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Sample records for arbustiva del monte

  1. Historic Hotel Del Monte Herrmann Hall Pocket Tour Guide

    OpenAIRE

    Dudley Knox Library

    2014-01-01

    A visit to the Naval Postgraduate School or Naval Support Activity Monterey provides an opportunity to enjoy the history of Hotel Del Monte and its enduring legacy of art, architecture and culture. Hotel Del Monte was the catalyst for California's modern-day tourism industry and a trendsetter in sports and recreation. This guide highlights the pioneering resort that transformed Monterey from a quiet pueblo to a vibrant tourist destination.

  2. E.D.A.R. Boadilla del Monte

    OpenAIRE

    Argüello Ron, Patricia

    2015-01-01

    El objeto del presente proyecto es definir y valorar las obras e instalaciones necesarias para la nueva estación depuradora de aguas residuales del municipio de Boadilla del Monte. Se trata de un municipio con fuerte expansión urbanística y, por tanto, con un importante crecimiento poblacional, lo que justifica la necesidad de construcción de una nueva estación de depuración para las aguas residuales. El proyecto tratará las alternativas de las instalaciones necesarias, valorándolas y llegand...

  3. Leguminosas arbustivas nativas para mejorar la agricultura maicera itinerante de Yucatán

    Directory of Open Access Journals (Sweden)

    A. Ayala S\\u00E1nchez

    2007-01-01

    Full Text Available En la búsqueda de mejorar el sistema de agricultura maicera de roza, tumba y quema, se desarrolló un experimento durante seis años y medio con los objetivos de evaluar el establecimiento y crecimiento de 18 leguminosas arbustivas como barbechos mejorados en cuatro años y su capacidad para mejorar la productividad de maíz de temporal en dos y medio años subsecuentes. Los barbechos mejorados fueron las especies de Acacia gaumeri, A. glomerosa, Bauhinia divaricata, B. ungulata, Caesalpinea gaumeri, C. yucatanensis, Gliricidia sepium, Leucaena leucocephala, Lonchocarpus rugosos, Lonchocarpus yucatanensis, Mimosa bahamensis, Piscidia piscipula, Pithecellobium albicans, Pithecellobium dulce, Pithecellobium leucospermun, Senna octucifolia, Senna racemosa y Sesbania sesban, además de dos barbechos de vegetación natural. Los resultados indicaron que el crecimiento de L. leucocephala, C. yucatanensis y P. piscipula fue mejor (P < 0.05. La incidencia de malezas bajo el dosel arbolado se redujo (P < 0.05 con L. leucocephala, P. dulce, Senna racemosa, A. gaumeri y P. albicans. Las especies que más leña produjeron (P < 0.05 fueron L. leucocephala,C. yucatanensis y P. piscipula; las que rebrotaron mejor (P < 0.05 fueron L. leucocephala, A. gaumeri, M. bahamensis, P. leucospermum, P. albicans, S. octucifolia, C. yucataneneis y C. gaumeri. Una vez eliminados los barbechos, el cultivo de maíz desarrolló mejor (P < 0.05 después de L. leucocephala, C. yucatanensis, S. racemosa, P. piscipula, P. albicans y M. bahamensis. Se concluye que L. leucocephala, C. yucataneneis, P. piscipula, A. gaumeri, P. albicans y G. sepium, en este orden, ofrecen mayor potencial para usarse como barbechos mejorados en los suelos Cambisol crómico del sur de Yucatán.

  4. Flora apícola primaveral en la región del Monte de la Provincia de La Pampa (Argentina Springtime beekeeping flora in the Monte region of La Pampa province (Argentine

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    Ofelia Naab

    Full Text Available Con el fin de evaluar la flora utilizada por Apis mellifera L. fueron analizadas muestras de miel inmadura y cargas corbiculares de dos apiarios demostradores ubicados en la Provincia Fitogeográfica del Monte, Provincia de La Pampa. Las muestras se extrajeron periódicamente durante la primavera y fueron analizadas aplicando las técnicas melisopalinológicas convencionales. La vegetación arbustiva nativa presentó la mayor abundancia y el mayor número de especies en óptima floración en noviembre. Las familias más representadas en los espectros polínicos de mieles inmaduras y de cargas corbiculares fueron: Zygophyllaceae ( Larrea divaricata Cav., Rhamnaceae ( Condalia microphylla Cav., Solanaceae ( Lycium sp., Asteraceae ( Senecio subulatus Don ex Hook. & Arn. y Verbenaceae ( Glandularia sp. - Junellia sp. - Verbena sp.. Los análisis polínicos evidenciaron que las especies nativas ofrecieron al mismo tiempo recursos nectaríferos y poliníferos sin embargo se observó una alta selección de pocos recursos florales. La oferta floral produjo mieles monoflorales de L. divaricata , C. microphylla y Lycium sp. Ambos apiarios pudieron diferenciarse teniendo en cuenta la diversidad de tipos polínicos y la presencia de ciertos taxones en las categorías de polen dominante y secundario.In order to evaluate the utilized flora by Apis mellifera L. we analized inmmature honey samples and corbicular pollen loads from two demonstrative apiaries located in the Monte Phytogeographical Province of La Pampa. The samples were periodically collected during springtime and were analyzed using the conventional melissopalynological techniques. The native flora presented the major abundance and the highest number of species at an optimum flowering level in november. The most represented families in the pollen spectrum of immature honeys and corbicular loads were: Zygophyllaceae ( Larrea divaricata Cav., Rhamnaceae ( Condalia microphylla Cav., Solanaceae

  5. La sauna de la Segunda Edad del Hierro del oppidum de Monte Ornedo (Cantabria, España

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    FERNÁNDEZ VEGA, P.A., MANTECÓN CALLEJO, L., CALLEJO GÓMEZ, J., BOLADO DEL CASTILLO, R.

    2014-01-01

    Full Text Available En el presente artículo se presenta los resultados de la excavación del Sondeo 3 del yacimiento prerromano de Monte Ornedo (Valdeolea, Cantabria, una estructura cuya compartimentación y funcionalidad parecen relacionarla con una sauna.

  6. Pervivencia de lo sagrado en el control del acceso, uso y manejo del monte-agua en la montaña texcocana.

    OpenAIRE

    Madrigal Calle, Beatriz Elena

    2013-01-01

    Este Trabajo buscó entender cómo la noción de lo sagrado controla el acceso, uso y manejo del monte-agua en las comunidades de Santa Catarina del Monte y Tequexquinahuac del municipio de Texcoco, Edo. de México. Durante 2011-2013, se hizo observación participante en las comunidades y entrevistas a los y las encargados(as) del agua, mayordomía, autoridades civiles, religiosas, jóvenes, ancianos, integrantes del Consejo Indígena Náhuatl de Texcoco, en Santa Catarina del Monte y, en Tequexquinah...

  7. Use of Monte Carlo Methods in brachytherapy; Uso del metodo de Monte Carlo en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Granero Cabanero, D.

    2015-07-01

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  8. Leguminosas arbustivas nativas para mejorar la agricultura maicera itinerante de Yucatán

    OpenAIRE

    A. Ayala Sánchez; Krishnamurthy, L.; J. A. Basulto Graniel; J. A. Leos Rodríguez

    2007-01-01

    En la búsqueda de mejorar el sistema de agricultura maicera de roza, tumba y quema, se desarrolló un experimento durante seis años y medio con los objetivos de evaluar el establecimiento y crecimiento de 18 leguminosas arbustivas como barbechos mejorados en cuatro años y su capacidad para mejorar la productividad de maíz de temporal en dos y medio años subsecuentes. Los barbechos mejorados fueron las especies de Acacia gaumeri, A. glomerosa, Bauhinia divaricata, B. ungulata, Caesalpinea gaume...

  9. “Paesaggi d’Acque”. Survey della laguna di Orbetello e del Monte Argentario

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    Matteo Dolci

    2014-08-01

    Full Text Available Il progetto “Paesaggi d’Acque” ha indagato il territorio delle lagune di Orbetello e del Monte Argentario attraverso la metodologia del survey, per ricostruire le dinamiche poleografiche e di strutturazione del paesaggio antropico, dalla Preistoria all’Altomedioevo. I dati della ricognizione di superficie sono stati registrati e posizionati su cartografia digitale in sistema GIS, così da permettere la lettura diacronica dei dati archeologici e da fornire supporto alle attività di tutela del territorio.

  10. Revalorización del patrimonio geológico como recurso turístico de Capilla del Monte

    OpenAIRE

    Zilio, Amalia; Zilio, Cristina

    2007-01-01

    El objetivo de este trabajo es revalorizar el patrimonio geológico dentro del inventario turístico de Capilla del Monte, reivindicando el uso sostenible del recurso. Cuenta con algunos sitios de singular importancia geológica que pueden atraer un segmento de visitantes con otro tipo de intereses. Se pueden practicar tanto el turismo científico como el turismo aventura, modalidades basadas en el aprovechamiento educativo y recreativo de los lugares, tomando conciencia de la importancia de su c...

  11. Ecología del gato montés ("Felis silvestris") y su relación con el conejo de monte ("Oryctolagus cuniculus")

    OpenAIRE

    Lozano Mendoza, Jorge

    2008-01-01

    Se ha estudiado la ecología del gato montés y su relación particular con el conejo de monte tanto en preferencias de hábitat, dieta, relaciones con ungulados y tendencias de población. El gato montés fue más abundante a escala de paisaje en los mosaicos formados por matorral y pastizal, siendo el matorral además la variable de hábitat más claramente asociada con la especie en todas las escalas espaciales. Por tanto, se identifica al matorral como un elemento estructural del medio clave para l...

  12. El peso del conejo de monte criado en jaula

    OpenAIRE

    P. González-Redondo

    1997-01-01

    Live weights of 19 wild rabbits (Orycrolagus cuniculus) reared in cages were measured and compared to the expected weights according to the growth curve followed by the wild rabbits growing in a natural environment. The results obtained, show that the rearing in captivity does not produces an increase in live weight of the wil rabbit. Los pesos de 19 conejos de monte (Orycrolagus cuniculus) criados en jaula fueron medidos y comparados con los pesos esperados segun una curva de crecimiento ...

  13. Mapping of landslide susceptibility of coastal cliffs : the Mont-Roig del Camp case study

    OpenAIRE

    Montoya-Montei, I.; Rodríguez-Santalla, I.; Sánchez-García, M.J.; Alcántara-Carrió, Javier; Martín-Velázquez, S.; Gómez-Ortiz, D.; Martín-Crespo, T.

    2012-01-01

    The weathered and fractured conglomerate cliffs of Mont Roig del Camp constitute a rock fall hazard for the surrounding pocket beaches and, therefore, for the population that frequent them, especially over the summer. Landslide susceptibility of the cliff has been assessed using the Rock Engineering System method (RES). The determinant and triggering factors considered in this study include: wave exposure, shoreline variations, cliff height, cliff slope, geotechnical quality of the rocky mass...

  14. 75 FR 44720 - Safety Zone; Live-Fire Gun Exercise, M/V Del Monte, James River, VA

    Science.gov (United States)

    2010-07-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Live-Fire Gun Exercise, M/V Del Monte....T05-0585 to read as follows: Sec. 165.T05-0585 Safety Zone; Live-Fire Gun Exercise, M/V Del...

  15. Inventario forestal del monte M-2009 del elenco denominado "Plaza de Buenavista" perteneciente al término municipal de Zarzalejo (Madrid)

    OpenAIRE

    Rica Fuentes, Amparo

    2012-01-01

    Se hace un estudio del monte de origen repoblación. Su especie principal es Pinus pinaster Ait., la secundaria es Pinus sylvestris L. y tiene presencia de Pinus nigra Arn. que no estaba prevista en el proyecto de repoblación, pero probablemente apareciera por mezcla de semillas. En los años 40 se cambió el uso del monte de agrícola a forestal, claro indicio de la baja productividad del suelo para el cultivo de cereales; de esta forma se dio a los propietarios de las distintas parcelas l...

  16. Nuevos grabados y pinturas en las cuevas del Monte del Castillo

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    Joaquín GONZÁLEZ ECHEGARAY

    2009-10-01

    Full Text Available Desde 1954 y 1956 fecha en que se publicaron las últimas noticias de descubrimientos de arte rupestre en las conocidas cuevas del Castillo y la Pasiega, hasta nuestros días, han proseguido realizándose minuciosas exploraciones en dichas cuevas, bajo la dirección del ingeniero Sr. García Lorenzo. Es de justicia citar aquí el nombre del guía de aquellas cuevas prehistóricas, don Felipe Puente, que tanto interés presta en estos trabajos y a quien directamente se deben la mayoría de los hallazgos.

  17. Proyecto de Ordenación del Monte de Utilidad Pública nº201 “Dehesa de Piedraluenga” en el Término Municipal de Santa Gadea Del Cid (Burgos)

    OpenAIRE

    Rábanos Martín, Nieves

    2014-01-01

    El objetivo de este proyecto es la ordenación del monte de U.P. nº 201 Dehesa de Piedraluenga, propiedad el primero del Ayuntamiento de Santa Gadea del Cid en la provincia de Burgos. El monte está situado en la comarca forestal de Miranda de Ebro, dentro de la Sección Territorial 2ª de la Unidad de Ordenación y Mejora del Medio Natural del Servicio Territorial de Medio Ambiente de Burgos. Además, se encuentra dentro del Parque Natural “Montes Obarenes- San Zadornil”. Uno de los objetivos b...

  18. "La Cruz del tío Ignacio", yacimiento Achelense, en Belver de los Montes, Zamora

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    Luis BENITO DEL REY

    2009-12-01

    Full Text Available RESUMEN: En este artículo se estudia una colección de artefactos líticos recogidos en el yacimiento de «La Cruz del tío Ignacio-, en Belver de los Montes (Zamora. Dichos objetos son analizados, aquí, bajo los aspectos tecnológicos y tipológicos, principalmente los núcleos, las lascas y la macroindustria (cantos tallados, triedros, hendidores y bifaces. Estos últimos útiles constituyen la parte mejor representada de la industria. El conjunto de artefactos analizados puede atribuirse, por sus características técnicas y tipológicas, al Achelense medio, que se encuentra, abundante, en toda la zona de la cuenca media occidental del Duero, y que está uniformado por la forma y el tamaño de la materia prima (el canto rodado de cuarcita, por la técnica y por la tipología.ABSTRACT: We try to analyse in this article a collection of stone artifacts gathered in the site of «La Cruz del Tío ignacio» (Belver de los Montes, Zamora, Spain. We analyse these objects under two perspectives, taking into account both the technological and the typological aspects and we concéntrate on core-tools, flake-tools and the macroindustry of pebble-tools, trihedral picks, cleavers and handaxex. These latter artifacts represent the best part of the industry. All these objects as a wole could be ascribed tot he Middle Acheulian if we take into consideration their technical and topological characteristics. Abundante samples of this period can be found all over the western middle basin of the River Duero. All these samples are standardized both by the form/size of the raw material (pebble of quartzite and by technological and typological elements.

  19. Estudio de impacto ambiental del Parque Eólico del monte Olvedo.

    OpenAIRE

    Muñoz Martinez, Eritz

    2013-01-01

    El crecimiento de la producción de energía eléctrica por medio de fuentes renovables es muy notable en nuestro país y en todo el mundo. La empresa ETER S.A. siguiendo esta tendencia y en su deseo de potenciar el nuevo subsector aparecido de miniexplotador de energía eólica, está planeando la instalación de un pequeño parque eólico en el monte Olvedo y sus alrededores, una pequeña cima situada en la provincia de Alava. En principio, el parque estaría compuesto de 16 aerogenerado...

  20. 77 FR 4897 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, VA

    Science.gov (United States)

    2012-02-01

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James... live-fire gun exercises on the M/V Del Monte. This action is intended to restrict vessel traffic movement to protect mariners from the hazards associated with the live-fire gun exercise. DATES: This...

  1. 76 FR 31848 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, Virginia

    Science.gov (United States)

    2011-06-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James... the live-fire gun exercises on the M/V Del Monte. This action is intended to restrict vessel traffic movement to protect mariners from the hazards associated with the live-fire gun exercise. DATES: This...

  2. Un edificio enterrado ritualmente: la Estructura 1 del montículo J8 del sitio manteño de Japoto, Manabí, Ecuador

    OpenAIRE

    Guinea, Mercedes

    2013-01-01

    El año 2007, durante los trabajos de campo del Proyecto Manabí Central en Japoto, se localizó una estructura que se había conservado, a pesar de la fragilidad de sus materiales de construcción, ya que fue enterrada intencionalmente debajo de toneladas de tierra y cascajo traído del estero cercano, visualizándose en el terreno como uno más de los montículos habitacionales del sitio. Un primer sondeo del montículo J8 reveló algunos de los elementos arquitectónicos de la E1, conformada básicamen...

  3. The origin of the Australasian marsupial fauna and the phylogenetic affinities of the enigmatic monito del monte and marsupial mole.

    OpenAIRE

    Springer, M S; Westerman, M; Kavanagh, J R; Burk, A; Woodburne, M O; Kao, D J; Krajewski, C

    1998-01-01

    Alternative hypotheses in higher-level marsupial systematics have different implications for marsupial origins, character evolution, and biogeography. Resolving the position of the South American monito del monte (Order Microbiotheria) is of particular importance in that alternate hypotheses posit sister-group relationships between microbiotheres and taxa with disparate temporal and geographic distributions: pediomyids; didelphids; dasyuromorphians; diprotodontians; all other australidelphian...

  4. Los montes y su desamortización en los pueblos del sur del valle de Toluca (México, 1880-1917

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    Cesar Fernando Escudero Martínez

    2015-02-01

    Full Text Available Este artículo pretende aproximarse al estudio de la desamortización de los montes en los pueblos del sur del valle de Toluca (1880-1917. Llama la atención al análisis de la explotación de la madera en beneficio de la industria, para establecer las diversas respuestas y medidas que adoptaron tanto los pueblos en cuestión, sus ayuntamientos y el gobierno estatal frente al fraccionamiento de la propiedad comunal de los montes, en el contexto de modernización económica e industrial que vivió el país. Si bien es cierto, la explotación de los montes y sus recursos respondió a una demanda externa, ésta propició que se alteraran las relaciones entre los habitantes y las autoridades por la extracción de recursos, especialmente porque la llegada de nuevos actores puso de manifiesto la importancia económica que había tomado el recurso forestal y los derivados que podían tomarse del monte, lo cual puede ser considerado como una señal del replanteamiento de los recursos en el contexto ya mencionado.

