolated main group element atoms, with high nuclearity clusters and metal cluster fluxionality. It will be obvious that main group element atoms strongly influence the geometry, stability and reactivity of the clusters. High nuclearity clusters are of interest in there own due to the diversity of the structures adopted, but their intermediate position between molecules and the metallic state makes them a fascinating research object too. These both sites of the metal cluster chemistry as well as the frequently observed ligand and core fluxionality are related to the cluster metal and surface analogy. (author)

  15. Disentangling Porterian Clusters

    DEFF Research Database (Denmark)

    Jagtfelt, Tue

    , contested theory become so widely disseminated and applied as a normative and prescriptive strategy for economic development? The dissertation traces the introduction of the cluster notion into the EU’s Lisbon Strategy and demonstrates how its inclusion originates from Porter’s colleagues: Professor Örjan...... to his membership on the Commission on Industrial Competitiveness, and that the cluster notion found in his influential book, Nations, represents a significant shift in his conception of cluster compared with his early conceptions. This shift, it is argued, is a deliberate attempt by Porter to create...... a paradigmatic textbook that follows Kuhn’s blueprint for scientific revolutions by instilling Nations with circular references and thus creating a local linguistic holism conceptualized through an encompassing notion of cluster. The dissertation concludes that the two research questions are philosophically...

  16. Remarks on stellar clusters

    International Nuclear Information System (INIS)

    Teller, E.

    1985-01-01

    In the following, a few simple remarks on the evolution and properties of stellar clusters will be collected. In particular, globular clusters will be considered. Though details of such clusters are often not known, a few questions can be clarified with the help of primitive arguments. These are:- why are spherical clusters spherical, why do they have high densities, why do they consist of approximately a million stars, how may a black hole of great mass form within them, may they be the origin of gamma-ray bursts, may their invisible remnants account for the missing mass of our galaxy. The available data do not warrant a detailed evaluation. However, it is remarkable that exceedingly simple models can shed some light on the questions enumerated above. (author)

  17. From collisions to clusters

    DEFF Research Database (Denmark)

    Loukonen, Ville; Bork, Nicolai; Vehkamaki, Hanna

    2014-01-01

    -principles molecular dynamics collision simulations of (sulphuric acid)1(water)0, 1 + (dimethylamine) → (sulphuric acid)1(dimethylamine)1(water)0, 1 cluster formation processes. The simulations indicate that the sticking factor in the collisions is unity: the interaction between the molecules is strong enough...... control. As a consequence, the clusters show very dynamic ion pair structure, which differs from both the static structure optimisation calculations and the equilibrium first-principles molecular dynamics simulations. In some of the simulation runs, water mediates the proton transfer by acting as a proton...... to overcome the possible initial non-optimal collision orientations. No post-collisional cluster break up is observed. The reasons for the efficient clustering are (i) the proton transfer reaction which takes place in each of the collision simulations and (ii) the subsequent competition over the proton...

  18. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  19. How Clusters Work

    Science.gov (United States)

    Technology innovation clusters are geographic concentrations of interconnected companies, universities, and other organizations with a focus on environmental technology. They play a key role in addressing the nation’s pressing environmental problems.

  20. Evolution of clustered storage

    CERN Multimedia

    CERN. Geneva; Van de Vyvre, Pierre

    2007-01-01

    The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

  1. Galaxy clusters and cosmology

    CERN Document Server

    White, S

    1994-01-01

    Galaxy clusters are the largest coherent objects in Universe. It has been known since 1933 that their dynamical properties require either a modification of the theory of gravity, or the presence of a dominant component of unseen material of unknown nature. Clusters still provide the best laboratories for studying the amount and distribution of this dark matter relative to the material which can be observed directly -- the galaxies themselves and the hot,X-ray-emitting gas which lies between them.Imaging and spectroscopy of clusters by satellite-borne X -ray telescopes has greatly improved our knowledge of the structure and composition of this intergalactic medium. The results permit a number of new approaches to some fundamental cosmological questions,but current indications from the data are contradictory. The observed irregularity of real clusters seems to imply recent formation epochs which would require a universe with approximately the critical density. On the other hand, the large baryon fraction observ...

  2. Applications of Clustering

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Applications of Clustering. Biology – medical imaging, bioinformatics, ecology, phylogenies problems etc. Market research. Data Mining. Social Networks. Any problem measuring similarity/correlation. (dimensions represent different parameters)

  3. Clustering Game Behavior Data

    DEFF Research Database (Denmark)

    Bauckhage, C.; Drachen, Anders; Sifa, Rafet

    2015-01-01

    of the causes, the proliferation of behavioral data poses the problem of how to derive insights therefrom. Behavioral data sets can be large, time-dependent and high-dimensional. Clustering offers a way to explore such data and to discover patterns that can reduce the overall complexity of the data. Clustering...... and other techniques for player profiling and play style analysis have, therefore, become popular in the nascent field of game analytics. However, the proper use of clustering techniques requires expertise and an understanding of games is essential to evaluate results. With this paper, we address game data...... scientists and present a review and tutorial focusing on the application of clustering techniques to mine behavioral game data. Several algorithms are reviewed and examples of their application shown. Key topics such as feature normalization are discussed and open problems in the context of game analytics...

  4. Clustering on Membranes

    DEFF Research Database (Denmark)

    Johannes, Ludger; Pezeshkian, Weria; Ipsen, John H

    2018-01-01

    Clustering of extracellular ligands and proteins on the plasma membrane is required to perform specific cellular functions, such as signaling and endocytosis. Attractive forces that originate in perturbations of the membrane's physical properties contribute to this clustering, in addition to direct...... protein-protein interactions. However, these membrane-mediated forces have not all been equally considered, despite their importance. In this review, we describe how line tension, lipid depletion, and membrane curvature contribute to membrane-mediated clustering. Additional attractive forces that arise...... from protein-induced perturbation of a membrane's fluctuations are also described. This review aims to provide a survey of the current understanding of membrane-mediated clustering and how this supports precise biological functions....

  5. Air void clustering.

    Science.gov (United States)

    2015-06-01

    Air void clustering around coarse aggregate in concrete has been identified as a potential source of : low strengths in concrete mixes by several Departments of Transportation around the country. Research was : carried out to (1) develop a quantitati...

  6. Speaker segmentation and clustering

    OpenAIRE

    Kotti, M; Moschou, V; Kotropoulos, C

    2008-01-01

    07.08.13 KB. Ok to add the accepted version to Spiral, Elsevier says ok whlile mandate not enforced. This survey focuses on two challenging speech processing topics, namely: speaker segmentation and speaker clustering. Speaker segmentation aims at finding speaker change points in an audio stream, whereas speaker clustering aims at grouping speech segments based on speaker characteristics. Model-based, metric-based, and hybrid speaker segmentation algorithms are reviewed. Concerning speaker...

  7. Fermion cluster algorithms

    International Nuclear Information System (INIS)

    Chandrasekharan, Shailesh

    2000-01-01

    Cluster algorithms have been recently used to eliminate sign problems that plague Monte-Carlo methods in a variety of systems. In particular such algorithms can also be used to solve sign problems associated with the permutation of fermion world lines. This solution leads to the possibility of designing fermion cluster algorithms in certain cases. Using the example of free non-relativistic fermions we discuss the ideas underlying the algorithm

  8. BUILDING e-CLUSTERS

    OpenAIRE

    Milan Davidovic

    2013-01-01

    E-clusters are strategic alliance in TIMES technology sector (Telecommunication, Information technology, Multimedia, Entertainment, Security) where products and processes are digitalized. They enable horizontal and vertical integration of small and medium companies and establish new added value e-chains. E-clusters also build supply chains based on cooperation relationship, innovation, organizational knowledge and compliance of intellectual properties. As an innovative approach for economic p...

  9. Clusters and exotic processes

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1975-01-01

    An attempt is made to present some data which may be construed as indicating that perhaps clusters play a role in high energy and exotic pion or kaon interactions with complex (A much greater than 16) nuclei. Also an attempt is made to summarize some very recent experimental work on pion interactions with nuclei which may or may not in the end support a picture in which clusters play an important role. (U.S.)

  10. Robust continuous clustering.

    Science.gov (United States)

    Shah, Sohil Atul; Koltun, Vladlen

    2017-09-12

    Clustering is a fundamental procedure in the analysis of scientific data. It is used ubiquitously across the sciences. Despite decades of research, existing clustering algorithms have limited effectiveness in high dimensions and often require tuning parameters for different domains and datasets. We present a clustering algorithm that achieves high accuracy across multiple domains and scales efficiently to high dimensions and large datasets. The presented algorithm optimizes a smooth continuous objective, which is based on robust statistics and allows heavily mixed clusters to be untangled. The continuous nature of the objective also allows clustering to be integrated as a module in end-to-end feature learning pipelines. We demonstrate this by extending the algorithm to perform joint clustering and dimensionality reduction by efficiently optimizing a continuous global objective. The presented approach is evaluated on large datasets of faces, hand-written digits, objects, newswire articles, sensor readings from the Space Shuttle, and protein expression levels. Our method achieves high accuracy across all datasets, outperforming the best prior algorithm by a factor of 3 in average rank.

  11. Cluster bomb ocular injuries.

    Science.gov (United States)

    Mansour, Ahmad M; Hamade, Haya; Ghaddar, Ayman; Mokadem, Ahmad Samih; El Hajj Ali, Mohamad; Awwad, Shady

    2012-01-01

    To present the visual outcomes and ocular sequelae of victims of cluster bombs. This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006). Data were gathered from the reports to the Information Management System for Mine Action. There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308) of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67%) with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes), corneal foreign bodies (9 eyes), corneal decompensation (2 eyes), ruptured cataract (6 eyes), and intravitreal foreign bodies (10 eyes). The corneas of one patient had extreme attenuation of the endothelium. Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs.

  12. Determination of atomic cluster structure with cluster fusion algorithm

    DEFF Research Database (Denmark)

    Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2005-01-01

    We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters.......We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters....

  13. PARATIROIDECTOMIA ENDOSCOPICA. ESTUDIO EXPERIMENTAL EN EL PERRO

    Directory of Open Access Journals (Sweden)

    Jorge Ramón Lucena Olavarrieta

    2008-01-01

    Full Text Available La primera paratiroidectomía exitosa fue realizada en Viena, Austria, en 1925. Los procedimientos laparoscópicos estuvieron inicialmente limitadas a las zonas corporales con cavidades preexistentes, recientemente, el acceso a espacios anatómicos potenciales ha extendido las indicaciones de la cirugía endoscópica minimamnete invasiva.Desde el primer reporte sobre la paratiroidectomía endoscópica en 1996, las técnicas video-asistidas han comenzado a utilizarse en la cirugía del cuello, y en varias series se han documentado la factibilidad y seguridad de este tipo de abordaje. La finalidad de esta investigación fue el determinar la factibilidad, seguridad y eficacia de la paratiroidectomía endoscopia en el modelo canino.Entre el 25 de noviembre del 2005 y 15 de octubre del 2007, se intervinieron en el Instituto de Cirugía Experimental de la Universidad Central de Venezuela 31 perros, mestizos sanos desparasitados,asignándose a dos grupos: homogéneos "A" 16, a cirugía convencional, "B" 15 a cirugía video-asistida. Se midieron las siguientes variables; sexo, peso, exámenes de laboratorio, laringoscopia pre y postoperatoria, posición, dirección de la incisión, longitud, localización, valores pre y postoperatorios de calcio, fósforo, proteína C reactiva, hemoglobina, hematocrito, tipo de disección, número y posición de las paratiroides, identificación de los nervios recurrentes y rama externa del nervio laríngeo superior, sangramiento, dificultades intraoperatorias, tiempo, resultado del estudio histopatológico.Las deducciones de este estudio experimental proporcionan evidencias de que la paratiroidectomía endoscópica es factible y segura. El abordaje mínimo tiene mejores resultados cosméticos y el potencial de disminuir la morbi-mortalidad.

  14. Cluster dynamics at different cluster size and incident laser wavelengths

    International Nuclear Information System (INIS)

    Desai, Tara; Bernardinello, Andrea

    2002-01-01

    X-ray emission spectra from aluminum clusters of diameter -0.4 μm and gold clusters of dia. ∼1.25 μm are experimentally studied by irradiating the cluster foil targets with 1.06 μm laser, 10 ns (FWHM) at an intensity ∼10 12 W/cm 2 . Aluminum clusters show a different spectra compared to bulk material whereas gold cluster evolve towards bulk gold. Experimental data are analyzed on the basis of cluster dimension, laser wavelength and pulse duration. PIC simulations are performed to study the behavior of clusters at higher intensity I≥10 17 W/cm 2 for different size of the clusters irradiated at different laser wavelengths. Results indicate the dependence of cluster dynamics on cluster size and incident laser wavelength

  15. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2006-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry...

  16. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2008-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry...

  17. Estudio de estabilidad de tabletas de propiltiouracilo 50 mg

    Directory of Open Access Journals (Sweden)

    María Olga Valdés Bendoyro

    Full Text Available Se desarrolló el estudio de estabilidad de las tabletas de propiltiouracilo 50 mg y se determinó su fecha de vencimiento. Este estudio se realizó por los métodos de vida de estante y de estabilidad acelerada mediante cromatografía líquida de alta eficiencia, validados en el Centro de Investigación y Desarrollo de Medicamentos. El estudio de vida de estante se desarrolló por un periodo de 24 meses a temperatura ambiente; mientras que el estudio de estabilidad acelerada se efectuó sometiendo el producto a la influencia de la luz, la humedad y la temperatura; se realizó el análisis durante 3 meses, para los 2 primeros y durante 6 meses para el estudio de la temperatura. La formulación de propiltiouracilo tabletas 50 mg cumplió con las especificaciones de calidad descritas en la farmacopea. Los resultados del estudio de estabilidad por vida de estante después de transcurridos los 24 meses indicaron que el producto mantenía los parámetros que determinan su calidad durante ese tiempo, y en los estudios acelerados no se observó degradación significativa del producto. Se estableció 2 años como fecha de vencimiento en las condiciones señaladas.

  18. GibbsCluster: unsupervised clustering and alignment of peptide sequences

    DEFF Research Database (Denmark)

    Andreatta, Massimo; Alvarez, Bruno; Nielsen, Morten

    2017-01-01

    motif characterizing each cluster. Several parameters are available to customize cluster analysis, including adjustable penalties for small clusters and overlapping groups and a trash cluster to remove outliers. As an example application, we used the server to deconvolute multiple specificities in large......-scale peptidome data generated by mass spectrometry. The server is available at http://www.cbs.dtu.dk/services/GibbsCluster-2.0....

  19. planes de estudio y orientaciones oficiales

    Directory of Open Access Journals (Sweden)

    María Eugenia Fernández Fraile

    2005-01-01

    Full Text Available El presente artículo se propone, a través del análisis de los cambios introducidos en los Planes de estudios que más incidencia tienen sobre la enseñanza de las lenguas vivas (1900, 1926, 1934, 1938, 1953/1957, 1970 y 1990, destacar las tendencias evolutivas o las líneas maestras que configuran el concepto del Francés como Lengua Extranjera en tanto que disciplina escolar Se abordan así, en una presentación cronológica, las siguientes cuestiones: la regulación de la materia en sus aspectos “materiales” (horario, cursos, el concepto “social” e “institucional” de la disciplina (en conexión con el resto de las lenguas vivas y, finalmente, los objetivos-contenidos didácticos y las orientaciones metodológicas presentes en los textos oficiales.

  20. Estudio comparativo de la cultura organizacional

    Directory of Open Access Journals (Sweden)

    Góngora, Norberto H.

    2014-12-01

    Full Text Available El presente trabajo da a conocer resultados parciales de la investigación realizada en el marco del proyecto acreditado “Estudio de las Culturas Organizacionales como determinantes de las personas que trabajan en ellas”, cuyo objetivo general es corroborar las características de cada tipo cultural descriptas en la teoría.Los datos que se exponen son el resultado de varios proyectos de investigación desarrollados utilizando la misma metodología. Se ha obtenido gran cantidad de información para analizar variables asociadas al análisis de la cultura organizacional y así, clasificar cada caso en un tipo cultural. Luego, a partir de la base de datos obtenida se han comparado los datos con las características que describe la teoría, a fin de verificarlos o ponerlos en discusión.La conclusión más importante es que la cultura incide en múltiples aspectos de las conductas de las personas y muchos fenómenos, entre ellos los estudiados en este trabajo, así lo demuestran. Es fundamental estudiar este aspecto de las organizaciones en profundidad y no sólo clasificarlas en uno u otro tipo cultural, ya que existen relaciones entre variables que brindan mayor información que resulta relevante para comprender el comportamiento de las personas.

  1. Un estudio de resentimiento en ancianos institucionalizados

    Directory of Open Access Journals (Sweden)

    Dante Gazzolo D.

    1987-06-01

    Full Text Available El presente estudio es una investigación realizada por los Servicios de Psicología del Instituto Nacional de Salud Mental "Honorio Delgado - Hideyo Noguchi", y del Hogar "lgnacia Rodulfa V da. de Canevaro", a través del cual se intenta un acercamiento al devenir psicológico del anciano institucionalizado. Este, al residir permanentemente al interior de un asilo, manifiesta sentimientos de frustración, fracaso y resentimiento, entre otros. Se intenta determinar el grado de: resentimiento que se hace presente en ancianos institucionalizados, tomando en cuenta variables diferenciadoras como condición de vivienda (nivel socio-económico, sexo, edad, estado civil, grado de instrucción, actividad laboral, presencia  o ausencia de hijos, y tiempo de residencia en el asilo.Para tal fin, se evaluó a una muestra de 53  ancianos, 32 mujeres y 21 hombres, 18 de nivel socio-económico alto, y 35 de nivel socio-económico bajo, a través de un Inventario de Actitudes hacia la Vida, encontrando que los sujetos de nivel socio-económico bajo presentan mayores grados de resentimiento que los sujetos de nivel socio-económico alto, observándose, de otro lado, mayores niveles de resentimiento en el sexo masculino que en el femenino.

  2. Anorexia nervosa: un estudio de casos

    Directory of Open Access Journals (Sweden)

    Lillyana Zusman Tinman

    2013-09-01

    Full Text Available La Anorexia Nervosa es un trastorno de alimentación que se define (etimológicamente como una "pérdida nerviosa del apetito". Se caracteriza por la actitud consciente, voluntaria y rotunda de los sujetos  de tener un exceso de peso que intentan modificar por vía de la inanición. A partir del estudio de casos, se propone la distinción entre una Anorexia Nervosa Estructural -aquella en la que predomina el conflicto intrapsíquico primario y arcaico, y que manifiesta una conducta aislada y retraída- y una Anorexia Nervosa Reactiva, aquella en la que predomina un conflicto intrafamiliar algo más posterior y, por lo tanto, una personalidad más abierta y compatible con el medio. Anorexia Nervosa is an Eating Disorder defined (etimoligacally as a "nervouse loss of apetite". It is characterized by a conscious, voluntary and categoric attitude of the sick patient to refrain from eating. He/she has a firm conviction of having excess weight which they try to modify by starvation. Through a case study, a distinction between two types of Anorexia Nervosa is proposed: a Structural Anorexia Nervosa -in which an intrapsyhic, primary, arcaic conflic prevails, leading to an isolated, withdrawal conduct- and a Reactive Anorexia Nervosa, in which a later intrafamilial conflict prevails leading, therefore, to a more open personality, compatible with the enviroment.

  3. Estudio electrofisiologico en la neuropatia por Vincristina

    Directory of Open Access Journals (Sweden)

    Olga P. Sanz

    1975-12-01

    Full Text Available Diez pacientes afectados por diversas patologías que requerían tratamiento crónico con Vincristina, fueron sometidos a estudios electrofisiológicos en los que se valoró: el número de unidades motoras (UM funcionantes en los músculos de la eminencia tenar, los valores de los incrementos medios de UM, velocidad de conducción motora y su latencia residual en el nervio mediano, la velocidad de conducción sensitiva del mismo nervio y el estado de la transmisión neuromuscular. Los valores obtenidos fueron comparados con grupos controles. Los resultados mostraron disminución del número de UM; las UM remanentes presentaron amplitud reducida junto a otras cuyo tamaño no superaba el del grupo control, hecho que sugiere la incapacidad de lograr una reinervación adecuada. Las velocidades de conducción motora y sensitiva mostraron valores diminuídos, con mayor compromiso en los segmentos distales. Junto a estos datos se halló respuesta miasteniforme al estímulo repetitivo. Todos estos resultados permiten postular la existencia de un compromiso de la unidad motora, abarcando todos sus segmentos, en pacientes intoxicados con Vincristina.

  4. ESTUDIOS CURRICULARES Y LA HISTORIA DEL PRESENTE

    Directory of Open Access Journals (Sweden)

    Thomas S. Popkewitz

    2010-01-01

    Full Text Available El campo de la historia del currículum, así como más ampliamente el de la historia de la educación, está organizado por tradiciones de historia intelectual y social; antes más preocupado por la organización y el cambio en las ideas; más recientemente con las ideas como representación institucional y cambios sociales encontrados en la política y en los actuales desarrollos programáticos. Este artículo formula una perspectiva sobre el currículum como una historia del presente. Se considera el currículum como "ordenanzas de conversión" pensando el currículum como narrativas de pertenencia nacional y ciencia emparejada con temas de salvación que generan tesis culturales sobre modos de vida. La sección segunda habla de la Educación Americana Progresiva en un reformismo protestante que, cruzado el Atlántico, se preocupa por la cuestión social. La sección final explora las tesis culturales generadas en la formación de las matemáticas, el alfabetismo, y el plan de estudios de música.

  5. Cluster Implantation and Deposition Apparatus

    DEFF Research Database (Denmark)

    Hanif, Muhammad; Popok, Vladimir

    2015-01-01

    In the current report, a design and capabilities of a cluster implantation and deposition apparatus (CIDA) involving two different cluster sources are described. The clusters produced from gas precursors (Ar, N etc.) by PuCluS-2 can be used to study cluster ion implantation in order to develop...

  6. Subspace K-means clustering

    NARCIS (Netherlands)

    Timmerman, Marieke E.; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-01-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the

  7. Los estudios culturales en Centroamérica.

    OpenAIRE

    Fumero, Patricia

    2012-01-01

    En el presente artículo se considerará el inicio de los estudios culturales en Centroamérica y las diversas corrientes que influyeron en este cambio. Posteriormente, se analizará la problemática que supone el estudio del istmo, en términos de su diversidad y del desarrollo de adecuadas perspectivas comparativas. Por último, se revisarán los avances logrados por los estudios literarios y los desafíos planteados en el futuro inmediato.

  8. Recursos bibliográgicos sobre los estudios en italiano

    OpenAIRE

    Caprara, Giovanni

    2009-01-01

    Este artículo bibliográfico busca ofrecer una visión panorámica actualizada (y representativa) de los Estudios de Traducción en lengua italiana. En ella se clasifican por temas objeto de estudio toda una serie de obras (libros, monografías colectivas, etc.) que inciden sobre el estudio de la Traducción e Interpretación desde la perspectiva de la lengua y la cultura italianas o que, aunque hayan sido realizados por autores extranjeros, su publicación utiliza como lengua vehicular de comunic...

  9. Estudio comparativo entre SIG propietario y SIG libre

    OpenAIRE

    Mesa Díaz, Juan Ramón

    2008-01-01

    Estudio comparativo entre SIG propietario y SIG libre, focalizado en los casos particulares de Geomedia Pro (SIG Propietario) y gvSIG (SIG Libre). En el estudio se procede a determinar cuáles son los aspectos destacables de un SIG, para poder evaluarlos, posteriormente, en los dos SIG objeto del estudio y obtener una ponderación definitoria de cada SIG. A continuación, algunos de los aspectos evaluados en cada SIG: interoperabilidad, conexión a bases de datos espaciales, aspectos económ...

  10. Projected coupled cluster theory.

    Science.gov (United States)

    Qiu, Yiheng; Henderson, Thomas M; Zhao, Jinmo; Scuseria, Gustavo E

    2017-08-14

    Coupled cluster theory is the method of choice for weakly correlated systems. But in the strongly correlated regime, it faces a symmetry dilemma, where it either completely fails to describe the system or has to artificially break certain symmetries. On the other hand, projected Hartree-Fock theory captures the essential physics of many kinds of strong correlations via symmetry breaking and restoration. In this work, we combine and try to retain the merits of these two methods by applying symmetry projection to broken symmetry coupled cluster wave functions. The non-orthogonal nature of states resulting from the application of symmetry projection operators furnishes particle-hole excitations to all orders, thus creating an obstacle for the exact evaluation of overlaps. Here we provide a solution via a disentanglement framework theory that can be approximated rigorously and systematically. Results of projected coupled cluster theory are presented for molecules and the Hubbard model, showing that spin projection significantly improves unrestricted coupled cluster theory while restoring good quantum numbers. The energy of projected coupled cluster theory reduces to the unprojected one in the thermodynamic limit, albeit at a much slower rate than projected Hartree-Fock.

  11. Globular Clusters - Guides to Galaxies

    CERN Document Server

    Richtler, Tom; Joint ESO-FONDAP Workshop on Globular Clusters

    2009-01-01

    The principal question of whether and how globular clusters can contribute to a better understanding of galaxy formation and evolution is perhaps the main driving force behind the overall endeavour of studying globular cluster systems. Naturally, this splits up into many individual problems. The objective of the Joint ESO-FONDAP Workshop on Globular Clusters - Guides to Galaxies was to bring together researchers, both observational and theoretical, to present and discuss the most recent results. Topics covered in these proceedings are: internal dynamics of globular clusters and interaction with host galaxies (tidal tails, evolution of cluster masses), accretion of globular clusters, detailed descriptions of nearby cluster systems, ultracompact dwarfs, formations of massive clusters in mergers and elsewhere, the ACS Virgo survey, galaxy formation and globular clusters, dynamics and kinematics of globular cluster systems and dark matter-related problems. With its wide coverage of the topic, this book constitute...

  12. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    Attribute clustering has been previously employed to detect statistical dependence between subsets of variables. We propose a novel attribute clustering algorithm motivated by research of complex networks, called the Star Discovery algorithm. The algorithm partitions and indirectly discards...... inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

  13. Exotic cluster structures on

    CERN Document Server

    Gekhtman, M; Vainshtein, A

    2017-01-01

    This is the second paper in the series of papers dedicated to the study of natural cluster structures in the rings of regular functions on simple complex Lie groups and Poisson-Lie structures compatible with these cluster structures. According to our main conjecture, each class in the Belavin-Drinfeld classification of Poisson-Lie structures on \\mathcal{G} corresponds to a cluster structure in \\mathcal{O}(\\mathcal{G}). The authors have shown before that this conjecture holds for any \\mathcal{G} in the case of the standard Poisson-Lie structure and for all Belavin-Drinfeld classes in SL_n, n<5. In this paper the authors establish it for the Cremmer-Gervais Poisson-Lie structure on SL_n, which is the least similar to the standard one.

  14. From superdeformation to clusters

    Energy Technology Data Exchange (ETDEWEB)

    Betts, R R [Argonne National Lab., IL (United States). Physics Div.

    1992-08-01

    Much of the discussion at the conference centred on superdeformed states and their study by precise gamma spectrometry. The author suggests that the study of superdeformation by fission fragments and by auto-scattering is of importance, and may become more important. He concludes that there exists clear evidence of shell effects at extreme deformation in light nuclei studied by fission or cluster decay. The connection between the deformed shell model and the multi-center shell model can be exploited to give give insight into the cluster structure of these extremely deformed states, and also gives hope of a spectroscopy based on selection rules for cluster decay. A clear disadvantage at this stage is inability to make this spectroscopy more quantitative through calculation of the decay widths. The introduction of a new generation of high segmentation, high resolution, particle arrays has and will have a major impact on this aspect of the study of highly deformed nuclei. 20 refs., 16 figs.

  15. Implantes dentales en pacientes adultos postrauma dentoalveolar. Estudio descriptivo

    Directory of Open Access Journals (Sweden)

    Edgardo González

    2016-04-01

    Conclusiones: En este estudio se presenta un protocolo establecido y se establece la necesidad de un diagnóstico detallado para planificar la rehabilitación mediante implantes dentales posterior a un trauma con un equipo multidisciplinario.

  16. Refractory chronic cluster headache

    DEFF Research Database (Denmark)

    Mitsikostas, Dimos D; Edvinsson, Lars; Jensen, Rigmor H

    2014-01-01

    Chronic cluster headache (CCH) often resists to prophylactic pharmaceutical treatments resulting in patients' life damage. In this rare but pragmatic situation escalation to invasive management is needed but framing criteria are lacking. We aimed to reach a consensus for refractory CCH definition...... for clinical and research use. The preparation of the final consensus followed three stages. Internal between authors, a larger between all European Headache Federation members and finally an international one among all investigators that have published clinical studies on cluster headache the last five years...

  17. I Cluster geografici

    Directory of Open Access Journals (Sweden)

    Maurizio Rosina

    2010-03-01

    Full Text Available Geographic ClustersOver the past decade, public alphanumeric database have been growing at exceptional rate. Most of data can be georeferenced, so that is possible gaining new knowledge from such databases. The contribution of this paper is two-fold. We first present a model of geographic clusters, which uses only geographic and functionally data properties. The model is useful to process huge amount of public/government data, even daily upgrading. After that, we merge the model into the framework GEOPOI (GEOcoding Points Of Interest, and show some graphic map results.

  18. I Cluster geografici

    Directory of Open Access Journals (Sweden)

    Maurizio Rosina

    2010-03-01

    Full Text Available Geographic Clusters Over the past decade, public alphanumeric database have been growing at exceptional rate. Most of data can be georeferenced, so that is possible gaining new knowledge from such databases. The contribution of this paper is two-fold. We first present a model of geographic clusters, which uses only geographic and functionally data properties. The model is useful to process huge amount of public/government data, even daily upgrading. After that, we merge the model into the framework GEOPOI (GEOcoding Points Of Interest, and show some graphic map results.

  19. Clustering via Kernel Decomposition

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Girolami, Mark A.; Larsen, Jan

    2006-01-01

    Methods for spectral clustering have been proposed recently which rely on the eigenvalue decomposition of an affinity matrix. In this work it is proposed that the affinity matrix is created based on the elements of a non-parametric density estimator. This matrix is then decomposed to obtain...... posterior probabilities of class membership using an appropriate form of nonnegative matrix factorization. The troublesome selection of hyperparameters such as kernel width and number of clusters can be obtained using standard cross-validation methods as is demonstrated on a number of diverse data sets....

  20. El estudio de la cadena productiva del fique

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Morales Rubiano

    2002-09-01

    Full Text Available El estudio recopila los resultados más importantes obtenidos en el trabajo de grado denominado "Estudio de factibilidad de la cadena productiva del fique cultivado en Colombia", el cual tomo como punto de referencia el sector fiquero para estimas la factibilidad de aplicar un esquema de cadena productiva, a través de la estructura y análisis estratégico del sistema.

  1. Multi-Optimisation Consensus Clustering

    Science.gov (United States)

    Li, Jian; Swift, Stephen; Liu, Xiaohui

    Ensemble Clustering has been developed to provide an alternative way of obtaining more stable and accurate clustering results. It aims to avoid the biases of individual clustering algorithms. However, it is still a challenge to develop an efficient and robust method for Ensemble Clustering. Based on an existing ensemble clustering method, Consensus Clustering (CC), this paper introduces an advanced Consensus Clustering algorithm called Multi-Optimisation Consensus Clustering (MOCC), which utilises an optimised Agreement Separation criterion and a Multi-Optimisation framework to improve the performance of CC. Fifteen different data sets are used for evaluating the performance of MOCC. The results reveal that MOCC can generate more accurate clustering results than the original CC algorithm.

  2. Photochemistry in rare gas clusters

    International Nuclear Information System (INIS)

    Moeller, T.; Haeften, K. von; Pietrowski, R. von

    1999-01-01

    In this contribution photochemical processes in pure rare gas clusters will be discussed. The relaxation dynamics of electronically excited He clusters is investigated with luminescence spectroscopy. After electronic excitation of He clusters many sharp lines are observed in the visible and infrared spectral range which can be attributed to He atoms and molecules desorbing from the cluster. It turns out that the desorption of electronically excited He atoms and molecules is an important decay channel. The findings for He clusters are compared with results for Ar clusters. While desorption of electronically excited He atoms is observed for all clusters containing up to several thousand atoms a corresponding process in Ar clusters is only observed for very small clusters (N<10). (orig.)

  3. Photochemistry in rare gas clusters

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, T.; Haeften, K. von; Pietrowski, R. von [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Hamburger Synchrotronstrahlungslabor; Laarman, T. [Universitaet Hamburg, II. Institut fuer Experimentalphysik, Luruper Chaussee 149, D-22761 Hamburg (Germany)

    1999-12-01

    In this contribution photochemical processes in pure rare gas clusters will be discussed. The relaxation dynamics of electronically excited He clusters is investigated with luminescence spectroscopy. After electronic excitation of He clusters many sharp lines are observed in the visible and infrared spectral range which can be attributed to He atoms and molecules desorbing from the cluster. It turns out that the desorption of electronically excited He atoms and molecules is an important decay channel. The findings for He clusters are compared with results for Ar clusters. While desorption of electronically excited He atoms is observed for all clusters containing up to several thousand atoms a corresponding process in Ar clusters is only observed for very small clusters (N<10). (orig.)

  4. Globular clusters, old and young

    International Nuclear Information System (INIS)

    Samus', N.N.

    1984-01-01

    The problem of similarity of and difference in the globular and scattered star clusters is considered. Star clusters in astronomy are related either to globular or to scattered ones according to the structure of Hertzsprung-Russell diagram constructed for star clusters, but not according to the appearance. The qlobular clusters in the Galaxy are composed of giants and subgiants, which testifies to the old age of the globular clusters. The Globular clusters in the Magellanic clouds are classified into ''red'' ones - similar to the globular clusters of the Galaxy, and ''blue'' ones - similar to them in appearance but differing extremely by the star composition and so by the age. The old star clusters are suggested to be called globular ones, while another name (''populous'', for example) is suggested to be used for other clusters similar to globular ones only in appearance

  5. Globular clusters and galaxy halos

    International Nuclear Information System (INIS)

    Van Den Bergh, S.

    1984-01-01

    Using semipartial correlation coefficients and bootstrap techniques, a study is made of the important features of globular clusters with respect to the total number of galaxy clusters and dependence of specific galaxy cluster on parent galaxy type, cluster radii, luminosity functions and cluster ellipticity. It is shown that the ellipticity of LMC clusters correlates significantly with cluster luminosity functions, but not with cluster age. The cluter luminosity value above which globulars are noticeably flattened may differ by a factor of about 100 from galaxy to galaxy. Both in the Galaxy and in M31 globulars with small core radii have a Gaussian distribution over luminosity, whereas clusters with large core radii do not. In the cluster systems surrounding the Galaxy, M31 and NGC 5128 the mean radii of globular clusters was found to increase with the distance from the nucleus. Central galaxies in rich clusters have much higher values for specific globular cluster frequency than do other cluster ellipticals, suggesting that such central galaxies must already have been different from normal ellipticals at the time they were formed

  6. Clustering of resting state networks.

    Directory of Open Access Journals (Sweden)

    Megan H Lee

    Full Text Available The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm.The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization.The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  7. Clustering in Ethiopia

    African Journals Online (AJOL)

    Background: The importance of local variations in patterns of health and disease are increasingly recognised, but, particularly in the case of tropical infections, available methods and resources for characterising disease clusters in time and space are limited. Whilst the Global Positioning System. (GPS) allows accurate and ...

  8. Hardness of Clustering

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Hardness of Clustering. Both k-means and k-medians intractable (when n and d are both inputs even for k =2). The best known deterministic algorithms. are based on Voronoi partitioning that. takes about time. Need for approximation – “close” to optimal.

  9. On small clusters

    International Nuclear Information System (INIS)

    Bernardes, N.

    1984-01-01

    A discussion is presented of zero-point motion effects on the binding energy of a small cluster of identical particles interacting through short range attractive-repulsive forces. The model is appropriate to a discussion of both Van der Waals as well as nuclear forces. (Author) [pt

  10. Emergence of regional clusters

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Østergaard, Christian Richter; Dalum, Bent

    2010-01-01

    The literature on regional clusters has increased considerably during the last decade. The emergence and growth patterns are usually explained by such factors as unique local culture, regional capabilities, tacit knowledge or the existence of location-specific externalities (knowledge spillovers...

  11. Supersonic copper clusters

    International Nuclear Information System (INIS)

    Powers, D.E.; Hansen, S.G.; Geusic, M.E.; Michalopoulos, D.L.; Smalley, R.E.

    1983-01-01

    Copper clusters ranging in size from 1 to 29 atoms have been prepared in a supersonic beam by laser vaporization of a rotating copper target rod within the throat of a pulsed supersonic nozzle using helium for the carrier gas. The clusters were cooled extensively in the supersonic expansion [T(translational) 1 to 4 K, T(rotational) = 4 K, T(vibrational) = 20 to 70 K]. These clusters were detected in the supersonic beam by laser photoionization with time-of-flight mass analysis. Using a number of fixed frequency outputs of an exciplex laser, the threshold behavior of the photoionization cross section was monitored as a function of cluster size.nce two-photon ionization (R2PI) with mass selective detection allowed the detection of five new electronic band systems in the region between 2690 and 3200 A, for each of the three naturally occurring isotopic forms of Cu 2 . In the process of scanning the R2PI spectrum of these new electronic states, the ionization potential of the copper dimer was determined to be 7.894 +- 0.015 eV

  12. Greedy subspace clustering.

    Science.gov (United States)

    2016-09-01

    We consider the problem of subspace clustering: given points that lie on or near the union of many low-dimensional linear subspaces, recover the subspaces. To this end, one first identifies sets of points close to the same subspace and uses the sets ...

  13. Data clustering algorithms and applications

    CERN Document Server

    Aggarwal, Charu C

    2013-01-01

    Research on the problem of clustering tends to be fragmented across the pattern recognition, database, data mining, and machine learning communities. Addressing this problem in a unified way, Data Clustering: Algorithms and Applications provides complete coverage of the entire area of clustering, from basic methods to more refined and complex data clustering approaches. It pays special attention to recent issues in graphs, social networks, and other domains.The book focuses on three primary aspects of data clustering: Methods, describing key techniques commonly used for clustering, such as fea

  14. Cluster structures in light nuclei

    International Nuclear Information System (INIS)

    Horiuchi, H.

    2000-01-01

    Complete text of publication follows. Clustering in neutron-rich nuclei is discussed. To understand the novel features (1,2,3) of the clustering in neutron-rich nuclei, the basic features of the clustering in stable nuclei (4) are briefly reviewed. In neutron-rich nuclei, the requirement of the stability of clusters is questioned and the threshold rule is no more obeyed. Examples of clustering in Be and B isotopes (4,5) are discussed in some detail. Possible existence of novel type of clustering near neutron dripline is suggested (1). (author)

  15. Cluster model of the nucleus

    International Nuclear Information System (INIS)

    Horiuchi, H.; Ikeda, K.

    1986-01-01

    This article reviews the development of the cluster model study. The stress is put on two points; one is how the cluster structure has come to be regarded as a fundamental structure in light nuclei together with the shell-model structure, and the other is how at present the cluster model is extended to and connected with the studies of the various subjects many of which are in the neighbouring fields. The authors the present the main theme with detailed explanations of the fundamentals of the microscopic cluster model which have promoted the development of the cluster mode. Examples of the microscopic cluster model study of light nuclear structure are given

  16. Las javieradas como caso de estudio

    Directory of Open Access Journals (Sweden)

    Mª Cruz Porcal Gonzalo

    2006-01-01

    Full Text Available A pesar de su todavía modesta participación en la economía y en el empleo regional, el turismo en Navarra ha mostrado durante los últimos años un significativo dinamismo tal y como, por ejemplo, lo testimonia el incremento del número de visitantes y de las empresas turísticas. Favorecido por una serie de circunstancias de índole variada, este desarrollo turístico se sustenta en una gran diversidad geográfica y cultural patente en los paisajes, el arte, las fiestas, la gastronomía, etc. Pero Navarra es, a su vez, una región que secularmente ha otorgado un gran peso a la tradición y a las creencias religiosas. En este contexto, algunas de las numerosas acciones emprendidas por la administración regional para dinamizar el sector turístico se han encaminado a revalorizar dos importantes legados culturales: el castillo de Javier y el Camino de Santiago. Se aprecia que ambos se hallan estrechamente relacionados con el turismo cultural, el turismo religioso y las peregrinaciones, unos fenómenos que hunden sus raíces en tiempos pasados pero que continúan teniendo en la actualidad una indudable relevancia a escala mundial. La intención primordial del presente trabajo es analizar el turismo de peregrinaciones en Navarra, más concretamente, el que tiene como destino del viaje la cuna de San Francisco Javier. Con dicho afán, se realiza una reflexión conceptual previa y un breve repaso de las fiestas y tradiciones religiosas que forman parte del patrimonio cultural intangible de Navarra, haciendo particular hincapié en las romerías y en el Camino de Santiago. Al hilo de ello, se afronta, a continuación, el estudio de la peregrinación más singular y populosa de Navarra: la Javierada. Su origen, sus principales rasgos, el perfil y las motivaciones de los peregrinos, los caracteres e hitos más importantes del recorrido, las peculiaridades del destino —entendido como lugar sagrado y espacio turístico— constituyen las principales

  17. TreeCluster: Massively scalable transmission clustering using phylogenetic trees

    OpenAIRE

    Moshiri, Alexander

    2018-01-01

    Background: The ability to infer transmission clusters from molecular data is critical to designing and evaluating viral control strategies. Viral sequencing datasets are growing rapidly, but standard methods of transmission cluster inference do not scale well beyond thousands of sequences. Results: I present TreeCluster, a cross-platform tool that performs transmission cluster inference on a given phylogenetic tree orders of magnitude faster than existing inference methods and supports multi...

  18. The rotation of galaxy clusters

    International Nuclear Information System (INIS)

    Tovmassian, H.M.

    2015-01-01

    The method for detection of the galaxy cluster rotation based on the study of distribution of member galaxies with velocities lower and higher of the cluster mean velocity over the cluster image is proposed. The search for rotation is made for flat clusters with a/b> 1.8 and BMI type clusters which are expected to be rotating. For comparison there were studied also round clusters and clusters of NBMI type, the second by brightness galaxy in which does not differ significantly from the cluster cD galaxy. Seventeen out of studied 65 clusters are found to be rotating. It was found that the detection rate is sufficiently high for flat clusters, over 60 per cent, and clusters of BMI type with dominant cD galaxy, ≈ 35 per cent. The obtained results show that clusters were formed from the huge primordial gas clouds and preserved the rotation of the primordial clouds, unless they did not have mergings with other clusters and groups of galaxies, in the result of which the rotation has been prevented

  19. Single-cluster dynamics for the random-cluster model

    NARCIS (Netherlands)

    Deng, Y.; Qian, X.; Blöte, H.W.J.

    2009-01-01

    We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to noninteger values q>1. Its results for static quantities are in a satisfactory agreement with those

  20. Choosing the Number of Clusters in K-Means Clustering

    Science.gov (United States)

    Steinley, Douglas; Brusco, Michael J.

    2011-01-01

    Steinley (2007) provided a lower bound for the sum-of-squares error criterion function used in K-means clustering. In this article, on the basis of the lower bound, the authors propose a method to distinguish between 1 cluster (i.e., a single distribution) versus more than 1 cluster. Additionally, conditional on indicating there are multiple…

  1. ESTUDIOS DE CASOS Y CONTROLES: A PROPÓSITO DE DOS ESTUDIOS EN CIMEL

    Directory of Open Access Journals (Sweden)

    Francisco Javier Bonilla-Escobar

    2013-08-01

    Full Text Available Los estudios de casos y controles han existido desde el siglo XIX con el analisis de Jhon Snow en Inglaterra sobre la fuente del Colera, y han tomado inusitada importancia despues de su puesta en marcha en diversos campos de la ciencia moderna (1, siendo objeto de amplias discusiones metodologicas hace mas de 50 anos. En los dos numeros anteriores de la revista CIMEL, se encuentran dos de estas publicaciones, tituladas: Factores asociados al Sindrome de Aspiracion Meconial en el hospital Jose Cayetano Heredia Piura-Peru, de Purizaca y col. (2, y Factores asociados al desarrollo de preeclampsia en un hospital de Piura, Peru, de Benites-Condor y col. (3. Reconociendo la importancia de este tipo de publicaciones y el trabajo requerido para su elaboracion, queremos mencionar aciertos y falencias metodologicas que hemos encontrado en estas publicaciones y las cuales afectan las afirmaciones de los autores

  2. Los estudios sobre paisaje en Estudios Geográficos (1940-2009

    Directory of Open Access Journals (Sweden)

    Arroyo Ilera, Fernando

    2010-12-01

    Full Text Available Not available.Los doscientos sesenta y nueve números editados de esta revista son un excelente banco de pruebas donde observar la evolución y los cambios experimentados por la Geografía española, en los últimos setenta años en los que Estudios Geográficos (EG se viene publicando ininterrumpidamente. La sucesión de temas, su tratamiento y enfoque, las citas bibliográficas, etc., constituyen una excelente referencia de gran interés para cualquier ciencia y, en especial para la nuestra, que ya en otras ocasiones ha sido utilizada para valorar la evolución metodológica de la Geografía.

  3. Heavy hitters via cluster-preserving clustering

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nelson, Jelani; Nguyen, Huy L.

    2016-01-01

    In the turnstile lp heavy hitters problem with parameter ε, one must maintain a high-dimensional vector xεRn subject to updates of the form update (i,Δ) causing the change xi≤ ← xi + Δ, where iε[n], ΔεR. Upon receiving a query, the goal is to report every "heavy hitter" iε[n] with |xi| ≥ε......|x|p as part of a list L⊆[n] of size O(1/εp), i.e. proportional to the maximum possible number of heavy hitters. For any pε(0,2] the COUNTSKETCH of [CCFC04] solves lp heavy hitters using O(ε-plog n) words of space with O(log n) update time, O(nlog n) query time to output L, and whose output after any query......, providing correctness whp. In fact, a simpler version of our algorithm for p = 1 in the strict turnstile model answers queries even faster than the "dyadic trick" by roughly a log n factor, dominating it in all regards. Our main innovation is an efficient reduction from the heavy hitters to a clustering...

  4. Evolution of the spherical clusters

    International Nuclear Information System (INIS)

    Surdin, V.G.

    1978-01-01

    The possible processes of the Galaxy spherical clusters formation and evolution are described on a popular level. The orbits of spherical cluster motion and their spatial velocities are determined. Given are the distrbutions of spherical cluster stars according to their velocities and the observed distribution of spherical clusters in the area of the Galaxy slow evolution. The dissipation and dynamic friction processes destructing clusters with the mass less than 10 4 of solar mass and bringing about the reduction of clusters in the Galaxy are considered. The paradox of forming mainly X-ray sources in spherical clusters is explained. The schematic image of possible ways of forming X-ray sources in spherical clusters is given

  5. Clusters in nuclei. Vol. 1

    International Nuclear Information System (INIS)

    Beck, Christian

    2010-01-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is presently one of the domains of heavy-ion nuclear physics facing both the greatest challenges and opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physics decided to team up in producing a comprehensive collection of lectures and tutorial reviews covering the field. This first volume, gathering seven extensive lectures, covers the follow topics: - Cluster Radioactivity - Cluster States and Mean Field Theories - Alpha Clustering and Alpha Condensates - Clustering in Neutron-rich Nuclei - Di-neutron Clustering - Collective Clusterization in Nuclei - Giant Nuclear Molecules By promoting new ideas and developments while retaining a pedagogical nature of presentation throughout, these lectures will both serve as a reference and as advanced teaching material for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  6. Structure and bonding in clusters

    International Nuclear Information System (INIS)

    Kumar, V.

    1991-10-01

    We review here the recent progress made in the understanding of the electronic and atomic structure of small clusters of s-p bonded materials using the density functional molecular dynamics technique within the local density approximation. Starting with a brief description of the method, results are presented for alkali metal clusters, clusters of divalent metals such as Mg and Be which show a transition from van der Waals or weak chemical bonding to metallic behaviour as the cluster size grows and clusters of Al, Sn and Sb. In the case of semiconductors, we discuss results for Si, Ge and GaAs clusters. Clusters of other materials such as P, C, S, and Se are also briefly discussed. From these and other available results we suggest the possibility of unique structures for the magic clusters. (author). 69 refs, 7 figs, 1 tab

  7. Random matrix improved subspace clustering

    KAUST Repository

    Couillet, Romain; Kammoun, Abla

    2017-01-01

    This article introduces a spectral method for statistical subspace clustering. The method is built upon standard kernel spectral clustering techniques, however carefully tuned by theoretical understanding arising from random matrix findings. We show

  8. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  9. Dynamical aspects of galaxy clustering

    International Nuclear Information System (INIS)

    Fall, S.M.

    1980-01-01

    Some recent work on the origin and evolution of galaxy clustering is reviewed, particularly within the context of the gravitational instability theory and the hot big-bang cosmological model. Statistical measures of clustering, including correlation functions and multiplicity functions, are explained and discussed. The close connection between galaxy formation and clustering is emphasized. Additional topics include the dependence of galaxy clustering on the spectrum of primordial density fluctuations and the mean mass density of the Universe. (author)

  10. [Cluster analysis in biomedical researches].

    Science.gov (United States)

    Akopov, A S; Moskovtsev, A A; Dolenko, S A; Savina, G D

    2013-01-01

    Cluster analysis is one of the most popular methods for the analysis of multi-parameter data. The cluster analysis reveals the internal structure of the data, group the separate observations on the degree of their similarity. The review provides a definition of the basic concepts of cluster analysis, and discusses the most popular clustering algorithms: k-means, hierarchical algorithms, Kohonen networks algorithms. Examples are the use of these algorithms in biomedical research.

  11. THE ASSEMBLY OF GALAXY CLUSTERS

    International Nuclear Information System (INIS)

    Berrier, Joel C.; Stewart, Kyle R.; Bullock, James S.; Purcell, Chris W.; Barton, Elizabeth J.; Wechsler, Risa H.

    2009-01-01

    We study the formation of 53 galaxy cluster-size dark matter halos (M = 10 14.0-14.76 M sun ) formed within a pair of cosmological Λ cold dark matter N-body simulations, and track the accretion histories of cluster subhalos with masses large enough to host ∼0.3 L * galaxies. By associating subhalos with cluster galaxies, we find the majority of galaxies in clusters experience no 'preprocessing' in the group environment prior to their accretion into the cluster. On average, 70% of cluster galaxies fall into the cluster potential directly from the field, with no luminous companions in their host halos at the time of accretion; less than 12% are accreted as members of groups with five or more galaxies. Moreover, we find that cluster galaxies are significantly less likely to have experienced a merger in the recent past (∼<6 Gyr) than a field halo of the same mass. These results suggest that local cluster processes such as ram pressure stripping, galaxy harassment, or strangulation play the dominant role in explaining the difference between cluster and field populations at a fixed stellar mass, and that pre-evolution or past merging in the group environment is of secondary importance for setting cluster galaxy properties for most clusters. The accretion times for z = 0 cluster members are quite extended, with ∼20% incorporated into the cluster halo more than 7 Gyr ago and ∼20% within the last 2 Gyr. By comparing the observed morphological fractions in cluster and field populations, we estimate an approximate timescale for late-type to early-type transformation within the cluster environment to be ∼6 Gyr.

  12. Chronorisk in cluster headache

    DEFF Research Database (Denmark)

    Barloese, Mads; Haddock, Bryan; Lund, Nunu T

    2018-01-01

    and a spectral analysis identifying oscillations in risk. Results The Gaussian model fit for the chronorisk distribution for all patients reporting diurnal rhythmicity (n = 286) had a goodness of fit R2 value of 0.97 and identified three times of increased risk peaking at 21:41, 02:02 and 06:23 hours....... In subgroups, three to five modes of increased risk were found and goodness of fit values ranged from 0.85-0.99. Spectral analysis revealed multiple distinct oscillation frequencies in chronorisk in subgroups including a dominant circadian oscillation in episodic patients and an ultradian in chronic....... Conclusions Chronorisk in cluster headache can be characterised as a sum of individual, timed events of increased risk, each having a Gaussian distribution. In episodic cluster headache, attacks follow a circadian rhythmicity whereas, in the chronic variant, ultradian oscillations are dominant reflecting...

  13. CSR in Industrial Clusters

    DEFF Research Database (Denmark)

    Lund-Thomsen, Peter; Pillay, Renginee G.

    2012-01-01

    Purpose – The paper seeks to review the literature on CSR in industrial clusters in developing countries, identifying the main strengths, weaknesses, and gaps in this literature, pointing to future research directions and policy implications in the area of CSR and industrial cluster development....... Design/methodology/approach – A literature review is conducted of both academic and policy-oriented writings that contain the keywords “industrial clusters” and “developing countries” in combination with one or more of the following terms: corporate social responsibility, environmental management, labor...... standards, child labor, climate change, social upgrading, and environmental upgrading. The authors examine the key themes in this literature, identify the main gaps, and point to areas where future work in this area could usefully be undertaken. Feedback has been sought from some of the leading authors...

  14. Clusters of Galaxies

    Science.gov (United States)

    Huchtmeier, W. K.; Richter, O. G.; Materne, J.

    1981-09-01

    The large-scale structure of the universe is dominated by clustering. Most galaxies seem to be members of pairs, groups, clusters, and superclusters. To that degree we are able to recognize a hierarchical structure of the universe. Our local group of galaxies (LG) is centred on two large spiral galaxies: the Andromeda nebula and our own galaxy. Three sr:naller galaxies - like M 33 - and at least 23 dwarf galaxies (KraanKorteweg and Tammann, 1979, Astronomische Nachrichten, 300, 181) can be found in the evironment of these two large galaxies. Neighbouring groups have comparable sizes (about 1 Mpc in extent) and comparable numbers of bright members. Small dwarf galaxies cannot at present be observed at great distances.

  15. Text Clustering Algorithm Based on Random Cluster Core

    Directory of Open Access Journals (Sweden)

    Huang Long-Jun

    2016-01-01

    Full Text Available Nowadays clustering has become a popular text mining algorithm, but the huge data can put forward higher requirements for the accuracy and performance of text mining. In view of the performance bottleneck of traditional text clustering algorithm, this paper proposes a text clustering algorithm with random features. This is a kind of clustering algorithm based on text density, at the same time using the neighboring heuristic rules, the concept of random cluster is introduced, which effectively reduces the complexity of the distance calculation.

  16. On clusters and clustering from atoms to fractals

    CERN Document Server

    Reynolds, PJ

    1993-01-01

    This book attempts to answer why there is so much interest in clusters. Clusters occur on all length scales, and as a result occur in a variety of fields. Clusters are interesting scientifically, but they also have important consequences technologically. The division of the book into three parts roughly separates the field into small, intermediate, and large-scale clusters. Small clusters are the regime of atomic and molecular physics and chemistry. The intermediate regime is the transitional regime, with its characteristics including the onset of bulk-like behavior, growth and aggregation, a

  17. Cosmology, Clusters and Calorimeters

    Science.gov (United States)

    Figueroa-Feliciano, Enectali

    2005-01-01

    I will review the current state of Cosmology with Clusters and discuss the application of microcalorimeter arrays to this field. With the launch of Astro-E2 this summer and a slew of new missions being developed, microcalorimeters are the next big thing in x-ray astronomy. I will cover the basics and not-so-basic concepts of microcalorimeter designs and look at the future to see where this technology will go.

  18. Three-atom clusters

    International Nuclear Information System (INIS)

    Pen'kov, F.M.

    1998-01-01

    The Born-Oppenheimer approximation is used to obtain an equation for the effective interaction in three atoms bound by a single electron. For low binding energies in an 'electron + atom' pair, long-range forces arise between the atoms, leading to bound states when the size of the three-atom cluster is a few tens of angstrom. A system made of alkali-metal atoms is considered as an example

  19. Seizure clusters: characteristics and treatment.

    Science.gov (United States)

    Haut, Sheryl R

    2015-04-01

    Many patients with epilepsy experience 'clusters' or flurries of seizures, also termed acute repetitive seizures (ARS). Seizure clustering has a significant impact on health and quality of life. This review summarizes recent advances in the definition and neurophysiologic understanding of clustering, the epidemiology and risk factors for clustering and both inpatient and outpatient clinical implications. New treatments for seizure clustering/ARS are perhaps the area of greatest recent progress. Efforts have focused on creating a uniform definition of a seizure cluster. In neurophysiologic studies of refractory epilepsy, seizures within a cluster appear to be self-triggering. Clinical progress has been achieved towards a more precise prevalence of clustering, and consensus guidelines for epilepsy monitoring unit safety. The greatest recent advances are in the study of nonintravenous route of benzodiazepines as rescue medications for seizure clusters/ARS. Rectal benzodiazepines have been very effective but barriers to use exist. New data on buccal, intramuscular and intranasal preparations are anticipated to lead to a greater number of approved treatments. Progesterone may be effective for women who experience catamenial clusters. Seizure clustering is common, particularly in the setting of medically refractory epilepsy. Clustering worsens health and quality of life, and the field requires greater focus on clarifying of definition and clinical implications. Progress towards the development of nonintravenous routes of benzodiazepines has the potential to improve care in this area.

  20. Privacy-preserving distributed clustering

    NARCIS (Netherlands)

    Erkin, Z.; Veugen, T.; Toft, T.; Lagendijk, R.L.

    2013-01-01

    Clustering is a very important tool in data mining and is widely used in on-line services for medical, financial and social environments. The main goal in clustering is to create sets of similar objects in a data set. The data set to be used for clustering can be owned by a single entity, or in some

  1. Electron localization in water clusters

    International Nuclear Information System (INIS)

    Landman, U.; Barnett, R.N.; Cleveland, C.L.; Jortner, J.

    1987-01-01

    Electron attachment to water clusters was explored by the quantum path integral molecular dynamics method, demonstrating that the energetically favored localization mode involves a surface state of the excess electron, rather than the precursor of the hydrated electron. The cluster size dependence, the energetics and the charge distribution of these novel electron-cluster surface states are explored. 20 refs., 2 figs., 1 tab

  2. Subspace K-means clustering.

    Science.gov (United States)

    Timmerman, Marieke E; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-12-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals).

  3. Support Policies in Clusters: Prioritization of Support Needs by Cluster Members According to Cluster Life Cycle

    Directory of Open Access Journals (Sweden)

    Gulcin Salıngan

    2012-07-01

    Full Text Available Economic development has always been a moving target. Both the national and local governments have been facing the challenge of implementing the effective and efficient economic policy and program in order to best utilize their limited resources. One of the recent approaches in this area is called cluster-based economic analysis and strategy development. This study reviews key literature and some of the cluster based economic policies adopted by different governments. Based on this review, it proposes “the cluster life cycle” as a determining factor to identify the support requirements of clusters. A survey, designed based on literature review of International Cluster support programs, was conducted with 30 participants from 3 clusters with different maturity stage. This paper discusses the results of this study conducted among the cluster members in Eskişehir- Bilecik-Kütahya Region in Turkey on the requirement of the support to foster the development of related clusters.

  4. Electronic structure of metal clusters

    International Nuclear Information System (INIS)

    Wertheim, G.K.

    1989-01-01

    Photoemission spectra of valence electrons in metal clusters, together with threshold ionization potential measurements, provide a coherent picture of the development of the electronic structure from the isolated atom to the large metallic cluster. An insulator-metal transition occurs at an intermediate cluster size, which serves to define the boundary between small and large clusters. Although the outer electrons may be delocalized over the entire cluster, a small cluster remains insulating until the density of states near the Fermi level exceeds 1/kT. In large clusters, with increasing cluster size, the band structure approaches that of the bulk metal. However, the bands remain significantly narrowed even in a 1000-atom cluster, giving an indication of the importance of long-range order. The core-electron binding-energy shifts of supported metal clusters depend on changes in the band structure in the initial state, as well as on various final-state effects, including changes in core hole screening and the coulomb energy of the final-state charge. For cluster supported on amorphous carbon, this macroscopic coulomb shift is often dominant, as evidenced by the parallel shifts of the core-electron binding energy and the Fermi edge. Auger data confirm that final-state effects dominate in cluster of Sn and some other metals. Surface atom core-level shifts provide a valuable guide to the contributions of initial-state changes in band structure to cluster core-electron binding energy shifts, especially for Au and Pt. The available data indicate that the shift observed in supported, metallic clusters arise largely from the charge left on the cluster by photoemission. As the metal-insulator transition is approached from above, metallic screening is suppressed and the shift is determined by the local environment. (orig.)

  5. Multiparticle production through isoscalar clusters

    International Nuclear Information System (INIS)

    Armburst, W.T.; Scott, D.M.

    1975-01-01

    The isoscalar cluster model for multiparticle production was extended to include clusters of A 2 meson pairs in addition to previously studied rho-rho and sigma clusters. The production of each type of cluster is given by an energy dependent Poisson distribution. The Poisson parameters determined from the charged particle multiplicity distributions indicate that the inclusion of A 2 -A 2 clusters does not improve the fit to the data. The predictions of the model for n 0 n/sub -/, f/sup 2//sub -,-/, and f/sup 2//sub 0,0/ compare favorably to the experimental values. (U.S.)

  6. ESTUDIOS DE PERIODISMO EN ARGENTINA: ANTECEDENTES E INTERROGANTES

    Directory of Open Access Journals (Sweden)

    Adriana Amado Suárez

    2014-06-01

    Full Text Available Este artículo presenta de forma resumida una revisión de antecedentes de los estudios empíricos de periodismo en Argentina. En las publicaciones de los últimos años los investigadores coincidían en señalar falta de datos de la profesión y el escaso desarrollo de los marcos teóricos afines a los estudios de periodismo. La investigación local priorizó abordajes y métodos que no se ocupan del conjunto de los periodistas. Antes bien, buena parte de la investigación confunde análisis de los medios y los mensajes con el estudio del periodismo y sigue sin brindar datos que permitan conocer las condiciones de trabajo y el perfil profesional de los periodistas argentinos.

  7. Ionization of nitrogen cluster beam

    International Nuclear Information System (INIS)

    Yano, Katsuki; Be, S.H.; Enjoji, Hiroshi; Okamoto, Kosuke

    1975-01-01

    A nitrogen cluster beam (neutral particle intensity of 28.6 mAsub(eq)) is ionized by electron collisions in a Bayard-Alpert gauge type ionizer. The extraction efficiency of about 65% is obtained at an electron current of 10 mA with an energy of 50 eV. The mean cluster size produced at a pressure of 663 Torr and temperature of 77.3 K is 2x10 5 molecules per cluster. By the Coulomb repulsion force, multiply ionized cluster ions are broken up into smaller fragments and the cluster ion size reduces to one-fourth at an electron current of 15 mA. Mean neutral cluster sizes depend strongly on the initial degree of saturation PHI 0 and are 2x10 5 , 7x10 4 and 3x10 4 molecules per cluster at PHI 0 's of 0.87, 0.66 and 0.39, respectively. (auth.)

  8. Dense Fe cluster-assembled films by energetic cluster deposition

    International Nuclear Information System (INIS)

    Peng, D.L.; Yamada, H.; Hihara, T.; Uchida, T.; Sumiyama, K.

    2004-01-01

    High-density Fe cluster-assembled films were produced at room temperature by an energetic cluster deposition. Though cluster-assemblies are usually sooty and porous, the present Fe cluster-assembled films are lustrous and dense, revealing a soft magnetic behavior. Size-monodispersed Fe clusters with the mean cluster size d=9 nm were synthesized using a plasma-gas-condensation technique. Ionized clusters are accelerated electrically and deposited onto the substrate together with neutral clusters from the same cluster source. Packing fraction and saturation magnetic flux density increase rapidly and magnetic coercivity decreases remarkably with increasing acceleration voltage. The Fe cluster-assembled film obtained at the acceleration voltage of -20 kV has a packing fraction of 0.86±0.03, saturation magnetic flux density of 1.78±0.05 Wb/m 2 , and coercivity value smaller than 80 A/m. The resistivity at room temperature is ten times larger than that of bulk Fe metal

  9. K-means Clustering: Lloyd's algorithm

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. K-means Clustering: Lloyd's algorithm. Refines clusters iteratively. Cluster points using Voronoi partitioning of the centers; Centroids of the clusters determine the new centers. Bad example k = 3, n =4.

  10. Estudio molecular de pacientes colombianos afectados por enanismo esencial

    OpenAIRE

    Navarrete Vargas, Julie Viviana

    2017-01-01

    Los síndromes de enanismo esencial microcefálico son un grupo de enfermedades monogénicas infrecuentes que se caracterizan principalmente por talla baja extrema proporcionada de inicio prenatal y microcefalia severa. En los pacientes que formaron parte del presente estudio se investigaron variantes en el gen PCNT debido a que presentaban hallazgos clínicos compatibles con el síndrome MOPD II (enanismo esencial osteodisplásico microcefálico tipo II). Posteriormente, se amplió el estudio con...