  5. Memoria de las excavaciones arqueológicas en el Poblado del monte Buruntza 1992-1996 (Andoain , Gipuzkoa.

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    Carlos Olaetxea

    1997-01-01

    Full Text Available Presentamos en este trabajo los resultados de 5 campañas de   excavaciones en el poblado fortificado del Monte Buruntza en Andoain, Gipuzkoa. Se trata de un poblado de la edad del hierro cuya principal actividad debió de desarrollarse entre los siglos V y VI antes de nuestra era. Se conocen bien los restos de la muralla que rodeaba el poblado, pero apenas hay restos de las casas del mismo. Se han podido recuperar muchos fragmentos cerámicos, todos ellos realizados a mano y algunos pocos fragmentos de hierro y restos de fundición de bronce. No aparecen resto de fauna debido probablemente a un proceso posdeposicional provocado por la acidez del suelo que afecta también de forma importante a las cerámicas.

  6. Valores y pautas de crianza familiar en los montes del Pas

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    Petra María PÉREZ ALONSO-GETA

    2009-11-01

    Full Text Available RESUMEN: La comunidad asentada en los montes del Pas es una sociedad que se define como agrícola, rural y campesina. La familia es a la vez unidad doméstica y productiva, ocupada básicamente en labores agrarias y ganaderas.El objetivo final de este estudio es el conocimiento de las pautas de crianza y transmisión cultural del pueblo pasiego. Tratamos de conocer mejor el mundo de la educación familiar para desde ese conocimiento avanzar adecuadamente en la toma de decisiones pedagógicas. Por los datos recogidos cabe hablar de la existencia de unas relaciones intergeneracionales cálidas y positivas, donde la atención, cooperación y solidaridad son un hecho. La familia comparte espacios, tiempos y tareas. Los niños aprenden a través del modelado los valores, normas y pautas de conducta. Enseñan a los niños a tener palabra, ser trabajadores y respetuosos. Los niños van al campo desde muy pequeños a ayudar. Trabajan mucho. Los valores que definen son la laboriosidad, el esfuerzo para el progreso económico, lealtad, tener palabra y solidaridad. Se ayudan mucho entre ellos.ABSTRACT: The community settled in the mountains of the Pas is a society which is described as agricultural and rural. The family is both the domestic and productive unit, basically working in farming and stockbreeding tasks.The final aim of this estudy is to know the nurturing and cultural transmission guidelines of the pasiego people. We aim to know the world of the education within the family better and, from this knowledge, to advance appropriately in the educational decission making. From the gathered data we may assume that there are warm and positive intergenerational relationships, where care, cooperation and solidarity are real. The familiy share spaces, time and tasks; children learn through the modeling of valúes, norms and guidelines. They are taught to have their own voice, to work hard and to be respectful. They do work hard. The defining valúes in

  7. Un progetto per l'attivazione di Agenda 21 Locale: monitoraggio della mammalofauna nell'area del Parco Regionale del Monte Cucco (Perugia

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    Roberta Mazzei

    2003-10-01

    Full Text Available Nell?ambito del progetto ?Attivazione Agenda 21 Locale? finalizzato alla realizzazione di studi per la certificazione e contabilizzazione ambientale, nel Parco Regionale del Monte Cucco, si è dato il via, a partire dal novembre del 2001, ad un?indagine di tipo qualitativo, mirata alla caratterizzazione dell?area Parco per quel che riguarda la presenza di specie di Mammiferi appenninici di interesse conservazionistico e naturalistico. Nel periodo che va dall?8 febbraio 2002 al 5 ottobre dello stesso anno, sono stati effettuati 16 transetti faunistici, distribuiti nell?arco delle quattro stagioni. Sono stati raccolti indici di presenza di 11 specie di Mammiferi appartenenti agli ordini degli Artiodattili, Carnivori, Lagomorfi, Insettivori e Roditori e i relativi IKA (indici chilometrici di abbondanza. I dati raccolti unitamente ad una ricognizione bibliografica, mirata a reperire informazioni pregresse e aggiornate sulla teriofauna locale, attraverso inoltre, l?effettuazione di interviste e il coinvolgimento della popolazione locale, hanno portato alla definizione di una Check-list della Mammalofauna del Parco, rappresentativa per il 56% di quella della Regione. La ricerca ha permesso di confermare per l?area la presenza del Lupo (Canis lupus e di evidenziare l?espansione a Sud del Capriolo (Capreolus capreolus. Parte integrante del progetto ?Cucco 21? era la definizione di proposte gestionali volte a migliorare il rapporto uomo-ambiente, laddove fossero state individuate situazioni di criticità oggettive o potenziali, in un?ottica di conservazione della risorsa naturale e di sviluppo delle attività antropiche. Significativi a tale proposito sono stati il caso del Cinghiale (Sus scrofa con l?osservazione del danno alle fitocenosi, soprattutto ai prati e pascoli cacuminali e del Capriolo. Per quest?ultima specie in funzione della sua espansione verso la parte meridionale del Parco, sono state avanzate delle

  8. Dirección de flujo y clasificación del agua subterránea, en Monte Alegre, sierra del Ajusco, México

    OpenAIRE

    René Morales Luis; Oscar L. Palacios Vélez; Luis Marín Stillman; Juan J. Peña Cabriales; Salvador Peña Díaz; Jorge D. Etchevers Barra; David J. Palma López; Marcos R. Soto Hernández

    2000-01-01

    La captación de los flujos subterráneos que afloran en las zonas montañosas aledañas a la Ciudad de México representan alternativas de abastecimiento de agua potable a bajo costo y ayudan a la solución de este problema, por lo que su caracterización geoquímica y de dirección de flujo es necesaria para su mejor aprovechamiento y cuidado. Por lo tanto, en este estudio se hizo un análisis geológico estructural y geoquímico del agua. Se encontró que en el valle de Monte Alegre la dirección del fl...

  9. Monte Carlo analysis of the Neutron Standards Laboratory of the CIEMAT; Analisis Monte Carlo del Laboratorio de Patrones Neutronicos del CIEMAT

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Av. Complutense 40, 28040 Madrid (Spain); Guzman G, K. A., E-mail: fermineutron@yahoo.com [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2014-10-15

    By means of Monte Carlo methods was characterized the neutrons field produced by calibration sources in the Neutron Standards Laboratory of the Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT). The laboratory has two neutron calibration sources: {sup 241}AmBe and {sup 252}Cf which are stored in a water pool and are placed on the calibration bench using controlled systems at distance. To characterize the neutrons field was built a three-dimensional model of the room where it was included the stainless steel bench, the irradiation table and the storage pool. The sources model included double encapsulated of steel, as cladding. With the purpose of determining the effect that produces the presence of the different components of the room, during the characterization the neutrons spectra, the total flow and the rapidity of environmental equivalent dose to 100 cm of the source were considered. The presence of the walls, floor and ceiling of the room is causing the most modification in the spectra and the integral values of the flow and the rapidity of environmental equivalent dose. (Author)

  10. Inventario y estudio de regeneración de Pinus sylvestris L. en los cuarteles A y B del Monte "Cabeza de Hierro" (Rascafría, Madrid)

    OpenAIRE

    Rubio Cuadrado, Álvaro

    2008-01-01

    En el presente trabajo se estudian los factores que más inciden en la aparición del suficiente regenerado para la persistencia de la masa de pino silvestre, en la estructura deseada y por medio de la dispersión de semillas, de los cuarteles A y B del monte “Cabeza de Hierro”, situado en el término municipal de Rascafría (Madrid). A partir del conocimiento de dichos factores se proporcionan unos valores orientativos que deben alcanzar para conseguir la aparición del suficiente regenerado en fu...

  11. Paleolimnología de la Laguna Cerrillo del medio, Monte, provincia de Buenos Aires Paleolimnology of Laguna Cerrillo del Medio, Monte, Buenos Aires Province

    Directory of Open Access Journals (Sweden)

    Nauris V. Dangavs

    2008-03-01

    Full Text Available Se caracterizaron el medio físico del ambiente, la fisiografía, el sistema geomorfológico de la región, las características hidrológicas y el origen de la cubeta lagunar. La geología superficial está definida por diez unidades estratigráficas (siete litoestratigráficas y tres pedoestratigráficas. La más antigua es la Formación Ensenada del Pleistoceno medio, que constituye el sustrato regional, donde se excavó la cubeta lagunar. Encima se dispone la Formación Buenos Aires del Pleistoceno tardío, en cuya parte cuspidal se sitúa un Geosuelo Sin Nombre. Las siguientes cuatro unidades corresponden a depósitos eólicos de dunas de arcilla y loéssicos de la Formación La Postrera I, II, III y IV, de edades dispares, que abarcan desde el Pleistoceno tardío al Holoceno tardío-tardío. La Formación La Postrera II y III poseen los Geosuelos Puesto Callejón Viejo y Puesto Berrondo respectivamente. En las playas afloran depósitos aluviales, que incrementan su espesor en el lecho lagunar. En los sedimentos colmatantes se reconocieron seis depósitos, cinco representan a ambientes acuáticos: Formación Luján, Miembros La Chumbiada, Lobos y Río Salado, del Pleistoceno tardío al Holoceno temprano a medio; formación subaluvial del Holoceno tardío y la actual formación aluvial. El sexto es un depósito eólico de duna de arcilla intracuencal del Pleistoceno tardío. El conjunto de los depósitos suprayacentes a la Formación Ensenada supera los 64 ka, representados por cinco episodios de clima seco que abarcan desde el loess Bonaerense hasta la pequeña edad de hielo (IS4, IS2, D3-L3, D2-L2, D1-L1 y cinco húmedos (IS3, S3, IS1, S1 y el actual.The regional physical environment was characterized, describing the physiographic and geomorphic features, the hydrologic regime and the origin of the shallow lake basin. The surficial geology is defined by ten stratigraphic units (seven lithostratigraphic units and three geosols; the oldest

  12. Composição e estrutura da comunidade arbórea e arbustiva em murundus no Pantanal de Poconé, Mato Grosso

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    Rodrigo Ferreira Morais

    2014-06-01

    Full Text Available Campos de murundus são áreas planas alagáveis, onde se encontram pequenas elevações (morrotes espalhadas na paisagem. Esses murundus apresentam solo e vegetação diferente da área circundante, uma vez que não se alagam no período chuvoso. Espera-se que o tamanho (m² e o volume (m³ dos murundus exerçam influência sobre a composição florística e a estrutura da comunidade vegetal. Assim, o objetivo deste trabalho foi analisar a composição florística e a estrutura da comunidade vegetal arbórea e arbustiva em murundus, no Pantanal de Poconé, MT, com a finalidade de responder a duas perguntas: (i Existe correlação entre a área e o volume do murundu com a riqueza e abundância da vegetação arbórea e arbustiva? (ii Existe correlação entre a área e o volume do murundu com a área basal das espécies arbóreas e arbustivas? Foram usadas parcelas para delimitar a área de campo de murundus a ser estudada. Nessas parcelas, formam mensurados a área e volume dos murundus e realizados os levantamentos florístico e fitossociológico. Foi verificado que área e volume influenciaram a riqueza, a abundância e a área basal das espécies.

  13. Volcano-estratigrafía y tectónica del Valle Central Occidentaly las estribaciones de los Montes del Aguacate a lo largo de la ruta 27, Costa Rica Volcano-stratigraphy and tectonics of the Western Central Valley and Montes del Aguacate along road 27, Costa Rica

    OpenAIRE

    Hernán Porras; Monserrat Cascante; Raquel Granados; Guillermo E Alvarado

    2012-01-01

    La Ruta 27, también conocida como carretera Ciudad Colón-Caldera, ofrece cortes geológicos de entre 5 y 40 m de altura que muestran una buena parte de la estratigrafía, en su mayoría volcánica y subvolcánica, del extremo occidental del Valle Central y las estribaciones de los Montes del Aguacate. Se observa una secuencia volcánica correlacionable con la Formación Grifo Alto (Plioceno), profundamente hidrotermalizada (alteración propilítica) en varios sectores, compuesta por lavas, brechas y d...

  14. Il paesaggio e i gesti del sacro: i casi di Pontecagnano e Monte Vetrano (Salerno)

    OpenAIRE

    Cerchiai, Luca

    2016-01-01

    Pontecagnano and the site of Monte Vetrano in the Agro Picentino provide some interesting cases for reconstructing cult practices and ritual actions integrated into the frame of the landscape: the paper reports the results of the excavations carried out in the two settlements for the construction of the third lane of the highway Salerno-Reggio Calabria and the WTE plant of Salerno.

  15. Livestock grazing, habitat protection and diversity of bees and wasps in the Central Monte desert Ganadería, protección del hábitat y diversidad de abejas y avispas en el desierto del Monte Central

    Directory of Open Access Journals (Sweden)

    Diego P. Vázquez

    2008-12-01

    Full Text Available Reserves aim mainly at preventing or mitigating human impacts on natural ecosystems. It is important to assess how well reserves meet this goal. We evaluated whether habitat protection offered by Ñacuñán Biosphere Reserve (Central Monte desert, Argentina results in detectable changes in habitat structure and the species richness and composition of bees and wasps. We conducted pan trap sampling and flower visitor observations in six pairs of protected and unprotected sites. Our results suggest that thirty fi ve years of cattle exclusion in Ñacuñán have had detectable effects on habitat structure. However, these changes in habitat structure translated only into partial and conflicting effects on hymenopteran richness, and did not have detectable effects on hymenopteran composition. Our study should be repeated with a greater sampling effort and throughout multiple years before our results can be applied to guide management decisions.El principal objetivo de las reservas es prevenir o mitigar los impactos humanos sobre los ecosistemas naturales. Es importante evaluar cuán bien las reservas alcanzan este objetivo. Evaluamos si la protección del hábitat que brinda la Reserva de la Biósfera de Ñacuñán (Monte Central, Argentina resulta en cambios detectables en la estructura del hábitat, y en la riqueza y la composición de especies de abejas y avispas. Realizamos muestreos con trampas bandeja y observaciones de visitantes florales en seis pares de sitios dentro y fuera de la reserva. Nuestros resultados sugieren que los treinta y cinco años de exclusión del ganado vacuno en Ñacuñán han tenido efectos detectables sobre la estructura del hábitat. Sin embargo, estos cambios en el hábitat se tradujeron sólo en efectos parciales y conflictivos sobre la riqueza de himenópteros, y no tuvieron efectos detectables sobre la composición de himenópteros. Nuestro estudio debería repetirse en el futuro, con un mayor esfuerzo de muestreo y

  16. Environmental and ecological architects: Guidelines for the Chilean temperate rainforest management derived from the monito del monte (Dromiciops gliroides conservation Arquitectos ambientales y ecológicos: Pautas para la gestión ambiental del bosque templado lluvioso de Chile derivadas de la conservación del monito del monte (Dromiciops gliroides

    Directory of Open Access Journals (Sweden)

    FRANCISCO E FONTÚRBEL

    2011-06-01

    Full Text Available Land use change is one of the main biodiversity threats. Due to this change, natural habitats such as the South American temperate rainforests have been rapidly degraded, fragmented, and lost. Consequently, the management and conservation of the remaining forest is a priority and having an appropriate environmental policy is mandatory for this purpose. Conservation actions in the temperate rainforest have been addressed from an individual species perspective, giving less attention to the ecosystem level conservation. Moreover, conservation-related information has not reflected yet on environmental policy development. We used the case study of the monito del monte (Dromiciops gliroides to illustrate how our current ecological and conservation knowledge of a species could be used to generate a new environmental policy. Dromiciops gliroides is a forest-dependent species with an important ecological role and quite unique evolutionary status. In order to guarantee the persistence of D. gliroides, we propose two habitat management components to be incorporated in management plans: structure and connectivity. Structure refers to spatial arrangement and key structural elements that determine habitat quality and connectivity refers to functional connectivity at the landscape level. The conservation of the monito del monte might also contribute to the conservation of many other forest-dependent species. By conserving such species it will be possible to conserve the ecological interactions and the eco-evolutionary processes, which ultimately determine the conservation of the temperate rainforest.El cambio de uso de la tierra es una de las principales amenazas a la biodiversidad. Hábitats naturales como el bosque templado lluvioso de Sudamérica han sido degradados, fragmentados y eliminados rápidamente. En consecuencia, es prioritario el manejo y conservación de los remanentes, para lo que es necesario contar con una política ambiental acorde. Las

  17. Stime di consistenza del cervo sardo nell'oasi di Monte Arcosu mediante la tecnica del pellets-group count

    OpenAIRE

    Murgia, Andrea; Cocco, Francesca; Murgia, Carlo; Deiana, Anna Maria

    2005-01-01

    This paper presents the results obtained during a research carried out from 2002 to 2003 in the Monte Arcosu Natural Park. The aim of this work has been to estimate the density values and the amount of population of Sardinian deer (Cervus elaphus corsicanus). Pellets-group count was the method used. Data obtained show the average density values in the study area (29.9 SE = 5.8 deer/Km2). A higher value has been obtained in the inner part of the Park. Data show that population is constant duri...

  18. Geología y geoquímica del granito de Montánchez (Cáceres

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    Arribas Moreno, A.

    1989-12-01

    Full Text Available The granite of Montánchez (Cáceres, Spain is located to the S.E. of the Albalá granite and is separated from it by a strongly tectonized zone. According to the mica content, three perografic facies have been distinguished in the Montánchez granite. Facies 1, is made up of medium to coarse grained, two mica granites richer in muscovite, which occupy the northern half of the granite and have been extremely deformed. Facies II, consiting of coarse to very coarse grained, sometimes porphyrblastic, two-mica granites, richer in biotite, has not been deformed, or very little. Facies III is made up of aplitic muscovite granties which are poor in biotite and rich in tourmaline. The Montánchez granite frecuently contains tonalitic xenolith, sometimes quitee large. Regarding the geochemistry of the Montánchez granite the major and some trace elements have been analyzed on 22 samples belonging to the three different facies and the tonalitic xenoliths. As for the major elements, the chemical-mineralogical parameters of la Roche, the binary diagrams of Harker, Larsen, la Roche and Deban and Le Fort, and the ternary diagrams Na2O, K2O, CaO, Na2O+K2O, Al2O3, CaO and AFM have been calculted. They indicate that these granties are made up alkaline rocks richer in Na than K, poor in Ca, and with a markedly peraluminous character. Concerning the distribution of the trace elements in the Montánchez granite the average conten in Rb, Ba, Sr, Zr and Nb lower and those in Sn and Zn higher, than the values reported by different autors for several world granites considered to be standard.El macizo granítico de Montánchez (Cáceres, España está situado al SE del granito de Albalá, del que le separa una banda fuertemente tectonizada. De acuerdo con su contenido en micas se han distinguido en él tres facies petrográficas. Facies 1, formada por grantios de dos micas, con moscovita dominante, ocupa la parte norte del macizo; es una facies muy deformada y con tama

  19. Antropología y tecnología social: mitos, saberes y realidades en torno a la mina en Real del Monte, Hidalgo

    OpenAIRE

    Anta Félez, José Luis; Lagunas Arias, David

    2011-01-01

    En este texto se presenta una lectura particular acerca del complejo de la minería. Tomando como ejemplo el caso de Real del Monte, y desde una perspectiva que va de lo local a lo global, se plantea la minería como un ejercicio de tecnología social que ha generado tanto represión como miseria y saqueo material. Subyacente a la mina aparecen varios planos semánticos, algunos complementarios entre sí, otros contrapuestos, que se analizan a lo largo del texto.