  11. Convex Clustering: An Attractive Alternative to Hierarchical Clustering

    Science.gov (United States)

    Chen, Gary K.; Chi, Eric C.; Ranola, John Michael O.; Lange, Kenneth

    2015-01-01

    The primary goal in cluster analysis is to discover natural groupings of objects. The field of cluster analysis is crowded with diverse methods that make special assumptions about data and address different scientific aims. Despite its shortcomings in accuracy, hierarchical clustering is the dominant clustering method in bioinformatics. Biologists find the trees constructed by hierarchical clustering visually appealing and in tune with their evolutionary perspective. Hierarchical clustering operates on multiple scales simultaneously. This is essential, for instance, in transcriptome data, where one may be interested in making qualitative inferences about how lower-order relationships like gene modules lead to higher-order relationships like pathways or biological processes. The recently developed method of convex clustering preserves the visual appeal of hierarchical clustering while ameliorating its propensity to make false inferences in the presence of outliers and noise. The solution paths generated by convex clustering reveal relationships between clusters that are hidden by static methods such as k-means clustering. The current paper derives and tests a novel proximal distance algorithm for minimizing the objective function of convex clustering. The algorithm separates parameters, accommodates missing data, and supports prior information on relationships. Our program CONVEXCLUSTER incorporating the algorithm is implemented on ATI and nVidia graphics processing units (GPUs) for maximal speed. Several biological examples illustrate the strengths of convex clustering and the ability of the proximal distance algorithm to handle high-dimensional problems. CONVEXCLUSTER can be freely downloaded from the UCLA Human Genetics web site at http://www.genetics.ucla.edu/software/ PMID:25965340

  12. Clustering of agricultural enterprises

    Directory of Open Access Journals (Sweden)

    Michaela Beranová

    2013-01-01

    Full Text Available Agricultural business is a very specific branch which is characterized by very low financial performance while this characteristic is given mainly by external factors as market pricing of agricultural commodities on one side, and production costs of agricultural commodities on the other side. This way, agricultural enterprises recognize negative values of gross margin in the Profit and Loss Statement but positive value of operating profit after even there are items of costs which are deducted. These results are derived from agricultural production subsidies which are recognized as income in the P/L Statement. In connection with this fact, the government subsidies are a substantial component of financial performance of agricultural enterprises.Primary research proceeded on the statistical sample of one hundred agricultural companies, has shown that also other specifics influencing financial performance of these businesses exist here. In order to determine the influences, the cluster analysis has been applied at using more than 10 variables. This approach has led to construction of clusters (groups of agricultural business entities with different characteristics of the group. The objective of this paper is to identify the main determinants of financial performance of agricultural enterprises and to determine their influences under different economic characteristics of these business entities. For this purpose, the regression analysis has been subsequently applied on the groups of companies coming out from the cluster analysis. Besides the operating profit which is the main driving force of financial performance measured with the economic value added (EVA in agricultural enterprises, also capital structure and cost of capital have been observed as very strong influences on financial performance but these factors have different directions of their influence on the economic value added under different financial characteristics of agricultural

  13. Hadoop cluster deployment

    CERN Document Server

    Zburivsky, Danil

    2013-01-01

    This book is a step-by-step tutorial filled with practical examples which will show you how to build and manage a Hadoop cluster along with its intricacies.This book is ideal for database administrators, data engineers, and system administrators, and it will act as an invaluable reference if you are planning to use the Hadoop platform in your organization. It is expected that you have basic Linux skills since all the examples in this book use this operating system. It is also useful if you have access to test hardware or virtual machines to be able to follow the examples in the book.

  14. Clusters in attractive colloids

    Energy Technology Data Exchange (ETDEWEB)

    Coniglio, A [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Complesso Universitario di Monte Sant' Angelo, via Cintia 80126 Naples (Italy); Arcangelis, L de [Dipartimento di Ingegneria dell' Informazione and CNISM II Universita di Napoli, Aversa (CE) (Italy); Candia, A de [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Complesso Universitario di Monte Sant' Angelo, via Cintia 80126 Naples (Italy); Gado, E Del [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Complesso Universitario di Monte Sant' Angelo, via Cintia 80126 Naples (Italy); Fierro, A [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Complesso Universitario di Monte Sant' Angelo, via Cintia 80126 Naples (Italy); Sator, N [Laboratoire de Physique Theorique de la Matiere Condensee, Universite Pierre et Marie Curie-Paris6, UMR (CNRS) 7600 Case 121, 4 Place Jussieu 75252 Paris Cedex 05 (France)

    2006-09-13

    We discuss how the anomalous increase of the viscosity in colloidal systems with short-range attraction can be related to the formation of long-living clusters. Based on molecular dynamics and Monte Carlo numerical simulations of different models, we propose a similar picture for colloidal gelation at low and intermediate volume fractions. On this basis, we analyze the distinct role played by the formation of long-living bonds and the crowding of the particles in the slow dynamics of attractive colloidal systems.

  15. Estudio de factibilidad para la implantación de un restaurante de cocina en Quito

    OpenAIRE

    Abril Donoso, Aníbal Trosky

    2007-01-01

    Componentes y sustentos técnicos. Identificación y descripción de la empresa. Análisis de la industria o sector. Productos y servicos de la empresa. Datos importantes para entrar al mercado. Estudio de mercado. Objetivs del estudio de mercado. Investigación del mercado objetivo. Estudio técnico. Objetivos del estudio técnico. Localización del proyecto. Ingeniería del proyecto. Organización y administración. Estudio financiero. Objetivos de estudio financiero. Sistema contable de la empresa. C...

  16. Trimming and clustering sugarcane ESTs

    Directory of Open Access Journals (Sweden)

    Guilherme P. Telles

    2001-12-01

    Full Text Available The original clustering procedure adopted in the Sugarcane Expressed Sequence Tag project (SUCEST had many problems, for instance too many clusters, the presence of ribosomal sequences, etc. We therefore redesigned the clustering procedure entirely, including a much more careful initial trimming of the reads. In this paper the new trimming and clustering strategies are described in detail and we give the new official figures for the project, 237,954 expressed sequence tags and 43,141 clusters.O método de clustering adotado no Projeto SUCEST (Sugarcane EST Project tinha vários problemas (muitos clusters, presença de seqüências de ribossomo etc. Nós assumimos a tarefa de reprojetar todo o processo de clustering, propondo uma "limpeza" inicial mais cuidadosa das seqüências. Neste artigo as estratégias de limpeza das seqüências e de clustering são descritas em detalhe, incluindo os números oficiais do projeto (237,954 ESTs e 43,141 clusters.

  17. Globular clusters - Fads and fallacies

    International Nuclear Information System (INIS)

    White, R.E.

    1991-01-01

    The types of globular clusters observed in the Milky Way Galaxy are described together with their known characteristics, with special attention given to correcting the erroneous statements made earlier about globular clusters. Among these are the following statements: the Galaxy is surrounded by many hundreds of globular clusters; all globular clusters are located toward the Galactic center, all globular clusters are metal poor and move about the Galaxy in highly elliptical paths; all globular clusters contain RR Lyrae-type variable stars, and the RR Lyrae stars found outside of globulars have come from cluster dissolution or ejection; all of the stars in a given cluster were born at the same time and have the same chemical composition; X-ray globulars are powered by central black holes; and the luminosity functions for globular clusters are well defined and well determined. Consideration is given to the fact that globular clusters in the Magellanic Clouds differ from those in the Milky Way by their age distribution and that the globulars of the SMC differ from those of the LMC

  18. Semi-supervised clustering methods.

    Science.gov (United States)

    Bair, Eric

    2013-01-01

    Cluster analysis methods seek to partition a data set into homogeneous subgroups. It is useful in a wide variety of applications, including document processing and modern genetics. Conventional clustering methods are unsupervised, meaning that there is no outcome variable nor is anything known about the relationship between the observations in the data set. In many situations, however, information about the clusters is available in addition to the values of the features. For example, the cluster labels of some observations may be known, or certain observations may be known to belong to the same cluster. In other cases, one may wish to identify clusters that are associated with a particular outcome variable. This review describes several clustering algorithms (known as "semi-supervised clustering" methods) that can be applied in these situations. The majority of these methods are modifications of the popular k-means clustering method, and several of them will be described in detail. A brief description of some other semi-supervised clustering algorithms is also provided.

  19. Macroeconomic Dimensions in the Clusterization Processes: Lithuanian Biomass Cluster Case

    Directory of Open Access Journals (Sweden)

    Navickas Valentinas

    2017-03-01

    Full Text Available The Future production systems’ increasing significance will impose work, which maintains not a competitive, but a collaboration basis, with concentrated resources and expertise, which can help to reach the general purpose. One form of collaboration among medium-size business organizations is work in clusters. Clusterization as a phenomenon has been known from quite a long time, but it offers simple benefits to researches at micro and medium levels. The clusterization process evaluation in macroeconomic dimensions has been comparatively little investigated. Thereby, in this article, the clusterization processes is analysed by concentrating our attention on macroeconomic factor researches. The authors analyse clusterization’s influence on country’s macroeconomic growth; they apply a structure research methodology for clusterization’s macroeconomic influence evaluation and propose that clusterization processes benefit macroeconomic analysis. The theoretical model of clusterization processes was validated by referring to a biomass cluster case. Because biomass cluster case is a new phenomenon, currently there are no other scientific approaches to them. The authors’ accomplished researches show that clusterization allows the achievement of a large positive slip in macroeconomics, which proves to lead to a high value added to creation, a faster country economic growth, and social situation amelioration.

  20. El fenómeno administrativo como objeto de estudio

    Directory of Open Access Journals (Sweden)

    Carlos Ramírez Cardona

    2013-07-01

    Full Text Available El perfil de la ciencia o de las ciencias llamadas administrativas resulta confuso cuan teoría general y el objeto de estudio de otras disciplinas relacionadas con el proceso administrativo o que constituyen campos de aplicación de principios y técnicas de la teoría general.

  1. Cluster Based Text Classification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    We propose a cluster based classification model for suspicious email detection and other text classification tasks. The text classification tasks comprise many training examples that require a complex classification model. Using clusters for classification makes the model simpler and increases...... the accuracy at the same time. The test example is classified using simpler and smaller model. The training examples in a particular cluster share the common vocabulary. At the time of clustering, we do not take into account the labels of the training examples. After the clusters have been created......, the classifier is trained on each cluster having reduced dimensionality and less number of examples. The experimental results show that the proposed model outperforms the existing classification models for the task of suspicious email detection and topic categorization on the Reuters-21578 and 20 Newsgroups...

  2. Laser ionization of molecular clusters

    International Nuclear Information System (INIS)

    Desai, S.; Feigerle, C.S.

    1995-01-01

    Multiphoton ionization coupled with mass spectrometry was used to investigate molecular cluster distributions. Three examples will be discussed in this presentation. First, in studies of neat nitric oxide clusters, (NO) m , an interesting odd-even intensity alternation was observed and will be discussed in terms of electron-pairing considerations. In a separate study, the binary clusters comprising nitric oxide and methane preferentially form a stoichiometric cluster made up of repeating units of (NO) 2 CH 4 . These presumably represent a particularly strongly bound open-quotes van der Waalsclose quotes subunit. Finally, in similar studies of neat carbon disulfide clusters, (CS 2 ) m , additional photon absorption after the two-photon ionization step stimulates a series of intracluster ion-molecular reactions leading to formation of S m + and (CS) m + polymers, as well as intermediate species such as S m + (CS 2 ). This molecular cluster analogue of open-quotes laser snowclose quotes will be described in detail

  3. Cluster polylogarithms for scattering amplitudes

    International Nuclear Information System (INIS)

    Golden, John; Paulos, Miguel F; Spradlin, Marcus; Volovich, Anastasia

    2014-01-01

    Motivated by the cluster structure of two-loop scattering amplitudes in N=4 Yang-Mills theory we define cluster polylogarithm functions. We find that all such functions of weight four are made up of a single simple building block associated with the A 2 cluster algebra. Adding the requirement of locality on generalized Stasheff polytopes, we find that these A 2 building blocks arrange themselves to form a unique function associated with the A 3 cluster algebra. This A 3 function manifests all of the cluster algebraic structure of the two-loop n-particle MHV amplitudes for all n, and we use it to provide an explicit representation for the most complicated part of the n = 7 amplitude as an example. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Cluster algebras in mathematical physics’. (paper)

  4. HÁBITOS DE ESTUDIO VS. FRACASO ACADÉMICO

    Directory of Open Access Journals (Sweden)

    Martha Rocío Torres Narváez

    2009-01-01

    Full Text Available El objetivo del artículo es exponer algunas estrategias de apoyo pedagógico que, articuladas con la estructura curricular del Programa de Fisioterapia de la Universidad del Rosario, apoyan el proceso de aprendizaje de los estudiantes a partir de las categorías analizadas con la aplicación del instrumento "Inventario de hábitos de estudio" a los estudiantes que cursaron una de las asignaturas de mayor fracaso académico. Los hábitos de estudio tienen una implicación en el rendimiento académico y esto influye en cómo se enfrenta el reto de asumir las responsabilidades de ser universitario. Como parte de la metodología, se realizó un análisis de los resultados de la aplicación del inventario antes nombrado, en aras de identificar y replantear las estrategias pedagógicas. Para esto se revisaron los planes de asignaturas y se determinaron las actividades extracurriculares que se diseñaron para abordar la problemática de la deserción estudiantil relacionada con el fracaso académico. El estudio realizado determinó la importancia del desarrollo de habilidades o hábitos de estudio apropiados para el buen desempeño del estudiante universitario. Además, comprobó que deben considerarse en el entorno universitario la cultura de aprendizaje en el proceso de formación, las habilidades de trabajo en equipo, la apropiación y el desarrollo de conocimiento, así como las buenas relaciones interpersonales, para disminuir el fracaso académico y mejorar los hábitos de estudio.

  5. Connecting Remote Clusters with ATM

    Energy Technology Data Exchange (ETDEWEB)

    Hu, T.C.; Wyckoff, P.S.

    1998-10-01

    Sandia's entry into utilizing clusters of networked workstations is called Computational Plant or CPlant for short. The design of CPlant uses Ethernet to boot the individual nodes, Myrinet to communicate within a node cluster, and ATM to connect between remote clusters. This SAND document covers the work done to enable the use of ATM on the CPlant nodes in the Fall of 1997.

  6. On origin of stellar clusters

    International Nuclear Information System (INIS)

    Tovmasyan, G.M.

    1977-01-01

    The ratios of the gas component of the mass of young stellar clusters to their stellar mass are considered. They change by more than four orders from one cluster to another. The results are in direct contradiction with the hypothesis of formation of cluster stars from a preliminarily existing gas cloud by its condensation, and they favour the Ambartsumian hypothesis of the joint origin of stars and gas clouds from superdense protostellar matter

  7. Random matrix improved subspace clustering

    KAUST Repository

    Couillet, Romain

    2017-03-06

    This article introduces a spectral method for statistical subspace clustering. The method is built upon standard kernel spectral clustering techniques, however carefully tuned by theoretical understanding arising from random matrix findings. We show in particular that our method provides high clustering performance while standard kernel choices provably fail. An application to user grouping based on vector channel observations in the context of massive MIMO wireless communication networks is provided.

  8. Quantum annealing for combinatorial clustering

    Science.gov (United States)

    Kumar, Vaibhaw; Bass, Gideon; Tomlin, Casey; Dulny, Joseph

    2018-02-01

    Clustering is a powerful machine learning technique that groups "similar" data points based on their characteristics. Many clustering algorithms work by approximating the minimization of an objective function, namely the sum of within-the-cluster distances between points. The straightforward approach involves examining all the possible assignments of points to each of the clusters. This approach guarantees the solution will be a global minimum; however, the number of possible assignments scales quickly with the number of data points and becomes computationally intractable even for very small datasets. In order to circumvent this issue, cost function minima are found using popular local search-based heuristic approaches such as k-means and hierarchical clustering. Due to their greedy nature, such techniques do not guarantee that a global minimum will be found and can lead to sub-optimal clustering assignments. Other classes of global search-based techniques, such as simulated annealing, tabu search, and genetic algorithms, may offer better quality results but can be too time-consuming to implement. In this work, we describe how quantum annealing can be used to carry out clustering. We map the clustering objective to a quadratic binary optimization problem and discuss two clustering algorithms which are then implemented on commercially available quantum annealing hardware, as well as on a purely classical solver "qbsolv." The first algorithm assigns N data points to K clusters, and the second one can be used to perform binary clustering in a hierarchical manner. We present our results in the form of benchmarks against well-known k-means clustering and discuss the advantages and disadvantages of the proposed techniques.

  9. Electronic and atomic impacts on large clusters

    International Nuclear Information System (INIS)

    Gspann, J.

    1982-01-01

    Describing first the generation and properties of molecular beams of large Van der Waals clusters such as speed distribution, cluster size distribution, and internal temperature of the clusters, the review then features the results of electronic impacts on large clusters: metastable electronic cluster excitations, ejection of positive cluster ions of less than 100 atoms from much larger parent clusters, and ionization of the large clusters. Atomic impacts at thermal energies are treated with respect to the scattering cross section of the clusters, their drag coefficient in free molecular flow, and the peculiarities of impacts on helium clusters of either isotope. (Auth.)

  10. BRIGHTEST CLUSTER GALAXIES AND CORE GAS DENSITY IN REXCESS CLUSTERS

    International Nuclear Information System (INIS)

    Haarsma, Deborah B.; Leisman, Luke; Donahue, Megan; Bruch, Seth; Voit, G. Mark; Boehringer, Hans; Pratt, Gabriel W.; Pierini, Daniele; Croston, Judith H.; Arnaud, Monique

    2010-01-01

    We investigate the relationship between brightest cluster galaxies (BCGs) and their host clusters using a sample of nearby galaxy clusters from the Representative XMM-Newton Cluster Structure Survey. The sample was imaged with the Southern Observatory for Astrophysical Research in R band to investigate the mass of the old stellar population. Using a metric radius of 12 h -1 kpc, we found that the BCG luminosity depends weakly on overall cluster mass as L BCG ∝ M 0.18±0.07 cl , consistent with previous work. We found that 90% of the BCGs are located within 0.035 r 500 of the peak of the X-ray emission, including all of the cool core (CC) clusters. We also found an unexpected correlation between the BCG metric luminosity and the core gas density for non-cool-core (non-CC) clusters, following a power law of n e ∝ L 2.7±0.4 BCG (where n e is measured at 0.008 r 500 ). The correlation is not easily explained by star formation (which is weak in non-CC clusters) or overall cluster mass (which is not correlated with core gas density). The trend persists even when the BCG is not located near the peak of the X-ray emission, so proximity is not necessary. We suggest that, for non-CC clusters, this correlation implies that the same process that sets the central entropy of the cluster gas also determines the central stellar density of the BCG, and that this underlying physical process is likely to be mergers.

  11. Urolitiasis obstructiva en ovinos: estudio de caso Urolitiasis obstructiva en ovinos: estudio de caso

    Directory of Open Access Journals (Sweden)

    Abner Josué Gutiérrez Chávez

    2012-02-01

    Full Text Available A 5-months-old, commercial-crossbreed male lamb was remitted to post-morten study. The clinical history about of animal included: signs of severe abdominal distension, anorexia, poliaquiuria, straguria and prolonged urination posture, urine dribbling and blood-tinged urine. Necropsy revealed ascitis and a hemorrhagic fibrine membrane floating in approximately 8 litres of urine caused by a rupture of the urinary bladder in consequence of a total blockage of urethral lumen by multiple small stones localized in the sigmoid flexure of the animal. Obstructive urolithiasis is a common problem in the fed-flocks affecting between 20 % and 30 % of the animals. A diet with adequate mineral balance could reduce the health risk of formation of urinary stones. Un ovino macho de 5 meses de edad fue presentado para su estudio patológico. La historia clínica del animal incluía: postración, dificultad para incorporarse, distensión abdominal severa, pérdida de apetito, estranguria, poliaquiuria y hematuria. A la necropsia se observó la presencia de 8 litros aproximadamente de orina en cavidad abdominal y una membrana fibrino-hemorrágica flotante adherida a la vejiga a nivel de la lesión de ruptura, por una sobre distensión provocada por la presencia obstructiva total de cálculos urinarios localizados en la luz de la uretra a nivel de la flexura sigmoidea del animal. La urolitiasis obstructiva es una patología que se presenta en el 20 % - 30 % de los animales en engorda. Un adecuado balance mineral de la dieta rica en concentrados puede reducir el riesgo de la formación de urolitos.

  12. Quasars in galaxy cluster environments

    International Nuclear Information System (INIS)

    Ellingson, E.

    1989-01-01

    The evolution of radio loud quasars is found to be strongly dependent upon their galaxy cluster environment. Previous studies have shown that bright quasars are found in rich clusters, while high luminosity quasars are found only in poorer environments. The analysis of low luminosity radio quiet quasars indicate that they are never found in rich environments, suggesting that they are a physically different class of objects. Properties of the quasar environment are investigated to determine constraints on the physical mechanisms of quasar formation and evolution. The optical cluster morphology indicates that the cluster cores have smaller radii and higher galaxy densities than are typical for low redshift clusters of similar richness. Radio morphologies may indicate that the formation of a dense intra-cluster medium is associated with the quasars' fading at these epochs. Galaxy colors appear to be normal, but there may be a tendency for clusters associated with high luminosity quasars to contain a higher fraction of gas-rich galaxies than those associated with low luminosity quasars. Multislit spectroscopic observations of galaxies associated with high luminosity quasars indicate that quasars are preferentially located in regions of low relative velocity dispersion, either in rich clusters of abnormally low dispersion, or in poor groups which are dynamically normal. This suggests that galaxy-galaxy interactions may play a role in quasar formation and sustenanace. Virialization of rich clusters and the subsequent increase in galaxy velocities may therefore be responsible for the fading of quasars in rich environments

  13. Anomalous properties of technetium clusters

    International Nuclear Information System (INIS)

    Kryuchkov, S.V.

    1985-01-01

    On the basis of critical evaluation of literature data in the field of chemistry of technetium cluster compounds with ligands of a weak field a conclusion is made on specific, ''anomalous'' properties of technetium cluster complexes which consist in an increased ability of the given element to the formation of a series of binuclear and multinuclear clusters, similar in composition and structure and easily transforming in each other. The majority of technetium clusters unlike similar compounds of other elements are paramagnetic with one unpaired electron on ''metallic'' MO of loosening type. All theoretical conceptions known today on the electronic structure of technetium clusters are considered. It is pointed out, that the best results in the explanation of ''anomalous'' properties of technetium clusters can be obtained in the framework of nonempirical methods of self-consistent field taking into account configuration interactions. It is also shown, that certain properties of technetium clusters can be explained on the basis of qualitative model of Coulomb repulsion of metal atoms in clusters. The conclusion is made, that technetium position in the Periodic table, as well as recently detected technetium property to the decrease of effective charge on its atoms during M-M bond formation promote a high ability of the element to cluster formation both with weak field ligands and with strong field one

  14. Optical properties of cluster plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Yasuaki; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Downer, M C

    1998-03-01

    It is shown that unlike a gas plasma or an electron plasma in a metal, an ionized clustered material (`cluster plasma`) permits propagation below the plasma cut-off of electromagnetic (EM) waves whose phase velocity is close to but below the speed of light. This results from the excitation of a plasma oscillation mode (and/or polarization mode) through the cluster surface which does not exist in usual gaseous plasma. The existence of this new optical mode, cluster mode, is confirmed via numerical simulation. (author)

  15. STM observations of ferromagnetic clusters

    International Nuclear Information System (INIS)

    Wawro, A.; Kasuya, A.

    1998-01-01

    Co, Fe and Ni clusters of nanometer size, deposited on silicon and graphite (highly oriented pyrolytic graphite), were observed by a scanning tunneling microscope. Deposition as well as the scanning tunneling microscope measurements were carried out in an ultrahigh vacuum system at room temperature. Detailed analysis of Co cluster height was done with the scanning tunneling microscope equipped with a ferromagnetic tip in a magnetic field up to 70 Oe. It is found that bigger clusters (few nanometers in height) exhibit a dependence of their apparent height on applied magnetic field. We propose that such behaviour originates from the ferromagnetic ordering of cluster and associate this effect to spin polarized tunneling. (author)

  16. Cluster processing business level monitor

    International Nuclear Information System (INIS)

    Muniz, Francisco J.

    2017-01-01

    This article describes a Cluster Processing Monitor. Several applications with this functionality can be freely found doing a search in the Google machine. However, those applications may offer more features that are needed on the Processing Monitor being proposed. Therefore, making the monitor output evaluation difficult to be understood by the user, at-a-glance. In addition, such monitors may add unnecessary processing cost to the Cluster. For these reasons, a completely new Cluster Processing Monitor module was designed and implemented. In the CDTN, Clusters are broadly used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

  17. Percolation with multiple giant clusters

    International Nuclear Information System (INIS)

    Ben-Naim, E; Krapivsky, P L

    2005-01-01

    We study mean-field percolation with freezing. Specifically, we consider cluster formation via two competing processes: irreversible aggregation and freezing. We find that when the freezing rate exceeds a certain threshold, the percolation transition is suppressed. Below this threshold, the system undergoes a series of percolation transitions with multiple giant clusters ('gels') formed. Giant clusters are not self-averaging as their total number and their sizes fluctuate from realization to realization. The size distribution F k , of frozen clusters of size k, has a universal tail, F k ∼ k -3 . We propose freezing as a practical mechanism for controlling the gel size. (letter to the editor)

  18. Star clusters in evolving galaxies

    Science.gov (United States)

    Renaud, Florent

    2018-04-01

    Their ubiquity and extreme densities make star clusters probes of prime importance of galaxy evolution. Old globular clusters keep imprints of the physical conditions of their assembly in the early Universe, and younger stellar objects, observationally resolved, tell us about the mechanisms at stake in their formation. Yet, we still do not understand the diversity involved: why is star cluster formation limited to 105M⊙ objects in the Milky Way, while some dwarf galaxies like NGC 1705 are able to produce clusters 10 times more massive? Why do dwarfs generally host a higher specific frequency of clusters than larger galaxies? How to connect the present-day, often resolved, stellar systems to the formation of globular clusters at high redshift? And how do these links depend on the galactic and cosmological environments of these clusters? In this review, I present recent advances on star cluster formation and evolution, in galactic and cosmological context. The emphasis is put on the theory, formation scenarios and the effects of the environment on the evolution of the global properties of clusters. A few open questions are identified.

  19. Integrative cluster analysis in bioinformatics

    CERN Document Server

    Abu-Jamous, Basel; Nandi, Asoke K

    2015-01-01

    Clustering techniques are increasingly being put to use in the analysis of high-throughput biological datasets. Novel computational techniques to analyse high throughput data in the form of sequences, gene and protein expressions, pathways, and images are becoming vital for understanding diseases and future drug discovery. This book details the complete pathway of cluster analysis, from the basics of molecular biology to the generation of biological knowledge. The book also presents the latest clustering methods and clustering validation, thereby offering the reader a comprehensive review o

  20. Cluster analysis of track structure

    International Nuclear Information System (INIS)

    Michalik, V.

    1991-01-01

    One of the possibilities of classifying track structures is application of conventional partition techniques of analysis of multidimensional data to the track structure. Using these cluster algorithms this paper attempts to find characteristics of radiation reflecting the spatial distribution of ionizations in the primary particle track. An absolute frequency distribution of clusters of ionizations giving the mean number of clusters produced by radiation per unit of deposited energy can serve as this characteristic. General computation techniques used as well as methods of calculations of distributions of clusters for different radiations are discussed. 8 refs.; 5 figs

  1. Cluster processing business level monitor

    Energy Technology Data Exchange (ETDEWEB)

    Muniz, Francisco J., E-mail: muniz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    This article describes a Cluster Processing Monitor. Several applications with this functionality can be freely found doing a search in the Google machine. However, those applications may offer more features that are needed on the Processing Monitor being proposed. Therefore, making the monitor output evaluation difficult to be understood by the user, at-a-glance. In addition, such monitors may add unnecessary processing cost to the Cluster. For these reasons, a completely new Cluster Processing Monitor module was designed and implemented. In the CDTN, Clusters are broadly used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

  2. Statistical measures of galaxy clustering

    International Nuclear Information System (INIS)

    Porter, D.H.

    1988-01-01

    Consideration is given to the large-scale distribution of galaxies and ways in which this distribution may be statistically measured. Galaxy clustering is hierarchical in nature, so that the positions of clusters of galaxies are themselves spatially clustered. A simple identification of groups of galaxies would be an inadequate description of the true richness of galaxy clustering. Current observations of the large-scale structure of the universe and modern theories of cosmology may be studied with a statistical description of the spatial and velocity distributions of galaxies. 8 refs

  3. Semi-supervised clustering methods

    Science.gov (United States)

    Bair, Eric

    2013-01-01

    Cluster analysis methods seek to partition a data set into homogeneous subgroups. It is useful in a wide variety of applications, including document processing and modern genetics. Conventional clustering methods are unsupervised, meaning that there is no outcome variable nor is anything known about the relationship between the observations in the data set. In many situations, however, information about the clusters is available in addition to the values of the features. For example, the cluster labels of some observations may be known, or certain observations may be known to belong to the same cluster. In other cases, one may wish to identify clusters that are associated with a particular outcome variable. This review describes several clustering algorithms (known as “semi-supervised clustering” methods) that can be applied in these situations. The majority of these methods are modifications of the popular k-means clustering method, and several of them will be described in detail. A brief description of some other semi-supervised clustering algorithms is also provided. PMID:24729830

  4. Statistical Significance for Hierarchical Clustering

    Science.gov (United States)

    Kimes, Patrick K.; Liu, Yufeng; Hayes, D. Neil; Marron, J. S.

    2017-01-01

    Summary Cluster analysis has proved to be an invaluable tool for the exploratory and unsupervised analysis of high dimensional datasets. Among methods for clustering, hierarchical approaches have enjoyed substantial popularity in genomics and other fields for their ability to simultaneously uncover multiple layers of clustering structure. A critical and challenging question in cluster analysis is whether the identified clusters represent important underlying structure or are artifacts of natural sampling variation. Few approaches have been proposed for addressing this problem in the context of hierarchical clustering, for which the problem is further complicated by the natural tree structure of the partition, and the multiplicity of tests required to parse the layers of nested clusters. In this paper, we propose a Monte Carlo based approach for testing statistical significance in hierarchical clustering which addresses these issues. The approach is implemented as a sequential testing procedure guaranteeing control of the family-wise error rate. Theoretical justification is provided for our approach, and its power to detect true clustering structure is illustrated through several simulation studies and applications to two cancer gene expression datasets. PMID:28099990

  5. NCG61/24: Plan de Estudios de M??ster en Biomedicina Regenerativa

    OpenAIRE

    Universidad de Granada

    2012-01-01

    Plan de Estudios de M??ster en Biomedicina Regenerativa. Resoluci??n de 5 de marzo de 2012, de la Universidad de Granada, por la que se publica el plan de estudios de M??ster en Biomedicina Regenerativa

  6. The Confucian Asian cluster

    Directory of Open Access Journals (Sweden)

    Ionel Sergiu Pirju

    2013-11-01

    Full Text Available The Confucian Asian cluster consists of China, Hong Kong, Japan, Singapore, South Korea, and Taiwan. Confucian tradition countries were defined by achieving a consistent performance in the global economy, they still representing the major competitors in the EU and North American countries. Their progress is defined by a great national management that was able to influence beneficial management systems applied in organizations, these rules characterized by authority; aims to ensure the confidence in business. This article will present the intercultural values characterizing it, the leadership style and also tracing major macroeconomic considerations. The research is synchronic, analysing the contemporary situation of these countries, and the analysis will be interdisciplinary exploratory, identifying specific regional cultural elements.

  7. Dynamics of star clusters

    International Nuclear Information System (INIS)

    Goodman, J.; Hut, P.

    1985-01-01

    The enigma of core collapse receives much attention in this volume. In addition, several observational papers summarize recent techniques and results and discuss the stellar dynamical implications of the enormous progress in the quality of surface photometry, proper motion studies, radial velocity determinations, as well as space-based measurements in a variety of wavelengths. The value of these Proceedings as a standard reference work is enhanced by the inclusion of two appendices, featuring English translations of two seminal papers on stellar dynamics published in Russian and not previously available in a Western language. A third appendix contains an up-to-date catalogue of observationally determined parameters of galactic globular clusters, as well as theoretically inferred parameters. This catalogue will prove to be an essential reference for phenomenonological studies and an ideal testing ground for new theoretical developments. (orig.)

  8. Performance criteria for graph clustering and Markov cluster experiments

    NARCIS (Netherlands)

    S. van Dongen

    2000-01-01

    textabstractIn~[1] a cluster algorithm for graphs was introduced called the Markov cluster algorithm or MCL~algorithm. The algorithm is based on simulation of (stochastic) flow in graphs by means of alternation of two operators, expansion and inflation. The results in~[2] establish an intrinsic

  9. Diametrical clustering for identifying anti-correlated gene clusters.

    Science.gov (United States)

    Dhillon, Inderjit S; Marcotte, Edward M; Roshan, Usman

    2003-09-01

    Clustering genes based upon their expression patterns allows us to predict gene function. Most existing clustering algorithms cluster genes together when their expression patterns show high positive correlation. However, it has been observed that genes whose expression patterns are strongly anti-correlated can also be functionally similar. Biologically, this is not unintuitive-genes responding to the same stimuli, regardless of the nature of the response, are more likely to operate in the same pathways. We present a new diametrical clustering algorithm that explicitly identifies anti-correlated clusters of genes. Our algorithm proceeds by iteratively (i). re-partitioning the genes and (ii). computing the dominant singular vector of each gene cluster; each singular vector serving as the prototype of a 'diametric' cluster. We empirically show the effectiveness of the algorithm in identifying diametrical or anti-correlated clusters. Testing the algorithm on yeast cell cycle data, fibroblast gene expression data, and DNA microarray data from yeast mutants reveals that opposed cellular pathways can be discovered with this method. We present systems whose mRNA expression patterns, and likely their functions, oppose the yeast ribosome and proteosome, along with evidence for the inverse transcriptional regulation of a number of cellular systems.

  10. Herd Clustering: A synergistic data clustering approach using collective intelligence

    KAUST Repository

    Wong, Kachun

    2014-10-01

    Traditional data mining methods emphasize on analytical abilities to decipher data, assuming that data are static during a mining process. We challenge this assumption, arguing that we can improve the analysis by vitalizing data. In this paper, this principle is used to develop a new clustering algorithm. Inspired by herd behavior, the clustering method is a synergistic approach using collective intelligence called Herd Clustering (HC). The novel part is laid in its first stage where data instances are represented by moving particles. Particles attract each other locally and form clusters by themselves as shown in the case studies reported. To demonstrate its effectiveness, the performance of HC is compared to other state-of-the art clustering methods on more than thirty datasets using four performance metrics. An application for DNA motif discovery is also conducted. The results support the effectiveness of HC and thus the underlying philosophy. © 2014 Elsevier B.V.

  11. Cluster algebras in mathematical physics

    International Nuclear Information System (INIS)

    Francesco, Philippe Di; Gekhtman, Michael; Kuniba, Atsuo; Yamazaki, Masahito

    2014-01-01

    This special issue of Journal of Physics A: Mathematical and Theoretical contains reviews and original research articles on cluster algebras and their applications to mathematical physics. Cluster algebras were introduced by S Fomin and A Zelevinsky around 2000 as a tool for studying total positivity and dual canonical bases in Lie theory. Since then the theory has found diverse applications in mathematics and mathematical physics. Cluster algebras are axiomatically defined commutative rings equipped with a distinguished set of generators (cluster variables) subdivided into overlapping subsets (clusters) of the same cardinality subject to certain polynomial relations. A cluster algebra of rank n can be viewed as a subring of the field of rational functions in n variables. Rather than being presented, at the outset, by a complete set of generators and relations, it is constructed from the initial seed via an iterative procedure called mutation producing new seeds successively to generate the whole algebra. A seed consists of an n-tuple of rational functions called cluster variables and an exchange matrix controlling the mutation. Relations of cluster algebra type can be observed in many areas of mathematics (Plücker and Ptolemy relations, Stokes curves and wall-crossing phenomena, Feynman integrals, Somos sequences and Hirota equations to name just a few examples). The cluster variables enjoy a remarkable combinatorial pattern; in particular, they exhibit the Laurent phenomenon: they are expressed as Laurent polynomials rather than more general rational functions in terms of the cluster variables in any seed. These characteristic features are often referred to as the cluster algebra structure. In the last decade, it became apparent that cluster structures are ubiquitous in mathematical physics. Examples include supersymmetric gauge theories, Poisson geometry, integrable systems, statistical mechanics, fusion products in infinite dimensional algebras, dilogarithm

  12. doméstico. Discusiones y estudios recientes

    Directory of Open Access Journals (Sweden)

    Patricia Arias

    2013-01-01

    Full Text Available Con base en la revisión de algunos estudios recientes que se han llevado a cabo en diver- sas comunidades rurales de las nuevas regiones migratorias, en este artículo se revisan, de manera crítica, dos interpretaciones de los estudios sobre la familia rural: la economía campesina como unidad de producción-consumo y el ciclo de desarrollo de la unidad doméstica. En las condiciones actuales la migración, interna e internacional, desem- peña un papel decisivo en las comunidades rurales. Muchos estudios han constatado la voluntad de las mujeres de salir de los grupos domésticos y sumarse a los flujos migra- torios por motivos particulares, por situaciones y demandas específicas de ellas; su salida ha contribuido al resquebrajamiento de los sistemas tradicionales de organización y re- producción de la familia campesina. Las feministas, y más tarde los estudios con la perspectiva de género, criticaron la visión de que las familias rurales constituían unidades de producción-consumo donde las decisiones correspondían a un modelo de estrategias familiares de sobrevivencia y reproducción (Hondagneu-Sotelo, 2007; Wolf, 1990. Ese modelo privilegiaba la homo- geneidad, la colectividad, la solidaridad y el consenso, es decir, suponía que en los hogares no había conflictos ni tensiones a la hora de tomar decisiones que a todos com- prometían (Ariza, 2007. La familia era una “unidad económica moral” que se susten- taba en los principios de “reciprocidad, consenso y altruismo” (Grasmuck y Pessar, 1991. Los estudios desde el enfoque de género señalaron que en las familias había relacio- nes de poder basadas en una distribución jerárquica y desigual de los derechos, recursos y autoridad que afectaban especialmente a las mujeres (Ariza, 2007; González Montes, 2002; Hondagneu-Sotelo, 2007; Wolf, 1990. Las críticas alcanzaron a los estudios migratorios: la migración no era un fenómeno exclusivamente de los hombres, las mi

  13. Apoyo a Estudios Geodinamicos con GPS en Guatemala

    Science.gov (United States)

    Robles, V. R.

    2013-05-01

    El Instituto Geografico Nacional de Guatemala implemento 17 estaciones GNSS en el año 2009, como un proyecto de credito mixto de donacion de equipamiento del Gobierno de Suiza, el cual, este equipamiento de estaciones CORS GNSS es un sistema de recepción y transmisión de datos crudos GPS RInex que utiliza la tecnologia Spider Web de Leica, asi mismo este sistema esta sirviendo para el espablecimiento de un marco geodesico nacional de coordenadas geodesicas oficiales, el cual se calculan u obtienen las velocidades en tiempos temporales programados de las 17 Estaciones CORS. La infraestructura del marco geodesico de Guatemala esta sirviendo de base para las aplicaciones de estudios geodinamicos como el monitoreo de del desplazamiento de las placas tectonicas por medio de un estudio que se inicio en el año de 1999, llamado medicion con GPS el sistema de Fallas de los rios Polochic Motagua de Guatemala, tambien para un estudio que se implemento para deformación de corteza terrestre local en un Volcan Activo de Guatemala llamado Pacaya. Para el estudio de medicion con GPS en el sistema de falla de los Rios del polochic Motagua se implementaron 16 puntos para medir con GPS de dos frecuencias en el año de 1999, el cual, tres puntos son estaciones geodesicas CORS IGS llamados GUAT, ELEN y HUEH, despues en el año de 2003 se hizo otra medicion en un total de 20 puntos, que permitió calcular las velocidades de desplazamieinto de los puntos en mención, usando como referencia el modelo NUVEL 1A de DeMets de la placa de Norteamerica. Este estudio fue en cooperación internacional por la universidad de Nice de Francia y el IGNde Francia. Para el estudio del monitoreo con GPS del volcan activo de Guatemala, se implementaron cuatro puntos al rededor del volcan, el cual, se realizan cuatro mediciones al año, que permiten determinar axialmente la distancias entre los puntos, y rebisar estadisticamente cual es el comportamiento de las distancias en funcion del tiempo, si

  14. The Nordic Mobile Telecommunication Cluster

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik

    2000-01-01

    A study of the historic role of the Nordic mobile telephone and telecommunications cluster and its background in both coordinated innovation policies and societal developments in Scandinavia.......A study of the historic role of the Nordic mobile telephone and telecommunications cluster and its background in both coordinated innovation policies and societal developments in Scandinavia....

  15. Yellow supergiants in open clusters

    International Nuclear Information System (INIS)

    Sowell, J.R.

    1986-01-01

    Superluminous giant stars (SLGs) have been reported in young globular clusters in the Large Magellanic Cloud (LMC). These stars appear to be in the post-asymptotic-giant-branch phase of evolution. This program was an investigation of galactic SLG candidates in open clusters, which are more like the LMC young globular clusters. These were chosen because luminosity, mass, and age determinations can be made for members since cluster distances and interstellar reddenings are known. Color magnitude diagrams were searched for candidates, using the same selection criteria as for SLGs in the LMC. Classification spectra were obtained of 115 program stars from McGraw-Hill Observatory and of 68 stars from Cerro Tololo Inter-American Observatory Chile. These stars were visually classified on the MK system using spectral scans of standard stars taken at the respective observations. Published information was combined with this program's data for 83 stars in 30 clusters. Membership probabilities were assigned to these stars, and the clusters were analyzed according to age. It was seen that the intrinsically brightest supergiants are found in the youngest clusters. With increasing cluster age, the absolute luminosities attained by the supergiants decline. Also, it appears that the evolutionary tracks of luminosity class II stars are more similar to those of class I than of class III

  16. Supersonic bare metal cluster beams

    International Nuclear Information System (INIS)

    Smalley, R.E.

    1991-01-01

    Progress continued this past year on two principal fronts in the study of bare metal clusters: photoelectron spectroscopy of mass selected negative ions, and surface chemisorption of cluster ions levitated in a superconducting magnet as monitored by fourier transform ion cyclotron resonance

  17. Two generalizations of Kohonen clustering

    Science.gov (United States)

    Bezdek, James C.; Pal, Nikhil R.; Tsao, Eric C. K.

    1993-01-01

    The relationship between the sequential hard c-means (SHCM), learning vector quantization (LVQ), and fuzzy c-means (FCM) clustering algorithms is discussed. LVQ and SHCM suffer from several major problems. For example, they depend heavily on initialization. If the initial values of the cluster centers are outside the convex hull of the input data, such algorithms, even if they terminate, may not produce meaningful results in terms of prototypes for cluster representation. This is due in part to the fact that they update only the winning prototype for every input vector. The impact and interaction of these two families with Kohonen's self-organizing feature mapping (SOFM), which is not a clustering method, but which often leads ideas to clustering algorithms is discussed. Then two generalizations of LVQ that are explicitly designed as clustering algorithms are presented; these algorithms are referred to as generalized LVQ = GLVQ; and fuzzy LVQ = FLVQ. Learning rules are derived to optimize an objective function whose goal is to produce 'good clusters'. GLVQ/FLVQ (may) update every node in the clustering net for each input vector. Neither GLVQ nor FLVQ depends upon a choice for the update neighborhood or learning rate distribution - these are taken care of automatically. Segmentation of a gray tone image is used as a typical application of these algorithms to illustrate the performance of GLVQ/FLVQ.

  18. Variation in verb cluster interruption

    NARCIS (Netherlands)

    Hendriks, Lotte

    2014-01-01

    Except for finite verbs in main clauses, verbs in Standard Dutch cluster together in a clause-final position. In certain Dutch dialects, non-verbal material can occur within this verb cluster (Verhasselt 1961; Koelmans 1965, among many others). These dialects vary with respect to which types of

  19. Chemical exposure and leukemia clusters

    International Nuclear Information System (INIS)

    Cartwright, R.A.

    1992-01-01

    This paper draws attention to the heterogeneous distribution of leukemia in childhood and in adults. The topic of cluster reports and generalized clustering is addressed. These issues are applied to what is known of the risk factor for both adult and childhood leukemia. Finally, the significance of parental occupational exposure and childhood leukemia is covered. (author). 23 refs

  20. Evaporation rate of nucleating clusters.

    Science.gov (United States)

    Zapadinsky, Evgeni

    2011-11-21

    The Becker-Döring kinetic scheme is the most frequently used approach to vapor liquid nucleation. In the present study it has been extended so that master equations for all cluster configurations are included into consideration. In the Becker-Döring kinetic scheme the nucleation rate is calculated through comparison of the balanced steady state and unbalanced steady state solutions of the set of kinetic equations. It is usually assumed that the balanced steady state produces equilibrium cluster distribution, and the evaporation rates are identical in the balanced and unbalanced steady state cases. In the present study we have shown that the evaporation rates are not identical in the equilibrium and unbalanced steady state cases. The evaporation rate depends on the number of clusters at the limit of the cluster definition. We have shown that the ratio of the number of n-clusters at the limit of the cluster definition to the total number of n-clusters is different in equilibrium and unbalanced steady state cases. This causes difference in evaporation rates for these cases and results in a correction factor to the nucleation rate. According to rough estimation it is 10(-1) by the order of magnitude and can be lower if carrier gas effectively equilibrates the clusters. The developed approach allows one to refine the correction factor with Monte Carlo and molecular dynamic simulations.

  1. A cluster algorithm for graphs

    NARCIS (Netherlands)

    S. van Dongen

    2000-01-01

    textabstractA cluster algorithm for graphs called the emph{Markov Cluster algorithm (MCL~algorithm) is introduced. The algorithm provides basically an interface to an algebraic process defined on stochastic matrices, called the MCL~process. The graphs may be both weighted (with nonnegative weight)

  2. Cluster Statistics of BTW Automata

    International Nuclear Information System (INIS)

    Ajanta Bhowal Acharyya

    2011-01-01

    The cluster statistics of BTW automata in the SOC states are obtained by extensive computer simulation. Various moments of the clusters are calculated and few results are compared with earlier available numerical estimates and exact results. Reasonably good agreement is observed. An extended statistical analysis has been made. (author)

  3. Filaments and clusters of galaxies

    International Nuclear Information System (INIS)

    Soltan, A.

    1987-01-01

    A statistical test to investigate filaments of galaxies is performed. Only particular form of filaments is considered, viz. filaments connecting Abell clusters of galaxies. Relative position of triplets ''cluster - field object - cluster'' is analysed. Though neither cluster sample nor field object sample are homogeneous and complete only peculiar form of selection effects could affect the present statistics. Comparison of observational data with simulations shows that less than 15 per cent of all field galaxies is concentrated in filaments connecting rich clusters. Most of the field objects used in the analysis are not normal galaxies and it is possible that this conclusion is not in conflict with apparent filaments seen in the Lick counts and in some nearby 3D maps of the galaxy distribution. 26 refs., 2 figs. (author)

  4. Radio investigations of clusters of galaxies

    International Nuclear Information System (INIS)

    Valentijn, E.A.

    1978-01-01

    This thesis contains a number of papers of the series entitled, A Westerbork Survey of Rich Clusters of Galaxies. The primary aim was to study the radio characteristics of cluster galaxies and especially the question whether their ''radio-activity'' is influenced by their location inside a cluster. It is enquired whether the presence of an intra-cluster medium (ICM), or the typical cluster evolution or cluster dynamical processes can give rise to radio-observable effects on the behaviour of cluster galaxies. 610 MHz WSRT observations of the Coma cluster (and radio observations of the Hercules supercluster) are presented. Extended radio sources in Abell clusters are then described. (Auth.)

  5. Semantic based cluster content discovery in description first clustering algorithm

    International Nuclear Information System (INIS)

    Khan, M.W.; Asif, H.M.S.

    2017-01-01

    In the field of data analytics grouping of like documents in textual data is a serious problem. A lot of work has been done in this field and many algorithms have purposed. One of them is a category of algorithms which firstly group the documents on the basis of similarity and then assign the meaningful labels to those groups. Description first clustering algorithm belong to the category in which the meaningful description is deduced first and then relevant documents are assigned to that description. LINGO (Label Induction Grouping Algorithm) is the algorithm of description first clustering category which is used for the automatic grouping of documents obtained from search results. It uses LSI (Latent Semantic Indexing); an IR (Information Retrieval) technique for induction of meaningful labels for clusters and VSM (Vector Space Model) for cluster content discovery. In this paper we present the LINGO while it is using LSI during cluster label induction and cluster content discovery phase. Finally, we compare results obtained from the said algorithm while it uses VSM and Latent semantic analysis during cluster content discovery phase. (author)

  6. Clustering methods for the optimization of atomic cluster structure

    Science.gov (United States)

    Bagattini, Francesco; Schoen, Fabio; Tigli, Luca

    2018-04-01

    In this paper, we propose a revised global optimization method and apply it to large scale cluster conformation problems. In the 1990s, the so-called clustering methods were considered among the most efficient general purpose global optimization techniques; however, their usage has quickly declined in recent years, mainly due to the inherent difficulties of clustering approaches in large dimensional spaces. Inspired from the machine learning literature, we redesigned clustering methods in order to deal with molecular structures in a reduced feature space. Our aim is to show that by suitably choosing a good set of geometrical features coupled with a very efficient descent method, an effective optimization tool is obtained which is capable of finding, with a very high success rate, all known putative optima for medium size clusters without any prior information, both for Lennard-Jones and Morse potentials. The main result is that, beyond being a reliable approach, the proposed method, based on the idea of starting a computationally expensive deep local search only when it seems worth doing so, is capable of saving a huge amount of searches with respect to an analogous algorithm which does not employ a clustering phase. In this paper, we are not claiming the superiority of the proposed method compared to specific, refined, state-of-the-art procedures, but rather indicating a quite straightforward way to save local searches by means of a clustering scheme working in a reduced variable space, which might prove useful when included in many modern methods.

  7. Estudio de la legislación ambiental en licencias de dragados de puertos en Brasil y España. Estudio de caso

    OpenAIRE

    VIÑES BERNARDO, MARGARITA

    2011-01-01

    Este TFC consistirá en la realización de un estudio de la legislación ambiental existente en relación al dragado de puertos en Brasil y en España, en el análisis de los procesos de licenciamiento y de la metodología de la monitorización del dragado aplicada en un estudio de caso. Viñes Bernardo, M. (2011). Estudio de la legislación ambiental en licencias de dragados de puertos en Brasil y España. Estudio de caso. http://hdl.handle.net/10251/10344. Archivo delegado

  8. A Linear Algebra Measure of Cluster Quality.

    Science.gov (United States)

    Mather, Laura A.

    2000-01-01

    Discussion of models for information retrieval focuses on an application of linear algebra to text clustering, namely, a metric for measuring cluster quality based on the theory that cluster quality is proportional to the number of terms that are disjoint across the clusters. Explains term-document matrices and clustering algorithms. (Author/LRW)

  9. Information Clustering Based on Fuzzy Multisets.

    Science.gov (United States)

    Miyamoto, Sadaaki

    2003-01-01

    Proposes a fuzzy multiset model for information clustering with application to information retrieval on the World Wide Web. Highlights include search engines; term clustering; document clustering; algorithms for calculating cluster centers; theoretical properties concerning clustering algorithms; and examples to show how the algorithms work.…

  10. Homicidas juveniles en Bogotá, estudio de grupos focales

    Directory of Open Access Journals (Sweden)

    Franklin Escobar Córdoba

    2015-07-01

    Materiales y Métodos. Estudio cualitativo mediante técnica de grupos focales. Resultados. Se encontró como el factor de riesgo más implicado la disponibilidad y uso de armas. Otros  factores de riesgo determinantes de la conducta delincuencial afectan la disposición del joven homicida para tener un comportamiento criminal y las estrategias de control que son elegidas por el individuo, dichos factores son apreciados de maneras distintas por los jóvenes homicidas y los no homicidas Conclusión. Este estudio arroja información clave que puede ser utilizada en el diseño e implementación de estrategias para enfrentar el homicidio juvenil como problema de salud pública.

  11. Ethical implications of excessive cluster sizes in cluster randomised trials.

    Science.gov (United States)

    Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

    2018-02-20

    The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

  12. La actuación y los Estudios Literarios

    Directory of Open Access Journals (Sweden)

    Karina Mauro

    2011-05-01

    de los estudios literarios en la investigación sobre la Actuación a partir del análisis de los conceptos de representación y mimesis aristotélica y de los problemas que acarrea la aplicación de estos conceptos en el análisis de la acción del actor en escena.

  13. Estudio hidrogeológico del valle de Mala

    OpenAIRE

    Ministerio de Agricultura. Dirección General de Aguas, Suelos e Irrigaciones

    1980-01-01

    Determina el recurso hídrico subterráneo del valle del río Mala, mediante el análisis e investigación de las características hidrogeológicas, en base a las informaciones de diferentes etapas del estudio; para de esta manera, racionalizar mejor su uso, dando cumplimiento así a lo dispuesto por la Ley General de Aguas.

  14. Generalidades de los estudios de casos y controles

    Directory of Open Access Journals (Sweden)

    Alejandro González Garay

    2018-01-01

    Full Text Available ANTECEDENTES: los estudios de casos y controles son de utilidad cuando se buscan factores de riesgo para enfermedades poco comunes o que tienen un periodo de latencia prologado. OBJETIVO: identificar las principales características del estudio de casos y controles (Ca-Co para favorecer la disminución de sesgos durante su evaluación o conducción. DESCRIPCIÓN: este diseño se caracteriza por la selección de sujetos con o sin el evento de interés. Éstos se comparan para identificar los factores de riesgo que favorecieron la presencia de este evento. La finalidad de este tipo de estudios es la de inferir una relación causal expresada mediante razón de momios y los intervalos de confianza al 95%. CONCLUSIONES: el diseño de Ca-CO es relativamente fácil y rápido de realizar. Sin embargo, es susceptible a múltiples fuentes de sesgo, las cuales deben de ser minimizadas para obtener mayor confiabilidad de las inferencias obtenidas.

  15. Estudios marxistas de la cultura y los medios

    Directory of Open Access Journals (Sweden)

    Roy Alfaro Vargas

    2016-05-01

    Full Text Available Este artículo introduce los Estudios Marxistas de la Cultura y los Medios (EMCM a Latinoamérica y expone los principales fundamentos teóricos y epistemológicos de los estudios marxistas de la cultura y los medios. Se analiza la relación entre la teoría de la auto-organización, la dialéctica y la teoría crítica, alrededor del estudio de la Web 2.0 y de los sitios de redes sociales. Además, se explica el rol de la teoría marxiana del valor dentro de los EMCM, como medio para establecer la crítica del trabajo digital alienado realizado por el usuario de los sitios de redes sociales. En este sentido, se expone el concepto de Web 3.0 como medio para la superación dialéctica de la Web 2.0, en cuanto proceso de participación democrática, basada en la construcción de medios alternativos.

  16. Cluster Correlation in Mixed Models

    Science.gov (United States)

    Gardini, A.; Bonometto, S. A.; Murante, G.; Yepes, G.

    2000-10-01

    We evaluate the dependence of the cluster correlation length, rc, on the mean intercluster separation, Dc, for three models with critical matter density, vanishing vacuum energy (Λ=0), and COBE normalization: a tilted cold dark matter (tCDM) model (n=0.8) and two blue mixed models with two light massive neutrinos, yielding Ωh=0.26 and 0.14 (MDM1 and MDM2, respectively). All models approach the observational value of σ8 (and hence the observed cluster abundance) and are consistent with the observed abundance of damped Lyα systems. Mixed models have a motivation in recent results of neutrino physics; they also agree with the observed value of the ratio σ8/σ25, yielding the spectral slope parameter Γ, and nicely fit Las Campanas Redshift Survey (LCRS) reconstructed spectra. We use parallel AP3M simulations, performed in a wide box (of side 360 h-1 Mpc) and with high mass and distance resolution, enabling us to build artificial samples of clusters, whose total number and mass range allow us to cover the same Dc interval inspected through Automatic Plate Measuring Facility (APM) and Abell cluster clustering data. We find that the tCDM model performs substantially better than n=1 critical density CDM models. Our main finding, however, is that mixed models provide a surprisingly good fit to cluster clustering data.

  17. Fission of Polyanionic Metal Clusters

    Science.gov (United States)

    König, S.; Jankowski, A.; Marx, G.; Schweikhard, L.; Wolfram, M.

    2018-04-01

    Size-selected dianionic lead clusters Pbn2 -, n =34 - 56 , are stored in a Penning trap and studied with respect to their decay products upon photoexcitation. Contrary to the decay of other dianionic metal clusters, these lead clusters show a variety of decay channels. The mass spectra of the fragments are compared to the corresponding spectra of the monoanionic precursors. This comparison leads to the conclusion that, in the cluster size region below about n =48 , the fission reaction Pbn2 -→Pbn-10 -+Pb10- is the major decay process. Its disappearance at larger cluster sizes may be an indication of a nonmetal to metal transition. Recently, the pair of Pb10- and Pbn-10 - were observed as pronounced fragments in electron-attachment studies [S. König et al., Int. J. Mass Spectrom. 421, 129 (2017), 10.1016/j.ijms.2017.06.009]. The present findings suggest that this combination is the fingerprint of the decay of doubly charged lead clusters. With this assumption, the dianion clusters have been traced down to Pb212 -, whereas the smallest size for the direct observation was as high as n =28 .

  18. A possibilistic approach to clustering

    Science.gov (United States)

    Krishnapuram, Raghu; Keller, James M.

    1993-01-01

    Fuzzy clustering has been shown to be advantageous over crisp (or traditional) clustering methods in that total commitment of a vector to a given class is not required at each image pattern recognition iteration. Recently fuzzy clustering methods have shown spectacular ability to detect not only hypervolume clusters, but also clusters which are actually 'thin shells', i.e., curves and surfaces. Most analytic fuzzy clustering approaches are derived from the 'Fuzzy C-Means' (FCM) algorithm. The FCM uses the probabilistic constraint that the memberships of a data point across classes sum to one. This constraint was used to generate the membership update equations for an iterative algorithm. Recently, we cast the clustering problem into the framework of possibility theory using an approach in which the resulting partition of the data can be interpreted as a possibilistic partition, and the membership values may be interpreted as degrees of possibility of the points belonging to the classes. We show the ability of this approach to detect linear and quartic curves in the presence of considerable noise.

  19. Conformational Clusters of Phosphorylated Tyrosine.

    Science.gov (United States)

    Abdelrasoul, Maha; Ponniah, Komala; Mao, Alice; Warden, Meghan S; Elhefnawy, Wessam; Li, Yaohang; Pascal, Steven M

    2017-12-06

    Tyrosine phosphorylation plays an important role in many cellular and intercellular processes including signal transduction, subcellular localization, and regulation of enzymatic activity. In 1999, Blom et al., using the limited number of protein data bank (PDB) structures available at that time, reported that the side chain structures of phosphorylated tyrosine (pY) are partitioned into two conserved conformational clusters ( Blom, N.; Gammeltoft, S.; Brunak, S. J. Mol. Biol. 1999 , 294 , 1351 - 1362 ). We have used the spectral clustering algorithm to cluster the increasingly growing number of protein structures with pY sites, and have found that the pY residues cluster into three distinct side chain conformations. Two of these pY conformational clusters associate strongly with a narrow range of tyrosine backbone conformation. The novel cluster also highly correlates with the identity of the n + 1 residue, and is strongly associated with a sequential pYpY conformation which places two adjacent pY side chains in a specific relative orientation. Further analysis shows that the three pY clusters are associated with distinct distributions of cognate protein kinases.

  20. THE EXTENDED VIRGO CLUSTER CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk; Rey, Soo-Chang; Lee, Youngdae; Chung, Jiwon; Pak, Mina; Yi, Wonhyeong; Lee, Woong [Department of Astronomy and Space Science, Chungnam National University, 99 Daehak-ro, Daejeon 305-764 (Korea, Republic of); Jerjen, Helmut [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Lisker, Thorsten [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg (ZAH), Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Sung, Eon-Chang [Korea Astronomy and Space Science institute, 776 Daedeokdae-ro, Daejeon 305-348 (Korea, Republic of)

    2015-01-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg{sup 2} or 60.1 Mpc{sup 2}. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s{sup –1}. In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

  1. Haplotyping Problem, A Clustering Approach

    International Nuclear Information System (INIS)

    Eslahchi, Changiz; Sadeghi, Mehdi; Pezeshk, Hamid; Kargar, Mehdi; Poormohammadi, Hadi

    2007-01-01

    Construction of two haplotypes from a set of Single Nucleotide Polymorphism (SNP) fragments is called haplotype reconstruction problem. One of the most popular computational model for this problem is Minimum Error Correction (MEC). Since MEC is an NP-hard problem, here we propose a novel heuristic algorithm based on clustering analysis in data mining for haplotype reconstruction problem. Based on hamming distance and similarity between two fragments, our iterative algorithm produces two clusters of fragments; then, in each iteration, the algorithm assigns a fragment to one of the clusters. Our results suggest that the algorithm has less reconstruction error rate in comparison with other algorithms

  2. Supersymmetry for nuclear cluster systems

    International Nuclear Information System (INIS)

    Levai, G.; Cseh, J.; Van Isacker, P.

    2001-01-01

    A supersymmetry scheme is proposed for nuclear cluster systems. The bosonic sector of the superalgebra describes the relative motion of the clusters, while its fermionic sector is associated with their internal structure. An example of core+α configurations is discussed in which the core is a p-shell nucleus and the underlying superalgebra is U(4/12). The α-cluster states of the nuclei 20 Ne and 19 F are analysed and correlations between their spectra, electric quadrupole transitions, and one-nucleon transfer reactions are interpreted in terms of U(4/12) supersymmetry. (author)

  3. Implementation of a cluster Beowulf

    International Nuclear Information System (INIS)

    Victorino Guzman, Jorge Enrique

    2001-01-01

    One of the simulation systems that put a great stress on computational resources and performance are the climatic models, with a high cost of implementation, making difficult its acquisition. An alternative that offers good performance at a reasonable cost is the construction of Cluster Beowulf that allows to emulate the behaviour of a computer with several processors. In the present article we discuss the requirements of hardware for the construction of the Cluster Beowulf, the software resources for the implementation of the model CCM3.6 and the performance of the Cluster Beowulf, of the Group of Investigation in Meteorology at the National University of Colombia, with different number of processors

  4. A Clustering Graph Generator

    Energy Technology Data Exchange (ETDEWEB)

    Winlaw, Manda [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); De Sterck, Hans [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    In very simple terms a network can be de ned as a collection of points joined together by lines. Thus, networks can be used to represent connections between entities in a wide variety of elds including engi- neering, science, medicine, and sociology. Many large real-world networks share a surprising number of properties, leading to a strong interest in model development research and techniques for building synthetic networks have been developed, that capture these similarities and replicate real-world graphs. Modeling these real-world networks serves two purposes. First, building models that mimic the patterns and prop- erties of real networks helps to understand the implications of these patterns and helps determine which patterns are important. If we develop a generative process to synthesize real networks we can also examine which growth processes are plausible and which are not. Secondly, high-quality, large-scale network data is often not available, because of economic, legal, technological, or other obstacles [7]. Thus, there are many instances where the systems of interest cannot be represented by a single exemplar network. As one example, consider the eld of cybersecurity, where systems require testing across diverse threat scenarios and validation across diverse network structures. In these cases, where there is no single exemplar network, the systems must instead be modeled as a collection of networks in which the variation among them may be just as important as their common features. By developing processes to build synthetic models, so-called graph generators, we can build synthetic networks that capture both the essential features of a system and realistic variability. Then we can use such synthetic graphs to perform tasks such as simulations, analysis, and decision making. We can also use synthetic graphs to performance test graph analysis algorithms, including clustering algorithms and anomaly detection algorithms.

  5. Re-estimating sample size in cluster randomized trials with active recruitment within clusters

    NARCIS (Netherlands)

    van Schie, Sander; Moerbeek, Mirjam

    2014-01-01

    Often only a limited number of clusters can be obtained in cluster randomised trials, although many potential participants can be recruited within each cluster. Thus, active recruitment is feasible within the clusters. To obtain an efficient sample size in a cluster randomised trial, the cluster

  6. Clusters and how to make it work : toolkit for cluster strategy

    NARCIS (Netherlands)

    Manickam, Anu; van Berkel, Karel

    2013-01-01

    Clusters are the magic answer to regional economic development. Firms in clusters are more innovative; cluster policy dominates EU policy; ‘top-sectors’ and excellence are the choice of national policy makers; clusters are ‘in’. But, clusters are complex, clusters are ‘messy’; there is no clear

  7. Normalization based K means Clustering Algorithm

    OpenAIRE

    Virmani, Deepali; Taneja, Shweta; Malhotra, Geetika

    2015-01-01

    K-means is an effective clustering technique used to separate similar data into groups based on initial centroids of clusters. In this paper, Normalization based K-means clustering algorithm(N-K means) is proposed. Proposed N-K means clustering algorithm applies normalization prior to clustering on the available data as well as the proposed approach calculates initial centroids based on weights. Experimental results prove the betterment of proposed N-K means clustering algorithm over existing...