  20. Proyecto de mejora selvícola en el monte perímetro de Puebla N.205 del C.U.P. término municipal de Puebla de la Sierra (Madrid)

    OpenAIRE

    Barrionuevo Escribano, Esther

    2010-01-01

    La redacción del presente proyecto de mejoras selvícolas del monte nº 205 de perímetro de Puebla de la Sierra (Madrid) atiende a una finalidad didáctica. El proyecto pretende planificar una serie de tratamientos para mejorar la situación actual del monte, especialmente la reducción de espesura.

  1. Petrogenesis of fertile mantle peridotites from the Monte del Estado massif (southwest Puerto Rico): a preserved section of Proto-Caribbean oceanic lithospheric mantle?

    Science.gov (United States)

    Marchesi, Claudio; Jolly, Wayne T.; Lewis, John F.; Garrido, Carlos J.; Proenza, Joaquín. A.; Lidiak, Edward G.

    2010-05-01

    The Monte del Estado massif is the largest and northernmost serpentinized peridotite belt in southwest Puerto Rico. It is mainly composed of spinel lherzolite and minor harzburgite with variable clinopyroxene modal abundances. Mineral and whole rock major and trace element compositions of peridotites coincide with those of fertile abyssal peridotites from mid ocean ridges. Peridotites lost 2-14 wt% of relative MgO and variable amounts of CaO by serpentinization and seafloor weathering. HREE contents in whole rock indicate that the Monte del Estado peridotites are residues after low to moderate degrees (2-15%) of fractional partial melting in the spinel stability field. However, very low LREE/HREE and MREE/HREE in clinopyroxene cannot be explained by melting models of a spinel lherzolite source and support that the Monte del Estado peridotites experienced initial low fractional melting degrees (~ 4%) in the garnet stability field. The relative enrichment of LREE in whole rock is not due to secondary processes but probably reflects the capture of percolating melt fractions along grain boundaries or as microinclusions in minerals, or the presence of exotic micro-phases in the mineral assemblage. We propose that the Monte del Estado peridotite belt represents a section of ancient Proto-Caribbean (Atlantic) lithospheric mantle originated by seafloor spreading between North and South America in the Late Jurassic-Early Cretaceous. This portion of oceanic lithospheric mantle was subsequently trapped in the forearc region of the Greater Antilles paleo-island arc generated by the northward subduction of the Caribbean plate beneath the Proto-Caribbean ocean. Finally, the Monte del Estado peridotites belt was emplaced in the Early Cretaceous probably as result of the change in subduction polarity of the Greater Antilles paleo-island arc without having been significantly modified by subduction processes.

  2. Edificio de oficinas del Monte de Piedad y Caja de Ahorros de Sevilla-España

    Directory of Open Access Journals (Sweden)

    Población Knappe, Eleuterio

    1981-03-01

    Full Text Available Architect The essential feature of the new building of the Pawnshop and Savings Bank in Seville, built on a site in an «L» form and affected in the course of the planning and building by successive changes of Ordenances, its attempt to harmonize with the surrounding architecture, respecting its traditional characteristics. The building, which has seven stories on a slope and two basements, broadcasts its different private and public missions by the volumes, forms and different exterior treatments, presenting particular attention to its functionality in accordance with the initial programme proposed by the organisation.

    La característica esencial de la nueva sede del Monte de Piedad y Caja de Ahorros de Sevilla, levantada sobre un solar en forma de «L» y afectada en el transcurso del proyecto y construcción por sucesivos cambios de Ordenanzas, armoniza con la arquitectura circundante, respetando sus características tradicionales. La edificación, de siete plantas sobre rasante y dos sótanos, patentiza su distinta misión privada y de cara al público a través de los volúmenes, formas y diferentes tratamientos exteriores, presentando una especial atención a su funcionalidad de acuerdo con el programa inicial planteado por la entidad.

  3. Proyecto de Senda Interpretativa de la gestión y uso del monte “El Viejo” a lo largo de la historia (Palencia)

    OpenAIRE

    Zorraquino Salvo, Iratxe

    2015-01-01

    Este trabajo fin de carrera trata de la definición de una senda por el Monte El Viejo, Palencia, en la que se marcan una serie de puntos de interés, en los cuales quedan reflejadas las señales de gestión y uso del monte a lo largo de la historia. La senda se señala con marcas de Senda Local y va acompañada de una topoguía disponible vía on-line.

  4. Vídeo del Eje temático 4. Bibliotecas CSIC y redes sociales Moderado por Carmen M. Pérez-Montes, Biblioteca Tomás Navarro Tomás del Centro de Ciencias Humanas y Sociales

    OpenAIRE

    Unidad de Recursos de Información Científica para la Investigación (URICI)

    2012-01-01

    Eje temático 4. Bibliotecas csic y redes sociales Moderado por Carmen M. Pérez-Montes, Biblioteca Tomás Navarro Tomás del Centro de Ciencias Humanas y Sociales.- Comunicación: redes sociales y ciencia (Antonio Lafuente, Investigador científico. Instituto de Historia, CCHS-CSIC).- Mesa redonda: Bibliotecas del CSIC y redes sociales.- WWW, blog, etc. de la Red de bibliotecas del CSIC. Análisis, uso, potencialidad (Juan Román, Unidad de Recursos de Información Científica para la Investigación...

  5. Estudio de la cubierta vegetal del Monte Forgoselo mediante imágenes de Landsat TM 5 (Galicia, NW España

    Directory of Open Access Journals (Sweden)

    Xana Álvarez-Bermúdez

    2015-01-01

    Full Text Available En el estudio que a continuación se describe, se pretende realizar una clasificación de la cubierta vegetal del Monte Forgoselo. Para ello hemos utilizado la Teledetección como herramienta, concretamente una imagen del satélite Landsat 5. Hemos realizado una clasificación digital supervisada de máxima probabilidad, de mínima distancia y de paralelepípedos. El resultado ha sido la división del Monte Forgoselo en categorías de estratos de vegetación, concretamente en pinar, matorral y pradera, alcanzando un coeficiente Kappa del 0,9762 y una precisión total del 98,3586%, lo que se traduce en una buena fiabilidad, Con nuestro estudio hemos comprobado que con el uso de dichas técnicas se puede llegar a realizar una ordenación de esta pequeña área rural, centrándose en el ámbito forestal. Así mismo, se concluye que el empleo de la Teledetección se considera factible en la realización de trabajos de mayor envergadura.

  6. Población y ocupación del espacio en la frontera del salado. Chascomús, Ranchos y Monte entre 1815 y 1838

    Directory of Open Access Journals (Sweden)

    Guillermo Banzato

    2000-06-01

    Full Text Available Los numerosos estudios sobre la sociedad rural rioplatense en el período colonial y pos independiente van mostrando, poco a poco, las características de la población, la composición familiar y la disponibilidad de mano de obra, tanto en las áreas de viejo asentamiento como en las más dinámicas de la frontera interior, de manera que puede continuarse la tarea con nuevas aproximaciones, comparando los resultados con los ya obtenidos. Esta será la perspectiva del presente trabajo, en el que se describirá la estructura poblacional de Chascomús entre 1815 y 1838, aunque sumando una relación que se aprecia ausente en los trabajos sobre el tema, como es la ocupación y acceso a la propiedad legal de la tierra. Debido a las características de las fuentes los partidos de Ranchos y Monte se incluirán parcialmente en el análisis

  7. Balance y modelización del acuífero karstico de los Montes Torozos (Valladolid, España

    Directory of Open Access Journals (Sweden)

    Germán Sanz-Lobón

    2015-01-01

    Full Text Available En este trabajo se presenta el balance hídrico de una masa de agua subterránea de naturaleza kárstica de la cuenca sedimentaria del Duero, centro oeste de España. Los datos obtenidos para la realización del balance han sido introducidos en una herramienta de simulación con el fin de conocer la evolución temporal de los recursos hídricos a lo largo del año hidrológico. Para ello se ha sido necesario recurrir a la utilización de técnicas geostadísticas y el programa Visual Modflow. La masa de agua de los Montes Torozos se trata de un acuífero kárstico libre y colgado de origen sedimentario, y su balance está determinado por las precipitaciones y por el drenaje.

  8. Modelización del monte bajo de castaño de Brañalonga (Tineo) mediante tecnología LiDAR

    OpenAIRE

    Arias Fernández, Marina

    2015-01-01

    El propósito del presente estudio de investigación es el desarrollo de modelos de predicción de variables dasométricas a partir de datos LiDAR del PNOA para el monte bajo de Castanea sativa, comparando los datos generados mediante tecnología LiDAR con los del inventario forestal tradicional. Se realizó el tratamiento previo de los datos LiDAR para la obtención de los estadísticos de las variables LiDAR. Se llevó a cabo un inventario forestal, en el cual se midió, entre otros parámetros, el di...

  9. La influencia del monte arbolado en las empresas transformadoras de la madera en Galicia

    Directory of Open Access Journals (Sweden)

    Miramontes Carballada, Ángel

    2013-06-01

    Full Text Available In studies on the creation of corporate production systems, the significance that the proximity of raw material can have on its success and creation is increasingly overlooked. It is true that advances in transportation, among other conditions, make it easy to move the processing plant farther away from where the raw material is supplied. However, in many activities the manufacturing location is still conditioned by the location and characteristics of the materials used in production. A good example is the timber industry. This article specifically focuses on showing the relationship, significance and economic potential of forest raw materials and the wood processing industry in Galicia.En los estudios sobre la conformación de sistemas productivos empresariales se olvida cada vez más, la significación que puede tener para su conformación y éxito la presencia de materia prima cercana. Es cierto, que los avances en los medios de transporte, entre otros condicionantes, facilitan que se aleje el lugar de transformación del de suministro de la materia prima. Sin embargo, en muchas actividades la presencia fabril está todavía muy condicionada por la localización y características de los materiales con los que fabricar. Un buen ejemplo es la industria de la madera. En concreto este artículo se centra en mostrar la relación, significación y potencialidad económica de la materia prima forestal y la industria de transformación de la madera en Galicia. [fr] Les études sur la formation des systèmes productifs commerciaux oublient de plus en plus l’importance que peut avoir pour leur formation et leur succès la présence proche de matières premières. Il est vrai que les progrès des moyens de transport, parmi d’autres autres conditions, facilitent l’éloignement du lieu de transformation de celui d’approvisionnement de la matière première. Cependant, en de nombreuses activités, la présence d’usines est encore fortement

  10. Simulation of the functioning of a gamma camera using Monte Carlo method; Simulacion del funcionamiento de una camara gamma mediante metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Oramas Polo, I.

    2014-07-01

    This paper presents the simulation of the gamma camera Park Isocam II by Monte Carlo code SIMIND. This simulation allows detailed assessment of the functioning of the gamma camera. The parameters evaluated by means of the simulation are: the intrinsic uniformity with different window amplitudes, the system uniformity, the extrinsic spatial resolution, the maximum rate of counts, the intrinsic sensitivity, the system sensitivity, the energy resolution and the pixel size. The results of the simulation are compared and evaluated against the specifications of the manufacturer of the gamma camera and taking into account the National Protocol for Quality Control of Nuclear Medicine Instruments of the Cuban Medical Equipment Control Center. The simulation reported here demonstrates the validity of the SIMIND Monte Carlo code to evaluate the performance of the gamma camera Park Isocam II and as result a computational model of the camera has been obtained. (Author)

  11. Contribución al conocimiento de la estratigrafía de las rocas sedimentarias de monte frío (jurásico inferior, valle superior del magdalena - colombia)

    OpenAIRE

    Rodríguez P., Miguel Angel; Rodríguez García, Gabriel; Viana R., Ricardo León

    2012-01-01

    Las Rocas Sedimentarias de Monte Frio representan el registro de un evento sedimentológico de origen marino con gran influencia volcánica subaérea del Jurasico inferior en eI Valle Superior del Magdalena. Estudios detallados recientes de esta unidad, aflorante en la región de Monte Frio al suroeste del Municipio de Natagaima (Tolima), han permitido precisar la conformación litológica, el espesor y las relaciones con las unidades adyacentes, características que son descritas en el presente art...

  12. Application of a Monte Carlo Penelope code at diverse dosimetric problems in radiotherapy; Aplicacion del codigo Monte Carlo Penelope a diversos problemas dosimetricos en radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.A.; Fernandez V, J.M.; Salvat, F. [Servicio de Oncologia Radioterapica. Hospital Clinico de Barcelona. Villarroel 170 08036 Barcelona (Spain)

    1998-12-31

    In the present communication it is presented the results of the simulation utilizing the Penelope code (Penetration and Energy loss of Positrons and Electrons) in several applications of radiotherapy which can be the radioactive sources simulation: {sup 192} Ir, {sup 125} I, {sup 106} Ru or the electron beams simulation of a linear accelerator Siemens KDS. The simulations presented in this communication have been on computers of type Pentium PC of 100 throughout 300 MHz, and the times of execution were from some hours until several days depending of the complexity of the problem. It is concluded that Penelope is a very useful tool for the Monte Carlo calculations due to its great ability and its relative handling facilities. (Author)

  13. Characterization of Siemens Bio graph 6 PET by Monte Carlo simulation; Caracterizacion del escaner PET Biograph 6 de Siemens mediante simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Gallego Franco, P.; Garcia Marcos, R.

    2015-07-01

    GAMOS simulation code based on Geant4 is a very powerful tool for the design and modeling optimization on Positron Emission Tomography (PET) systems. In order to obtain a proper image quality, it results to be extremely important determine the optimal activity which is going to be delivered. For this reason a study about the internal system parameters that affects image quality, such as scatter fraction (SF) and the count rate equivalent noise (NEC), has been carried out. The study involves the comparison of experimental measures on both parameters, with those obtained by Monte Carlo simulation of Siemens Pet Biograph 6 True Point with True V option. Based on simulations results, a paralizable dead-time model that adjusts, depending on the activity provided, the proper dead-time for scanner detectors. Also a study about the variation of this proper dead-time with the activity has been carried out. (Author)

  14. Monte Carlo simulation for radiation transport. Applications in medical physics; Simulacion Monte Carlo del transporte de la radiacion. Aplicaciones en el campo de fisica medica

    Energy Technology Data Exchange (ETDEWEB)

    Sempau, J. [Universitat Politecnica de Catalunya (Spain)

    2002-07-01

    Monte Carlo (MC) simulation is the most accurate technique currently available for solving problems related with the transport of radiation in complex geometries, such as those encountered in medical application. In this work we present a brief description of the basic features of the MC simulation of photons, electrons and positrons. Some of the most relevant applications of this technique in the field of medical physics are also discussed, namely, imaging in nuclear medicine, diagnostic radiology, calculations related with radiotherapy (i.e.,teletherapy, dose planning and brachytherapy) and microdosimetry. It is foreseen that this latter field will encompass the most challenging problems for the application of radiation physics to medicine during the 21 st century. (Author) 12 refs.

  15. Tamaño y composición de la colonia de tres especies de hormigas del género Pogonomyrmex (Hymenoptera: Formicidae en la porción central del desierto del Monte, Argentina Colony size and composition in three Pogonomyrmex ant species (Hymenoptera: Formicidae in the central Monte desert, Argentina

    Directory of Open Access Journals (Sweden)

    Beatriz E. Nobua Behrmann

    2010-06-01

    Full Text Available El tamaño de la colonia es un atributo fundamental en la biología de las hormigas ya que está asociado a características ecológicamente relevantes, como sus estrategias de alimentación. Mientras que el tamaño de la colonia de varias especies de hormigas granívoras del género Pogonomyrmex de América del Norte se ha estudiado en detalle, no existe tal información para las especies de América del Sur. En este trabajo, se determinó el tamaño y la composición de la colonia y se describió la estructura del nido de tres especies de Pogonomyrmex que habitan la porción central del desierto del Monte en Argentina: P. mendozanus Cuezzo & Claver, P. inermis Forel y P. rastratus Mayr. Para ello, se excavaron dos nidos de cada especie y se recolectaron todos los individuos encontrados. Las tres especies tienen colonias pequeñas, compuestas por 300-1.100 individuos, de los cuales aproximadamente el 70% son obreras adultas. La estructura de sus nidos es relativamente simple, similar a la de la mayoría de las especies norteamericanas estudiadas, pero con un menor desarrollo en profundidad y un número menor de cámaras; probablemente se deba al menor número de obreras que poseen. Estas características (colonias pequeñas y nidos poco desarrollados son consideradas típicas para las especies del género Pogonomyrmex de América del Sur, lo que las diferencia de la mayoría de sus congéneres estudiados en América del Norte.Colony size in ants is associated with important ecological characteristics such as foraging strategy. Though colony size has been studied with some detail for several North American species of Pogonomyrmex harvester ants, it remains unknown for South American species. We studied colony size, composition, and nest structure of three species of Pogonomyrmex harvester ants inhabiting the central Monte desert in Argentina: P. mendozanus Cuezzo & Claver, P. inermis Forel and P. rastratus Mayr. We excavated two nests of each

  16. La vulnerabilitat de les zones d'interfase urbana i forestal davant els incendis : estudi de cas de l'incendi de Mont-Roig del Camp (Baix Camp)

    OpenAIRE

    Mira i Pou, Núria; Badia i Perpinyà, Anna

    2008-01-01

    L'incendi de Mont-roig del Camp (Baix Camp) del juliol del 2007 va posar en evidència la manca de planificació i prevenció de les zones que se situen a la interfase entre l'urbà i el forestal. L'experiència dels darrers incendis en zones urbanes ha mostrat la vulnerabilitat d'aquestes àrees davant una nova tipologia d'incendis que no presenta les mateixes característiques que els incendis forestals que tots coneixem, i que s'han anomenat incendis d'interfase urbana i forestal. El present arti...