  8. Noninvasive neuromodulation in cluster headache

    DEFF Research Database (Denmark)

    Láinez, Miguel J A; Jensen, Rigmor

    2015-01-01

    PURPOSE OF REVIEW: Neuromodulation is an alternative in the management of medically intractable cluster headache patients. Most of the techniques are invasive, but in the last 2 years, some studies using a noninvasive device have been presented. The objective of this article is to review the data...... using this approach. RECENT FINDINGS: Techniques as occipital nerve stimulation or sphenopalatine ganglion stimulation are recommended as first-line therapy in refractory cluster patients, but they are invasive and maybe associated with complications. Noninvasive vagal nerve stimulation with an external...... device has been tried in cluster patients. Results from clinical practice and a single randomized clinical trial have been presented showing a reduction of the number of cluster attacks/week in the patients treated with the device. The rate of adverse events was low and most of them were mild. SUMMARY...

  9. Clustering of financial time series

    Science.gov (United States)

    D'Urso, Pierpaolo; Cappelli, Carmela; Di Lallo, Dario; Massari, Riccardo

    2013-05-01

    This paper addresses the topic of classifying financial time series in a fuzzy framework proposing two fuzzy clustering models both based on GARCH models. In general clustering of financial time series, due to their peculiar features, needs the definition of suitable distance measures. At this aim, the first fuzzy clustering model exploits the autoregressive representation of GARCH models and employs, in the framework of a partitioning around medoids algorithm, the classical autoregressive metric. The second fuzzy clustering model, also based on partitioning around medoids algorithm, uses the Caiado distance, a Mahalanobis-like distance, based on estimated GARCH parameters and covariances that takes into account the information about the volatility structure of time series. In order to illustrate the merits of the proposed fuzzy approaches an application to the problem of classifying 29 time series of Euro exchange rates against international currencies is presented and discussed, also comparing the fuzzy models with their crisp version.

  10. Infrared spectroscopy of ionic clusters

    International Nuclear Information System (INIS)

    Price, J.M.

    1990-11-01

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm -1 region. The species studied include: the hydrated hydronium ions, H 3 O + (H 2 O) 3 -10 , ammoniated ammonium ions, NH 4 + (NH 3 ) 1 -10 and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH 4 + (NH 3 ) n (H 2 O) m (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs

  11. Computer simulation of defect cluster

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, Eiichi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1996-04-01

    In order to elucidate individual element process of various defects and defect clusters of used materials under irradiation environments, interatomic potential with reliability was investigated. And for comparison with experimental results, it is often required to adopt the temperature effect and to investigate in details mechanism of one dimensional motion of micro conversion loop and so forth using the molecular dynamic (MD) method. Furthermore, temperature effect is also supposed for stable structure of defects and defect clusters, and many problems relating to alloy element are also remained. And, simulation on photon life at the defects and defect clusters thought to be important under comparison with equipment can also be supposed an improvement of effectiveness due to relation to theses products. In this paper, some topics in such flow was extracted to explain them. In particular, future important problems will be potential preparation of alloy, structure, dynamic behavior and limited temperature of intralattice atomic cluster. (G.K.)

  12. Transformation kinetics for nucleus clusters

    International Nuclear Information System (INIS)

    Villa, Elena; Rios, Paulo R.

    2009-01-01

    A rigorous mathematical approach based on stochastic geometry concepts is presented to extend previous Johnson-Mehl, Avrami, Kolmogorov treatment of transformation kinetics to situations in which nuclei are not homogeneously located in space but are located in clusters. An exact analytical solution is presented here for the first time assuming that nucleation sites follow a Matern cluster process. The influence of Matern cluster process parameters on subsequent growth kinetics and the microstructural path are illustrated by means of numerical examples. Moreover, using the superposition principle, exact analytical solutions are also obtained when nucleation takes place by a combination of a Matern cluster process and an inhomogeneous Poisson point process. The new solutions presented here significantly increase the number of exactly solvable cases available to formal kinetics.

  13. Infrared spectroscopy of ionic clusters

    Energy Technology Data Exchange (ETDEWEB)

    Price, J.M. (California Univ., Berkeley, CA (USA). Dept. of Chemistry Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm{sup {minus}1} region. The species studied include: the hydrated hydronium ions, H{sub 3}O{sup +} (H{sub 2}O){sub 3 {minus}10}, ammoniated ammonium ions, NH{sub 4}{sup +}(NH{sub 3}){sub 1 {minus}10} and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH{sub 4}{sup +}(NH{sub 3}){sub n}(H{sub 2}O){sub m} (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs.

  14. Cluster randomization and political philosophy.

    Science.gov (United States)

    Chwang, Eric

    2012-11-01

    In this paper, I will argue that, while the ethical issues raised by cluster randomization can be challenging, they are not new. My thesis divides neatly into two parts. In the first, easier part I argue that many of the ethical challenges posed by cluster randomized human subjects research are clearly present in other types of human subjects research, and so are not novel. In the second, more difficult part I discuss the thorniest ethical challenge for cluster randomized research--cases where consent is genuinely impractical to obtain. I argue that once again these cases require no new analytic insight; instead, we should look to political philosophy for guidance. In other words, the most serious ethical problem that arises in cluster randomized research also arises in political philosophy. © 2011 Blackwell Publishing Ltd.

  15. INNOVATIVE CLUSTER OR COMPETITIVENESS POLE?

    Directory of Open Access Journals (Sweden)

    Liliana Scutaru

    2015-02-01

    Full Text Available The paper analyzes the situation of clusters in Romania and their areas of activity and innovation in entrepreneurship Romanian state. It is made also a territorial distribution of clusters on the eight regions. The findings lead to the conclusion that there are some clusters that have the vocation to become poles of competitiveness in areas such as renewable energy, automotive, electronics, health, biotechnology, mechatronics or ICT (Information and Communication Technology which represent the resources for future of the Romanian economy. Regarding the degree of innovation of Romanian Small and Medium Enterprises (SMEs, the level is relatively modest, 30.8% of all enterprises being innovative. If we were to answer the question the title suggests, we would say "yes" to both since the innovative cluster as well as the competitiveness pole promotes par excellence, innovation through study, research and stimulation of creativity. And this is more than enough to support economic growth of Romania and maintain the competitiveness worldwide.

  16. Air void clustering : [technical summary].

    Science.gov (United States)

    2015-06-01

    Air void clustering around coarse aggregate in concrete has been : identified as a potential source of low strengths in concrete mixes by : several Departments of Transportation around the country. Research : was carried out to (1) develop a quantita...

  17. Are clusters of dietary patterns and cluster membership stable over time? Results of a longitudinal cluster analysis study.

    Science.gov (United States)

    Walthouwer, Michel Jean Louis; Oenema, Anke; Soetens, Katja; Lechner, Lilian; de Vries, Hein

    2014-11-01

    Developing nutrition education interventions based on clusters of dietary patterns can only be done adequately when it is clear if distinctive clusters of dietary patterns can be derived and reproduced over time, if cluster membership is stable, and if it is predictable which type of people belong to a certain cluster. Hence, this study aimed to: (1) identify clusters of dietary patterns among Dutch adults, (2) test the reproducibility of these clusters and stability of cluster membership over time, and (3) identify sociodemographic predictors of cluster membership and cluster transition. This study had a longitudinal design with online measurements at baseline (N=483) and 6 months follow-up (N=379). Dietary intake was assessed with a validated food frequency questionnaire. A hierarchical cluster analysis was performed, followed by a K-means cluster analysis. Multinomial logistic regression analyses were conducted to identify the sociodemographic predictors of cluster membership and cluster transition. At baseline and follow-up, a comparable three-cluster solution was derived, distinguishing a healthy, moderately healthy, and unhealthy dietary pattern. Male and lower educated participants were significantly more likely to have a less healthy dietary pattern. Further, 251 (66.2%) participants remained in the same cluster, 45 (11.9%) participants changed to an unhealthier cluster, and 83 (21.9%) participants shifted to a healthier cluster. Men and people living alone were significantly more likely to shift toward a less healthy dietary pattern. Distinctive clusters of dietary patterns can be derived. Yet, cluster membership is unstable and only few sociodemographic factors were associated with cluster membership and cluster transition. These findings imply that clusters based on dietary intake may not be suitable as a basis for nutrition education interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Clustering Coefficients for Correlation Networks.

    Science.gov (United States)

    Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu

    2018-01-01

    Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly

  19. Clustering Coefficients for Correlation Networks

    Directory of Open Access Journals (Sweden)

    Naoki Masuda

    2018-03-01

    Full Text Available Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients

  20. Clustering Coefficients for Correlation Networks

    Science.gov (United States)

    Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu

    2018-01-01

    Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly

  1. Clustering of Sun Exposure Measurements

    OpenAIRE

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai; Philipsen, Peter Alshede; Thieden, Elisabeth; Wulf, Hans Christian

    2002-01-01

    In a medically motivated Sun-exposure study, questionnaires concerning Sun-habits were collected from a number of subjects together with UV radiation measurements. This paper focuses on identifying clusters in the heterogeneous set of data for the purpose of understanding possible relations between Sun-habits exposure and eventually assessing the risk of skin cancer. A general probabilistic framework originally developed for text and Web mining is demonstrated to be useful for clustering of b...

  2. IntroductionThe Cluster mission

    Directory of Open Access Journals (Sweden)

    M. Fehringer

    Full Text Available The Cluster mission, ESA’s first cornerstone project, together with the SOHO mission, dating back to the first proposals in 1982, was finally launched in the summer of 2000. On 16 July and 9 August, respectively, two Russian Soyuz rockets blasted off from the Russian cosmodrome in Baikonour to deliver two Cluster spacecraft, each into their proper orbit. By the end of August 2000, the four Cluster satellites had reached their final tetrahedral constellation. The commissioning of 44 instruments, both individually and as an ensemble of complementary tools, was completed five months later to ensure the optimal use of their combined observational potential. On 1 February 2001, the mission was declared operational. The main goal of the Cluster mission is to study the small-scale plasma structures in three dimensions in key plasma regions, such as the solar wind, bow shock, magnetopause, polar cusps, magnetotail and the auroral zones. With its unique capabilities of three-dimensional spatial resolution, Cluster plays a major role in the International Solar Terrestrial Program (ISTP, where Cluster and the Solar and Heliospheric Observatory (SOHO are the European contributions. Cluster’s payload consists of state-of-the-art plasma instrumentation to measure electric and magnetic fields from the quasi-static up to high frequencies, and electron and ion distribution functions from energies of nearly 0 eV to a few MeV. The science operations are coordinated by the Joint Science Operations Centre (JSOC, at the Rutherford Appleton Laboratory (UK, and implemented by the European Space Operations Centre (ESOC, in Darmstadt, Germany. A network of eight national data centres has been set up for raw data processing, for the production of physical parameters, and their distribution to end users all over the world. The latest information on the Cluster mission can be found at http://sci.esa.int/cluster/.

  3. IntroductionThe Cluster mission

    Directory of Open Access Journals (Sweden)

    C. P. Escoubet

    2001-09-01

    Full Text Available The Cluster mission, ESA’s first cornerstone project, together with the SOHO mission, dating back to the first proposals in 1982, was finally launched in the summer of 2000. On 16 July and 9 August, respectively, two Russian Soyuz rockets blasted off from the Russian cosmodrome in Baikonour to deliver two Cluster spacecraft, each into their proper orbit. By the end of August 2000, the four Cluster satellites had reached their final tetrahedral constellation. The commissioning of 44 instruments, both individually and as an ensemble of complementary tools, was completed five months later to ensure the optimal use of their combined observational potential. On 1 February 2001, the mission was declared operational. The main goal of the Cluster mission is to study the small-scale plasma structures in three dimensions in key plasma regions, such as the solar wind, bow shock, magnetopause, polar cusps, magnetotail and the auroral zones. With its unique capabilities of three-dimensional spatial resolution, Cluster plays a major role in the International Solar Terrestrial Program (ISTP, where Cluster and the Solar and Heliospheric Observatory (SOHO are the European contributions. Cluster’s payload consists of state-of-the-art plasma instrumentation to measure electric and magnetic fields from the quasi-static up to high frequencies, and electron and ion distribution functions from energies of nearly 0 eV to a few MeV. The science operations are coordinated by the Joint Science Operations Centre (JSOC, at the Rutherford Appleton Laboratory (UK, and implemented by the European Space Operations Centre (ESOC, in Darmstadt, Germany. A network of eight national data centres has been set up for raw data processing, for the production of physical parameters, and their distribution to end users all over the world. The latest information on the Cluster mission can be found at http://sci.esa.int/cluster/.

  4. Vacancy clusters at nanoparticle surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Moxom, J.; Somieski, B.; White, C.W. [Oak Ridge National Lab., TN (United States); Mills, A.P. Jr. [Bell Labs., Lucent Technologies, Murray Hill, NJ (United States); Suzuki, R.; Ishibashi, S. [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Ueda, A.; Henderson, D. [Physics Dept., Fisk Univ., Nashville, TN (United States)

    2001-07-01

    We detect vacancy clusters at Au nanoparticle surfaces using a combination of positron lifetime spectroscopy, 1- detector, and 2-detector measurements of Doppler broadening of annihilation radiation. Gold nanoparticles are formed by MeV implantation of gold ions into MgO (100) followed by annealing. Clusters of two Mg and two O vacancies (v{sub 4}) are attached to the gold nanoparticle surfaces within the projected range (R{sub p}). (orig.)

  5. Vacancy clusters at nanoparticle surfaces

    International Nuclear Information System (INIS)

    Xu, J.; Moxom, J.; Somieski, B.; White, C.W.; Mills, A.P. Jr.; Suzuki, R.; Ishibashi, S.; Ueda, A.; Henderson, D.

    2001-01-01

    We detect vacancy clusters at Au nanoparticle surfaces using a combination of positron lifetime spectroscopy, 1- detector, and 2-detector measurements of Doppler broadening of annihilation radiation. Gold nanoparticles are formed by MeV implantation of gold ions into MgO (100) followed by annealing. Clusters of two Mg and two O vacancies (v 4 ) are attached to the gold nanoparticle surfaces within the projected range (R p ). (orig.)

  6. Speckle imaging of globular clusters

    International Nuclear Information System (INIS)

    Sams, B.J. III

    1990-01-01

    Speckle imaging is a powerful tool for high resolution astronomy. Its application to the core regions of globular clusters produces high resolution stellar maps of the bright stars, but is unable to image the faint stars which are most reliable dynamical indicators. The limits on resolving these faint, extended objects are physical, not algorithmic, and cannot be overcome using speckle. High resolution maps may be useful for resolving multicomponent stellar systems in the cluster centers. 30 refs

  7. Cluster structure in Cf nuclei

    International Nuclear Information System (INIS)

    Singh, Shailesh K.; Biswal, S.K.; Bhuyan, M.; Patra, S.K.; Gupta, R.K.

    2014-01-01

    Due to the availability of advance experimental facilities, it is possible to probe the nuclei upto their nucleon level very precisely and analyzed the internal structure which will help us to resolve some mysterious problem of the decay of nuclei. Recently, the relativistic nuclear collision, confirmed the α cluster type structure in the 12 C which is the mile stone for the cluster structure in nuclei. The clustering phenomena in light and intermediate elements in nuclear chart is very interesting. There is a lot of work done by our group in the clustering behaviour of the nuclei. In this paper, the various prospectus of clustering in the isotopes of Cf nucleus including fission state is discussed. Here, 242 Cf isotope for the analysis, which is experimentally known is taken. The relativistic mean field model with well established NL3 parameter set is taken. For getting the exact ground state configuration of the isotopes, the calculation for minimizing the potential energy surface is performed by constraint method. The clustering structure of other Cf isotopes is discussed

  8. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  9. Identification of Urban Leprosy Clusters

    Directory of Open Access Journals (Sweden)

    José Antonio Armani Paschoal

    2013-01-01

    Full Text Available Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1% of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3% were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease.

  10. Clusters in Nuclei. Vol. 2

    International Nuclear Information System (INIS)

    Beck, Christian

    2012-01-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This second volume follows the successful Lect. Notes Phys. 818 (Vol.1), and comprises six extensive lectures covering the following topics: - Microscopic cluster models - Neutron halo and break-up reactions - Break-up reaction models for two- and three-cluster projectiles - Clustering effects within the di-nuclear model - Nuclear alpha-particle condensates - Clusters in nuclei: experimental perspectives By promoting new ideas and developments while retaining a pedagogical style of presentation throughout, these lectures will serve as both a reference and an advanced teaching manual for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  11. Clusters in Nuclei. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Christian (ed.) [Strasbourg Univ. (France). Inst. Pluridiciplinaire Hubert Curien

    2012-07-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This second volume follows the successful Lect. Notes Phys. 818 (Vol.1), and comprises six extensive lectures covering the following topics: - Microscopic cluster models - Neutron halo and break-up reactions - Break-up reaction models for two- and three-cluster projectiles - Clustering effects within the di-nuclear model - Nuclear alpha-particle condensates - Clusters in nuclei: experimental perspectives By promoting new ideas and developments while retaining a pedagogical style of presentation throughout, these lectures will serve as both a reference and an advanced teaching manual for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  12. Star clusters and K2

    Science.gov (United States)

    Dotson, Jessie; Barentsen, Geert; Cody, Ann Marie

    2018-01-01

    The K2 survey has expanded the Kepler legacy by using the repurposed spacecraft to observe over 20 star clusters. The sample includes open and globular clusters at all ages, including very young (1-10 Myr, e.g. Taurus, Upper Sco, NGC 6530), moderately young (0.1-1 Gyr, e.g. M35, M44, Pleiades, Hyades), middle-aged (e.g. M67, Ruprecht 147, NGC 2158), and old globular clusters (e.g. M9, M19, Terzan 5). K2 observations of stellar clusters are exploring the rotation period-mass relationship to significantly lower masses than was previously possible, shedding light on the angular momentum budget and its dependence on mass and circumstellar disk properties, and illuminating the role of multiplicity in stellar angular momentum. Exoplanets discovered by K2 in stellar clusters provides planetary systems ripe for modeling given the extensive information available about their ages and environment. I will review the star clusters sampled by K2 across 16 fields so far, highlighting several characteristics, caveats, and unexplored uses of the public data set along the way. With fuel expected to run out in 2018, I will discuss the closing Campaigns, highlight the final target selection opportunities, and explain the data archive and TESS-compatible software tools the K2 mission intends to leave behind for posterity.

  13. Identification of Urban Leprosy Clusters

    Science.gov (United States)

    Paschoal, José Antonio Armani; Paschoal, Vania Del'Arco; Nardi, Susilene Maria Tonelli; Rosa, Patrícia Sammarco; Ismael, Manuela Gallo y Sanches; Sichieri, Eduvaldo Paulo

    2013-01-01

    Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1%) of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3%) were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease. PMID:24288467

  14. Estudios pioneros en torno al origen del lenguaje natural

    Directory of Open Access Journals (Sweden)

    Martínez Contreras, Jorge

    2011-02-01

    Full Text Available It has being an ancient desire to ask apes what their natural lives are. De la Mettrie was the first to propose, in the 18th C., that the sign language of deaf adults could be used with them since they do not speak. We enhance here some of the pioneering projects of the two strategies for this endeavor: the use of ASL and the utilization of lexigrams and computers. Besides the ancient communicative quest with them, the evolutionist’s perspective has seen in these studies a way to find out how the natural language (NL emerged in hominids. If it is clear that apes do no possess totally the NL, the linguistic turn in primatology has left way, as in philosophy, to more complex field and laboratory cognitive studies of less anthropocentric nature.

    Tratar de hablar con los simios y preguntarles cosas sobre su vida natural es un viejo deseo. De la Mettrie propone, en el s. XVIII, que se les enseñe el lenguaje de los sordos en vista de que no pueden hablar. Resaltamos aquí algunos estudios pioneros en relación con las dos estrategias llevadas a cabo para tratar de hablar con los simios: el uso del lenguaje americano de sordos (ASL y el de los lexigramas y computadoras. Además del viejo interés interrogativo humano hacia ellos, la perspectiva evolucionista ha visto en estos estudios un medio de investigar cómo surgió el lenguaje natural (LN en homínidos. Si queda claro que los simios no poseen totalmente el LN, el giro lingüistico en primatología ha cedido, como en filosofía, el paso a estudios cognitivos más complejos, de campo y de laboratorio, de orientación menos antropomórfica.

  15. Hierarchical Aligned Cluster Analysis for Temporal Clustering of Human Motion.

    Science.gov (United States)

    Zhou, Feng; De la Torre, Fernando; Hodgins, Jessica K

    2013-03-01

    Temporal segmentation of human motion into plausible motion primitives is central to understanding and building computational models of human motion. Several issues contribute to the challenge of discovering motion primitives: the exponential nature of all possible movement combinations, the variability in the temporal scale of human actions, and the complexity of representing articulated motion. We pose the problem of learning motion primitives as one of temporal clustering, and derive an unsupervised hierarchical bottom-up framework called hierarchical aligned cluster analysis (HACA). HACA finds a partition of a given multidimensional time series into m disjoint segments such that each segment belongs to one of k clusters. HACA combines kernel k-means with the generalized dynamic time alignment kernel to cluster time series data. Moreover, it provides a natural framework to find a low-dimensional embedding for time series. HACA is efficiently optimized with a coordinate descent strategy and dynamic programming. Experimental results on motion capture and video data demonstrate the effectiveness of HACA for segmenting complex motions and as a visualization tool. We also compare the performance of HACA to state-of-the-art algorithms for temporal clustering on data of a honey bee dance. The HACA code is available online.

  16. Instituciones educativas sustentables en Colombia caso de estudio colegio Rochester

    OpenAIRE

    García Gonzalez, Verónica; Bonilla Ruiz, Juliana; Cadena Sanchez, Laura Andrea

    2015-01-01

    En el proyecto en curso se pretende explicar cuáles son las condiciones y requisitos para implementar la cultura de organizaciones verdes en las instituciones educativas de nuestro país. Partiendo desde la transformación del colegio Rochester en un green school, teniendo en cuenta los requerimientos que exige el sistema de certificación LEED “Leadership Energy & Enviromental Desing” y los procesos administrativos que este involucra. Este estudio se llevara a cabo a través de una metodología q...

  17. Estudio de los Tweens y las Redes Sociales, Tacna, 2016.

    OpenAIRE

    Mamani Mamani, Deysi Gaby; Gonzalo Jara, Gustavo Richard; Yufra Tozo, Wilfredo Renato

    2016-01-01

    La tesis propuesta en las siguientes páginas: “Estudio de los Tweens y las Redes Sociales, Tacna, 2016”, busca poner en evidencia las preferencias, razones de uso, y uso, de las redes sociales por parte del grupo etario conformado por los tweens o pre adolescentes (Niños entre 8 y 12 años). La investigación presentada es de carácter descriptivo, de diseño no experimental y transversal, y se llevó a cabo aplicando un cuestionario (Asistido), conformado por 11 preguntas, a 146 niños entre la...

  18. Estudio del abandono empleando un modelo de riesgos proporcionales

    OpenAIRE

    Gonzalez, Mariana Verónica

    2017-01-01

    En este trabajo se aplica  un modelo de riesgo semi-paramétrico para identificar algunas variables que contribuyen a explicar el fenómeno del abandono estudiantil en una unidad académica de la Universidad Nacional de Córdoba (UNC), Argentina. La inactividad académica prolongada se toma como proxy de la variable dependiente. Los resultados muestran que el promedio del secundario aparece como importante predictor de la deserción. Además, se detectó que los estudiantes que costean sus estudios c...

  19. Cuidadores de Cartagena y su contexto de cuidado: estudio comparativo

    OpenAIRE

    Montalvo-Prieto, Amparo; Flórez-Torres, Inna Elida

    2009-01-01

    Objetivo: comparar las características sociodemográficas y de relación de cuidado de cuidadores de niños y adultos con enfermedades crónicas discapacitantes de Cartagena, Colombia. Método: estudio descriptivo, cuantitativo, de corte transversal. Se realizó un muestreo no probabilístico, por conveniencia, entre el 2006 y el 2007. Participaron 300 cuidadores: 98 de niños y 202 de adultos con enfermedades crónicas. Se utilizó la encuesta de caracterización de los cuidadores. Para describir las a...

  20. Aborto y Parlamento: un estudio sobre Brasil, Uruguay y Argentina

    OpenAIRE

    Rocha,Maria Isabel Baltar da; Rostagnol,Susana; Gutiérrez,María Alicia

    2009-01-01

    El presente trabajo desarrolla un estudio comparativo entre Brasil, Argentina y Uruguay sobre las legislaciones y las acciones de diversos actores en relación a la despenalización y/o legalización del aborto. El tema se instala en la agenda pública en los tres países a partir del proceso de democratización iniciado en la década de los 80 produciéndose diversas intervenciones tanto del movimiento de mujeres, como de las corporaciones médicas y otros actores sociales en el transcurso de la déca...

  1. Estudios de impacto ambiental en viaductos de gran longitud

    OpenAIRE

    Moya Matute, David

    2009-01-01

    El contenido de esta tesina forma parte de un proyecto concedido por el Ministerio de Educación y Ciencia en el año 2006 y coordinado entre el Departamento de Ingeniería de la Construcción de la UPC y el Departamento de Ingeniería Civil de la UCLM. El objeto de dicho proyecto de investigación es el estudio de la optimización de viaductos de gran longitud desde distintas vertientes, como son: estructural, plazo de ejecución, impacto ambiental, seguridad y salud, costes globales, et...

  2. Análisis y estudio del microcemento

    OpenAIRE

    PENADÉS SANZ, JONATAN

    2015-01-01

    [es] El presente Trabajo Final de Grado trata sobre el microcemento, que es un revestimiento continuo multicapa a base de resinas poliméricas, áridos y elementos cementosos. En este trabajo se analizan sus propiedades y su forma de aplicación, también se mencionan algunos consejos a tener en cuenta para su correcto empleo, y se estudian tanto sus ventajas e inconvenientes como sus rendimientos y costes. Además del estudio teórico se desarrolla una aplicación práctica mediante la realización d...

  3. Estudio de viabilidad de una central de restaurantes

    OpenAIRE

    Sáez Lanaspa, Idoya

    2015-01-01

    Mediante este estudio de viabilidad hemos analizado un nuevo campo dentro de la gastronomía y veremos su impacto en el mercado. Queremos presentar un nuevo concepto de restaurante, fuera de lo tradicional, de comida rápida basado en el buen gusto, la comida saludable e inspirado en una nueva idea de servicio más común en otros países como Estados Unidos. Instalado en un contenedor reciclado, reformado y adaptado con zona de comedor y cocina visible, creando un ambiente agrad...

  4. Estudio de factibilidad para un calzado personalizable femenino

    OpenAIRE

    Durán Pimienta, Oscar Adrián; Jaimes Santamaría, Juan Camilo

    2011-01-01

    El presente documento describe el proceso de investigación realizado por dos estudiantes de la Universidad EAFIT sobre la factibilidad de desarrollar un calzado personalizable femenino, en este proceso se llevaron a cabo diferentes estudios primarios con el fin de poseer una contextualización sobre la situación económica tanto del sector calzado, cuero y sus manufacturas, como del país -- Además se realizó una investigación sobre los diferentes procesos necesarios para la realizac...

  5. Aprender a dormir sin mam??: estudio de casos

    OpenAIRE

    ??lvarez Lozano, Marta

    2015-01-01

    Dado el caso de un ni??o con un h??bito incorrecto de sue??o, con sus correspondientes consecuencias, se lleva a cabo un estudio de casos que pretende modificar este h??bito a trav??s de un programa de intervenci??n basado en la reeducaci??n del sue??o mediante la modificaci??n de conducta. Para proceder a modificarla se ha trabajado con un m??todo de desensibilizaci??n sistem??tica, que a su vez, se ayuda de un sistema de econom??a de fichas para causar motivaci??n en el sujeto, y adem??s, d...

  6. Aproximaciones proteómicas para el estudio del envejecimiento

    OpenAIRE

    Fanjul Hevia, Víctor

    2014-01-01

    La población mundial está envejeciendo progresivamente y la edad es el factor principal de riesgo de enfermedad cardiovascular (ECV), que a su vez es el principal problema de salud en países desarrollados. Aún no se conocen en profundidad los mecanismos moleculares que provocan el envejecimiento ni aquéllos que originan la ECV, y su estudio podría conducir hacia el desarrollo de estrategias preventivas o de terapias que alarguen significativamente la vida y mejoren su calidad. La progeria ...

  7. Stuart Hall sobre “hacer estudios culturales”

    OpenAIRE

    Mato, Daniel; Universidad Nacional Tres de Febrero (Untref), Buenos Aires, Argentina

    2016-01-01

    Traducción de Emeshe Juhász MininbergEmeshe Juhász Mininberg es escritora e investigadora independiente. Doctora en Filosofía y Letras, Yale University, Estados Unidos. Traductora y editora de textos de crítica cultural y de artes plásticas. Ha publicado varios artículos sobre ciudadanía, cultura e identidad nacional en tiempos de globalización, que aparecen, entre otros, en Cultura, política y sociedad: perspectivas latinoamericanas (Clacso, 2005) y en el Diccionario de estudios culturales l...

  8. Estudio electrocinético de un suelo sometido

    OpenAIRE

    Hernandez-luis, Felipe; Ramirez, Carolina; Arbelo, Carmen

    2011-01-01

    En el presente trabajo se analizan algunos cambios producidos en las propiedades de un suelo sometido a impacto térmico. Para llevar a cabo este estudio se utiliza una técnica electrocinética basada en los mismos principios que la electrorremediación. El análisis se enfoca en la variación, durante el tratamiento, de la corriente de electrólisis y de la diferencia de potencial generada en el interior del suelo en una región cercana a la cámara de los electrodos...

  9. Estudio de la Esquizofrenia en el Núcleo Familiar

    OpenAIRE

    Núñez-Borja Castro, Luis Alberto

    2017-01-01

    La presente tesis desarrolla el Estudio de la Esquizofrenia en la familia a partir de tres casos de hogares que cuentan entre sus miembros con un paciente diagnosticado con Esquizofrenia y con el cual conviven día a día. Se evaluó los cambios que ocurren y están ocurriendo en el comportamiento en el seno de tres familias que viven con un paciente diagnosticado con este trastorno mental. Para llevar a cabo esta investigación se trabajó con una muestra de tres pacientes aquejados con este...

  10. Estado Actual y Retos Futuros en el Estudio del Burnout

    OpenAIRE

    Salanova Soria, Marisa; Llorens Gumbau, Susana

    2008-01-01

    El objetivo principal de este artículo es ofrecer una revisión de la actual investigación aplicada del síndrome de quemarse por el trabajo o burnout. Comenzamos con el concepto de burnout, su evolución desde los primeros estudios en ocupaciones de servicios, hasta la actualidad en donde la investigación ha demostrado la importancia de considerar otras ocupaciones, y ampliar las dimensiones clave del burnout. En segundo lugar, examinaremos cómo evaluar el burnout, en función de la pos...

  11. Modelos parentales en el contexto urbano: un estudio exploratorio

    OpenAIRE

    Martínez Licona, José Francisco; García Rodrigo, María Isabel; Collazo Martínez, Jonathan Carlos

    2017-01-01

    Resumen: El propósito de este trabajo es explorar las características que tienen las familias potosinas en cuanto a su cultura parental; es decir, explorar sus pautas de crianza, los diferentes vínculos de apego que se construyen y los patrones de éxito que se promueven para relacionarlos con sus características biográficas. El estudio se efectuó en la zona conurbada de San Luis Potosí (México), con la participación de 1008 familias de diferentes niveles culturales y se utilizó un instrumento...

  12. Estudio de los galactanos del alga roja pterocladiella Capillacea

    OpenAIRE

    Errea, María Inés

    2001-01-01

    Existen dos familias de polisacáridos sintetizados por algas rojas, los carragenanos y el ágar, que, debido a sus propiedades reológicas, que les permiten estabilizar soluciones o emulsiones acuosas, son utilizados en la industria farmacéutica y alimentaria de todo el mundo. Este Trabajo de Tesis comprende los tópicos que se indican a continuación: a) Estudio de la estructura de los galactanos que componen el sistema de polisacáridos de la agarofita Plerocladíella capillacea (Gelidiales, Geli...