  17. Study of the heterogeneities effect in the dose distributions of Leksell Gamma Knife (R), through Monte Carlo simulation; Estudio del efecto de las heterogeneidades en las distribuciones de dosis del Leksell GammaKnife (R), mediante simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Al-Dweri, F.M.O.; Lallena R, A.M. [Universidad de Granada, Granada (Spain)]. e-mail: elrc@nuclear.inin.mx

    2005-07-01

    In this work they are studied, by means of Monte Carlo simulation, the effects that take place in the dose profiles that are obtained with the Leksell Gamma Knife (R), when they are kept in account heterogeneities. The considered heterogeneities simulate the skull and the spaces of air that are in the head, like they can be the nasal breasts or the auditory conduits. The calculations were made using the Monte Carlo Penelope simulation code (v. 2003). The geometry of each one of the 201 sources that this instrument is composed, as well as of the corresponding channels of collimation of the Gamma Knife (R), it was described by means of a simplified model of geometry that has been recently studied. The obtained results when they are kept in mind the heterogeneities they present non worthless differences regarding those obtained when those are not considered. These differences are maximum in the proximities of the interfaces among different materials. (Author)

  18. Livestock grazing, habitat protection and diversity of bees and wasps in the Central Monte desert Ganadería, protección del hábitat y diversidad de abejas y avispas en el desierto del Monte Central

    OpenAIRE

    DIEGO P. VÁZQUEZ; Valeria Aschero; Erica L. Stevani

    2008-01-01

    Reserves aim mainly at preventing or mitigating human impacts on natural ecosystems. It is important to assess how well reserves meet this goal. We evaluated whether habitat protection offered by Ñacuñán Biosphere Reserve (Central Monte desert, Argentina) results in detectable changes in habitat structure and the species richness and composition of bees and wasps. We conducted pan trap sampling and flower visitor observations in six pairs of protected and unprotected sites. Our results sugges...

  19. Notas sobre a composição arbóreo-arbustiva de uma fisionomia das savanas de Roraima, Amazônia Brasileira Notes on the woody composition of a vegetation physionomy of the Roraima's savannas, Brazilian Amazonia

    OpenAIRE

    Reinaldo Imbrozio Barbosa; Sebastião Pereira do Nascimento; Paulo Atlântico Figueiredo de Amorim; Rosemberg Ferreira da Silva

    2005-01-01

    Foi realizado um inventário florístico das espécies arbóreo-arbustivas presentes em uma das unidades de vegetação que compõem a paisagem de savanas do Estado de Roraima, extremo norte da Amazônia brasileira. Esta unidade é caracterizada por ser densamente colonizada por ninhos do cupim Cornitermes ovatus Emerson. Foram observadas 29 espécies (15 famílias botânicas) em três localidades utilizadas para a amostragem. O total de espécies, por localidade, variou de 12 a 20. As espécies mais abunda...

  20. Sedici anni di censimenti del cervo sardo (Cervus elaphus corsicanus) nella riserva naturale WWF di Monte Arcosu

    OpenAIRE

    Murgia, Carlo; Murgia, Andrea; Deiana, Anna Maria

    2005-01-01

    This paper describes data collected about consistence, density and social structure of Sardinian deer (Cervus elaphus corsicanus Erxleben, 1777) subspecies of European deer (Cervus elaphus Linnaeus, 1758) from 1989 to 2004. The study area is located in the WWF Faunal Park of Monte Arcosu (south-western of Sardinia). The flora of the Reserve is typical Mediterranean vegetation. The data have been collected with two different methods, using both roaring census and direct observations. Results s...

  1. Contemplación y santidad : trabajos, quietud y quietismo en la " Subida del Monte "

    OpenAIRE

    Vilas-Boas Tavares, Pedro

    2010-01-01

    En prenant comme point de départ le motif récurrent de l’Ascension du Mont de la Perfection, magistralement commenté, entre autres, par Bernardino Laredo et Saint Jean de la Croix, nous nous placerons dans le cadre mystique molinosien. En recourant de manière instrumentale à la gravure de La Croce del niente, de Pier Matteo Petrucci (1676), admirateur et disciple des orientations du Guide Spirituel, de Miguel de Molinos, nous essayerons de démontrer les dangers’ et ambiguïtés d’un langage sus...

  2. FACTORES ASOCIADOS AL PERFIL DE LÍPIDOS SANGUÍNEOS EN LOS PACIENTES DEL ÁREA DE SALUD DE MONTES DE OCA, COSTA RICA

    OpenAIRE

    Erick G. Gutiérrez Peña; Juan José Romero Zúñiga

    2011-01-01

    En este estudio se analiza la asociación entre la exposición a diversos factores —de biotipo, socioeconómicos y patológicos— y la alteración del perfil de lípidos sanguíneos (dislipidemia) en pacientes adscritos al Área de Salud de Montes de Oca. Se realizó un estudio de caso-control, con un total de 135 casos e igual cantidad de controles, entre 20 y 65 años, a los que se les hizo un perfil de lípidos sanguíneos durante el año 2006. Las variables estudiadas fueron: edad, sexo, índice de masa...

  3. Estudio de la mortalidad posterior a un incendio en Pinus halepensis Mill. en los montes de El Cabezo y Los Titonares de Segorbe, comarca del Alto Palancia (Castellón)

    OpenAIRE

    BORDÓN PÉREZ, PABLO

    2012-01-01

    Bordón Pérez, P. (2012). Estudio de la mortalidad posterior a un incendio en Pinus halepensis Mill. en los montes de El Cabezo y Los Titonares de Segorbe, comarca del Alto Palancia (Castellón). http://hdl.handle.net/10251/16909. Archivo delegado

  4. Los depositos de yeso intrasedimentario del arroyo El Siasgo, partidos de Monte y General Paz, provincia de Buenos Aires

    Directory of Open Access Journals (Sweden)

    N. V. Dangavs

    2002-09-01

    Full Text Available El arroyo El Siasgo es un afluente del río Salado, situado en la región NE de la provincia de Buenos Aires. En su cuenca inferior, su curso recorta una gran depresión, remanente de una antigua cuenca de deflación colmatada, donde se desarrollaron, desde el Pleistoceno superior, diversos ambientes sedimentarios, principalmente acuáticos. Actualmente, se desarrolla, en esta depresión, un ambiente léntico temporario de 2.750 ha, dividido en dos cuerpos mediante un estrechamiento de la cubeta de 2 km de largo y 0,7 km de ancho. Al norte del estrechamiento se sitúa el cuerpo menor, denominado "La Cañada" y hacia el sur el mayor o "laguna del Siasgo". En los sedimentos clásticos hospedantes de este paleoambiente léntico múltiple aparece una importante acumulación de yeso intrasedimentario en distintos niveles estratigráficos (Formaciones Lobos, Luján y La Postrera I, cristalizado principalmente en tamaño arena, con diversidad de hábitos, texturas, fábricas y estructuras. Los sedimentos hospedantes del yeso son esencialmente fangos, cuya textura original se encuentra modificada por la presencia del mineral epigénico en fangos y limos arenosos e incluso en arenas fangosas. Este depósito yesífero abarca una superficie de 25,6 km², con un espesor medio de 2,15 m en el subambiente "del Siasgo" y de 0,91 m en "La Cañada". El volumen de sedimentos con yeso alcanza a 48 hm³ y la ley mineral mínima es 53,5% en la "laguna del Siasgo", con un total de 53.623.000 de toneladas de yeso impuro, mientras que en "La Cañada, con una ley media de 20,1 %, solamente alcanza a 1.361.000 toneladas de yeso impuro. Cabe señalar, que la baja ley del mineral en "La Cañada" descarta su aprovechamiento como recurso económico, mientras que el yeso presente en el subambiente "del Siasgo" es de alta potencialidad para su explotación, incluso en su valor mínimo. Estos yesos son el producto de la interacción de aguas superficiales y subterr

  5. Cultura forestal e imágenes del monte: el aprovechamiento forestal en la pequeña agricultura familiar

    OpenAIRE

    Mendez, Cecilia Diaz; Álvarez, Manuel Fonseca

    2000-01-01

    El siguiente trabajo parte de la necesidad de conocer el tipo de cultura forestal de las explotaciones familiares agrarias del norte de España. Nos encontramos con unos grupos familiares que regentan explotaciones agroganaderas de reducidas dimensiones y que cuentan con una parte de su superficie susceptible de ser aprovechada forestalmente. Se trata de explotaciones cuyas posibilidades de viabilidad, en muchos casos, pasan por diversificar su actividad productiva principal, la ganadería. Asi...

  6. Volcano-estratigrafía y tectónica del Valle Central Occidentaly las estribaciones de los Montes del Aguacate a lo largo de la ruta 27, Costa Rica Volcano-stratigraphy and tectonics of the Western Central Valley and Montes del Aguacate along road 27, Costa Rica

    Directory of Open Access Journals (Sweden)

    Hernán Porras

    2012-12-01

    Full Text Available La Ruta 27, también conocida como carretera Ciudad Colón-Caldera, ofrece cortes geológicos de entre 5 y 40 m de altura que muestran una buena parte de la estratigrafía, en su mayoría volcánica y subvolcánica, del extremo occidental del Valle Central y las estribaciones de los Montes del Aguacate. Se observa una secuencia volcánica correlacionable con la Formación Grifo Alto (Plioceno, profundamente hidrotermalizada (alteración propilítica en varios sectores, compuesta por lavas, brechas y depósitos epivolcánicos, (depósitos fluviales de corrientes hiperconcentradas, depósitos de debris avalanches algunos ligera a moderadamente basculados, cortados por diques. Una serie de depósitos de debris avalanches antiguos también está presente, relacionados con el vulcanismo de los Montes del Aguacate. Localmente, una secuencia de varias unidades de mesobrechas de bloques andesíticos vidriosos, monomícticos en una matriz de cenizas vitro-cristalina, se interpreta como posibles depósitos asociados a flujos de bloques y cenizas, posiblemente en correspondencia con un vulcanismo coetáneo con la Formación Monteverde (Pleistoceno Inferior. Al menos 4 unidades de depósitos de debris flow/debris avalanche del Pleistoceno Medio se asocian a la Formación Nuestro Amo (Pleistoceno Medio. Sobre ellos se presentan los pórfidos andesíticos de la Formación Colima Inferior, seguidos de las ignimbritas de las formaciones Puente de Mulas y Tiribí, todas del Pleistoceno Medio, las que contienen niveles ignimbríticos hiperconcentrados e intercalaciones fluviales con espesores decrecientes. Un pliegue de propagación, que afecta a estas ignimbritas, es considerado indicio de la existencia de una tectónica de cabalgamiento de tipo piel delgada con vergencia al SW, activa al menos desde el Pleistoceno Medio. Gran parte del basculamiento de las rocas expuestas a lo largo de la Ruta 27, su tipo de fracturamiento, fallamiento y plegamiento, y la

  7. Circuitos del conocimiento: el Arte de la lengua índica de Valera y su inclusión en las polémicas sobre el Sacro Monte de Granada

    Directory of Open Access Journals (Sweden)

    José Alejandro Cárdenas Bunsen

    2014-07-01

    Full Text Available ResumenA partir del examen de documentos inéditos, este artículo muestra que Blas Valera (1545-1597 fue autor de un Arte de la lengua índica, que circulaba en Sevilla en 1595. Sostiene también que Valera puede ser identificado como el director detrás del Arte y vocabulario en la lengua general del Perú, publicado anónimamente en 1586. El estudio reconstruye, además, el contexto intelectual que hizo posible la circulación de la obra de Valera y los criterios filológicos que permitieron insertar su obra en las discusiones sobre las reliquias y libros del Sacro Monte de Granada y sus implicaciones sobre la historia de la iglesia primitiva española.Palabras clave: Blas Valera, Sacro Monte de Granada, Inca Garcilaso de la Vega, Tercer Concilio de LimaAbstractRelying on unpublished documents, this article maintains that Blas Valera (1545-1597 authored an unknown Arte de la lengua índica that circulated in Seville in 1595. It also argues that Valera can be identified as the single director behind the Arte y vocabulario en la lengua general del Perú that was published anonymously in 1586. In addition, this study reconstructs the intellectual milieu that made the circulation of Valera’s grammar possible and the philological criteria that laid the groundwork for its insertion in the debate regarding the relics and leaden books recently discovered at Granada’s Sacro Monte, and their implications for the history of Spain’s early Church.Keywords: Blas Valera, Sacro Monte de Granada, Inca Garcilaso de la Vega, Lima’s Third Council

  8. Inseguridad ciudadana y la evaluación del espacio público de Montes de Oca (Costa Rica)

    OpenAIRE

    Verónica Ovares Fallas; Jessica Quirós Loría

    2015-01-01

    El tema de la salud mental debe abordarse tanto desde factores individuales como colectivos, así que es fundamental que la Psicología se enfoque en el entorno donde se desarrollan las personas. En Costa Rica, una de las problemáticas más sobresalientes en los últimos años es la inseguridad ciudadana, la cual, según los planteamientos de este documento, está influenciada por características del espacio público, que tiene una función importante en la promoción de la salud. En el presente ...

  9. Estudio del efecto del aceite esencial de orégano de monte (Lippia origanoides) del Alto Patía sobre la metanogénesis y la actividad fibrolítica del ecosistema ruminal

    OpenAIRE

    Rodríguez Quiroz, Tatiana Alejandra

    2014-01-01

    Este estudio evaluó por primera vez el aceite esencial de orégano (AEO) nativo colombiano Lippia origanoides Kunth (componente principal timol 70%) como modulador de la estructura de la comunidad de los metanógenos ruminales, la actividad fibrolítica y consecuentemente sobre la metanogenesis ruminal. En primera instancia se evaluó el efecto de la dosis del AEO sobre la producción de metano y DIVMS en fermentaciones in vitro utilizando como sustrato Penisetum cladestinum con cin...

  10. FACTORES ASOCIADOS AL PERFIL DE LÍPIDOS SANGUÍNEOS EN LOS PACIENTES DEL ÁREA DE SALUD DE MONTES DE OCA, COSTA RICA

    Directory of Open Access Journals (Sweden)

    Erick G. Gutiérrez Peña

    2011-07-01

    Full Text Available En este estudio se analiza la asociación entre la exposición a diversos factores —de biotipo, socioeconómicos y patológicos— y la alteración del perfil de lípidos sanguíneos (dislipidemia en pacientes adscritos al Área de Salud de Montes de Oca. Se realizó un estudio de caso-control, con un total de 135 casos e igual cantidad de controles, entre 20 y 65 años, a los que se les hizo un perfil de lípidos sanguíneos durante el año 2006. Las variables estudiadas fueron: edad, sexo, índice de masa corporal, tipo de aseguramiento, estado de portador de hipertensión arterial, de diabetes mellitus o de ambas patologías crónicas a la vez. Se realizó un análisis univariado, seguido de un análisis multivariado, mediante un modelo logístico múltiple. La única variable asociada con la dislipidemia fue el índice de masa corporal, tanto en el análisis univariado como en el multivariado; las variables restantes no mostraron asociación estadística. Aquellos pacientes con mayor índice de masa corporal presentan un mayor riesgo de tener un perfil alterado de lípidos sanguíneos.

  11. Paleoenvironmental reconstruction of the coastal Monte Léon and Santa Cruz formations (Early Miocene) at Rincón del Buque, Southern Patagonia: A revisited locality

    Science.gov (United States)

    Raigemborn, M. Sol; Matheos, Sergio D.; Krapovickas, Verónica; Vizcaíno, Sergio F.; Bargo, M. Susana; Kay, Richard F.; Fernicola, Juan C.; Zapata, Luciano

    2015-07-01

    Sedimentological, ichnological and paleontological analyses of the Early Miocene uppermost Monte León Formation and the lower part of the Santa Cruz Formation were carried out in Rincón del Buque (RDB), a fossiliferous locality north of Río Coyle in Santa Cruz Province, Patagonia, Argentina. This locality is of special importance because it contains the basal contact between the Monte Léon (MLF) and the Santa Cruz (SCF) formations and because it preserves a rich fossil assemblage of marine invertebrates and marine trace fossils, and terrestrial vertebrates and plants, which has not been extensively studied. A ˜90 m-thick section of the MLF and the SCF that crops out at RDB was selected for this study. Eleven facies associations (FA) are described, which are, from base to top: subtidal-intertidal deposits with Crassotrea orbignyi and bioturbation of the Skolithos-Cruziana ichnofacies (FA1); tidal creek deposits with terrestrial fossil mammals and Ophiomorpha isp. burrows (FA2); tidal flat deposits with Glossifungites ichnofacies (FA3); deposits of tidal channels (FA4) and tidal sand flats (FA5) both with and impoverish Skolithos ichnofacies associated; marsh deposits (FA6); tidal point bar deposits recording a depauperate mixture of both the Skolithos and Cruziana ichnofacies (FA7); fluvial channel deposits (FA8); fluvial point bar deposits (FA9); floodplain deposits (FA10); and pyroclastic and volcaniclastic deposits of the floodplain where terrestrial fossil mammal remains occur (FA11). The transition of the MLF-SCF at RDB reflects a changing depositional environment from the outer part of an estuary (FA1) through the central (FA2-6) to inner part of a tide-dominated estuary (FA7). Finally a fluvial system occurs with single channels of relatively low energy and low sinuosity enclosed by a broad, low-energy floodplain dominated by partially edaphized ash-fall, sheet-flood, and overbank deposits (FA8-11). Pyroclastic and volcaniclastic materials throughout the

  12. Body mass variation in the Geoffroy's cat (Oncifelis geoffroyi Variaciones de la masa corporal del gato montés (Oncifelis geoffroyi

    Directory of Open Access Journals (Sweden)

    MAURO LUCHERINI

    2006-06-01

    Full Text Available We report new data on the intersexual and geographical variation in body mass of the Geoffroy's cat (Oncifelis geoffroyi d'Orbigny and Gervais 1844, a little known small cat from South America, and combine them with the existing information to compare alternative hypotheses for variation in body mass. Most data on the body mass of O. geoffroyi have been obtained from previous research on this felid in four study areas of southern Brazil and central and southern Argentina. These data were added to those reported for other three additional locations. Our results set the body mass of O. geoffroyi to 4.26 ± 1.03 kg (mean ± SD, n = 56. We also show that males generally are heavier than females throughout most of this species' distributional range. Body mass dimorphism is 1.34 on average, but ranges from 1.19 and 1.21 in Uruguay and southern Chile, respectively, to 1.76 in the northern Pampas of Argentina. When data from the best sampled areas are considered (Torres del Paine, Lihué Calel, southern Pampas, Campos del Tuyú and southern Brazil, only male body mass varies with geographic location. More intriguingly, no correlation was found between body mass and latitude. Our results suggest a smaller mean weight of O. geoffroyi relative to what was previously published, but also suggest a wider variation. Our analysis do not support Bergmann's rule, according to which the largest individuals would occur in the southernmost regions of this cat's geographic distribution, while they seem supportive of a sexually-selected process affecting sexual size dimorphism in the Geoffroy's catSe reportan nuevos datos sobre la variación intersexual y geográfica de la masa corporal en el gato montés (Oncifelis geoffroyi d'Orbigny and Gervais 1844, un félido pequeño y poco conocido de América del Sur, y los combinamos con la información existente para evaluar dos hipótesis que explicarían esta variación. La mayor parte de los datos sobre masa corporal de O

  13. Estado ecológico de los ríos incluidos dentro del parque Nacional de Ordesa y Monte Perdido (Cuenca del Ebro, Aragón, mediante indicadores de macroinvertebrados

    Directory of Open Access Journals (Sweden)

    Valladolid, María

    2015-12-01

    Full Text Available We provide information about the ecological status of Arazas, Bellós and Yaga rivers (Ordesa y Monte Perdido National Park, obtained from samples collected by volunteers during the 2013 spring-summer season, included in the “Volunteering activities in the Parks Network” program (MAGRAMA. In each river three points have been selected, all belonging to Type 27: High mountain rivers, except one that is Type 26: Humid calcareous mountain river. For each point several macroinvertebrate indexes (IBMWP, IASPT, NFAM, NFPLE and EPT and their ecological quality ratios (EQR were calculated. As a whole, 72% of the IBMWP measurements show Very good or Good quality, a 22% Moderate and a 6% Deficient. The Yaga River showed all the measures as Very Good-Good while in the Arazas River we found the three classes of quality cited. In general, for each river the values of the indexes are decreasing from mouth to source, while most of values are increasing in a temporal pattern (from spring to late summer in each sampling point, except in two points, Arazas-3 and Bellós-2, that show the opposite pattern.Se presenta información sobre el estado ecológico de los ríos Arazas, Bellós y Yaga (Parque Nacional de Ordesa y Monte Perdido, obtenida a partir de muestras recolectadas en la primavera-verano de 2013 por voluntarios, dentro del programa “Actividades de voluntariado en la Red de Parques” (MAGRAMA. En cada río se seleccionaron tres puntos de muestreo, todos pertenecientes al Tipo 27: Ríos de alta montaña, excepto uno, del Tipo 26: Ríos de montaña húmeda calcárea. Para cada punto se ha calculado una serie de índices de macroinvertebrados (IBMWP, IASPT, NFAM, NFPLE y EPT y sus ratios de estado ecológico (EQR. En total, el 72% de las medidas del IBMWP dan una calidad Muy buena o Buena, un 22% Moderada y un 6% Deficiente. El río Yaga presentó todas las medidas de calidad Muy Buena-Buena, mientras que en el río Arazas encontramos las tres clases

  14. Depreciación de la plata, políticas públicas y desarrollo empresarial. Las pequeñas y medianas empresas mineras mexicanas de Pachuca y Real del Monte

    Directory of Open Access Journals (Sweden)

    Uribe Salas, José Alfredo

    2011-08-01

    Full Text Available This article studies the business strategies and capacity of small and medium-sized mining enterprises that operated in the Pachuca-Real del Monte mining district in Mexico in the late 19th century. In a regional economic context dominated by the monopoly of the Compañía de Minas Real del Monte y Pachuca, small and medium-sized enterprises managed to obtain advantages from both the silver depreciation in the international currency markets and the Mexican public policies focused precisely on mitigating the fall in the price of silver after 1873. The way that some minor and medium-sized local entrepreneurs injected new life into mining activities in the region, thereby actually benefiting from the international circumstances, is analysed. In sum, it was the small and medium-sized mining companies that supported the productive and business development that characterized the period of mining growth in the district during the dictatorship of President Porfirio Díaz.

    Se estudian las estrategias empresariales y la capacidad de las pequeñas y medianas empresas mineras que operaron en el Distrito de Real del Monte y Pachuca para obtener ventajas relativas tanto de la depreciación de la plata en los mercados internacionales como de las políticas públicas establecidas por los gobiernos mexicanos después de 1873 para paliar la caída del valor argentífero, en un contexto de monopolio minero-metalúrgico promovido por la Compañía de Minas Pachuca y Real del Monte. Se analiza cómo algunos pequeños y medianos empresarios locales dieron nuevos bríos a la actividad minera y cómo se vieron beneficiados con la situación internacional. Se concluye que fueron las pequeñas y medianas empresas las que sustentaron el desarrollo productivo y empresarial que caracterizó el auge minero en la región de estudio durante periodo porfirista en México.

  15. Notas sobre a composição arbóreo-arbustiva de uma fisionomia das savanas de Roraima, Amazônia Brasileira Notes on the woody composition of a vegetation physionomy of the Roraima's savannas, Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Reinaldo Imbrozio Barbosa

    2005-06-01

    Full Text Available Foi realizado um inventário florístico das espécies arbóreo-arbustivas presentes em uma das unidades de vegetação que compõem a paisagem de savanas do Estado de Roraima, extremo norte da Amazônia brasileira. Esta unidade é caracterizada por ser densamente colonizada por ninhos do cupim Cornitermes ovatus Emerson. Foram observadas 29 espécies (15 famílias botânicas em três localidades utilizadas para a amostragem. O total de espécies, por localidade, variou de 12 a 20. As espécies mais abundantes foram Byrsonima verbascifolia (L. DC. e Mimosa microcephala Humb. & Bonpl. ex Willd. (subarbustivas, Byrsonima cf. intermedia A. Juss. e Randia formosa (Jack. K. Schum. (arbustivas e, Byrsonima crassifolia (L. H.B.K. e Curatella americana L. (arbóreas. Oito espécies são comuns às três localidades. A diversidade medida pelo Índice de Shannon (H' foi baixa para todos os locais amostrados (A floristic inventory of woody species was carried out in one of the vegetation units that compose the savannas landscape of the Roraima State, northernmost of Brazilian Amazonia. This unit is characterized by dense colonization of nests of termites Cornitermes ovatus Emerson. Twenty nine woody species were observed (15 botany families in three localities used for sampling. The total of species varied from 12 to 20 by locality. The most abundant species were Byrsonima verbascifolia (L. DC. and Mimosa microcephala Humb. & Bonpl. ex Willd. (dwarf shrubs, Byrsonima cf. intermedia A. Juss. and Randia formosa (Jack. K. Schum. (shrubby and, Byrsonima crassifolia (L. H.B.K. and Curatella americana L. (arboreal. Eight species are common to all localities. Diversity measured by the Index of Shannon (H' was low for all the areas sampled (<0.90 indicating high specimens concentration in few species. The Index of Sørensen indicated similarities (± 0.60 among studied areas, suggesting a group of landscapes with common plant diversity, representing a same

  16. Valutazione del potenziale di sequestro del carbonio forestale nella serie di vegetazione Galio-Scabri Quercetum ilicis: il caso di studio del Monte Arci: Sardegna centrale

    OpenAIRE

    Schirru, Matilde Silvia

    2015-01-01

    The main goal of this research is to verify the feasibility and applicability of procedures aimed at estimating forest carbon stocks for different land use categories at the local scale. As a case study the Monte Arci - Distretto forestale dell'Arci Grighine (central-western Sardinia), was chosen. In this ambit, the vegetation series of the Galio scabri-Quercetum ilicis was evaluated, on a total area of 1,650 hectares of woods and shrubs. The investigation started from unpublished inventory d...

  17. Dosimetric effect of statistics noise of the TC image in the simulation Monte Carlo of radiotherapy treatments; Efecto dosimetrico del ruido estadistico de la imagen TC en la simulacion Monte Carlo de tratamientos de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Laliena Bielsa, V.; Jimenez Albericio, F. J.; Gandia Martinez, A.; Font Gomez, J. A.; Mengual Gil, M. A.; Andres Redondo, M. M.

    2013-07-01

    The source of uncertainty is not exclusive of the Monte Carlo method, but it will be present in any algorithm which takes into account the correction for heterogeneity. Although we hope that the uncertainty described above is small, the objective of this work is to try to quantify depending on the CT study. (Author)

  18. Aplicación del Método de Monte Carlo en el Análisis de Materiales Utilizados en Detectores Flat Panel para Obtener Espectros de Rayos X.

    OpenAIRE

    Pozuelo, Fausto; Querol Vives, Andrea; Gallardo Bermell, Sergio; Ródenas Diago, José; Verdú Martín, Gumersindo Jesús

    2013-01-01

    En este trabajo se propone el uso de un detector flat panel junto a una cuña de polimetilmetacrilato (PMMA) para estimar el espectro de rayos X utilizando el método de Monte Carlo y técnicas de reconstrucción. El código MCNP5 se ha utilizado para modelar distintos flat panel y obtener las curvas de dosis y las funciones respuesta del sistema. La mayor parte de los flat panel actuales utilizan materiales que presentan discontinuidades debidas al borde K en el coeficiente másico de absorción de...

  19. Los insectos galícolas en Schinus fasciculata (Anacardiaceae) en el Espinal del centro de Argentina

    OpenAIRE

    Melisa Malcolm; Antonia J. Oggero; Marcelo D. Arana; María del Carmen Tordable; Graciela T. Boito

    2015-01-01

    La más compleja de las interacciones que plantas e insectos han desarrollado durante el transcurso de su evolución, son las agallas. Las especies de insectos galícolas se encuentran en la mayoría de las regiones biogeográficas, principalmente en ambientes xéricos, de los cuales un ejemplo lo constituye la ecorregión del Espinal, ubicada en la Provincia Biogeográfica de la Pampa, Subregión Chaqueña. Schinus fasciculata (Griseb.) I.M. Johnst. (Anacardiaceae) es una especie arbórea o arbustiva r...

  20. Calibration of the identiFINDER detector for the iodine measurement in thyroid using the Monte Carlo method; Calibracion del detector identiFINDER para la medicion de yodo en tiroides utilizando el metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ramos M, D.; Yera S, Y.; Lopez B, G. M.; Acosta R, N.; Vergara G, A., E-mail: dayana@cphr.edu.cu [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/ 41 y 47, Playa, 10600 La Habana (Cuba)

    2014-08-15

    This work is based on the determination of the detection efficiency of {sup 125}I and {sup 131}I in thyroid of the identiFINDER detector using the Monte Carlo method. The suitability of the calibration method is analyzed, when comparing the results of the direct Monte Carlo method with the corrected, choosing the latter because the differences with the real efficiency stayed below 10%. To simulate the detector their geometric parameters were optimized using a tomographic study, what allowed the uncertainties minimization of the estimates. Finally were obtained the simulations of the detector geometry-point source to find the correction factors to 5 cm, 15 cm and 25 cm, and those corresponding to the detector-simulator arrangement for the method validation and final calculation of the efficiency, demonstrating that in the Monte Carlo method implementation if simulates at a greater distance than the used in the Laboratory measurements an efficiency overestimation can be obtained, while if simulates at a shorter distance this will be underestimated, so should be simulated at the same distance to which will be measured in the reality. Also, is achieved the obtaining of the efficiency curves and minimum detectable activity for the measurement of {sup 131}I and {sup 125}I. In general is achieved the implementation of the Monte Carlo methodology for the identiFINDER calibration with the purpose of estimating the measured activity of iodine in thyroid. This method represents an ideal way to replace the lack of patterns solutions and simulators assuring the capacities of the Internal Contamination Laboratory of the Centro de Proteccion e Higiene de las Radiaciones are always calibrated for the iodine measurement in thyroid. (author)

  1. Monte Carlo techniques for the study of cancer patients fractionation in head and neck treated with radiotherapy; Tecnicas de Monte Carlo para el estudio del fraccionamiento en pacientes de cancer de cabeza y cuello tratados con radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco Herrera, M. A.; Jimenez Dominguez, M.; Perucha Ortega, M.; Herrador Cordoba, M.

    2011-07-01

    The dose fractionation than the standard head and neck cancer in some situations involve a significant increase of local control and overall survival. There is clinical evidence of these results in case of hyperfractionated treatments, although the choice of optimal fractionation generally is not obtained from the results of any model, in this study has provided the tumor control probability (TCP) for various subdivisions modified (hypo fractionated and hyperfractionated) using Monte Carlo simulation techniques.

  2. Efecto de las acciones antrópicas sobre la estabilidad de agregados del suelo en zonas semiáridas

    OpenAIRE

    Campoy Cervellera, Manuel Jesús

    2015-01-01

    En zonas semiáridas, como la del sudeste español, la progresiva degradación que sufren sus suelos afecta a la vegetación que soportan los mismos. La regeneración de las propiedades físicas de suelos degradados es necesaria para favorecer la implantación de la vegetación, frenando de esta manera la erosión y el lixiviado de contaminantes. El objetivo de esta Tesis fue comprobar y cuantificar el efecto de diversas acciones antrópicas (prácticas de revegetación con arbustivas mediante el uso de ...

  3. Los depositos de yeso intrasedimentario del arroyo El Siasgo, partidos de Monte y General Paz, provincia de Buenos Aires Intrasedimentary gypsum deposits of El Siasgo Creek, Monte and General Paz districts, Buenos Aires Province

    Directory of Open Access Journals (Sweden)

    N. V. Dangavs

    2002-09-01

    Full Text Available El arroyo El Siasgo es un afluente del río Salado, situado en la región NE de la provincia de Buenos Aires. En su cuenca inferior, su curso recorta una gran depresión, remanente de una antigua cuenca de deflación colmatada, donde se desarrollaron, desde el Pleistoceno superior, diversos ambientes sedimentarios, principalmente acuáticos. Actualmente, se desarrolla, en esta depresión, un ambiente léntico temporario de 2.750 ha, dividido en dos cuerpos mediante un estrechamiento de la cubeta de 2 km de largo y 0,7 km de ancho. Al norte del estrechamiento se sitúa el cuerpo menor, denominado "La Cañada" y hacia el sur el mayor o "laguna del Siasgo". En los sedimentos clásticos hospedantes de este paleoambiente léntico múltiple aparece una importante acumulación de yeso intrasedimentario en distintos niveles estratigráficos (Formaciones Lobos, Luján y La Postrera I, cristalizado principalmente en tamaño arena, con diversidad de hábitos, texturas, fábricas y estructuras. Los sedimentos hospedantes del yeso son esencialmente fangos, cuya textura original se encuentra modificada por la presencia del mineral epigénico en fangos y limos arenosos e incluso en arenas fangosas. Este depósito yesífero abarca una superficie de 25,6 km², con un espesor medio de 2,15 m en el subambiente "del Siasgo" y de 0,91 m en "La Cañada". El volumen de sedimentos con yeso alcanza a 48 hm³ y la ley mineral mínima es 53,5% en la "laguna del Siasgo", con un total de 53.623.000 de toneladas de yeso impuro, mientras que en "La Cañada, con una ley media de 20,1 %, solamente alcanza a 1.361.000 toneladas de yeso impuro. Cabe señalar, que la baja ley del mineral en "La Cañada" descarta su aprovechamiento como recurso económico, mientras que el yeso presente en el subambiente "del Siasgo" es de alta potencialidad para su explotación, incluso en su valor mínimo. Estos yesos son el producto de la interacción de aguas superficiales y subterr

  4. Estudio de impacto ambiental en la Zona 12, Monte U.P. la Matea, T.M. de Enguera (Valencia), del parque de aerogeneradores

    OpenAIRE

    Sánchiz Martínez, María del Carmen; Gómez Marín, Lucía

    2012-01-01

    El objetivo del proyecto es realizar un estudio de los impactos ambientales del proyecto de instalación de 70 aerogeneradores en la sierra de Enguera, por parte de la empresa Acciona. Este estudio tendrá cuatro partes principales: 1. Inventariar el entorno donde se ubicara el parque eólico, valorando la calidad y destacando sus elementos más singulares. 2. Identificar, describir y cuantificar los impactos producidos por la realización del parque tanto en fase de construcción como ...

  5. El arzobispo don Pedro de Castro Cabeza de Vaca y Quiñones y la influencia del Sacro Monte en el desarrollo inmaculista en Granada.

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    José Antonio Peinado Guzmán

    2015-12-01

    Full Text Available The figure of archbishop don Pedro de Castro was extremely important for the development of immaculist devotion in Granada in the 16th century and beginning of the 17th century. In the wake of the famous discoveries of the Sacro Monte, it will produce an evolution of this belief in land Granada at the request of this prelate, who took the issue as one of his personal priorities in his episcopate. Intelligent handling of the issue by the Archbishop, while the findings of the Sacro Monte were subsequently convicted of Rome, eventually landing in the erection of the Abbey, in the ideological use of all of this, as well as the extension of the conceptionism in Granada.