  13. Efectividad de la maniobra de Sellick: un estudio con Glidescope

    OpenAIRE

    Muñoz Ávalos, Natalia; Robledo, María de la Flor

    2014-01-01

    La compresión cricoidea fue descrita en 1961 por Sellick como método para reducir el riesgo de broncoaspiración durante la fase de inducción de una anestesia general, formando parte de los pilares de la secuencia de intubación rápida. No obstante, cada vez son más los detractores que cuestionan la efectividad de esta maniobra a la luz de las últimas publicaciones . El presente estudio propone verificar la efectividad de la presión cricoidea en ocluir la luz esofágica mediante visión dir...

  14. Estudios sobre metales arqueológicos quemados

    OpenAIRE

    Montero Ruiz, Ignacio; Rovira Llorens, Salvador

    2002-01-01

    El registro arqueológico nos ofrece materiales metálicos que han sido sometidos a un proceso de quemado ya sea intencional, por su inclusión en ajuares funerarios con el rito de cremación, bien de manera accidental por fuegos o incendios. Se intentan observar e identificar las huellas que este proceso ha podido dejar en materiales metálicos no ferreos: unas veces visualmente reconocibles por la propia deformación del objeto y otras acudiendo a los estudios metalográficos para observar la estr...

  15. Traumatismo torácico. Estudio de un cuatrienio

    OpenAIRE

    Moya Rosa, Enrique J; Marrero Peláez, Niuris

    2002-01-01

    Se realizó un estudio descriptivo con los expedientes clínicos de 252 pacientes afectados por trauma de tórax, ingresados en la unidad de politrauma del Hospital Provincial Docente Manuel Ascunce Domenech de Camagüey, desde enero de 1996 a diciembre de1999. Analizamos las variables edad, sexo, causas, tipo de lesión, su relación con otras regiones lesionadas, así como el estado de los pacientes al egresar. Existió un predominio del sexo masculino con respecto al femenino; los grupos de edades...

  16. El abandono en las etapas iniciales de los estudios superiores

    OpenAIRE

    Norma Zandomeni; Sandra Canale; Andrea Pacifico; Fernanda Pagura

    2016-01-01

    En este artículo se presenta una investigación sobre abandono de los estudios superiores realizada en una universidad argentina. Con un abordaje metodológico cuanti-cualitativo, se analizan datos secundarios y se recupera la perspectiva de distintos actores mediante talleres, encuestas y entrevistas. Se aborda el abandono que se produce en el proceso del ingreso y el generado en los dos primeros años, tanto en su cuantificación como en los factores que operan en el mismo. En el primer caso el...

  17. Cosmology with clusters in the CMB

    International Nuclear Information System (INIS)

    Majumdar, Subhabrata

    2008-01-01

    Ever since the seminal work by Sunyaev and Zel'dovich describing the distortion of the CMB spectrum, due to photons passing through the hot inter cluster gas on its way to us from the surface of last scattering (the so called Sunyaev-Zel'dovich effect (SZE)), small scale distortions of the CMB by clusters has been used to detect clusters as well as to do cosmology with clusters. Cosmology with clusters in the CMB can be divided into three distinct regimes: a) when the clusters are completely unresolved and contribute to the secondary CMB distortions power spectrum at small angular scales; b) when we can just about resolve the clusters so as to detect the clusters through its total SZE flux such that the clusters can be tagged and counted for doing cosmology and c) when we can completely resolve the clusters so as to measure their sizes and other cluster structural properties and their evolution with redshift. In this article, we take a look at these three aspects of SZE cluster studies and their implication for using clusters as cosmological probes. We show that clusters can be used as effective probes of cosmology, when in all of these three cases, one explores the synergy between cluster physics and cosmology as well take clues about cluster physics from the latest high precision cluster observations (for example, from Chandra and XMM - Newton). As a specific case, we show how an observationally motivated cluster SZ template can explain the CBI-excess without the need for a high σ 8 . We also briefly discuss 'self-calibration' in cluster surveys and the prospect of using clusters as an ensemble of cosmic rulers to break degeneracies arising in cluster cosmology.

  18. Electronic and chemical properties of indium clusters

    International Nuclear Information System (INIS)

    Rayane, D.; Khardi, S.; Tribollet, B.; Broyer, M.; Melinon, P.; Cabaud, B.; Hoareau, A.

    1989-01-01

    Indium clusters are produced by the inert gas condensation technique. The ionization potentials are found higher for small clusters than for the Indium atom. This is explained by the p character of the bonding as in aluminium. Doubly charge clusters are also observed and fragmentation processes discussed. Finally small Indium clusters 3< n<9 are found very reactive with hydrocarbon. (orig.)

  19. Bayesian Decision Theoretical Framework for Clustering

    Science.gov (United States)

    Chen, Mo

    2011-01-01

    In this thesis, we establish a novel probabilistic framework for the data clustering problem from the perspective of Bayesian decision theory. The Bayesian decision theory view justifies the important questions: what is a cluster and what a clustering algorithm should optimize. We prove that the spectral clustering (to be specific, the…

  20. FORMATION OF A INNOVATION REGIONAL CLUSTER MODEL

    Directory of Open Access Journals (Sweden)

    G. S. Merzlikina

    2015-01-01

    Full Text Available Summary. As a result of investigation of science and methodical approaches related problems of building and development of innovation clusters there were some issues in functional assignments of innovation and production clusters. Because of those issues, article’s authors differ conceptions of innovation cluster and production cluster, as they explain notion of innovation-production cluster. The main goal of this article is to reveal existing organizational issues in cluster building and its successful development. Based on regional clusters building analysis carried out there was typical practical structure of cluster members interaction revealed. This structure also have its cons, as following: absence cluster orientation to marketing environment, lack of members’ prolonged relations’ building and development system, along with ineffective management of information, financial and material streams within cluster, narrow competence difference and responsibility zones between cluster members, lack of transparence of cluster’s action, low environment changes adaptivity, hard to use cluster members’ intellectual property, and commercialization of hi-tech products. When all those issues listed above come together, it reduces life activity of existing models of innovative cluster-building along with practical opportunity of cluster realization. Because of that, authors offer an upgraded innovative-productive cluster building model with more efficient business processes management system, which includes advanced innovative cluster structure, competence matrix and subcluster responsibility zone. Suggested model differs from other ones by using unified innovative product development control center, which also controls production and marketing realization.

  1. An introduction to cluster science

    CERN Document Server

    Dinh, Phuong Mai; Suraud, Eric

    2013-01-01

    Filling the need for a solid textbook, this short primer in cluster science is ideal for a one-semester lecture for advanced undergraduate students. It is based on a series of lectures given by the well-established and recognized authors for the past ten years. The book covers both the basics of the domain as well as up-to-date developments. It can be divided roughly into two parts. The first three chapters introduce basic concepts of cluster science. Chapter 1 provides a general introduction, complemented by chapter 2 on experimental and chapter 3 on theoretical aspects. The second half of the book is devoted to a systematic presentation of free cluster properties, and to a thorough discussion of the impact of clusters in other domains of science. These explicitly worked-out links between cluster physics and other research areas are unique both in terms of fundamental aspects and of applications, and cannot be found elsewhere in the literature. Also suitable for researchers outside of the field looking for...

  2. Large scale cluster computing workshop

    International Nuclear Information System (INIS)

    Dane Skow; Alan Silverman

    2002-01-01

    Recent revolutions in computer hardware and software technologies have paved the way for the large-scale deployment of clusters of commodity computers to address problems heretofore the domain of tightly coupled SMP processors. Near term projects within High Energy Physics and other computing communities will deploy clusters of scale 1000s of processors and be used by 100s to 1000s of independent users. This will expand the reach in both dimensions by an order of magnitude from the current successful production facilities. The goals of this workshop were: (1) to determine what tools exist which can scale up to the cluster sizes foreseen for the next generation of HENP experiments (several thousand nodes) and by implication to identify areas where some investment of money or effort is likely to be needed. (2) To compare and record experimences gained with such tools. (3) To produce a practical guide to all stages of planning, installing, building and operating a large computing cluster in HENP. (4) To identify and connect groups with similar interest within HENP and the larger clustering community

  3. Reduct Driven Pattern Extraction from Clusters

    Directory of Open Access Journals (Sweden)

    Shuchita Upadhyaya

    2009-03-01

    Full Text Available Clustering algorithms give general description of clusters, listing number of clusters and member entities in those clusters. However, these algorithms lack in generating cluster description in the form of pattern. From data mining perspective, pattern learning from clusters is as important as cluster finding. In the proposed approach, reduct derived from rough set theory is employed for pattern formulation. Further, reduct are the set of attributes which distinguishes the entities in a homogenous cluster, hence these can be clear cut removed from the same. Remaining attributes are then ranked for their contribution in the cluster. Pattern is formulated with the conjunction of most contributing attributes such that pattern distinctively describes the cluster with minimum error.

  4. Kinetic and radiation processes in cluster plasmas

    International Nuclear Information System (INIS)

    Smirnov, B.M.

    1996-01-01

    The analysis of processes is made for a cluster plasma which is a xenon arc plasma of a high pressure with an admixture of tungsten cluster ions. Because cluster ions emit radiation, this system is a light source which parameters are determined by various processes such as heat release and transport of charged particles in the plasma, radiative processes involving clusters, processes of cluster evaporation and attachment of atoms to it that leads to an equilibrium between clusters and vapor of their atoms, processes of cluster generation, processes of the ionization equilibrium between cluster ions and plasma electrons, transport of cluster ions in the discharge plasma in all directions. These processes govern by properties of a specific cluster plasma under consideration. (author)

  5. Aplicaciones de data mining al estudio de la biodiversidad

    OpenAIRE

    Santa María, Cristóbal; Soria, Marcelo A.

    2011-01-01

    El trabajo propone la utilización conjunta de técnicas de data mining y simulación para evaluar la riqueza y diversidad de comunidades microbianas. Se parte de una muestra formada por distintas secuencias de ADN que se alinean para luego ser agrupadas según su similaridad en clusters. Cada uno de estos clusters es una especie y el propósito es estimar su número y distribución en la comunidad basándose en la información que da la muestra. La técnica de rarefacción, sustentada en el procedimien...

  6. Estudio sobre el estado nutricional, calidad de vida, y capacidad funcional en pacientes con fibromialgia. Estudio ENCAVI

    OpenAIRE

    Arranz, Laura Isabel

    2012-01-01

    [spa] La fibromialgia es una enfermedad reumática, clasificada con el código OMS CIE-10- M79.7 (versión 2007), de carácter crónico que causa dolor muscular generalizado, rigidez, fatiga, alteraciones del sueño y trastornos cognitivos entre otros síntomas. La prevalencia en España está alrededor del 2.4%, aunque algunos estudios han situado esta cifra entorno al 4%, siendo las mujeres las que más la padecen, con gran diferencia respecto a los hombres. La fibromialgia, además, se presenta frecu...

  7. Contexto actual de los estudios preclínicos

    Directory of Open Access Journals (Sweden)

    Thelvia I. Ramos

    2016-09-01

    Full Text Available El desarrollo acelerado de la Industria Biofarmacéutica, y en particular de la producción de biológicos, ha permitido el incremento de la investigación clínica, teniendo en consideración la novedad de las sustancias que se desarrollan. El éxito de un producto solo se logra a través de la realización de los estudios clínicos controlados, lo cual significa que este ha sido validado a través de un sistema de gestión de calidad, principal determinante para que la molécula en estudio, pueda ser autorizada y comercializada posterior a la demostración de su seguridad y eficacia. Previo a la presentación de una solicitud para un nuevo producto ante las autoridades regulatorias, es necesario pasar por la etapa de investigación preclínica.

  8. Viviendo en Flatland. El estudio comparado del crimen violento

    Directory of Open Access Journals (Sweden)

    Luis David Ramírez de Garay

    2013-05-01

    Full Text Available Esta nota de investigación indaga sobre el notorio rezago que la criminología y la sociología del crimen tienen en la aplicación de la metodología comparada. A diferencia de la ciencia política y algunas áreas de la investigación sociológica, la metodología comparada no ocupa un lugar preponderante en la investigación empírica del crimen. Sin embargo, existen algunos valiosos ejemplos sobre las ventajas del estudio comparado del crimen y del crimen violento. Por ello, incluyo una breve revisión del estado actual de dichos estudios y de sus inherentes limitaciones teóricas y metodológicas. Finalmente, concluyo la nota presentando mi propuesta para incorporar la metodología comparada en la agenda de investigación sobre las bases sociales del crimen y del crimen violento

  9. ESTUDIO CINEANTROPOMÉTRICO DEL JUGADOR DE TENIS ADOLESCENTE

    Directory of Open Access Journals (Sweden)

    Gema Torres Luque

    2006-01-01

    Full Text Available El propósito de este estudio fue aproximarse al perfil cineantropométrico de jugadores de tenis de edad adolescente. Para ello se seleccionaron 75 jugadores de tenis (47 varones y 26 mujeres a los cuales se les determinó el perfil antropométrico, composición corporal y somatotipo, mostrando a su vez las diferencias en cuanto al género. Todas las valoraciones se realizaron siguiendo las recomendaciones del Grupo Español de Cineantropometría, los tenistas fueron evaluados a la misma hora del día. Los resultados muestran diferencias significativamente mayores en los tenistas en peso, talla, perímetros bioestiloide y bicondíleo húmero, así como en diámetros en brazo contraído y perímetro del muslo y pierna. A su vez, las tenistas muestran un mayor porcentaje de grasa corporal y un menor porcentaje de masa ósea, no existiendo diferencias significativas respecto al porcentaje de masa muscular. El somatotipo marca una tendencia ecto mesomórfica para el género masculino, y una tendencia meso endomórfica para el género femenino. El estudio cineantropométrico del tenista adolescente permitirá una aproximación de referencia al perfil funcional del tenista y contribuir al máximo rendimiento deportivo.

  10. Estudio de inmunogenicidad para dos vacunas recombinantes contra hepatitis B

    Directory of Open Access Journals (Sweden)

    O. Juliao

    1991-12-01

    Full Text Available Este estudio compara la inmunogenicidad (seroconversión, seroprotección e Hiperrespuesta, producida por dos vacunas recombinantes contra la hepatitis B (Engerix-B de Bélgica y Cubana, en dos esquemas (012 y 016 meses, empleando los métodos de cuantificación para Anti-HBsAg (Abbott y Organón, los cuales fueron también comparados. En el estudio participaron 257 voluntarios,  divididos al azar en 4 grupos (dos vacunas, dos esquemas. Resultados: los dos métodos de Abbon y Organon, no presentan diferencias estadísticas significativas. La vacuna cubana muestra una mayor respuesta inmunogénica para dos dosis de vacuna y para el esquema 012. No hay diferencia entre los esquemas 012 y 016 y en el esquema 016 no se ven diferencias estadísticamente significativas con la vacuna Engerix-B. En esta Última el esquema 016 muestra mejores resultados que el 012.

  11. Litiasis renal: estudio y manejo endocrinológico

    Directory of Open Access Journals (Sweden)

    V. Gilberto González, Dr.

    2013-09-01

    Full Text Available La litiasis renal es causa de importante morbilidad y costo económico, afectando hasta el 15% de la población. Además, la litiasis renal puede ser expresión también de enfermedades extrarrenales, entre las cuales destaca riesgo aumentado de osteoporosis. Estudios nacionales muestran que las causas de litiasis renal en Chile son similares a las comunicadas internacionalmente, destacando la hipercalciuria idiopática como el principal factor de riesgo. A pesar de los avances en técnicas urológicas de remoción de cálculo, éstas no modifican la historia natural de la litiasis renal. Así, en los pacientes sin tratamiento médico, la recurrencia es la regla más que la excepción. En esta revisión se actualiza el estudio y manejo endocrinológico de la litiasis renal, para el cual la evidencia muestra que éste es eficaz y seguro en la prevención de recurrencia de litiasis renal y control de enfermedades asociadas, complementando así el manejo urológico de esta importante enfermedad.

  12. Preliminares al Estudio del Chancro y la Fusariosis del Cacao

    Directory of Open Access Journals (Sweden)

    Garcés O. Carlos

    1939-08-01

    Full Text Available El presente estudio es el fruto de año y medio de investigaciones continuas, durante las cuales el autor ha pretendido recoger el máximum de observaciones personales que puede obtenerse cuando, a más de la deficiencia técnica y de laboratorio que ocurre en quienes se inician en Patología Vegetal, se dispone de medios que requiere habilidad y conocimientos profundos por parte del observador y considerable campo de experimentación. No hay por este motivo creación de doctrinas sino simplemente exposición de observaciones experimentales, que pueden estar erradas por deficiencia técnica, pero que se han efectuado con gran pulcritud de conciencia. El autor agradece sinceramente q quienes con voluntad inmejorable se prestaron a suministrarle toda clase de datos relacionados con este estudio y rinde homenaje de cordial reconocimiento al doctor Ramón Mejía Franco, constante propulsor de sus esfuerzos y guía seguro en la mayor parte de las experimentaciones.

  13. LIDERAZGO MULTICULTURAL: ESTUDIO COMPARATIVO INDIA-MÉXICO

    Directory of Open Access Journals (Sweden)

    BERTA ERMILA MADRIGAL TORRES

    2017-01-01

    Full Text Available En este artículo se presenta un estudio de caso de una empresa donde colaboran directivos de dos culturas: México e India; se plantean preguntas de investigación como: ¿cuáles son los valores, actitudes y habilidades que ambas culturas esperan de sus líderes?, ¿cuáles son las habilidades del líder y sus estilos de liderazgo? y ¿cuál es la distancia y dimensión del poder de los líderes de ambas culturas? Se diseñó un instrumento con las cinco características de la descripción de la personalidad enumeradas por Goldberg (1990, la aproximación de estilo de liderazgo de Madrigal (2009, y dimensión de la incertidumbre y distancia del poder con la teoría de Northouse (2012. Para poder llevar a cabo este estudio se encuestaron a 102 directivos de cultura india y mexicana en diferentes aspectos relacionados con la percepción de liderazgo. Los resultados demuestran que tanto los mexicanos como los indios tienden a preferir un estilo de liderazgo democrático. Finalmente se presentan como hallazgos las diferencias existentes en el colectivismo institucional y en la orientación al futuro de ambas culturas.

  14. Connection between Seyfert galaxies and clusters

    International Nuclear Information System (INIS)

    Petrosyan, A.R.

    1988-01-01

    To identify Seyfert galaxies that are members of clusters, the sample of known Seyfert galaxies (464 objects) is tested against the Zwicky, Abell, and southern clusters. On the basis of the criteria adopted in the paper, 67 Seyfert galaxies are selected as probable members of Zwicky clusters, 15 as members of Abell clusters, and 18 as members of southern clusters. Lists of these objects are given

  15. Estudio epidemiológico de salud oral en adultos. Comunidad Valenciana, 2006

    OpenAIRE

    Eustaquio Raga, Mª Vicenta

    2008-01-01

    RESUMEN En las últimas dos décadas se han venido realizando estudios epidemiológicos de salud oral en adultos en las diferentes comunidades autónomas españolas. Así la ausencia de dicho estudio de ámbito autonómico valenciano justifica plenamente su realización. En la realización del presente estudio nos hemos propuesto como objetivo general el evaluar el estado de salud bucodental de la población adulta y mayor de la Comunidad Valenciana. Se ha diseñado un estudio transversal o de p...

  16. OBSERVED SCALING RELATIONS FOR STRONG LENSING CLUSTERS: CONSEQUENCES FOR COSMOLOGY AND CLUSTER ASSEMBLY

    International Nuclear Information System (INIS)

    Comerford, Julia M.; Moustakas, Leonidas A.; Natarajan, Priyamvada

    2010-01-01

    Scaling relations of observed galaxy cluster properties are useful tools for constraining cosmological parameters as well as cluster formation histories. One of the key cosmological parameters, σ 8 , is constrained using observed clusters of galaxies, although current estimates of σ 8 from the scaling relations of dynamically relaxed galaxy clusters are limited by the large scatter in the observed cluster mass-temperature (M-T) relation. With a sample of eight strong lensing clusters at 0.3 8 , but combining the cluster concentration-mass relation with the M-T relation enables the inclusion of unrelaxed clusters as well. Thus, the resultant gains in the accuracy of σ 8 measurements from clusters are twofold: the errors on σ 8 are reduced and the cluster sample size is increased. Therefore, the statistics on σ 8 determination from clusters are greatly improved by the inclusion of unrelaxed clusters. Exploring cluster scaling relations further, we find that the correlation between brightest cluster galaxy (BCG) luminosity and cluster mass offers insight into the assembly histories of clusters. We find preliminary evidence for a steeper BCG luminosity-cluster mass relation for strong lensing clusters than the general cluster population, hinting that strong lensing clusters may have had more active merging histories.

  17. Percolation technique for galaxy clustering

    Science.gov (United States)

    Klypin, Anatoly; Shandarin, Sergei F.

    1993-01-01

    We study percolation in mass and galaxy distributions obtained in 3D simulations of the CDM, C + HDM, and the power law (n = -1) models in the Omega = 1 universe. Percolation statistics is used here as a quantitative measure of the degree to which a mass or galaxy distribution is of a filamentary or cellular type. The very fast code used calculates the statistics of clusters along with the direct detection of percolation. We found that the two parameters mu(infinity), characterizing the size of the largest cluster, and mu-squared, characterizing the weighted mean size of all clusters excluding the largest one, are extremely useful for evaluating the percolation threshold. An advantage of using these parameters is their low sensitivity to boundary effects. We show that both the CDM and the C + HDM models are extremely filamentary both in mass and galaxy distribution. The percolation thresholds for the mass distributions are determined.

  18. Binding energies of cluster ions

    International Nuclear Information System (INIS)

    Parajuli, R.; Matt, S.; Scheier, P.; Echt, O.; Stamatovic, A.; Maerk, T.D.

    2002-01-01

    The binding energy of charged clusters may be measured by analyzing the kinetic energy released in the metastable decay of mass selected parent ions. Using finite heat bath theory to determine the binding energies of argon, neon, krypton, oxygen and nitrogen from their respective average kinetic energy released were carried out. A high-resolution double focussing two-sector mass spectrometer of reversed Nier-Johnson type geometry was used. MIKE ( mass-analysed ion kinetic energy) were measured to investigate decay reactions of mass-selected ions. For the inert gases neon (Ne n + ), argon (Ar n + ) and krypton (Kr n + ), it is found that the binding energies initially decrease with increasing size n and then level off at a value above the enthalpy of vaporization of the condensed phase. Oxygen cluster ions shown a characteristic dependence on cluster size (U-shape) indicating a change in the metastable fragmentation mechanism when going from the dimer to the decamer ion. (nevyjel)

  19. Stream Clustering of Growing Objects

    Science.gov (United States)

    Siddiqui, Zaigham Faraz; Spiliopoulou, Myra

    We study incremental clustering of objects that grow and accumulate over time. The objects come from a multi-table stream e.g. streams of Customer and Transaction. As the Transactions stream accumulates, the Customers’ profiles grow. First, we use an incremental propositionalisation to convert the multi-table stream into a single-table stream upon which we apply clustering. For this purpose, we develop an online version of K-Means algorithm that can handle these swelling objects and any new objects that arrive. The algorithm also monitors the quality of the model and performs re-clustering when it deteriorates. We evaluate our method on the PKDD Challenge 1999 dataset.

  20. Calibrating the Planck Cluster Mass Scale with Cluster Velocity Dispersions

    Science.gov (United States)

    Amodeo, Stefania; Mei, Simona; Stanford, Spencer A.; Bartlett, James G.; Melin, Jean-Baptiste; Lawrence, Charles R.; Chary, Ranga-Ram; Shim, Hyunjin; Marleau, Francine; Stern, Daniel

    2017-08-01

    We measure the Planck cluster mass bias using dynamical mass measurements based on velocity dispersions of a subsample of 17 Planck-detected clusters. The velocity dispersions were calculated using redshifts determined from spectra that were obtained at the Gemini observatory with the GMOS multi-object spectrograph. We correct our estimates for effects due to finite aperture, Eddington bias, and correlated scatter between velocity dispersion and the Planck mass proxy. The result for the mass bias parameter, (1-b), depends on the value of the galaxy velocity bias, {b}{{v}}, adopted from simulations: (1-b)=(0.51+/- 0.09){b}{{v}}3. Using a velocity bias of {b}{{v}}=1.08 from Munari et al., we obtain (1-b)=0.64+/- 0.11, I.e., an error of 17% on the mass bias measurement with 17 clusters. This mass bias value is consistent with most previous weak-lensing determinations. It lies within 1σ of the value that is needed to reconcile the Planck cluster counts with the Planck primary cosmic microwave background constraints. We emphasize that uncertainty in the velocity bias severely hampers the precision of the measurements of the mass bias using velocity dispersions. On the other hand, when we fix the Planck mass bias using the constraints from Penna-Lima et al., based on weak-lensing measurements, we obtain a positive velocity bias of {b}{{v}}≳ 0.9 at 3σ .

  1. Oxygen treatment of cluster headache

    DEFF Research Database (Denmark)

    Petersen, Anja S; Barloese, Mads C J; Jensen, Rigmor H

    2014-01-01

    PURPOSE: Our aim was to review the existing literature to document oxygen's therapeutic effect on cluster headache. METHOD: A PubMed search resulted in 28 hits, and from these and their references we found in total 11 relevant studies. We included six studies that investigated the efficacy......, but not a prophylactic effect. Despite the fact that only a few high-quality RCT studies are available, oxygen treatment is close to an ideal treatment because it is effective and safe. However, sufferers of cluster headache do not always have access to oxygen because of logistic and financial concerns....

  2. Epistemic communities and cluster dynamics

    DEFF Research Database (Denmark)

    Håkanson, Lars

    2003-01-01

    This paper questions the prevailing notions that firms within industrial clusters have privi-leged access to `tacit knowledge' that is unavailable - or available only at high cost - to firms located elsewhere, and that such access provides competitive advantages that help to explain the growth...... and development of both firms and regions. It outlines a model of cluster dynam-ics emphasizing two mutually interdependent processes: the concentration of specialized and complementary epistemic communities, on the one hand, and entrepreneurship and a high rate of new firm formation on the other....

  3. Thermodynamic basis for cluster kinetics

    DEFF Research Database (Denmark)

    Hu, Lina; Bian, Xiufang; Qin, Xubo

    2006-01-01

    Due to the inaccessibility of the supercooled region of marginal metallic glasses (MMGs) within the experimental time window, we study the cluster kinetics above the liquidus temperature, Tl, to acquire information on the fragility of the MMG systems. Thermodynamic basis for the stability...... of locally ordered structure in the MMG liquids is discussed in terms of the two-order-parameter model. It is found that the Arrhenius activation energy of clusters, h, is proportional to the chemical mixing enthalpy of alloys, Hchem. Fragility of the MMG forming liquids can be described by the ratio...

  4. Clustering of Sun Exposure Measurements

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai

    2002-01-01

    In a medically motivated Sun-exposure study, questionnaires concerning Sun-habits were collected from a number of subjects together with UV radiation measurements. This paper focuses on identifying clusters in the heterogeneous set of data for the purpose of understanding possible relations between...... Sun-habits exposure and eventually assessing the risk of skin cancer. A general probabilistic framework originally developed for text and Web mining is demonstrated to be useful for clustering of behavioral data. The framework combines principal component subspace projection with probabilistic...

  5. Clustering in Hilbert simplex geometry

    KAUST Repository

    Nielsen, Frank

    2017-04-03

    Clustering categorical distributions in the probability simplex is a fundamental primitive often met in applications dealing with histograms or mixtures of multinomials. Traditionally, the differential-geometric structure of the probability simplex has been used either by (i) setting the Riemannian metric tensor to the Fisher information matrix of the categorical distributions, or (ii) defining the information-geometric structure induced by a smooth dissimilarity measure, called a divergence. In this paper, we introduce a novel computationally-friendly non-Riemannian framework for modeling the probability simplex: Hilbert simplex geometry. We discuss the pros and cons of those three statistical modelings, and compare them experimentally for clustering tasks.

  6. Collaborative Clustering for Sensor Networks

    Science.gov (United States)

    Wagstaff. Loro :/; Green Jillian; Lane, Terran

    2011-01-01

    Traditionally, nodes in a sensor network simply collect data and then pass it on to a centralized node that archives, distributes, and possibly analyzes the data. However, analysis at the individual nodes could enable faster detection of anomalies or other interesting events, as well as faster responses such as sending out alerts or increasing the data collection rate. There is an additional opportunity for increased performance if individual nodes can communicate directly with their neighbors. Previously, a method was developed by which machine learning classification algorithms could collaborate to achieve high performance autonomously (without requiring human intervention). This method worked for supervised learning algorithms, in which labeled data is used to train models. The learners collaborated by exchanging labels describing the data. The new advance enables clustering algorithms, which do not use labeled data, to also collaborate. This is achieved by defining a new language for collaboration that uses pair-wise constraints to encode useful information for other learners. These constraints specify that two items must, or cannot, be placed into the same cluster. Previous work has shown that clustering with these constraints (in isolation) already improves performance. In the problem formulation, each learner resides at a different node in the sensor network and makes observations (collects data) independently of the other learners. Each learner clusters its data and then selects a pair of items about which it is uncertain and uses them to query its neighbors. The resulting feedback (a must and cannot constraint from each neighbor) is combined by the learner into a consensus constraint, and it then reclusters its data while incorporating the new constraint. A strategy was also proposed for cleaning the resulting constraint sets, which may contain conflicting constraints; this improves performance significantly. This approach has been applied to collaborative

  7. Estudio del impacto ambiental de medicamentos de control especial en Bogotá, Colombia. Caso de estudio: Lorazepam

    Directory of Open Access Journals (Sweden)

    Ibeth Eileen López

    2016-01-01

    Full Text Available El aumento de la población y la cobertura de los sistemas de salud, así como el crecimiento del mercado farmacéutico, ha dado lugar a la presencia de una nueva generación de residuos peligrosos, que no habían sido considerados como tal. En Colombia, no se han realizado suficientes estudios relacionados con el impacto ambiental ocasionado por la disposición final de medicamentos, porque no existen cifras disponibles acerca de la cantidad depositada diariamente en rellenos sanitarios, destruida en plantas gestoras de residuos peligrosos o encontrada en plantas de tratamiento de aguas residuales. Se encontró en esta investigación que sólo en Bogotá, se destruyen en promedio anualmente 9.310.123 unidades farmacéuticas de productos de control especial, sin considerar las unidades desechadas a nivel doméstico. Para estudiar el impacto ambiental, se seleccionó el principio activo lorazepam, la información sobre la cantidad del medicamento consumida y destruida en plantas gestoras de residuos peligrosos en la ciudad de Bogotá, durante los años 2012 y 2013, fue aportada por el Fondo Nacional de Estupefacientes. Los datos fueron evaluados utilizando la matriz de Leopold, software especializado y ensayos de laboratorio complementarios. Este estudio pretende sensibilizar a fabricantes, prescriptores y pacientes sobre la responsabilidad ambiental en el uso de medicamentos de control especial.

  8. Estudio de Recursos Humanos del Sector Salud en Colombia.

    Directory of Open Access Journals (Sweden)

    Gustavo Malagón Londoño

    1997-12-01

    Full Text Available

    Antecedentes


    Siendo el recurso humano el en cargado de movilizar los demás recursos e impulsarlos de tal manera que conlleve a una dinámica de producción masiva de bienes o servicios, su estudio para llegar a una identificación real, categorización, clasificación; es necesario en cualquier área del conocimiento.

    Frente al nuevo esquema de prestación de servicios propuestos, los profesionales de la salud han perdido aquella posición digna, de respeto y liderazgo dentro del sistema y dentro de su entorno social, lo cual ha llevado a muchos de ellos a desertar de sus oficios originales, con lo cual se llega a la falla en la instauración del Sistema.

    Así mismo la Ley 100 de 1993 que debió ser vista como una nueva oportunidad de negocios dentro de las diferentes profesiones de la salud, se transformó en una seria amenaza para el ejercicio independiente de cada profesión.

    No es apropiado ni satisfactorio dejar un proceso decisorio de tal magnitud en manos de otros sectores que únicamente verán y obtendrán estadísticas del acceso de la población colombiana a estudios superiores y los renglones en los cuales quieren desempeñarse y se desempeñarán en un futuro. El sector de la salud debe tomar un claro papel protagónico frente a la promulgación de políticas de formación y utilización de su recurso humano.

    La Academia Nacional de Medicina consciente del vacío existente en el sector con respecto al tema, ha querido desde su posición estratégica con respecto a las profesiones del área y las universidades, liderar un proceso que conlleve a la organización de un Estudio del recurso humano del Sector Salud en Colombia, tomando como punto de partida el censo de los trabajadores de la salud en todas las áreas, de tal manera que se identifique su disponibilidad, su capacidad, la ubicación, las facilidades laborales en zonas aisladas y su grado de satisfacción, entre otras

  9. Properties of the open cluster system

    International Nuclear Information System (INIS)

    Janes, K.A.; Tilley, C.; Lynga, G.