  6. Sísmica de reflexión de alta resolución en el estudio del Cuaternario de áreas de pie de monte

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    G. González Bonorino

    2003-03-01

    Full Text Available Se realizaron varias pruebas piloto con sísmica de reflexión de baja profundidad en depósitos de abanicos aluviales distales en la provincia de Salta, Argentina. Las pruebas incluyen dos áreas con características de subsuelo contrastantes. En el sector nororiental de la provincia, los depósitos del extenso abanico aluvial del Bermejo son arenosos y macizos, casi sin intercalaciones arcillosas; la napa se encontraba a más de 40 m de profundidad al tiempo del estudio. La otra zona de prueba se ubica al sur de la ciudad de Salta, donde coalescen abanicos aluviales pequeños que rellenan el valle de Lerma con depósitos de arena y grava, los cuales en los tramos distales se interdigitan con potentes capas arcillosas; la napa en esta área se hallaba a una profundidad mayor de 20 m al momento del estudio. La operación sísmica empleó un sismógrafo Geometrics R24 con 24 canales activos que se aumentaron a 48 mediante un "roll-over switch", alcanzando un máximo de cobertura de 1200%. Se probaron dos fuentes de sonido: una masa de 5 kg y una escopeta calibre 12. Principalmente por razones operativas se eligió como fuente la masa. Las pruebas en el abanico del Bermejo dieron registros de baja calidad, probablemente debido a la rápida pérdida de energía en las areas poco consolidadas y secas. Localmente, sin embargo, pudieron distinguirse tres unidades sísmicas y el techo del Terciario posiblemente fue detectado. Las pruebas en eje del valle de Lerma dieron registros sísmicos de excelente calidad. Se distinguieron cuatro unidades sísmicas. Un reflector débil a aproximadamente 220 mseg coincide con un cambio de las velocidades a unos 2500 m/seg y puede corresponder con el techo del sustrato terciario. Una potente capa de arcilla a una profundidad de 25 a 50 m puede claramente mapearse como un acuitardo. Los resultados de este estudio piloto demuestran que la sísmica de reflexión de poca profundidad puede ser aplicada con provecho en el

  7. Use of Monte Carlo simulation software for the calculation of the effective dose in cone beam Tomography; Uso del software de simulacion Monte Carlo para el calculo de la dosis efectiva en Tomografia de haz conico

    Energy Technology Data Exchange (ETDEWEB)

    Gomes B, W. O., E-mail: wilsonottobatista@gmail.com [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Bardalho, 40301-015 Salvador, Bahia (Brazil)

    2015-10-15

    Full text: In this study irradiation geometry applicable to PCXMC and the consequent calculation of effective dose in applications of cone beam computed tomography (CBCT) was developed. Two different CBCT equipment s for dental applications were evaluated: Care Stream Cs-9000 3-Dimensional and Gendex GXCB-500 tomographs. Each protocol initially was characterized by measuring the surface kerma input and the product air kerma-area, P{sub KA}. Then, technical parameters of each of the predetermined protocols and geometric conditions in the PCXMC software were introduced to obtain the values of effective dose. The calculated effective dose is within the range of 9.0 to 15.7 μSv for Cs 9000 3-D and in the range 44.5 to 89 mSv for GXCB-500 equipment. These values were compared with dosimetric results obtained using thermoluminescent dosimeters implanted in anthropomorphic mannequin and were considered consistent. The effective dose results are very sensitive to the radiation geometry (beam position); this represents a factor of fragility software usage, but on the other hand, turns out to be a very useful tool for quick conclusions regarding the optimization process of protocols. We can conclude that the use of Monte Carlo simulation software PCXMC is useful in the evaluation of test protocols of CBCT in dental applications. (Author)

  8. Balance y modelización del acuífero karstico de los Montes Torozos (Valladolid, España)

    OpenAIRE

    Germán Sanz-Lobón; Roberto Martínez-Alegría; Javier Taboada; Teresa Albuquerque; Margarida Antunes; Isabel Montequi

    2015-01-01

    En este trabajo se presenta el balance hídrico de una masa de agua subterránea de naturaleza kárstica de la cuenca sedimentaria del Duero, centro oeste de España. Los datos obtenidos para la realización del balance han sido introducidos en una herramienta de simulación con el fin de conocer la evolución temporal de los recursos hídricos a lo largo del año hidrológico. Para ello se ha sido necesario recurrir a la utilización de técnicas geostadísticas y el programa Visual Modflow. La masa de a...

  9. Espectro trófico de Chelonoidis chilensis (Chelonii: Testudinidae en la provincia fitogeográfica del monte (Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Richard, Enrique

    1994-01-01

    Full Text Available Between 1983 and 1991, 83 field trips were made to the biogeographical province of Monte, in Mendoza province, Argentina, in order to study the trophic spectrum of Chelonoidis chilensis, among other ecoethological aspects. The trophic period extends from September to April. Adults are herbivorous in strict sense, but this may change according to the available resourees. Trophic spectrum is composed by 14 items (Families of vegetables. Some items have toxic or potentially toxit substances. Finally, the diet of Ch. chilensis is compared with the one of Ch. donosobarrosi and with other desert tortoises.

  10. Propuesta de un sistema de indicadores para evaluar el impacto del turismo en la pobreza de la localidad de Monte Hermoso

    Directory of Open Access Journals (Sweden)

    Silvina Elías

    2012-11-01

    Full Text Available Este trabajo plantea un sistema de indicadores de la actividad turística en la localidad de Monte Hermoso (Provincia de Buenos Aires, República Argentina basado en el modelo DPSIR (Driving Forces, Pressures, States, Impacts and Responses. Las limitaciones propias de este modelo, así como aquellas referidas a la información disponible presentan algunas dificultades. Sin embargo, avanzar en su implementación permitirá tomar acciones de política que se orienten a la disminución de la pobreza en la citada localidad, generando igualdad de oportunidades para todos los actores involucrados.

  11. Abiotic gradients drive floristic composition and structure of plant communities in the Monte Desert Gradientes abióticos dirigen la composición florística y la estructura de las comunidades de plantas en el Desierto del Monte

    Directory of Open Access Journals (Sweden)

    PABLO ACEBES

    2010-01-01

    Full Text Available Defining plant communities in desert zones is difficult due to large scale homogeneity and small scale heterogeneity, thus making provision of systematic information for conservation decisions problematic. We analysed plant communities of the most arid sector of Monte Desert for structure, plant composition and environmental variables. Small-scale variables such as slope, rock cover, bare ground and litter, as well as large-scale ones such as species diversity, composition and similarity within and between sites were included. Analyses of floristic composition showed the difficulty of segregating distinct communities due to high internal heterogeneity and overlap between the different sites. Only mesquite woodlands, a community situated at the extreme of the soil moisture-gradient was segregated. Ordination on structural variables was somewhat more successful in segregating communities on the basis of substrate type and of tree and shrub cover. Our results showed the difficulty distinguishing plant communities in temperate deserts, suggesting the existence of relatively stable assemblages of species at the extremes of the gradients and of great heterogeneity within and between sites. They cannot be defined by floristic variables solely, but require environmental information also.La definición de comunidades discretas de plantas en zonas desérticas es complejo debido tanto a su homogeneidad a gran escala como a su heterogeneidad a pequeña escala, lo que acaba generando dificultades para la toma de decisiones de conservación. En este trabajo analizamos las comunidades de plantas del sector más árido del Desierto del Monte en función de su estructura y composición florística. Se han utilizado también variables ambientales estimadas a pequeña escala como la pendiente o la superficie de roca, suelo desnudo y hojarasca, así como variables que operan a mayor escala como la diversidad de especies, la composición florística y la similitud

  12. Quantitative elemental determination of the particulate matter in the atmosphere of Pachuca city and the Real del Monte village, Hidalgo by means of PIXE technique; Determinacion elemental cuantitativa de la materia particulada en la atmosfera de la ciudad de Pachuca y el poblado de Real del Monte, Hidalgo, mediante la tecnica PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Guasso G, C.L. [ITT, 50000 Toluca (Mexico)

    2001-07-01

    All the pollutants that are generated so much of anthropogenic activities as natural cause effects to the health, and of course its increase the atmospheric pollution. Today in day for the great advance of the technology other pollutants are even generated but noxious to the human being's health, such it is the case of the particles, which are also called particulate matter airborne (MPA). This has motivated, to establish control measures leaning in collection strategies and certified analysis techniques, accurate and reliable. In the National Institute of Nuclear Research (ININ) they have been carried out studies on particulate matter airborne. In 1991 it was installed, calibrated and validated the nuclear technique of atomic origin based on proton beams known as PIXE. The characterization of the (MPA) it is carried out applying this technique and the collection by means of Dichotomous collectors (SFU). The thesis work that is presented next, includes the topic of the atmospheric pollution by particulate matter airborne (MPA) in a mining region, inside the Hidalgo State. The study was carried out during the 1998 winter season, only embracing the whole month of March in alternate days giving a total of 112 samples. Two sites that are highly active in the mining were studied, these are: the Real del Monte town and the Hidalgo state capital: Pachuca. Four samples per day were collected beginning to the 7:00 am--7:00 pm (daytime period) and concluding to the 7:00 pm -7:00 am (nocturne period). The characterization of its elementary content is carried out using the X-ray emission induced by particles technique (PIXE) that is a nuclear technique able to analyze 23 chemical elements beginning from the Al to the Pb, it requires of a very small sample quantity, it is very sensitive and it is not destructive. This characterization one carries out so much for fraction PM{sub 2.5} (fine) like as PM{sub 10} (thick) in both sites, also it was analyzed the temporary

  13. Interrelación de los ambientes eólico y marino a través del análisis textural y mineralógico de las arenas de Monte Hermoso, Argentina Aeolian and marine environments relationships through textural and mineralogical análisis of the sands from Monte Hermoso, Argentina.

    Directory of Open Access Journals (Sweden)

    Elba Fernández

    2003-12-01

    Full Text Available El objetivo de este trabajo es investigar la mutua influencia entre los ambientes eólico y marino, en un sector de playa de la ciudad balnearia de Monte Hermoso, a través de las características texturales y mineralógicas de los sedimentos. Para tratar de interpretar la dirección de movimiento del sedimento, se realizó un muestreo de la playa en los subambientes definidos particularmente para este estudio: base de médano, berma, playa media, playa baja y bajamar, de dos perfiles perpendiculares a la línea de costa y separados entre sí por 200 m. De las correspondientes muestras de arena se obtuvieron sus distribuciones granométricas y parámetros estadísticos, con los que se realizaron diagramas de dispersión confrontando de a pares esos valores. También fue aplicada la matriz de tendencia de dichos parámetros, para reflejar los cambios que pueden ocurrir entre las fuentes de aporte de un sedimento y su depósito. Las arenas de base de médano y de bajamar fueron estudiadas en su composición mineralógica y caracteres morfológicos y brillo superficial, para diferenciar el material que es movilizado por el viento de aquel que lo es por el agua y comparadas con una muestra de la media cara de sotavento de un médano costero. Considerando que los médanos costeros son originados por el aporte de arena de playa que realizan los vientos provenientes del mar y que la playa se preserva en base al aporte del médano por la predominancia de vientos continentales, se han considerado y procesado datos de dirección e intensidad de los mismos. Los resultados de los análisis granométricos determinaron que las arenas se clasifican como finas y moderadamente bien seleccionadas. Las principales variaciones texturales entre perfiles se producen primordialmente en el sector de playa media con referencia a los parámetros de media, asimetría y curtosis, no así al de selección del material. En los gráficos de correlación de media, selecci

  14. Estudio del Fenómeno Explosión de Superficie en la Reacción NO+CO en Pt(100 por Simulación de Monte Carlo Dinámico Study of the Surface Explosion Phenomenon in the NO+CO Reaction on Pt(100 by Dynamic Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Salomón de J Alas

    2009-01-01

    Full Text Available Se presenta el estudio de la reducción catalítica de NO por CO en una superficie de Pt(100 por medio de una simulación de Monte Carlo dinámico. El objetivo es analizar la evolución temporal y espacio-temporal del sistema. Considerando un mecanismo de reacción tipo Langmuir-Hinshelwood, se construye un modelo donde se involucran todos los pasos elementales de la reacción y se simula la llamada explosión de superficie. El análisis también considera recientes evidencias experimentales concernientes a la formación y decaimiento de una especie intermediaria (N-NO* como el paso de reacción principal en la producción de N2. Los resultados de la simulación están de acuerdo con resultados experimentales de espectroscopia de desorción de masas. Además, la simulación permite correlacionar los máximos de producción de N2 y CO2 con la formación de patrones espaciales tipo célula sobre la superficie.In this work the catalytic reduction of NO by CO on a Pt(100 surface by dynamic Monte Carlo simulation is presented. The objective is to analyze the temporal and spatial-temporal behavior. A Langmuir-Hinshelwood mechanism and a model where all the reaction steps are taken into account are considered and the so-called surface explosion is simulated. The analysis also includes recent experimental evidences concerning the formation and decay of a (N-NO* intermediary species which turns out to be important for the N2 formation. These simulation results show good quantitative agreement with experimental results obtained from isothermal mass spectroscopy desorption. Furthermore, the simulations allow correlating the maximum production of N2 with the formation of cellular patterns on the surface.

  15. Archeologia dell’edilizia storica e costruzione del documento archeologico. Problemi di popolamento mediterraneo. II. Organizzazione del cantiere di una fortezza rurale di XIII secolo: il cassero di Montelaterone (Monte Amiata - Toscana

    Directory of Open Access Journals (Sweden)

    Nucciotti, Michele

    2003-12-01

    Full Text Available This paper aims to show the organization of the stonework in the fortress of Montelaterone (Amiata, Tuscany, by comparing documental and archaeological sources. The building analysed is found in a historical sub-region, Mount Amiata, which from the 11th to the 14th century was progressively under the control of a great imperial abbey (San Asalvatore di Monte Amiata of one of the principal aristocratic Tuscan families, the Aldobrandeschi, until control passed to Siena in the 14th century. The University of Florence since 1997 has been involved in an archaeological project aimed at studying how power was structured by the leading local groups and their architectonic policy. This paper presents the results of the study of the castle at Montelaterone. Its construction, carried out in Siena in the 1260s, represented a profound transformation in the organization of architectonic activity and of existing relationships between the local community and the lords of the abbey of San Salvatore in favour of the former.No disponible.

  16. El pavimento pretensado del Centro de Explotación de la Blécherette Mont-sur-Lausanne – Suiza

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1975-12-01

    establecimiento de un programa muy detallado de los trabajos a realizar, el cálculo, por su parte, hubo de tener en cuenta las especiales características de las sobrecargas que excluían, de entrada, la utilización de métodos empíricos. Los cálculos se hicieron con una cierta analogía respecto a los de un puente de carretera, pero con todos los elementos bidireccionales. Gracias al ordenador y después de alguna experiencia, el dimensionamiento del pretensado y la verificación de los esfuerzos de flexión se desarrollaron normalmente. Por ei contrario, al abordarse el control al punzonamiento de la losa y la seguridad a la rotura, se entró en un campo muy complejo en donde, a falta de investigaciones más profundas o de ensayos sobre modelo, los métodos tradicionales hubieron de ser adaptados con intuición y lógica.

  17. Analysis of the uranium price predicted to 24 months, implementing neural networks and the Monte Carlo method like predictive tools; Analisis del precio del uranio pronosticado a 24 meses, implementando redes neuronales y el metodo de Monte Carlo como herramientas predictivas

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel E, J.; Ramirez S, J. R.; Palacios H, J. C., E-mail: jaime.esquivel@fi.uaemex.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The present work shows predicted prices of the uranium, using a neural network. The importance of predicting financial indexes of an energy resource, in this case, allows establishing budgetary measures, as well as the costs of the resource to medium period. The uranium is part of the main energy generating fuels and as such, its price rebounds in the financial analyses, due to this is appealed to predictive methods to obtain an outline referent to the financial behaviour that will have in a certain time. In this study, two methodologies are used for the prediction of the uranium price: the Monte Carlo method and the neural networks. These methods allow predicting the indexes of monthly costs, for a two years period, starting from the second bimonthly of 2011. For the prediction the uranium costs are used, registered from the year 2005. (Author)

  18. Geomorfología Regional y Ordenación Integral del Territorio: nuevas perspectivas basadas en la incertidumbre y la complejidad de las formas del terreno. Aplicación en la cuenca del Río Bullaque (Montes de Toledo, España)

    OpenAIRE

    Muñoz-Rojas, José; Carrasco, Rosa M.; Pedraza Gilsanz, Javier de

    2009-01-01

    La Geomorfología Regional, definida como ciencia que se ocupa de describir y explicar la distribución espacial de las formas del terreno a escala regional y sub-regional, ha sido considerada por la planificación física y la ordenación del territorio más clásicas, como la única disciplina capaz de analizar las “líneas maestras” que definen el carácter complejo del territorio y del paisaje. La utilización del relieve como base física para la delimitación y definición de unidades territoriale...

  19. Exploring Monte Carlo methods

    CERN Document Server

    Dunn, William L

    2012-01-01

    Exploring Monte Carlo Methods is a basic text that describes the numerical methods that have come to be known as "Monte Carlo." The book treats the subject generically through the first eight chapters and, thus, should be of use to anyone who wants to learn to use Monte Carlo. The next two chapters focus on applications in nuclear engineering, which are illustrative of uses in other fields. Five appendices are included, which provide useful information on probability distributions, general-purpose Monte Carlo codes for radiation transport, and other matters. The famous "Buffon's needle proble

  20. Verification of the model of a photon beam of 6 MV in a Monte Carlo planning comparison with collapsed cone in in homogeneous medium; Verificacion del modelado de un haz de fotones de 6 MV en un planificador Monte Carlo. Comparacion con Collapsed Cone en medio no homogeneo

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Ros, J. C.; Jerez Sainz, M. I.; Lobato Munoz, M.; Jodar Lopez, C. A.; Ruiz Lopez, M. A.; Carrasco rodriguez, J. L.; Pamos Urena, M.

    2013-07-01

    We evaluated the Monte Carlo Monaco Planner v2.0.3 for calculation between non-homogeneous low density (equivalent to lung), as a complement to the verification of modeling in homogeneous medium and prior to the introduction of the SBRT technique. We performed the same tests on Pinnacle v8.0m, with the same purpose. We compare the results obtained with the algorithm Monte Carlo of Monaco and the Collapsed Cone of Pinnacle. (Author)

  1. Los insectos galícolas en Schinus fasciculata (Anacardiaceae en el Espinal del centro de Argentina

    Directory of Open Access Journals (Sweden)

    Melisa Malcolm

    2015-03-01

    Full Text Available La más compleja de las interacciones que plantas e insectos han desarrollado durante el transcurso de su evolución, son las agallas. Las especies de insectos galícolas se encuentran en la mayoría de las regiones biogeográficas, principalmente en ambientes xéricos, de los cuales un ejemplo lo constituye la ecorregión del Espinal, ubicada en la Provincia Biogeográfica de la Pampa, Subregión Chaqueña. Schinus fasciculata (Griseb. I.M. Johnst. (Anacardiaceae es una especie arbórea o arbustiva representativa de la ecorregión del Espinal que presenta diversas agallas entomógenas. Los objetivos del presente trabajo son identificar las especies de insectos que producen agallas en hojas y tallos de Schinus fasciculata en un relicto de Espinal de la provincia de Córdoba y caracterizar exomorfológicamente las agallas. Se seleccionaron 18 ejemplares de S. fasciculata distribuidos en cuatro transectas de 100 m2. Se caracterizaron cinco morfotipos de agallas, tres en hojas, inducidas por insectos del orden Hemiptera y dos en tallos, originadas por insectos del orden Lepidoptera. Los insectos productores de las mismas fueron identificados a nivel de especie y los distintos morfotipos de agallas fueron únicos para cada especie de insecto inductor.

  2. Verification of the model of a photon beam of 6 MV in a Monte Carlo planning comparison with collapsed cone in homogeneous medium; Verificacion del modelado de un haz de fotones de 6 MV en un planificador Monte Carlo. Comparacion con collapsed cone en medio homegeneo

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Ros, J. C.; Jerez Sainz, M. I.; Jodar Lopez, C. A.; Lobato Munoz, M.; Ruiz Lopez, M. A.; Carrasco Rodriguez, J. L.; Pamos Urena, M.