    1988-01-01

    A system of weights corresponding to the precision of open cluster data is described. Using these weights, some properties of open clusters can be studied more accurately than was possible earlier. It is clear that there are three types of objects: unbound clusters, bound clusters in the thin disk, and older bound clusters. Galactic gradients of metallicity, longevity, and linear diameter are studied. Distributions at right angles to the galactic plane are discussed in the light of the different cluster types. The clumping of clusters in complexes is studied. An estimate of the selection effects influencing the present material of open cluster data is made in order to evaluate the role played by open clusters in the history of the galactic disk. 58 references

  10. A COMPARISON OF TWO FUZZY CLUSTERING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Samarjit Das

    2013-10-01

    Full Text Available - In fuzzy clustering, unlike hard clustering, depending on the membership value, a single object may belong exactly to one cluster or partially to more than one cluster. Out of a number of fuzzy clustering techniques Bezdek’s Fuzzy C-Means and GustafsonKessel clustering techniques are well known where Euclidian distance and Mahalanobis distance are used respectively as a measure of similarity. We have applied these two fuzzy clustering techniques on a dataset of individual differences consisting of fifty feature vectors of dimension (feature three. Based on some validity measures we have tried to see the performances of these two clustering techniques from three different aspects- first, by initializing the membership values of the feature vectors considering the values of the three features separately one at a time, secondly, by changing the number of the predefined clusters and thirdly, by changing the size of the dataset.

  11. Cluster Analysis of Maize Inbred Lines

    Directory of Open Access Journals (Sweden)

    Jiban Shrestha

    2016-12-01

    Full Text Available The determination of diversity among inbred lines is important for heterosis breeding. Sixty maize inbred lines were evaluated for their eight agro morphological traits during winter season of 2011 to analyze their genetic diversity. Clustering was done by average linkage method. The inbred lines were grouped into six clusters. Inbred lines grouped into Clusters II had taller plants with maximum number of leaves. The cluster III was characterized with shorter plants with minimum number of leaves. The inbred lines categorized into cluster V had early flowering whereas the group into cluster VI had late flowering time. The inbred lines grouped into the cluster III were characterized by higher value of anthesis silking interval (ASI and those of cluster VI had lower value of ASI. These results showed that the inbred lines having widely divergent clusters can be utilized in hybrid breeding programme.

  12. Chaos theory perspective for industry clusters development

    Science.gov (United States)

    Yu, Haiying; Jiang, Minghui; Li, Chengzhang

    2016-03-01

    Industry clusters have outperformed in economic development in most developing countries. The contributions of industrial clusters have been recognized as promotion of regional business and the alleviation of economic and social costs. It is no doubt globalization is rendering clusters in accelerating the competitiveness of economic activities. In accordance, many ideas and concepts involve in illustrating evolution tendency, stimulating the clusters development, meanwhile, avoiding industrial clusters recession. The term chaos theory is introduced to explain inherent relationship of features within industry clusters. A preferred life cycle approach is proposed for industrial cluster recessive theory analysis. Lyapunov exponents and Wolf model are presented for chaotic identification and examination. A case study of Tianjin, China has verified the model effectiveness. The investigations indicate that the approaches outperform in explaining chaos properties in industrial clusters, which demonstrates industrial clusters evolution, solves empirical issues and generates corresponding strategies.

  13. Star formation and substructure in galaxy clusters

    International Nuclear Information System (INIS)

    Cohen, Seth A.; Hickox, Ryan C.; Wegner, Gary A.; Einasto, Maret; Vennik, Jaan

    2014-01-01

    We investigate the relationship between star formation (SF) and substructure in a sample of 107 nearby galaxy clusters using data from the Sloan Digital Sky Survey. Several past studies of individual galaxy clusters have suggested that cluster mergers enhance cluster SF, while others find no such relationship. The SF fraction in multi-component clusters (0.228 ± 0.007) is higher than that in single-component clusters (0.175 ± 0.016) for galaxies with M r 0.1 <−20.5. In both single- and multi-component clusters, the fraction of star-forming galaxies increases with clustercentric distance and decreases with local galaxy number density, and multi-component clusters show a higher SF fraction than single-component clusters at almost all clustercentric distances and local densities. Comparing the SF fraction in individual clusters to several statistical measures of substructure, we find weak, but in most cases significant at greater than 2σ, correlations between substructure and SF fraction. These results could indicate that cluster mergers may cause weak but significant SF enhancement in clusters, or unrelaxed clusters exhibit slightly stronger SF due to their less evolved states relative to relaxed clusters.

  14. Innovation performance and clusters : a dynamic capability perspective on regional technology clusters

    NARCIS (Netherlands)

    Röttmer, Nicole

    2009-01-01

    This research provides a novel, empirically tested, actionable theory of cluster innovativeness. Cluster innovativeness has for long been subject of research and resulting policy efforts. The cluster's endowment with assets, such as specialized labor, firms, research institutes, existing regional

  15. Cluster-cluster aggregation of Ising dipolar particles under thermal noise

    KAUST Repository

    Suzuki, Masaru; Kun, Ferenc; Ito, Nobuyasu

    2009-01-01

    The cluster-cluster aggregation processes of Ising dipolar particles under thermal noise are investigated in the dilute condition. As the temperature increases, changes in the typical structures of clusters are observed from chainlike (D1

  16. PFI-ZEKE (Pulsed Field Ionization-Zero Electron Kinetic Energy) para el estudio de iones

    Science.gov (United States)

    Castaño, F.; Fernández, J. A.; Basterretxea, A. Longarte. F.; Sánchez Rayo, M. N.; Martínez, R.

    descubierta, que va en contra de lo esperado en otros sistemas físicos y que consiste en que los altos estados Rydberg de átomos, moléculas y sus complejos de van der Waals (o de los iones) tienen tiempos de vida de centenas de μ s. En resumen, el experimento y la espectroscopía ZEKE consiste en excitar un átomo, molécula o cluster sucesivamente a dos estados excitados selectivos de manera que el final sea un estado Rydberg. A continuación se aplica un campo eléctrico variable que lo ioniza y después de un cierto retraso se aplica un campo eléctrico de extracción, tanto para el electrón como para el ión. El espectro de los iones, es un espectro ZEKE. Hay varias alternativas para hacer este último proceso. El estudio de la espectroscopía y propiedades de iones y sus clusters requiere el conocimiento detallado de la espectroscopía de la molécula neutra, los estados Rydberg, de los confórmeros y sus complejos. Todo ello implica el haber estudiado los sistemas por LIF, REMPI y doble resonancia (hole burning IR-UV, UV-UV). Además solo es posible interpretar los resultados y obtener la información contenida en los espectros con ayuda de cálculos cuánticos ab initio. Hasta el momento hemos aplicado tanto el ZEKE como el conjunto de técnicas mencionadas anteriormente, a varias molécula de interés químico general como anilina y sus derivados, así como sus complejos con agua y amoniaco. Sin embargo, el método es muy versátil y puede aplicarse a iones de átomos, iones múltiples, moléculas sencillas y sus clusters así como a sus semi-reacciones. Como ejemplo de uno de estos espectros PFI-ZEKE se presenta aquí el caso del amonibenzonitrilo, ABN y solamente en su estado fundamental. En la conferencia se presentarán espectros ZEKE del ABN y moléculas similares en estados vibracionales intermedios (islas de estabilidad), así como la determinación de potenciales de ionización precisos, energías de enlace de compuestos del ión con varios disolventes y

  17. Innovation, learning and cluster dynamics

    NARCIS (Netherlands)

    B. Nooteboom (Bart)

    2004-01-01

    textabstractThis chapter offers a theory and method for the analysis of the dynamics, i.e. the development, of clusters for innovation. It employs an analysis of three types of embedding: institutional embedding, which is often localized, structural embedding (network structure), and relational

  18. An Improved Cluster Richness Estimator

    Energy Technology Data Exchange (ETDEWEB)

    Rozo, Eduardo; /Ohio State U.; Rykoff, Eli S.; /UC, Santa Barbara; Koester, Benjamin P.; /Chicago U. /KICP, Chicago; McKay, Timothy; /Michigan U.; Hao, Jiangang; /Michigan U.; Evrard, August; /Michigan U.; Wechsler, Risa H.; /SLAC; Hansen, Sarah; /Chicago U. /KICP, Chicago; Sheldon, Erin; /New York U.; Johnston, David; /Houston U.; Becker, Matthew R.; /Chicago U. /KICP, Chicago; Annis, James T.; /Fermilab; Bleem, Lindsey; /Chicago U.; Scranton, Ryan; /Pittsburgh U.

    2009-08-03

    Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the L{sub X}-richness relation, from {sigma}{sub lnL{sub X}}{sup 2} = (0.86 {+-} 0.02){sup 2} to {sigma}{sub lnL{sub X}}{sup 2} = (0.69 {+-} 0.02){sup 2}. Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to our more sophisticated treatment of galaxy color data. We also demonstrate the scatter in the L{sub X}-richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can be easily generalized to other mass tracers.

  19. Clustering Teachers' Motivations for Teaching

    Science.gov (United States)

    Visser-Wijnveen, Gerda J.; Stes, Ann; Van Petegem, Peter

    2014-01-01

    The motivation to teach is a powerful, yet neglected, force in teaching at institutes of higher education. A better understanding of academics' motivations for teaching is necessary. The aim of this mixed-method study was to identify groups with distinctively different motivations for teaching. Six clusters were identified: expertise, duty,…

  20. Clusters of Pneumocystis carinii pneumonia

    DEFF Research Database (Denmark)

    Helweg-Larsen, J; Tsolaki, A G; Miller, Raymonde

    1998-01-01

    Genotyping at the internal transcribed spacer (ITS) regions of the nuclear rRNA operon was performed on isolates of P. carinii sp. f. hominis from three clusters of P. carinii pneumonia among eight patients with haematological malignancies and six with HIV infection. Nine different ITS sequence...

  1. Fission approach to cluster radioactivity

    Indian Academy of Sciences (India)

    2015-08-04

    Aug 4, 2015 ... Also, the analytical superasymmetric fission (ASAF) model is successfully employed to make a systematic search and to predict, with other models, cluster ... those of the staff, the journals, various programmes, and Current Science, has changed from 'ias.ernet.in' (or 'academy.ias.ernet.in') to 'ias.ac.in'. Thus ...

  2. Metalloid Aluminum Clusters with Fluorine

    Science.gov (United States)

    2016-12-01

    metal clusters containing Al4 units. The Al4 was evaluated when attached to an alkaline or transitional metals, namely Na, Li, Be, Cu and Zn. Mandado...i i i n r r r   and therefore the dimensionality goes as 3 3N . This changes the problem to a many one electron problem. Recall that

  3. Agglomerative clustering of growing squares

    NARCIS (Netherlands)

    Castermans, Thom; Speckmann, Bettina; Staals, Frank; Verbeek, Kevin; Bender, M.A.; Farach-Colton, M.; Mosteiro, M.A.

    2018-01-01

    We study an agglomerative clustering problem motivated by interactive glyphs in geo-visualization. Consider a set of disjoint square glyphs on an interactive map. When the user zooms out, the glyphs grow in size relative to the map, possibly with different speeds. When two glyphs intersect, we wish

  4. The Cluster as Market Organization

    DEFF Research Database (Denmark)

    Maskell, Peter; Lorenzen, Mark

    2003-01-01

    by any common ownership or management. So hierarchies they are certainly not.Yet, it is usually taken for granted that clusters, almost regardless of how they are defined, allexpatriate the 'swollen middle' of various hybrid 'forms of long-term contracting, reciprocaltrading, regulation, franchising...

  5. Projection-based curve clustering

    International Nuclear Information System (INIS)

    Auder, Benjamin; Fischer, Aurelie

    2012-01-01

    This paper focuses on unsupervised curve classification in the context of nuclear industry. At the Commissariat a l'Energie Atomique (CEA), Cadarache (France), the thermal-hydraulic computer code CATHARE is used to study the reliability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code is quite complex and CPU time-consuming, it has to be approximated by a regression model. This regression process involves a clustering step. In the present paper, the CATHARE output curves are clustered using a k-means scheme, with a projection onto a lower dimensional space. We study the properties of the empirically optimal cluster centres found by the clustering method based on projections, compared with the 'true' ones. The choice of the projection basis is discussed, and an algorithm is implemented to select the best projection basis among a library of orthonormal bases. The approach is illustrated on a simulated example and then applied to the industrial problem. (authors)

  6. The state and creative clusters

    DEFF Research Database (Denmark)

    Vang, Jan; Jakobsen, Hannes

    2013-01-01

    creative industries, especially film industries outside Hollywood. Based on an original empirical study of the Danish film cluster we show how it has emerged almost from scratch and positioned itself as a noteworthy player on the global scene industry during the last 20 years. Special attention is paid...

  7. Cluster structure of light nuclei

    Science.gov (United States)

    Iachello, Francesco

    2018-02-01

    Matter and charge densities of kα structures with k=2 (8Be), k=3 (12C) and k=4 (16O) calculated within the framework of the algebraic cluster model (ACM) are briefly reviewed and explicitly displayed. Their parameters are determined from a comparison with electron scattering data.

  8. Geometric structure of percolation clusters.

    Science.gov (United States)

    Xu, Xiao; Wang, Junfeng; Zhou, Zongzheng; Garoni, Timothy M; Deng, Youjin

    2014-01-01

    We investigate the geometric properties of percolation clusters by studying square-lattice bond percolation on the torus. We show that the density of bridges and nonbridges both tend to 1/4 for large system sizes. Using Monte Carlo simulations, we study the probability that a given edge is not a bridge but has both its loop arcs in the same loop and find that it is governed by the two-arm exponent. We then classify bridges into two types: branches and junctions. A bridge is a branch iff at least one of the two clusters produced by its deletion is a tree. Starting from a percolation configuration and deleting the branches results in a leaf-free configuration, whereas, deleting all bridges produces a bridge-free configuration. Although branches account for ≈43% of all occupied bonds, we find that the fractal dimensions of the cluster size and hull length of leaf-free configurations are consistent with those for standard percolation configurations. By contrast, we find that the fractal dimensions of the cluster size and hull length of bridge-free configurations are given by the backbone and external perimeter dimensions, respectively. We estimate the backbone fractal dimension to be 1.643 36(10).

  9. Dairy cluster design for Myanmar

    NARCIS (Netherlands)

    Zijlstra, J.; Lee, van der J.

    2015-01-01

    At the request of the Dutch and Myanmar governments, a project team consisting of researchers from Wageningen University & Research centre and experts from dairy processor Royal FrieslandCampina, feed company Royal De Heus and AgriWorks consultancy have developed a design for a dairy cluster in

  10. Clustering problems for geochemical data

    International Nuclear Information System (INIS)

    Kane, V.E.; Larson, N.M.

    1977-01-01

    The Union Carbide Corporation, Nuclear Division, Uranium Resource Evaluation Project uses a two-stage sampling program to identify potential uranium districts. Cluster analysis techniques are used in locating high density sampling areas as well as in identifying potential uranium districts. Problems are considered involving the analysis of multivariate censored data, laboratory measurement error, and data standardization

  11. Motivic amplitudes and cluster coordinates

    International Nuclear Information System (INIS)

    Golden, J.K.; Goncharov, A.B.; Spradlin, M.; Vergu, C.; Volovich, A.

    2014-01-01

    In this paper we study motivic amplitudes — objects which contain all of the essential mathematical content of scattering amplitudes in planar SYM theory in a completely canonical way, free from the ambiguities inherent in any attempt to choose particular functional representatives. We find that the cluster structure on the kinematic configuration space Conf n (ℙ 3 ) underlies the structure of motivic amplitudes. Specifically, we compute explicitly the coproduct of the two-loop seven-particle MHV motivic amplitude A 7,2 M and find that like the previously known six-particle amplitude, it depends only on certain preferred coordinates known in the mathematics literature as cluster X-coordinates on Conf n (ℙ 3 ). We also find intriguing relations between motivic amplitudes and the geometry of generalized associahedrons, to which cluster coordinates have a natural combinatoric connection. For example, the obstruction to A 7,2 M being expressible in terms of classical polylogarithms is most naturally represented by certain quadrilateral faces of the appropriate associahedron. We also find and prove the first known functional equation for the trilogarithm in which all 40 arguments are cluster X-coordinates of a single algebra. In this respect it is similar to Abel’s 5-term dilogarithm identity

  12. Transportation: Grade 8. Cluster IV.

    Science.gov (United States)

    Calhoun, Olivia H.

    A curriculum guide for grade 8, the document is devoted to the occupational cluster "Transportation." It is divided into five units: surface transportation, interstate transportation, air transportation, water transportation, and subterranean transportation (the Metro). Each unit is introduced by a statement of the topic, the unit's…

  13. Fission approach to cluster radioactivity

    Indian Academy of Sciences (India)

    point Rt = Re + Rd. Here R0 is the radius of the parent nucleus, Re and Rd are the radii. 0. 0.5. 1 ... The standard r.m.s. deviations of log T values for 580 α emitters ... the total of 27 cluster emissions with standard deviations under one order of ...

  14. Symplectic Maps from Cluster Algebras

    Directory of Open Access Journals (Sweden)

    Allan P. Fordy

    2011-09-01

    Full Text Available We consider nonlinear recurrences generated from the iteration of maps that arise from cluster algebras. More precisely, starting from a skew-symmetric integer matrix, or its corresponding quiver, one can define a set of mutation operations, as well as a set of associated cluster mutations that are applied to a set of affine coordinates (the cluster variables. Fordy and Marsh recently provided a complete classification of all such quivers that have a certain periodicity property under sequences of mutations. This periodicity implies that a suitable sequence of cluster mutations is precisely equivalent to iteration of a nonlinear recurrence relation. Here we explain briefly how to introduce a symplectic structure in this setting, which is preserved by a corresponding birational map (possibly on a space of lower dimension. We give examples of both integrable and non-integrable maps that arise from this construction. We use algebraic entropy as an approach to classifying integrable cases. The degrees of the iterates satisfy a tropical version of the map.

  15. Highly reddened Ara cluster revisited

    International Nuclear Information System (INIS)

    Koornneef, J.

    1976-01-01

    New infrared observations in a highly reddened (Asub(V)>12sup(m)) cluster in Ara are presented and discussed. Some of the stars, previously classified as M-type supergiants, exhibit a strong infrared excess to be attributed to thermospheres

  16. Clusters and the Cosmic Web

    NARCIS (Netherlands)

    Weygaert, R. van de

    2006-01-01

    Abstract: We discuss the intimate relationship between the filamentary features and the rare dense compact cluster nodes in this network, via the large scale tidal field going along with them, following the cosmic web theory developed Bond et al. The Megaparsec scale tidal shear pattern is

  17. Clustering semantics for hypermedia presentation

    NARCIS (Netherlands)

    Alberink, M.J.; Rutledge, L.W.; Hardman, H.L.; Veenstra, M.J.A.

    2004-01-01

    Semantic annotations of media repositories make relationships among the stored media and relevant concepts explicit. However, these relationships and the media they join are not directly presentable as hypermedia. Previous work shows how clustering over the annotations in the repositories can

  18. Automated Clustering of Similar Amendments

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The Italian Senate is clogged by computer-generated amendments. This talk will describe a simple strategy to cluster them in an automated fashion, so that the appropriate Senate procedures can be used to get rid of them in one sweep.

  19. Charge exchange in galaxy clusters

    Science.gov (United States)

    Gu, Liyi; Mao, Junjie; de Plaa, Jelle; Raassen, A. J. J.; Shah, Chintan; Kaastra, Jelle S.

    2018-03-01

    Context. Though theoretically expected, the charge exchange emission from galaxy clusters has never been confidently detected. Accumulating hints were reported recently, including a rather marginal detection with the Hitomi data of the Perseus cluster. As previously suggested, a detection of charge exchange line emission from galaxy clusters would not only impact the interpretation of the newly discovered 3.5 keV line, but also open up a new research topic on the interaction between hot and cold matter in clusters. Aim. We aim to perform the most systematic search for the O VIII charge exchange line in cluster spectra using the RGS on board XMM-Newton. Methods: We introduce a sample of 21 clusters observed with the RGS. In order to search for O VIII charge exchange, the sample selection criterion is a >35σ detection of the O VIII Lyα line in the archival RGS spectra. The dominating thermal plasma emission is modeled and subtracted with a two-temperature thermal component, and the residuals are stacked for the line search. The systematic uncertainties in the fits are quantified by refitting the spectra with a varying continuum and line broadening. Results: By the residual stacking, we do find a hint of a line-like feature at 14.82 Å, the characteristic wavelength expected for oxygen charge exchange. This feature has a marginal significance of 2.8σ, and the average equivalent width is 2.5 × 10-4 keV. We further demonstrate that the putative feature can be barely affected by the systematic errors from continuum modeling and instrumental effects, or the atomic uncertainties of the neighboring thermal lines. Conclusions: Assuming a realistic temperature and abundance pattern, the physical model implied by the possible oxygen line agrees well with the theoretical model proposed previously to explain the reported 3.5 keV line. If the charge exchange source indeed exists, we expect that the oxygen abundance could have been overestimated by 8-22% in previous X

  20. Antes de los Estudios Culturales. Robert Warshow y la experiencia

    Directory of Open Access Journals (Sweden)

    Antonio Lastra

    2008-01-01

    Full Text Available Este artículo estudia la influencia del concepto de experiencia que desarrolla Robert Warshow. Warshow ha supuesto el contrapunto americano a las teorías desarrolladas por Walter Benjamien en Europa. Si bien ambos insistieron en la pobreza de la experiencia, como resultado de la tecnificación de la sociedad, Warshow supo introducir matizaciones que influyeron en todo el círculo de intelectuales concentrados en Nueva York durante la etapa de consolidación de los Estudios Culturales. This paper studies the influence of the experience concept by Robert Warshow. Warshow is the American counterpoint to theories developed by Walter Benjamin in Europe. Although both insisted in the poverty of experience, as a result of technique, Warshow knew how to introduce nuances that influenced intellectuals in New York as Cultural Studies emerged.

  1. Tiempo de Respuestas y Experiencia de Usuario Estudio Experimental

    Directory of Open Access Journals (Sweden)

    Delvis Echeverria

    2016-12-01

    Full Text Available La investigación está fundamentada por un estudio experimental, enfocado en la evaluación del comportamiento de los usuarios finales interactuando con tiempos de respuestas en aplicaciones reales. Se tomará como base el aporte de los autores Doherty y Thadani, investigadores de IBM relacionado con los tiempos de respuestas, y las investigaciones de Jacob Nielsen. Se llevarán a cabo un test con usuarios finales, y se expondrán optimizaciones a través de del uso de herramientas que contribuirán a mejorar los tiempos de respuestas de las aplicaciones web. Todo esto engloba una primera instancia de un proyecto que se está llevando a cabo en la empresa GeneXus Consulting, pretendiéndose lograr un punto de encuentro entre el rendimiento de las aplicaciones y la experiencia de usuario.

  2. Primeros resultados sobre el estudio de oscilaciones no radiales

    Science.gov (United States)

    Córsico, A.; Benvenuto, O. G.

    En el Observatorio de La Plata se ha comenzado a elaborar un código de pulsaciones el cual resuelve el problema de las oscilaciones no radiales en el caso adiabático. Dicho código está basado en la técnica de diferencias finitas ampliamente usado en cálculos de estructura y evolución estelar. En este trabajo se presentan los primeros resultados encontrados aplicando el código mencionado al caso de una polítropa de índice n=3. Se presentan los valores de las autofrecuencias y las autofunciones para diferentes modos de pulsación de dicha configuración politrópica. En un futuro próximo, se aplicará este programa al estudio de las pulsaciones no radiales de estrellas enanas blancas.

  3. Estudios inmunologicos en hamsters (Cricetus auratus infectados con Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Eduardo Monge

    1986-08-01

    Full Text Available Los resultados de este trabajo muestran que el hamster (Cricetus auratus puede ser utilizado como un modelo experimental para estudios inmunológicos en la infección por Schistosoma mansoni. Los datos obtenidos, relativos a inmunidad concomitante, producción de anticuerpo letal e inmunosupresión se asemejan a los conseguidos en otros modelos experimentales ya establecidos. Estas observaciones indican que el hámster, además de ser un hospedero satisfactorio para el mantenimiento del parásito en el laboratorio, puede ser considerado como un modelo experimental alterno cuyo crecimiento y mantenimiento son relativamente simples y además es un animal de fácil manejo.

  4. Gordailu, Centro de Patrimonio Cultural Mueble de Gipuzkoa. Estudios previos

    Directory of Open Access Journals (Sweden)

    Maite Barrio Olano

    2009-08-01

    Full Text Available La Diputación Foral de Gipuzkoa ha impulsado la creación de una nueva infraestructura cultural: el Centro de Patrimonio Cultural Mueble de Gipuzkoa, denominado Gordailu (palabra en euskera cuyo significado es “depósito”. Este Centro tendrá como misión la gestión integral del patrimonio cultural mueble del territorio, partiendo de un núcleo central, el depósito in situ de colecciones de distinta titularidad. Dentro de la variedad de temas de estudio y análisis que implica un proyecto de esta envergadura, en el presente artículo se relatan los relativos al plan de necesidades, evaluación de colecciones y definición de condiciones medioambientales.

  5. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    Science.gov (United States)

    Arnal, E. M.; Cappa, C.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de 21-cm del Hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100 micrones, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5 Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  6. El abandono en las etapas iniciales de los estudios superiores

    Directory of Open Access Journals (Sweden)

    Norma Zandomeni

    2016-01-01

    Full Text Available En este artículo se presenta una investigación sobre abandono de los estudios superiores realizada en una universidad argentina. Con un abordaje metodológico cuanti-cualitativo, se analizan datos secundarios y se recupera la perspectiva de distintos actores mediante talleres, encuestas y entrevistas. Se aborda el abandono que se produce en el proceso del ingreso y el generado en los dos primeros años, tanto en su cuantificación como en los factores que operan en el mismo. En el primer caso el abandono se asocia principalmente a factores exógenos a la institución mientras que en el segundo toman fuerza factores internos a la universidad.

  7. El experimento formativo en el estudio del lenguaje egocentrico

    OpenAIRE

    Rosalía Montealegre

    1998-01-01

    Este escrito analiza dos métodos experimentales: el genético-modelador y el estadístico (método de evaluación cuantitativa) en el estudio de lenguaje egocéntrico como regulador y planificador de la acción en el niño. Se presentan unas retlexiones teóricas sobre los métodos y su empleo en la investigación realizada por la autora en la Universidad Estatal de Moscú sobre «El papel del lenguaje en la solución de tareas espaciales por niños de edad preescolar». A diferencia de la...

  8. Estudio comparativo del desarrollo de las inteligencias múltiples en alumnos que cursan o no estudios de danza en un conservatorio

    OpenAIRE

    Athanassopoulos-Zamorano, Néstor

    2015-01-01

    El objetivo de este trabajo es analizar si al comparar dos grupos de estudiantes, formados por alumnos que cursan estudios de danza en el conservatorio y alumnos que no los cursan, existen diferencias estadísticamente significativas en las Inteligencias Múltiples. La muestra total del estudio está compuesta por 175 personas, conformando dos grandes grupos, alumnos que estudian danza de manera oficial y alumnos que no estudian danza de manera oficial. Para conocer el nivel de las Inteligenc...

  9. Estudio de preformulación del citrato de dietilcarbamazina

    Directory of Open Access Journals (Sweden)

    Rafael León Rodríguez

    1999-08-01

    Full Text Available Se realizó el estudio de preformulación del citrato de dietilcarbamazina con el objetivo de conocer las características físico-químicas y tecnológicas de este fármaco para el posterior desarrollo de una tableta de 50 mg de dosis, el cual incluyó la determinación del tamaño de partícula micronizada y sin micronizar según el método de microscopia óptica, de manera que quedó demostrado la influencia que presenta éste en la disolución del fármaco in vitro. Se efectuó el estudio de incompatibilidad principio activo-excipientes mediante el método de calorimetría diferencial de barrido; no se encontró ninguna interacción entre éstos, en las condiciones de trabajo experimentales. Se estudiaron otras propiedades físico-químicas y tecnológicas del fármaco.The study of diethycarbamazine citrate preformulation with a view to finding uot the physico - chemical and tachnological characteristics of this pharmaceutical for further production of a 50 mg tablet was performed. This study included the determination of the size of micronized and non-micronized particles by optical microscopy in which the influence of size on the pharmaceutical dissolving in vitro was shown. Drug - excipient incompatibility was analysed using differential scannig calorimetry and no interaction was found under experimental working conditions. Other physico-chemical & technological properties of this pharmaceutical were examined.

  10. Un estudio exploratorio de capacidades emocionales en adultos mayores

    Directory of Open Access Journals (Sweden)

    Zoe S. Bello Dávila

    2012-01-01

    Full Text Available Abstract The study of the emotional world of the elderly is a fundamental requisite for guaranteeing the well-being and health of this group. The objective of this research paper was to characterize a group of elderly people according to their motional capabilities. The group consisted of 122 elderly persons: 107 female, 15 male. All attendants participated in a “Círculo de Abuelos” (Circle of Grandparents. The study was descriptive, it sought to gather information about the responses of older adults in situations of emotional content by completing a questionnaire. The results provided a profile of capacities where areas of strength and weakness are clearly distinguished. Selfconfidence and the possibility of fulfilling projects are among the strengths while the weaknesses are found in interpersonal or intrapersonal managing of emotions. These results have led to a better understanding of the emotional world of the elderly and guide future educational activities. Resumen El estudio del mundo emocional de los adultos mayores es un requisito fundamental para garantizar el estado de bienestar y salud de los mismos. El presente artículo de investigación se fijó como objetivo caracterizar a un grupo de ancianos, en función de sus capacidades emocionales. Los participantes fueron 122 ancianos, en concreto 107 mujeres y 15 hombres, que asisten a un “Círculo de Abuelos”. El estudio fue de tipo descriptivo, pues pretendió recoger información acerca de las respuestas de los adultos mayores ante situaciones de contenido emocional que se exploran por medio de un cuestionario elaborado al efecto. Los resultados ofrecen un perfil de capacidades en que la autoconfianza y la posibilidad de elaborar proyectos se erigen como fortalezas, mientras que las debilidades se expresan en las dificultades para el manejo emocional tanto a nivel intra como interpersonal. Estos resultados han permitido lograr una mejor comprensión del mundo emocional del

  11. Progressive Exponential Clustering-Based Steganography

    Directory of Open Access Journals (Sweden)

    Li Yue

    2010-01-01

    Full Text Available Cluster indexing-based steganography is an important branch of data-hiding techniques. Such schemes normally achieve good balance between high embedding capacity and low embedding distortion. However, most cluster indexing-based steganographic schemes utilise less efficient clustering algorithms for embedding data, which causes redundancy and leaves room for increasing the embedding capacity further. In this paper, a new clustering algorithm, called progressive exponential clustering (PEC, is applied to increase the embedding capacity by avoiding redundancy. Meanwhile, a cluster expansion algorithm is also developed in order to further increase the capacity without sacrificing imperceptibility.

  12. Co-clustering models, algorithms and applications

    CERN Document Server

    Govaert, Gérard

    2013-01-01

    Cluster or co-cluster analyses are important tools in a variety of scientific areas. The introduction of this book presents a state of the art of already well-established, as well as more recent methods of co-clustering. The authors mainly deal with the two-mode partitioning under different approaches, but pay particular attention to a probabilistic approach. Chapter 1 concerns clustering in general and the model-based clustering in particular. The authors briefly review the classical clustering methods and focus on the mixture model. They present and discuss the use of different mixture

  13. Super computer made with Linux cluster

    International Nuclear Information System (INIS)

    Lee, Jeong Hun; Oh, Yeong Eun; Kim, Jeong Seok

    2002-01-01

    This book consists of twelve chapters, which introduce super computer made with Linux cluster. The contents of this book are Linux cluster, the principle of cluster, design of Linux cluster, general things for Linux, building up terminal server and client, Bear wolf cluster by Debian GNU/Linux, cluster system with red hat, Monitoring system, application programming-MPI, on set-up and install application programming-PVM, with PVM programming and XPVM application programming-open PBS with composition and install and set-up and GRID with GRID system, GSI, GRAM, MDS, its install and using of tool kit

  14. Estudio epidemiológico de la dermatitis atópica desde la farmacia comunitaria: Estudio DAFAC

    Directory of Open Access Journals (Sweden)

    Moreno P.

    2014-03-01

    Full Text Available Objetivos: Diseñar y evaluar la utilidad de un protocolo de actuación del farmacéutico comunitario ante las consultas realizadas sobre dermatitis atópica en la farmacia comunitaria, acordando con dermatólogos los criterios de derivación. Conocer los motivos de consulta más habituales y determinar en qué casos constituyen motivo de derivación al médico. Métodos: Estudio epidemiológico realizado en farmacias comunitarias españolas entre febrero del 2011 y enero del 2012. Se incluyeron en el estudio todos los usuarios de las farmacias que consultan un problema de salud dermatológico. Los farmacéuticos participantes, tras recibir formación específica online, aplicaron el protocolo de actuación consensuado. Se registraron los motivos de consulta, los casos de derivación al médico, la existencia de sobreinfecciones, el uso de productos adecuados para el cuidado de la piel. Resultados/Discusión: Participaron 259 farmacéuticos de 15 comunidades autónomas que registraron 688 intervenciones válidas. La distribución por sexo de los pacientes corresponde a 354 (51,5 % de sexo masculino y 334 (48,5 % del femenino, con mayor incidencia de la patología en menores de 14 años. En el 70% de los casos no se requirió la derivación al dermatólogo. Motivos de consulta: prurito, irritación, dificultad para dormir, ansiedad y estrés, y sobreinfección (35%, principal causa de derivación. La elaboración y difusión del protocolo y criterios de derivación, así como los resultados del estudio a los socios de SEFAC (Sociedad Española de Farmacia Comunitaria y al resto de farmacéuticos comunitarios permitirán la resolución de muchos de los casos de dermatitis atópica, contribuyendo así a la mejora de la calidad de vida del paciente.

  15. Modelo de estudio de dos informativas familias colombianas con Síndrome de Usher

    Directory of Open Access Journals (Sweden)

    C. González

    2001-07-01

    Full Text Available Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

  16. Modelo de estudio de dos informativas familias colombianas con Síndrome de Usher

    OpenAIRE

    Tamayo ML.; González C.; Gelvez N.

    2001-01-01

    Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

  17. Electricity Consumption Clustering Using Smart Meter Data

    Directory of Open Access Journals (Sweden)

    Alexander Tureczek

    2018-04-01

    Full Text Available Electricity smart meter consumption data is enabling utilities to analyze consumption information at unprecedented granularity. Much focus has been directed towards consumption clustering for diversifying tariffs; through modern clustering methods, cluster analyses have been performed. However, the clusters developed exhibit a large variation with resulting shadow clusters, making it impossible to truly identify the individual clusters. Using clearly defined dwelling types, this paper will present methods to improve clustering by harvesting inherent structure from the smart meter data. This paper clusters domestic electricity consumption using smart meter data from the Danish city of Esbjerg. Methods from time series analysis and wavelets are applied to enable the K-Means clustering method to account for autocorrelation in data and thereby improve the clustering performance. The results show the importance of data knowledge and we identify sub-clusters of consumption within the dwelling types and enable K-Means to produce satisfactory clustering by accounting for a temporal component. Furthermore our study shows that careful preprocessing of the data to account for intrinsic structure enables better clustering performance by the K-Means method.

  18. Los estudios longitudinales en la prevención de las enfermedades cardiovasculares

    Directory of Open Access Journals (Sweden)

    Ignacio Balaguer Vintró

    2004-01-01

    Full Text Available Los estudios longitudinales de cohortes bien definidas han contribuido a la identificación de los factores de riesgo de la cardiopatía coronaria y otras complicaciones clínicas de la aterosclerosis. Después de comentar las conclusiones de los estudios de la aterosclerosis experimental y los factores de riesgo sugeridos por el estudio de una serie de infartos de miocardio en adultos jóvenes en comparación con controles apareados, se expone la metodología, el desarrollo y los resultados de los estudios longitudinales realizados en Estados Unidos desde 1949: Twin Cities, Framingham, Pooling Project, Western Collaborative, Puerto Rico, Evans County, NI-HONSAN, San Francisco, Harvard, Bogalusa y CARDIA. Se presta especial atención a las hipótesis propuestas al inicio del estudio de Framingham y a los obstáculos y cambios para continuar el proyecto después de los primeros veinticuatro años. A continuación se expone el Seven Countries Study, ideado y dirigido por Ancel Keys y primer estudio realizado con metodología centralizada en varios países, y los estudios longitudinales realizados en diversos países de Europa: Whitehall, Manresa, París, British Regional, Northwick Park, Caerphilly, Speedwell, PROCAM. Se analiza el papel de los estudios longitudinales en la metodología de los estudios posteriores: hijos e hijas de los participantes en Framingham, estudios longitudinales basados en cuestionarios, estudios de otros posibles factores de riesgo, prevalencia de factores de riesgo en estudios retrospectivos, ensayos de intervención primaria (MRFT, WHO European Collaborative Trial y el de Goteburgo y la participación de los equipos entrenados en el Proyecto MONICA. Se señalan los temas todavía en debate en relación con la metodología y los resultados de los estudios longitudinales: exámenes periódicos de los participantes en las cohortes de los estudios epidemiológicos, cambios en la definición de nuevos casos de accidentes

  19. Cluster Ions and Atmospheric Processes

    Science.gov (United States)

    D'Auria, R.; Turco, R. P.

    We investigate the properties and possible roles of naturally occurring ions under at- mospheric conditions. Among other things, the formation of stable charged molecular clusters represents the initial stages of aerosol nucleation [e.g., Keesee and Castle- man, 1982], while the conversion of vapor to aggregates is the first step in certain atmospheric phase transitions [e.g. Hamill and Turco, 2000]. We analyze the stability and size distributions of common ionic clusters by solving the differential equations describing their growth and loss. The necessary reaction rate coefficients are deter- mined using kinetic and thermodynamic data. The latter are derived from direct labo- ratory measurements of equilibrium constants, from the classical charged liquid drop model applied to large aggregates (i.e., the Thomson model [Thomson, 1906]), and from quantum mechanical calculations of the thermodynamic potentials associated with the cluster structures. This approach allows us to characterize molecular clusters across the entire size range from true molecular species to larger aggregates exhibiting macroscopic behavior [D'Auria, 2001]. Cluster systems discussed in this talk include the proton hydrates (PHs) and nitrate-water and nitrate-nitric acid series [D'Auria and Turco, 2001]. These ions have frequently been detected in the stratosphere and tropo- sphere [e.g., Arnold et al., 1977; Viggiano and Arnold, 1981]. We show how the pro- posed hybrid cluster model can be extended to a wide range of ion systems, including non-proton hydrates (NPHs), mixed-ligand clusters such as nitrate-water-nitric acid and sulfate-sulfuric acid-water, as well as more exotic species containing ammonia, pyridine and other organic compounds found on ions [e.g., Eisele, 1988; Tanner and Eisele, 1991]. References: Arnold, F., D. Krankowsky and K. H. Marien, First mass spectrometric measurements of posi- tive ions in the stratosphere, Nature, 267, 30-32, 1977. D'Auria, R., A study of ionic

  20. Dynamics of rich clusters of galaxies. I. The Coma cluster

    International Nuclear Information System (INIS)

    Kent, S.M.; Gunn, J.E.

    1982-01-01

    The structure and dynamics of the Coma cluster are analyzed using self-consistent equilibrium dynamical models. Observational material for Coma is culled from a variety of sources. Projected surface, density, and velocity-dispersion profiles are derived extending out to a radius of 3 0 from the cluster center, which are essentially free from field contamination. Segregation of galaxies by luminosity and morphology are discussed and a quantitative estimate of the latter is made. The method of constructing self-consistent dynamical models is discussed. Four different forms of the distribution function are analyzed allowing for different possible dependences of f on energy and angular momentum. Properties of typical models that might resemble actual clusters are presented, and the importance of having velocity-dispersion information is empha sized. The effect of a central massive object such as a cD galaxy on the core structure is illustrated. A comparison of these models with Coma reveals that only models with a distribution function in which the ratio of tangential to radial velocity dispersions is everywhere constant give acceptable fits. In particular, it is possible to rule out models that have isotropic motions in the core and predominantly radial motions in the halo. For H 0 = 50, the best-fitting models give a total projected mass inside 3 0 of 2.9 x 10 15 M/sub sun/ , a core radius of 340--400 kpc (8.5'--10'), an upper limit to any central massive object of approx.10 13 M/sub sun/ , and a mass-to-blue-light ratio of M/L = 181. From cosmological considerations the cluster ''edge'' is determined to lie at rapprox.5 0 --6 0 . The possible distribution of ''dark matter'' in Coma is discussed and it is argued that this distribution cannot be significantly different from that of the galaxies. The dynamics of morphological segregation are examined quantitatively, and are explained at least qualitatively

  1. Centro de Estudios para el Desarrollo Rural Sustentable y la Soberanía Alimentaria (CEDRSSA. Estudios e investigaciones: nueva ruralidad; enfoques y propuestas para América Latina

    Directory of Open Access Journals (Sweden)

    Rosa Inés Babilonia Ballesteros

    2014-01-01

    Full Text Available Centro de Estudios para el Desarrollo Rural Sustentable y la Soberanía Alimentaria (CEDRSSA. Estudios e investigaciones:nueva ruralidad; enfoques y propuestas para América Latina.

  2. Cluster concept in multiple hadron production

    International Nuclear Information System (INIS)

    Dremin, I.M.; Quigg, C.

    1978-01-01

    The general features of high-energy collisions of elementary particles are outlined. It is argued that multiple production occurs through the production of hadronic clusters. The history and present status of the cluster concept are surveyed

  3. Facilitating Cluster Evolution in Peripheral Regions

    DEFF Research Database (Denmark)

    Christensen, Jesper Lindgaard; Stoerring, Dagmara

    2012-01-01

    This paper discusses the feasibility and dilemmas in stimulating high-tech clusters in peripheral regions. In recent years innovation and cluster policy to a large extend has been focused upon stimulating collective learning processes and building social capital. This has in turn accentuated a need...... to focus on the carriers of the cluster policy. Despite this importance of the role of policy actors, research in cluster development and even cluster policy has generally not emphasized a more precise specification of this role. This paper contributes to this debate by substantiating the concept...... of “clusterpreneurs” defined as important actors in cluster formation. We illustrate the role of clusterpreneurs by the example of a biomedical technology cluster initiative in North Jutland, Denmark and point to the presence of different types of dilemmas connected with cluster policy. We show how the presence...

  4. Frequent Pattern Mining Algorithms for Data Clustering

    DEFF Research Database (Denmark)

    Zimek, Arthur; Assent, Ira; Vreeken, Jilles

    2014-01-01

    that frequent pattern mining was at the cradle of subspace clustering—yet, it quickly developed into an independent research field. In this chapter, we discuss how frequent pattern mining algorithms have been extended and generalized towards the discovery of local clusters in high-dimensional data......Discovering clusters in subspaces, or subspace clustering and related clustering paradigms, is a research field where we find many frequent pattern mining related influences. In fact, as the first algorithms for subspace clustering were based on frequent pattern mining algorithms, it is fair to say....... In particular, we discuss several example algorithms for subspace clustering or projected clustering as well as point out recent research questions and open topics in this area relevant to researchers in either clustering or pattern mining...

  5. Cluster-like headache aura status

    NARCIS (Netherlands)

    Langedijk, M; van der Naalt, J; Luijckx, GJ; De Keyser, J

    We describe a patient with successive attacks (40 to 90 minutes) of cluster-like headache associated with aphasia, and contralateral hemihypesthesia and hemiplegia. The condition can best be described as cluster-like headache aura status.

  6. Diskless Linux Cluster How-To

    National Research Council Canada - National Science Library

    Shumaker, Justin L

    2005-01-01

    Diskless linux clustering is not yet a turn-key solution. The process of configuring a cluster of diskless linux machines requires many modifications to the stock linux operating system before they can boot cleanly...

  7. Computational Design of Clusters for Catalysis

    Science.gov (United States)

    Jimenez-Izal, Elisa; Alexandrova, Anastassia N.

    2018-04-01

    When small clusters are studied in chemical physics or physical chemistry, one perhaps thinks of the fundamental aspects of cluster electronic structure, or precision spectroscopy in ultracold molecular beams. However, small clusters are also of interest in catalysis, where the cold ground state or an isolated cluster may not even be the right starting point. Instead, the big question is: What happens to cluster-based catalysts under real conditions of catalysis, such as high temperature and coverage with reagents? Myriads of metastable cluster states become accessible, the entire system is dynamic, and catalysis may be driven by rare sites present only under those conditions. Activity, selectivity, and stability are highly dependent on size, composition, shape, support, and environment. To probe and master cluster catalysis, sophisticated tools are being developed for precision synthesis, operando measurements, and multiscale modeling. This review intends to tell the messy story of clusters in catalysis.

  8. Context-sensitive intra-class clustering

    KAUST Repository

    Yu, Yingwei; Gutierrez-Osuna, Ricardo; Choe, Yoonsuck

    2014-01-01

    This paper describes a new semi-supervised learning algorithm for intra-class clustering (ICC). ICC partitions each class into sub-classes in order to minimize overlap across clusters from different classes. This is achieved by allowing partitioning

  9. Classical Music Clustering Based on Acoustic Features

    OpenAIRE

    Wang, Xindi; Haque, Syed Arefinul

    2017-01-01

    In this paper we cluster 330 classical music pieces collected from MusicNet database based on their musical note sequence. We use shingling and chord trajectory matrices to create signature for each music piece and performed spectral clustering to find the clusters. Based on different resolution, the output clusters distinctively indicate composition from different classical music era and different composing style of the musicians.

  10. Clusters, Connectivity and Catch-up

    DEFF Research Database (Denmark)

    Lorenzen, Mark; Mudambi, Ram

    2013-01-01

    In this article, we make two important contributions to the literature on clusters. First, we provide a broader theory of cluster connectivity that has hitherto focused on organization-based pipelines and MNE subsidiaries, by including linkages in the form of personal relationships. Second, we us...... by contrasting two emerging economy case studies: Bollywood, the Indian filmed entertainment cluster in Mumbai and the Indian software cluster in Bangalore....

  11. The Centaurus cluster of galaxies. Pt. 3

    International Nuclear Information System (INIS)

    Lucey, J.R.; Currie, M.J.; Dickens, R.J.

    1986-05-01

    Previous work by the authors has shown that the Centaurus cluster (α = 12sup(h) 47 delta = -41 0 ) is composed of two velocity components, Cen30 (mean velocity 3000 km s -1 ) and Cen45 (mean velocity 4500 km s -1 ), which very probably lie within one cluster. In this paper the internal structure of the cluster is described and the spatial and velocity distributions of the different galaxy types within the cluster are discussed. (author)

  12. Gene cluster statistics with gene families.

    Science.gov (United States)

    Raghupathy, Narayanan; Durand, Dannie

    2009-05-01

    Identifying genomic regions that descended from a common ancestor is important for understanding the function and evolution of genomes. In distantly related genomes, clusters of homologous gene pairs are evidence of candidate homologous regions. Demonstrating the statistical significance of such "gene clusters" is an essential component of comparative genomic analyses. However, currently there are no practical statistical tests for gene clusters that model the influence of the number of homologs in each gene family on cluster significance. In this work, we demonstrate empirically that failure to incorporate gene family size in gene cluster statistics results in overestimation of significance, leading to incorrect conclusions. We further present novel analytical methods for estimating gene cluster significance that take gene family size into account. Our methods do not require complete genome data and are suitable for testing individual clusters found in local regions, such as contigs in an unfinished assembly. We consider pairs of regions drawn from the same genome (paralogous clusters), as well as regions drawn from two different genomes (orthologous clusters). Determining cluster significance under general models of gene family size is computationally intractable. By assuming that all gene families are of equal size, we obtain analytical expressions that allow fast approximation of cluster probabilities. We evaluate the accuracy of this approximation by comparing the resulting gene cluster probabilities with cluster probabilities obtained by simulating a realistic, power-law distributed model of gene family size, with parameters inferred from genomic data. Surprisingly, despite the simplicity of the underlying assumption, our method accurately approximates the true cluster probabilities. It slightly overestimates these probabilities, yielding a conservative test. We present additional simulation results indicating the best choice of parameter values for data

  13. Orbit Clustering Based on Transfer Cost

    Science.gov (United States)

    Gustafson, Eric D.; Arrieta-Camacho, Juan J.; Petropoulos, Anastassios E.

    2013-01-01

    We propose using cluster analysis to perform quick screening for combinatorial global optimization problems. The key missing component currently preventing cluster analysis from use in this context is the lack of a useable metric function that defines the cost to transfer between two orbits. We study several proposed metrics and clustering algorithms, including k-means and the expectation maximization algorithm. We also show that proven heuristic methods such as the Q-law can be modified to work with cluster analysis.

  14. Clustering with Obstacles in Spatial Databases

    OpenAIRE

    El-Zawawy, Mohamed A.; El-Sharkawi, Mohamed E.

    2009-01-01

    Clustering large spatial databases is an important problem, which tries to find the densely populated regions in a spatial area to be used in data mining, knowledge discovery, or efficient information retrieval. However most algorithms have ignored the fact that physical obstacles such as rivers, lakes, and highways exist in the real world and could thus affect the result of the clustering. In this paper, we propose CPO, an efficient clustering technique to solve the problem of clustering in ...

  15. The detection of neutron clusters

    Energy Technology Data Exchange (ETDEWEB)

    Marques, F.M.; Labiche, M.; Orr, N.A.; Angelique, J.C. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire] [and others

    2001-11-01

    A new approach to the production and detection of bound neutron clusters is presented. The technique is based on the breakup of beams of very neutron-rich nuclei and the subsequent detection of the recoiling proton in a liquid scintillator. The method has been tested in the breakup of {sup 11}Li, {sup 14}Be and {sup 15}B beams by a C target. Some 6 events were observed that exhibit the characteristics of a multi-neutron cluster liberated in the breakup of {sup 14}Be, most probably in the channel {sup 10}Be+{sup 4}n. The various backgrounds that may mimic such a signal are discussed in detail. (author)

  16. Mutation Clusters from Cancer Exome.

    Science.gov (United States)

    Kakushadze, Zura; Yu, Willie

    2017-08-15

    We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

  17. Fragmentation of percolation cluster perimeters

    Science.gov (United States)

    Debierre, Jean-Marc; Bradley, R. Mark

    1996-05-01

    We introduce a model for the fragmentation of porous random solids under the action of an external agent. In our model, the solid is represented by a bond percolation cluster on the square lattice and bonds are removed only at the external perimeter (or `hull') of the cluster. This model is shown to be related to the self-avoiding walk on the Manhattan lattice and to the disconnection events at a diffusion front. These correspondences are used to predict the leading and the first correction-to-scaling exponents for several quantities defined for hull fragmentation. Our numerical results support these predictions. In addition, the algorithm used to construct the perimeters reveals itself to be a very efficient tool for detecting subtle correlations in the pseudo-random number generator used. We present a quantitative test of two generators which supports recent results reported in more systematic studies.

  18. Tuning Properties in Silver Clusters

    KAUST Repository

    Joshi, Chakra Prasad

    2015-07-09

    The properties of Ag nanoclusters are not as well understood as those of their more precious Au cousins. However, a recent surge in the exploration of strategies to tune the physicochemical characteristics of Ag clusters addresses this imbalance, leading to new insights into their optical, luminescence, crystal habit, metal-core, ligand-shell and environmental properties. In this Perspective, we provide an overview of the latest strategies along with a brief introduction of the theoretical framework necessary to understand the properties of silver nanoclusters and the basis for their tuning. The advances in cluster research and the future prospects presented in this Perspective will eventually guide the next large systematic study of nanoclusters, resulting in a single collection of data similar to the periodic table of elements.

  19. Galaxy clustering: a point process

    OpenAIRE

    Hurtado Gil, Lluis

    2016-01-01

    El 'clustering' de galàxies és l'agregació de galàxies en l'universe produida per la força de la gravetat. Les galàxies tendeixen a formar estructures de major tamany tal com 'clusters' o filaments que formen la xarxa còsmica ('Cosmic Web'). Aquesta Estructura a Gran Escala de l'Univers es pot entendre com el resultat de la distribució de galàxies, un procés en el qual totes les galàxies estan subjectes a forces comuns i comparteixen propietats universals. L'anàlisis d'aquesta distribució es ...

  20. Privacy-preserving distributed clustering

    DEFF Research Database (Denmark)

    Erkin, Zekeriya; Veugen, Thijs; Toft, Tomas

    2013-01-01

    with any other entity, including the service provider. Such privacy concerns lead to trust issues between entities, which clearly damages the functioning of the service and even blocks cooperation between entities with similar data sets. To enable joint efforts with private data, we propose a protocol......, or in some cases, information from different databases is pooled to enrich the data so that the merged database can improve the clustering effort. However, in either case, the content of the database may be privacy sensitive and/or commercially valuable such that the owners may not want to share their data...... provider with computations. Experimental results clearly indicate that the work we present is an efficient way of deploying a privacy-preserving clustering algorithm in a distributed manner....

  1. Groups and clusters of galaxies

    International Nuclear Information System (INIS)

    Bijleveld, W.

    1984-01-01

    In this thesis, a correlative study is performed with respect to the radio and X-ray parameters of galaxy clusters and groups of galaxies (Msub(v)-Psub(1.4); Msub(v)-Lsub(x); Lsub(x)-Psub(1.4); R-Msub(v) correlations). Special attention is paid to correlations with cD and elliptical galaxies. It is concluded that in rich clusters massive cD galaxies form; massive galaxies are able to bind a large X-ray halo; strong X-ray emitters fuel their central radio sources at a high rate; the total gas content of groups is low, which implies that the contribution of groups to the total matter density in the universe is small. (Auth.)

  2. Clustering fossils in solid inflation

    Energy Technology Data Exchange (ETDEWEB)

    Akhshik, Mohammad, E-mail: m.akhshik@ipm.ir [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2015-05-01

    In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tenor perturbation induces observable clustering fossils in the form of quadrupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar bispectrum for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with the Planck constraints. Specializing to this allowed range of model parameter we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of the scalar perturbations. We argue that the imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

  3. Tuning Properties in Silver Clusters

    KAUST Repository

    Joshi, Chakra Prasad; Bootharaju, Megalamane Siddaramappa; Bakr, Osman

    2015-01-01

    The properties of Ag nanoclusters are not as well understood as those of their more precious Au cousins. However, a recent surge in the exploration of strategies to tune the physicochemical characteristics of Ag clusters addresses this imbalance, leading to new insights into their optical, luminescence, crystal habit, metal-core, ligand-shell and environmental properties. In this Perspective, we provide an overview of the latest strategies along with a brief introduction of the theoretical framework necessary to understand the properties of silver nanoclusters and the basis for their tuning. The advances in cluster research and the future prospects presented in this Perspective will eventually guide the next large systematic study of nanoclusters, resulting in a single collection of data similar to the periodic table of elements.

  4. Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de lv

    OpenAIRE

    Gullian, Mariel; Rodríguez, Jenny

    2002-01-01

    Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV

  5. Inelastic neutron scattering from clusters

    International Nuclear Information System (INIS)

    Gudel, H.U.

    1985-01-01

    Magnetic excitations in clusters of paramagnetic ions have non-vanishing cross-sections for inelastic neutron scattering (INS). Exchange splittings can be determined, the temperature dependence of exchange can be studied, intra- and intercluster effects can be separated and magnetic form factors determined. INS provides a more direct access to the molecular properties than bulk techniques. Its application is restricted to complexes with no or few (< 10%) hydrogen atoms

  6. Cluster analysis for portfolio optimization

    OpenAIRE

    Vincenzo Tola; Fabrizio Lillo; Mauro Gallegati; Rosario N. Mantegna

    2005-01-01

    We consider the problem of the statistical uncertainty of the correlation matrix in the optimization of a financial portfolio. We show that the use of clustering algorithms can improve the reliability of the portfolio in terms of the ratio between predicted and realized risk. Bootstrap analysis indicates that this improvement is obtained in a wide range of the parameters N (number of assets) and T (investment horizon). The predicted and realized risk level and the relative portfolio compositi...

  7. Bernoulli cluster field: Voronoi tessellations

    Czech Academy of Sciences Publication Activity Database

    Saxl, Ivan; Ponížil, P.

    2002-01-01

    Roč. 47, č. 2 (2002), s. 157-167 ISSN 0862-7940. [Programs and Algorithms of Numerical Mathematics (PANMď00). Lázně Libverda, 12.06.2000-16.06.2000] R&D Projects: GA ČR GA201/99/0269; GA MŠk PG96108 Keywords : cluster point process%Voronoi tessellation%induced tessellation Subject RIV: BE - Theoretical Physics

  8. Metal interactions with boron clusters

    International Nuclear Information System (INIS)

    Grimes, R.N.

    1982-01-01

    This book presents information on the following topics: the structural and bonding features of metallaboranes and metallacarboranes; transition-metal derivatives of nido-boranes and some related species; interactions of metal groups with the octahydrotriborate (1-) anion, B 3 H 8 ; metallaboron cage compounds of the main group metals; closo-carborane-metal complexes containing metal-carbon and metal-boron omega-bonds; electrochemistry of metallaboron cage compounds; and boron clusters with transition metal-hydrogen bonds

  9. Clusters in nonsmooth oscillator networks

    Science.gov (United States)

    Nicks, Rachel; Chambon, Lucie; Coombes, Stephen

    2018-03-01

    For coupled oscillator networks with Laplacian coupling, the master stability function (MSF) has proven a particularly powerful tool for assessing the stability of the synchronous state. Using tools from group theory, this approach has recently been extended to treat more general cluster states. However, the MSF and its generalizations require the determination of a set of Floquet multipliers from variational equations obtained by linearization around a periodic orbit. Since closed form solutions for periodic orbits are invariably hard to come by, the framework is often explored using numerical techniques. Here, we show that further insight into network dynamics can be obtained by focusing on piecewise linear (PWL) oscillator models. Not only do these allow for the explicit construction of periodic orbits, their variational analysis can also be explicitly performed. The price for adopting such nonsmooth systems is that many of the notions from smooth dynamical systems, and in particular linear stability, need to be modified to take into account possible jumps in the components of Jacobians. This is naturally accommodated with the use of saltation matrices. By augmenting the variational approach for studying smooth dynamical systems with such matrices we show that, for a wide variety of networks that have been used as models of biological systems, cluster states can be explicitly investigated. By way of illustration, we analyze an integrate-and-fire network model with event-driven synaptic coupling as well as a diffusively coupled network built from planar PWL nodes, including a reduction of the popular Morris-Lecar neuron model. We use these examples to emphasize that the stability of network cluster states can depend as much on the choice of single node dynamics as it does on the form of network structural connectivity. Importantly, the procedure that we present here, for understanding cluster synchronization in networks, is valid for a wide variety of systems in

  10. Clustering in a quark gas

    International Nuclear Information System (INIS)

    Welke, G.M.; Heiss, W.D.

    1986-01-01

    In an infinite one-dimensional quark gas it is shown that a static color force, which increases at large distance, leads to a density fluctuation in the ground state. A self-consistent mean field can only be found for an effectively attractive quark-quark interaction that increases less than linearly at large distances. For a fixed coupling constant, the clustering disappears at high quark density

  11. Intuitionistic fuzzy aggregation and clustering

    CERN Document Server

    Xu, Zeshui

    2012-01-01

    This book offers a systematic introduction to the clustering algorithms for intuitionistic fuzzy values, the latest research results in intuitionistic fuzzy aggregation techniques, the extended results in interval-valued intuitionistic fuzzy environments, and their applications in multi-attribute decision making, such as supply chain management, military system performance evaluation, project management, venture capital, information system selection, building materials classification, and operational plan assessment, etc.

  12. Entrepreneurial culture in innovative biotech clusters.

    NARCIS (Netherlands)

    Ruel, Hubertus Johannes Maria; Frolova, P.; Groen, Arend J.

    2012-01-01

    This paper presents a study on the determinants of entrepreneurial culture in innovative biotech clusters. A literature review led to the identification of nine determinants. For the empirical study four clusters in Western Europe with a high entrepreneurial culture were selected. Cluster

  13. Clustering Millions of Faces by Identity.

    Science.gov (United States)

    Otto, Charles; Wang, Dayong; Jain, Anil K

    2018-02-01

    Given a large collection of unlabeled face images, we address the problem of clustering faces into an unknown number of identities. This problem is of interest in social media, law enforcement, and other applications, where the number of faces can be of the order of hundreds of million, while the number of identities (clusters) can range from a few thousand to millions. To address the challenges of run-time complexity and cluster quality, we present an approximate Rank-Order clustering algorithm that performs better than popular clustering algorithms (k-Means and Spectral). Our experiments include clustering up to 123 million face images into over 10 million clusters. Clustering results are analyzed in terms of external (known face labels) and internal (unknown face labels) quality measures, and run-time. Our algorithm achieves an F-measure of 0.87 on the LFW benchmark (13 K faces of 5,749 individuals), which drops to 0.27 on the largest dataset considered (13 K faces in LFW + 123M distractor images). Additionally, we show that frames in the YouTube benchmark can be clustered with an F-measure of 0.71. An internal per-cluster quality measure is developed to rank individual clusters for manual exploration of high quality clusters that are compact and isolated.

  14. Scaling in patterns produces by cluster deposition

    DEFF Research Database (Denmark)

    Kyhle, Anders; Sørensen, Alexis Hammer; Oddershede, Lene

    1997-01-01

    Cluster deposition on flat substrates can lead to surprising patterns. This pattern formation can be related either to phenomena taking place at the substrate surface or to dynamics in the cluster beam. We describe the observation of a pattern of particles each being an aggregate of Cu clusters. ...

  15. Water Cluster Leaders Meeting Summary Report 2016

    Science.gov (United States)

    As part of its efforts to support environmental technology innovation clusters, U.S. EPA hosted a Water Technology Innovation Cluster Leaders Meeting on September 25, 2016, in New Orleans, Louisiana. The meeting was an opportunity for cluster leaders from across the globe to meet...

  16. Statistical issues in galaxy cluster cosmology

    DEFF Research Database (Denmark)

    Mantz, Adam; Allen, Steven W.; Rapetti Serra, David Angelo

    2013-01-01

    The number and growth of massive galaxy clusters is a sensitive probe of cosmological structure formation and dark energy. Surveys at various wavelengths can detect clusters to high redshift, but the fact that cluster mass is not directly observable complicates matters, requiring us to simultaneo...

  17. Periodic cluster mutations and related integrable maps

    International Nuclear Information System (INIS)

    Fordy, Allan P

    2014-01-01

    One of the remarkable properties of cluster algebras is that any cluster, obtained from a sequence of mutations from an initial cluster, can be written as a Laurent polynomial in the initial cluster (known as the ‘Laurent phenomenon’). There are many nonlinear recurrences which exhibit the Laurent phenomenon and thus unexpectedly generate integer sequences. The mutation of a typical quiver will not generate a recurrence, but rather an erratic sequence of exchange relations. How do we ‘design’ a quiver which gives rise to a given recurrence? A key role is played by the concept of ‘periodic cluster mutation’, introduced in 2009. Each recurrence corresponds to a finite dimensional map. In the context of cluster mutations, these are called ‘cluster maps’. What properties do cluster maps have? Are they integrable in some standard sense?In this review I describe how integrable maps arise in the context of cluster mutations. I first explain the concept of ‘periodic cluster mutation’, giving some classification results. I then give a review of what is meant by an integrable map and apply this to cluster maps. Two classes of integrable maps are related to interesting monodromy problems, which generate interesting Poisson algebras of functions, used to prove complete integrability and a linearization. A connection to the Hirota–Miwa equation is explained. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Cluster algebras in mathematical physics’. (review)

  18. Graph coarsening and clustering on the GPU

    NARCIS (Netherlands)

    Fagginger Auer, B.O.; Bisseling, R.H.

    2013-01-01

    Agglomerative clustering is an effective greedy way to quickly generate graph clusterings of high modularity in a small amount of time. In an effort to use the power offered by multi-core CPU and GPU hardware to solve the clustering problem, we introduce a fine-grained sharedmemory parallel graph

  19. Local Clusters in a Globalized World

    DEFF Research Database (Denmark)

    Reinau, Kristian Hegner

    Currently there is growing focus on how cluster internal and cluster external relations affect the creation of knowledge in companies placed in clusters. However, the current theories on this topic are too simple and the interplay between internal and external relations is relatively unknown. Thi...

  20. Microassembly using a Cluster of Paramagnetic Microparticles

    NARCIS (Netherlands)

    Khalil, I.S.M.; Brink, F.V; Sardan Sukas, Ö.; Misra, Sarthak

    2013-01-01

    We use a cluster of paramagnetic microparticles to carry out a wireless two-dimensional microassembly operation. A magnetic-based manipulation system is used to control the motion of the cluster under the influence of the applied magnetic fields. Wireless motion control of the cluster is implemented