    2013-07-01

    We evaluated the Monte Carlo Monaco Planner v2.0.3 by planners of the SEFM Protocol [1] to the modeling of the photon beam of 6 MV of a linear accelerator Elekta Synergy with collimator MLC Beam Modulator. We compare the Monte Carlo calculation with profiles on water measurement DFS = 100 cm, absorbed dose and dose levels for rectangular, asymmetric fields and different DFS. We compare the results with those obtained with the algorithm Collapsed Cone of Pinnacle Scheduler v8.0m. (Author)

  3. Monte Carlo Radiative Transfer

    CERN Document Server

    Whitney, Barbara A

    2011-01-01

    I outline methods for calculating the solution of Monte Carlo Radiative Transfer (MCRT) in scattering, absorption and emission processes of dust and gas, including polarization. I provide a bibliography of relevant papers on methods with astrophysical applications.

  4. Monte Carlo transition probabilities

    OpenAIRE

    Lucy, L. B.

    2001-01-01

    Transition probabilities governing the interaction of energy packets and matter are derived that allow Monte Carlo NLTE transfer codes to be constructed without simplifying the treatment of line formation. These probabilities are such that the Monte Carlo calculation asymptotically recovers the local emissivity of a gas in statistical equilibrium. Numerical experiments with one-point statistical equilibrium problems for Fe II and Hydrogen confirm this asymptotic behaviour. In addition, the re...

  5. Fundamentals of Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-16

    This is a powerpoint which serves as lecture material for the Parallel Computing summer school. It goes over the fundamentals of Monte Carlo. Welcome to Los Alamos, the birthplace of “Monte Carlo” for computational physics. Stanislaw Ulam, John von Neumann, and Nicholas Metropolis are credited as the founders of modern Monte Carlo methods. The name “Monte Carlo” was chosen in reference to the Monte Carlo Casino in Monaco (purportedly a place where Ulam’s uncle went to gamble). The central idea (for us) – to use computer-generated “random” numbers to determine expected values or estimate equation solutions – has since spread to many fields. "The first thoughts and attempts I made to practice [the Monte Carlo Method] were suggested by a question which occurred to me in 1946 as I was convalescing from an illness and playing solitaires. The question was what are the chances that a Canfield solitaire laid out with 52 cards will come out successfully? After spending a lot of time trying to estimate them by pure combinatorial calculations, I wondered whether a more practical method than “abstract thinking” might not be to lay it out say one hundred times and simply observe and count the number of successful plays... Later [in 1946], I described the idea to John von Neumann, and we began to plan actual calculations." - Stanislaw Ulam.

  6. Santiago del Estero: de rieles, obrajes y quebracho. Análisis de la configuración territorial del período técnico iniciado con la llegada del ferrocarril al monte chaco-santiagueño

    Directory of Open Access Journals (Sweden)

    María de Estrada

    2011-06-01

    Full Text Available En este trabajo se pretende analizar un período técnico específico para la configuración territorial de la provincia de Santiago del Estero signado por la llegada del ferrocarril. La introducción de este fenómeno técnico, comprendido como plantea Milton Santos (1996:36, no como una técnica específica, sino como totalidad que modificará por completo la organización del espacio, incorporará los obrajes como forma de organización de la mano de obra, transformará la localización de los centros poblados y generará la apertura a un mercado de tierras inmenso que será aprovechado por un grupo de capitalistas foráneos. La reconstrucción de este período específico es clave para comprender la relación entre el arrasamiento de los frondosos bosques del chaco santiagueño y el empobrecimiento de la población, así como la concentración de tierras en propietarios con orígenes e intereses lejanos al propio lugar.

  7. Avaliação bromatológica de espécies arbóreas e arbustivas de pastagens em três municípios do Estado de Pernambuco = Chemical composition of tree and bush species occurring in pastures of three locations in Pernambuco State

    Directory of Open Access Journals (Sweden)

    Anália Carmem Silva de Almeida

    2006-01-01

    Full Text Available A pesquisa foi realizada nos Campos Experimentais de Itambé, Caruaru e Serra Talhada, pertencentes à Empresa Pernambucana de Pesquisa Agropecuária, e objetivou avaliar características bromatológicas de espécies arbóreas e arbustivas de pastagens. Para análises bromatológicas foram coletadas, nas épocas seca e chuvosa, amostras compostas de folhas e galhos com até 5,0 cm de diâmetro de espécies arbóreas e arbustivas presentes em áreas de pastagens. Os teores médios de MS das plantas foram de 38,89%, 48,27% e 55,20% nos Municípios de Itambé, Caruaru e Serra Talhada, respectivamente. Para PB, observou-se valores de 15,87%, 14,09% e 10,19%, respectivamente. Os valores de FDN e de FDA foram de 52,37% e 37,63%, 46,33% e 30,33%, 50,25% e 35,07%, respectivamente. As espécies, independente do local, apresentaram melhor composição bromatológica no período chuvoso.Para utilização de espécies em sistemas silvipastoris, além da avaliação de características qualitativas, devem-se considerar aspectos de facilidade de propagação, adaptação às condições edafoclimáticas, tipo de animal e objetivo do sistema de produção animal. The research was conducted at the Experimental Fields of Itambé, Caruaru and Serra Talhada, owned by the Agricultural Research Companyof Pernambuco (IPA. The aim was to analyze the chemical characteristics of tree and bush species grown on pasture land. In each Experimental Station, data was collected from a random sampling, during the dry and rainy seasons. Samples consisted of leaves and branches up to 5.0 cm of diameter. The average MS concentrations were 38.89, 48.27 and 55.20%. As for PB, the values observed were 15.87, 14.09 and 10.19%. The NFD and ADF concentrations were 52.37 and 37.63, 46.33 and 30.33, 50.25 and 35.07%, for Itambé, Caruaru and Serra Talhada, respectively. The studied species, independent of the region, presented better chemistry composition during the rainy season. Thus

  8. Conocimiento, uso y valor cultural de seis presas del jaguar (Panthera onca y su relación con éste, en San Nicolás de los Montes, San Luis Potosí, Mexico Knowledge, use and cultural value of six prey of jaguar (Panthera onca and their relationship with this species in San Nicolás de los Montes, San Luis Potosí, Mexico

    Directory of Open Access Journals (Sweden)

    Dulce M. Ávila-Nájera

    2011-09-01

    Full Text Available Durante 2007 se obtuvo información del conocimiento y la percepción que los pobladores del ejido tienen sobre el jaguar, sus presas y los factores que afectan la distribución y su conservación. Mediante el índice de importancia cultural (IIC se determinó el conocimiento que los ejidatarios tienen de las presas, y el uso y valor que les otorgan. Las presas que reconocieron importantes fueron venado cola blanca (Odocoileus virginianus, temazate (Mazama temama, pecarí (Tayassu pecari, tejón (Nasua narica, armadillo (Dasypus novemcinctus y tepezcuintle (Cuniculus paca; 72% de los encuestados también identificaron especies domésticas como presas del jaguar. Según su percepción, las más abundantes son pecarí, tejón y armadillo. El valor de uso más importante es el alimenticio, puesto que 82% de los encuestados ha consumido alguna especie silvestre. El valor más alto del IIC fue para el venado (27.17. En el ejido se considera perjudicial el jaguar por alimentarse del ganado. Los pobladores y los jaguares utilizan las mismas especies para obtener beneficio. El presente estudio constituye una base para el desarrollo de trabajos tendientes a manejar y conservar los recursos naturales que existen en el ejido considerando las necesidades de la población humana, de su fauna silvestre y la relación entre éstas.During 2007, we obtained information about the knowledge, perception of rural people regarding jaguar, its preys and the factors that affect its distribution and conservation. Additionally, we determined with the Index of Cultural Importance the knowledge, use and value that rural people assign to preys of the jaguar. They recognized as important prey species of the jaguar to white-tailed deer (Odocoileus virginianus, brocket (Mazama temama, pecari (Tayassu peccari, coati (Nasua narica, armadillo (Dasypus novemcinctus and paca (Cuniculus paca. Most of the villagers (72% identified also domestic species as preys of the jaguar

  9. Circuitos del conocimiento: el Arte de la lengua índica de Valera y su inclusión en las polémicas sobre el Sacro Monte de Granada

    OpenAIRE

    José Alejandro Cárdenas Bunsen

    2014-01-01

    ResumenA partir del examen de documentos inéditos, este artículo muestra que Blas Valera (1545-1597) fue autor de un Arte de la lengua índica, que circulaba en Sevilla en 1595. Sostiene también que Valera puede ser identificado como el director detrás del Arte y vocabulario en la lengua general del Perú, publicado anónimamente en 1586. El estudio reconstruye, además, el contexto intelectual que hizo posible la circulación de la obra de Valera y los criterios filológicos que permitieron insert...

  10. Amenazas y oportunidades ante el cambio global en los montes españoles: el proyecto MONTES Consolider

    OpenAIRE

    E. Doblas-Miranda; Retana, J; Equipo MONTES Consolider

    2011-01-01

    El mundo se enfrenta a una situación de cambio global en el que una combinación de alteraciones ambientales y bióticas (cambios en la composición atmosférica, en el clima, en el uso del suelo, en el régimen de incendios o en la introducción de especies) amenazan a muchos de los ecosistemas naturales y los servicios que estos proporcionan tales como mantenimiento del ciclo del carbono, la regulación de los recursos hídricos o la biodiversidad, entre otros. El proyecto MONTES surge como un prog...

  11. MONTE-4 for Monte Carlo simulations with high performance

    International Nuclear Information System (INIS)

    The Monte Carlo machine MONTE-4, has been developed based on the architecture of existing supercomputer with a design philosophy to realize high performance in vector-parallel processing of Monte Carlo codes for particle transport problems. The effective performance of this Monte Carlo machine is presented through practical applications of multi-group criticality safety code KENO-IV and continuous-energy neutron/photon transport code MCNP. Ten times speedup has been obtained on MONTE-4 compared with the execution time in the scalar processing. (K.A.)

  12. Monte Carlo photon benchmark problems

    International Nuclear Information System (INIS)

    Photon benchmark calculations have been performed to validate the MCNP Monte Carlo computer code. These are compared to both the COG Monte Carlo computer code and either experimental or analytic results. The calculated solutions indicate that the Monte Carlo method, and MCNP and COG in particular, can accurately model a wide range of physical problems. 8 refs., 5 figs

  13. Diferenciación del aparato digestivo de los rumiantes: comparación entre oveja (Ovis aries), rebeco (Rupricapra Pyrenaica) y cabra montés (Capra pyrenaica)

    OpenAIRE

    Mantecón, Ángel R.; Frutos, Pilar; Lavín, Santiago; De Marco, I.; Lavín, Paz

    1993-01-01

    [ES] Se han utilizado los datos correspondientes a 11 ovejas (Ovisaries), l0 cabras monteses (Capra pyrenaica) y 24 rebecos (Rupicapra pyrenaica). El aparato digestivo, una vez separada la grasa omental y mesentérica, ss fraccionó en los siguientes compartimentos: retículo-rumen, omaso, abomaso, intestino delgado, intestino grueso y ciego. El peso total del aparato digestivo vacío y de todos sus compartimentos fue mayor en las ovejas que en los rebecos, ocupando la ...

  14. ¿''Globalización sostenible''? Desarrollo sostenible como pegamento para el montón de cristales trizados del neoliberalismo Sustainable globalization? Sustainable development as a fix for neo-liberalism heap of broken glass

    Directory of Open Access Journals (Sweden)

    Ulrich Brand

    2003-01-01

    Full Text Available En la Cumbre Mundial sobre Medio Ambiente y Desarrollo en Johannesburgo a mediados del año 2002, se pudo ver claramente que los entendimientos y las prácticas del desarrollo sostenible están en un callejón sin salida. Eso tiene que ver con el hecho que se habían ignorado los procesos mucho más dinámicos de la globalización neoliberal y de la reestructuración del mundo, incluyendo la nueva legitimidad de las guerras en los años 90s. Después del 11 de septiembre del año 2001, argumentan los autores, se hizo evidente que vivimos en una situación no hegemónica con implicaciones específicas. Pero el ''desarrollo sostenible'' no se fracturó como contra discurso. Al contrario, sus orientaciones y prácticas eran cada vez más compatibles con la reestructuración dominante. El desarrollo sostenible perdió sus implicaciones críticas con su enfoque en la cooperación y el conocimiento moderno occidental, su conceptualización tecnócrata de la política, la predominancia de las cuestiones medioambientales sobre las del desarrollo y el Estado-nación como área privilegiada para la implementación de políticas. Además, las instituciones internacionales del desarrollo sostenible (en el artículo se toma como ejemplo del Convenio sobre Diversidad Biológica son parte de la economización de la naturaleza. Finalmente, en el último tiempo ganaron legitimidad las iniciativas que intentan establecer mecanismos militares en países del Sur que se justifican con la necesidad de políticas de desarrollo sostenible. Actualmente, el ''proceso de Río'' trata de reconciliar los procesos de globalización con el desarrollo sostenible y, eventualmente, el término ''globalización sostenible'' va a surgir como nuevo paradigma para las orientaciones y prácticas dominantes. Al final del artículo, los autores argumentan que los desafíos más dinámicos contra la globalización neoliberal y la militarización emergen en otro terreno político que

  15. Structured Monte Carlo. Estimated value at risk in a stock portfolio in Colombia Montecarlo estructurado. Estimación del valor en riesgo en un portafolio accionario en Colombia

    Directory of Open Access Journals (Sweden)

    María Auxiliadora Vergara Cogollo

    2009-12-01

    Full Text Available De acuerdo con el estudio que se presenta, por las características de los activos que lo conforman, el método de Montecarlo Estructurado es el más completo y robusto para la medición del valor en riesgo (VaR de un portafolio hipotético de acciones colombianas de alta y mediana bursatilidad, en comparación con métodos paramétricos o de simulación histórica. Sin embargo, para su aplicación, es necesaria una cuidadosa modelación del comportamiento de las distintas variables de riesgo. La presencia de colas pesadas en las series de retornos de estos activos obliga al uso de modelos de volatilidad del tipo GARCH, EGARCH, PARCH y APARCH. Se evalúa su capacidad de pronóstico del VaR del periodo siguiente en paralelo con el obtenido por el método Normal. Los modelos tipo Garch pronostican mejor el VaR, puesto que logran capturar el efecto de colas pesadas en las series. Definido el proceso estocástico que siguen los activos, se procede a su cálculo con Montecarlo Estructurado. This research explores various methods to estimate Value at Risk for a portfolio of high and medium liquidity Colombian stocks. It concludes that, according to the characteristics of these assets, Full Montecarlo is more robust than other parametric methods –particularly the Normal method-, and the historical simulation. However, to avoid model risk, it requires a correct specification of the stochastic process followed by each of the risk factors. Given the evidence of fat tails on the return series, volatility models such as GARCH, EGARCH, PARCH and APARCH are used for this purpose. After that, we compare the one-step ahead VaR forecast given by these models with the one obtained by parametric methods. It is found that Garch models predict VaR better since they capture the fat tails characteristic of these series. Once the stochastic process for each asset is properly identified, the Full Montecarlo is applied to estimate VaR.

  16. Fundamentals of Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-16

    This is a powerpoint presentation which serves as lecture material for the Parallel Computing summer school. It goes over the fundamentals of the Monte Carlo calculation method. The material is presented according to the following outline: Introduction (background, a simple example: estimating π), Why does this even work? (The Law of Large Numbers, The Central Limit Theorem), How to sample (inverse transform sampling, rejection), and An example from particle transport.

  17. Contributon Monte Carlo

    International Nuclear Information System (INIS)

    The contributon Monte Carlo method is based on a new recipe to calculate target responses by means of volume integral of the contributon current in a region between the source and the detector. A comprehensive description of the method, its implementation in the general-purpose MCNP code, and results of the method for realistic nonhomogeneous, energy-dependent problems are presented. 23 figures, 10 tables

  18. Restauración forestal y medioambiental en zonas afectadas por sequía en el monte La Sierra AL1052, del T.M. de Orihuela (Alicante)

    OpenAIRE

    BOTELLA CERECEDA, ÁNGELA

    2015-01-01

    [ES] Como consecuencia de la escasez de precipitaciones durante el año hidrológico 2013-2014, especialmente en el sur de la Comunidad Valenciana y Murcia, donde las precipitaciones han sido mayoritariamente escasas, gran parte de las masas arbóreas de Pino halepensis, han sufrido un elevado estrés hídrico lo que ha producido su decaimiento y definitivo secado. Esta situación de debilidad del arbolado ha producido la aparición de insectos barrenadores como el Tomicus destruens, que ha prol...

  19. MontePython: Implementing Quantum Monte Carlo using Python

    OpenAIRE

    J.K. Nilsen

    2006-01-01

    We present a cross-language C++/Python program for simulations of quantum mechanical systems with the use of Quantum Monte Carlo (QMC) methods. We describe a system for which to apply QMC, the algorithms of variational Monte Carlo and diffusion Monte Carlo and we describe how to implement theses methods in pure C++ and C++/Python. Furthermore we check the efficiency of the implementations in serial and parallel cases to show that the overhead using Python can be negligible.

  20. Monts Jura Jazz Festival

    CERN Multimedia

    Jazz Club

    2012-01-01

    The 5th edition of the "Monts Jura Jazz Festival" that will take place on September 21st and 22nd 2012 at the Esplanade du Lac in Divonne-les-Bains. This festival is organized by the "CERN Jazz Club" with the support of the "CERN Staff Association". This festival is a major musical event in the French/Swiss area and proposes a world class program with jazz artists such as D.Lockwood and D.Reinhardt. More information on http://www.jurajazz.com.

  1. Monts Jura Jazz Festival

    CERN Multimedia

    2012-01-01

    The 5th edition of the "Monts Jura Jazz Festival" will take place at the Esplanade du Lac in Divonne-les-Bains, France on September 21 and 22. This festival organized by the CERN Jazz Club and supported by the CERN Staff Association is becoming a major musical event in the Geneva region. International Jazz artists like Didier Lockwood and David Reinhardt are part of this year outstanding program. Full program and e-tickets are available on the festival website. Don't miss this great festival!

  2. Optimization of Monte Carlo simulations

    OpenAIRE

    Bryskhe, Henrik

    2009-01-01

    This thesis considers several different techniques for optimizing Monte Carlo simulations. The Monte Carlo system used is Penelope but most of the techniques are applicable to other systems. The two mayor techniques are the usage of the graphics card to do geometry calculations, and raytracing. Using graphics card provides a very efficient way to do fast ray and triangle intersections. Raytracing provides an approximation of Monte Carlo simulation but is much faster to perform. A program was ...

  3. Quantum Gibbs ensemble Monte Carlo

    International Nuclear Information System (INIS)

    We present a path integral Monte Carlo method which is the full quantum analogue of the Gibbs ensemble Monte Carlo method of Panagiotopoulos to study the gas-liquid coexistence line of a classical fluid. Unlike previous extensions of Gibbs ensemble Monte Carlo to include quantum effects, our scheme is viable even for systems with strong quantum delocalization in the degenerate regime of temperature. This is demonstrated by an illustrative application to the gas-superfluid transition of 4He in two dimensions

  4. Monte Carlo techniques

    International Nuclear Information System (INIS)

    The course of ''Monte Carlo Techniques'' will try to give a general overview of how to build up a method based on a given theory, allowing you to compare the outcome of an experiment with that theory. Concepts related with the construction of the method, such as, random variables, distributions of random variables, generation of random variables, random-based numerical methods, will be introduced in this course. Examples of some of the current theories in High Energy Physics describing the e+e- annihilation processes (QED, Electro-Weak, QCD) will also be briefly introduced. A second step in the employment of this method is related to the detector. The interactions that a particle could have along its way, through the detector as well as the response of the different materials which compound the detector will be quoted in this course. An example of detector at LEP era, in which these techniques are being applied, will close the course. (orig.)

  5. MCMini: Monte Carlo on GPGPU

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Ryan C. [Los Alamos National Laboratory

    2012-07-25

    MCMini is a proof of concept that demonstrates the possibility for Monte Carlo neutron transport using OpenCL with a focus on performance. This implementation, written in C, shows that tracing particles and calculating reactions on a 3D mesh can be done in a highly scalable fashion. These results demonstrate a potential path forward for MCNP or other Monte Carlo codes.

  6. Are the vegetation structure and composition of the shrubby Caatinga free from edge influence? A estrutura e a composição da vegetação da Caatinga arbustiva são livres da influência de borda?

    Directory of Open Access Journals (Sweden)

    André Maurício de Melo Santos

    2008-12-01

    Full Text Available Edge influence, or edge effect, drives many biological changes in fragmented landscapes. This has been extensively studied in many forest ecosystems, but it remains to be described for the Brazilian Caatinga. Based on the biotic and physical conditions of the shrubby Caatinga, our prediction a priori was that this type of vegetation is free from edge influence in terms of vegetation structure and composition. We sampled shrubs, cacti and trees in twenty 200 m² plots on old edges (>60 yrs old and interior of a 690 ha fragment, partially isolated and surrounded by Opuntia ficus-indica cacti. Plant height, stem diameter at ground level, stem density, species richness and diversity were statistically equal between edge and interior habitats. Magnitude of edge influence varied from -0.027 to 0.027, indicating low ecological importance of edge creation for the measured variables. Additionally, floristic similarity between habitats was 90% and a principal component analysis showed that species composition varied in a similar manner at edges and interiors. These results indicate that the vegetation of the sampled fragment is not ecologically affected by the creation of edges and suggests that changes in physical conditions and resource availability after edge creation are not enough to eliminate established plants or to alter recruitment and survival of new individuals.A influência de borda, ou efeito de borda, leva a diversas alterações biológicas em paisagens fragmentadas. Embora muito estudada em ecossistemas florestais, a influência de borda permanece desconhecida para a Caatinga. Baseada nas condições físicas e biológicas da Caatinga arbustiva, nossa predição a priori foi que este tipo de vegetação não sofre influência de borda em termos de estrutura e composição de espécies. Nós amostramos arbustos, cactos e árvores em 20 parcelas de 200 m² em bordas antigas (> 60 anos de idade e interiores de um fragmento de 690 ha

  7. Monte Carlo Methods in Physics

    International Nuclear Information System (INIS)

    Method of Monte Carlo integration is reviewed briefly and some of its applications in physics are explained. A numerical experiment on random generators used in the monte Carlo techniques is carried out to show the behavior of the randomness of various methods in generating them. To account for the weight function involved in the Monte Carlo, the metropolis method is used. From the results of the experiment, one can see that there is no regular patterns of the numbers generated, showing that the program generators are reasonably good, while the experimental results, shows a statistical distribution obeying statistical distribution law. Further some applications of the Monte Carlo methods in physics are given. The choice of physical problems are such that the models have available solutions either in exact or approximate values, in which comparisons can be mode, with the calculations using the Monte Carlo method. Comparison show that for the models to be considered, good agreement have been obtained

  8. El orégano de monte (Lippia origanoides) del Alto Patía: efecto del método de obtención de sus extractos sobre la composición y la actividad antioxidante de los mismos

    OpenAIRE

    Vásquez Carreño, Diana Rocío

    2012-01-01

    Los aceites esenciales de orégano (AEO) presentan alta actividad antioxidante y ésta ha sido asociada a su composición. En este estudio se comparó la composición y actividad antioxidante de los AEO de L. origanoides nativo del Alto Patía obtenidos por arrastre con vapor (AV), hidrodestilación (HD) y extracción con fluidos supercríticos (EFS). La actividad antioxidante fue evaluada mediante las técnicas de actividad antiradicalaria (DPPH), el poder de reducción del hierro (FRAP), la capacidad ...

  9. Relationships between Prosopis flexuosa (Fabaceae and cattle in the Monte desert: Seeds, seedlings and saplings on cattle-use site classes Interacciones entre Prosopis flexuosa (Fabaceae y el ganado en el desierto de Monte: Semillas, plántulas y renovales en los sitios de uso del ganado

    Directory of Open Access Journals (Sweden)

    CLAUDIA M CAMPOS

    2011-06-01

    , or sapling, defecation and trampling appear to be important processes in the seed dispersal cycle. In this sense, cattle could benefit the establishment of P. flexuosa.El destino de las semillas de Prosopis flexuosa dispersadas por ganado depende de los patrones de deposición de excrementos y movimientos de forrajeo. Nuestra hipótesis es que las variables respuesta relacionadas con el aporte y el destino de semillas, plántulas y renovales son explicadas por diferencias entre los sitios de actividad del ganado. Definimos sitios con alto tránsito de animales ("senderos" y "periferia de senderos", sitios utilizados para descanso y alimentación ("bajo Prosopis" y sitios de paso para animales aislados ("bajo arbustos" y "suelo descubierto". Considerando los sitios de actividad establecidos, nuestros objetivos fueron cuantificar y comparar: (1 semillas transportadas en los excrementos, (2 plántulas 10 meses después de la deposición, (3 renovales establecidos, (4 semillas germinadas en los excrementos, supervivencia de plántulas y semillas que permanecieron en los excrementos. El trabajo se realizó en un campo ganadero de Ñacuñán (Mendoza, Argentina, dentro de cuatro áreas donde se establecieron parcelas de 25 ha. En los sitios se encontró un aporte diferencial de semillas: en sitios de descanso y alimentación ("bajo Prosopis" y de tránsito intenso ("periferia" los animales depositaron las mayores cantidades de semillas. Diez meses después, las semillas germinaron con las primeras lluvias; el mayor número de plántulas se registró en sitios de tránsito intenso ("senderos" y "periferia" y de descanso y alimentación ("bajo Prosopis". A largo plazo, en la "periferia" se establece la mayor cantidad de renovales. Inmediatamente después de la deposición, germinó un número muy bajo de semillas y las plántulas no sobrevivieron más de una semana. En los sitios más transitados por el ganado, los excrementos se desintegraron por pisoteo y la persistencia

  10. Parallelizing Monte Carlo with PMC

    Energy Technology Data Exchange (ETDEWEB)

    Rathkopf, J.A.; Jones, T.R.; Nessett, D.M.; Stanberry, L.C.

    1994-11-01

    PMC (Parallel Monte Carlo) is a system of generic interface routines that allows easy porting of Monte Carlo packages of large-scale physics simulation codes to Massively Parallel Processor (MPP) computers. By loading various versions of PMC, simulation code developers can configure their codes to run in several modes: serial, Monte Carlo runs on the same processor as the rest of the code; parallel, Monte Carlo runs in parallel across many processors of the MPP with the rest of the code running on other MPP processor(s); distributed, Monte Carlo runs in parallel across many processors of the MPP with the rest of the code running on a different machine. This multi-mode approach allows maintenance of a single simulation code source regardless of the target machine. PMC handles passing of messages between nodes on the MPP, passing of messages between a different machine and the MPP, distributing work between nodes, and providing independent, reproducible sequences of random numbers. Several production codes have been parallelized under the PMC system. Excellent parallel efficiency in both the distributed and parallel modes results if sufficient workload is available per processor. Experiences with a Monte Carlo photonics demonstration code and a Monte Carlo neutronics package are described.

  11. Técnicas Monte Carlo aplicadas a la resolución de ecuaciones en derivadas parciales

    OpenAIRE

    Armando Serrano Lombillo

    2009-01-01

    En este trabajo se aplican las técnicas Monte Carlo a la resolución de ecuaciones en derivadas parciales, en concreto a la ecuación del calor. Si bien estas técnicas no mejoran las técnicas clásicas proporcionan una manera alternativa y más intuitiva de entender los métodos tradicionales. La última parte del trabajo se dedica al estudio estadístico de la importancia de cuatro factores en la precisión del método Monte Carlo. Para realizar el estudio se utilizó Statgraphics y Mathematica....

  12. Amenazas y oportunidades ante el cambio global en los montes españoles: el proyecto MONTES Consolider

    Directory of Open Access Journals (Sweden)

    E. Doblas-Miranda

    2011-01-01

    Full Text Available El mundo se enfrenta a una situación de cambio global en el que una combinación de alteraciones ambientales y bióticas (cambios en la composición atmosférica, en el clima, en el uso del suelo, en el régimen de incendios o en la introducción de especies amenazan a muchos de los ecosistemas naturales y los servicios que estos proporcionan tales como mantenimiento del ciclo del carbono, la regulación de los recursos hídricos o la biodiversidad, entre otros. El proyecto MONTES surge como un programa de investigación sobre la relación entre los factores de cambio global y los servicios ecosistémicos en el monte mediterráneo, con el objetivo de orientar las oportunidades de manejo forestal y su adaptación al cambio. Este objetivo se organiza en tres ejes que combinan el análisis de la influencia del cambio global en el monte, el modo en que el monte puede a su vez modificar los efectos del cambio global y la variación de dichas interacciones mediante la gestión forestal. Para ello, MONTES se encuentra estructurado en siete módulos de trabajo que condensan todas las posibles interacciones entre factores y servicios: (1 las interacciones entre el monte y la atmósfera, (2 cambios en la fijación de carbono en los montes, (3 cambios en la distribución de especies causados por el cambio climático, (4 consecuencias sobre la disponibilidad de agua, (5 consecuencias de los cambios de uso del suelo y fragmentación en la conservación de especies, (6 vulnerabilidad de las especies al fuego y gestión preventiva de los grandes incendios, (7 invasiones ecológicas y consecuencias en la biodiversidad, más un octavo módulo centrado en la transversalidad e interacciones entre módulos. El proyecto incorpora la escala de parcela, local y regional utilizando información existente y a través de nueve áreas de estudio distribuidas por toda España que cubren montañas no mediterráneas (Pirineos y Montseny, montañas (Sierra Nevada, Alto Tajo

  13. Proton Upset Monte Carlo Simulation

    Science.gov (United States)

    O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.

    2009-01-01

    The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.

  14. El bronce final y la Edad del Hierro en "Cerro del Berrueco" (Ávila-Salamanca

    Directory of Open Access Journals (Sweden)

    J. Francisco FABIÁN GARCÍA

    2009-10-01

    Full Text Available El Cerro del Berrueco es un monte-isla enclavado en las inmediaciones del Sistema Central y, más concretamente, de las Sierras de Gredos y Béjar, en el sector Sur-Occidental de la Meseta Norte. Corresponde una parte de él a la provincia de Avila y otra, más extensa, a la de Salamanca.

  15. Del Piero

    OpenAIRE

    Umbaca, Enzo

    2015-01-01

    Rifacendosi al “Pinturicchio”, epiteto con cui Gianni Agnelli consacrava il calciatore Alessandro Del Piero un “artista del calcio”, Enzo Umbaca scrisse al popolare personaggio invitandolo a collaborare ad una performance durante la quale Pinturicchio-Del Piero avrebbe affrescato il muro di una galleria torinese calciando un pallone macchiato di grafite contro un muro sul quale è appesa la copia di un opera del Pinturicchio.

  16. Monte Carlo Particle Lists: MCPL

    CERN Document Server

    Kittelmann, Thomas; Knudsen, Erik B; Willendrup, Peter; Cai, Xiao Xiao; Kanaki, Kalliopi

    2016-01-01

    A binary format with lists of particle state information, for interchanging particles between various Monte Carlo simulation applications, is presented. Portable C code for file manipulation is made available to the scientific community, along with converters and plugins for several popular simulation packages.

  17. Food habits of two syntopic canids, the maned wolf (Chrysocyon brachyurus and the crab-eating fox (Cerdocyon thous, in southeastern Brazil Hábitos alimentarios de dos cánidos sintópicos, el aguara guazú (Chrysocyon brachyurus y el zorro del monte (Cerdocyon thous, en el sudeste de Brasil

    Directory of Open Access Journals (Sweden)

    ADRIANA DE ARRUDA BUENO

    2004-03-01

    Full Text Available The maned wolf (Chrysocyon brachyurus and the crab-eating fox (Cerdocyon thous are two South American canids with large overlap in their geographic distribution. However, there are few data on the comparative ecology of these species. The aim of this research was to quantify the diet of these two canids living in syntopy at three levels: frequency of occurrence, minimum number of individuals preyed and estimated biomass ingested. Additionally, seasonality in the consumption of major groups of food items and aspects of prey size distribution were assessed. The study took place in the Experimental Station of Itapetininga, São Paulo State, Brazil. General results showed that both canids are omnivorous in accordance with other studies. By occurrences, the wolves consumed vegetal and animal food in similar proportions, whereas the foxes consumed more animals, mainly insects. In contrast, both canids ingested mainly animal food if biomass is considered. The maned wolf consumed more wolf's fruit (Solanum lycocarpum and small mammals in the dry season, and miscellaneous fruits during the wet season. The crab-eating fox also ingested more miscellaneous fruits in the wet season, but the insects were mostly consumed during dry months. The crab-eating fox is more generalist than the maned wolf, but the wolf seems better able to handle distinct prey types. The distribution of prey sizes suggested separate food niches: while the maned wolf consumed a larger spectrum of prey sizes, especially small vertebrates between 10.1 and 100.0 g, the crab-eating fox consumed smaller prey, mainly insects between 0.01 and 0.1 gEl aguara guazú (Chrysocyon brachyurus y el zorro del monte (Cerdocyon thous son dos cánidos sudamericanos cuyas distribuciones geográficas se sobreponen extensamente. Sin embargo, hay pocos datos sobre la ecología comparativa de estas especies. El objetivo de esta investigación fue cuantificar la dieta de estos dos cánidos en sintopia en

  18. Propuesta metodológica para la ordenación integral de montes de la Red Natura 2000

    OpenAIRE

    Velázquez Saornil, Javier

    2008-01-01

    La presente Tesis Doctoral propone una metodología para la ordenación integral de espacios forestales de la Red Natura 2000, que dé respuesta tanto a las disposiciones establecidas en la Directiva Hábitats, como a los requerimientos específicos de gestión de la ordenación tradicional de montes. Para ello, se propone la adaptación de la estructura y los contenidos del proyecto de ordenación de montes, recogido en las correspondientes instrucciones generales para la ordenación de montes, par...

  19. Cambios en el uso del suelo y deforestación en el sur de los estados de Campeche y Quintana Roo, México

    Directory of Open Access Journals (Sweden)

    Sergio Cortina Villar

    1999-01-01

    Full Text Available Mediate la interpretacion de imágenes LANDSAT MSS se examina que proporción de la superficie de selvas y sabanas fue transformadas en áreas agricolas y ganaderas, entre 1975 y 1990, en viejos y nuevos ejidos ubicados a lo largo de la carretera Escárcega- Chetumal. en los años setenta, estos ejidos fueron objeto de un programa e colonizacion dirigida financiado por el gobierno federal, proceso que incluyó el desmote de las selvas para establecer áreas agrícolas y ganderas modernas. Contra la idea de que la mayor parte de las selvas habian sido destruidas, los resultados indican que, al término el periodo estudiado, un 25% de las selvas del área en estudio habian sido desmontadas y un 43% de la superficie desmontada habia dejado d utilizarse en la produccion agropecuaria y estba cubierta por vegetacion secundaria arbustiva o arbórea

  20. Metodología para la evaluación del potencial insecticida de especies forestales.

    Directory of Open Access Journals (Sweden)

    Morales Soto León

    2000-06-01

    Full Text Available La diversidad florística de Colombia plantea enormes retos de investigación, con miras a una utilización racional e integral de sus recursos forestales. Las plantas con efectos biocidas utilizables en el control de plagas o enfermedades revisten una singular importancia. El objetivo de este trabajo es plantear una metodología de fácil aplicación, bajo costo y rápidos resultados, que permita acopiar la información necesaria sobre el mayor número de especies con potencial en este sentido. La metodología plantea la siguiente secuencia: selección de las especies vegetales de interés, apoyada en los reportes bibliográficos, conocimiento ancestral y observaciones personales; recolección del material en el campo; preparación del extracto total a partir del material seco; pruebas iniciales con Artemia salina Lech. para detectar actividad biológica, a través de la determinación de la LC50 (las especies con LC50 menores de 1000 ppm se consideran promisorias y ameritan procesos posteriores de fraccionamiento químico, bioensayos con las sustancias más promisorias sobre algún organismo de interés particular y determinación final de los compuestos activos en la planta. La metodología descrita fue empleada en la evaluación del potencial de acción biocida de 5 especies arbóreas o arbustivas, Guarea guidonia (L. Sleumer y Trichia hirta L. (Meliaceae, Machaerium moritzianum Benth. (Fabaceae, Swinglea glutinosa Merrill. (Rutaceae y Mammea americana L. (Clusiaceae. Se utilizó para los bioensayos iniciales el microcrustáceo Artemia salina Leach como indicador del potencial biocida con el fin de seleccionar las dos especies más promisorias a partir de las LC50 obtenidas. Con las dos se realizaron los bioensayos para evaluar la acción fagoinhibidora en la hormiga arriera Atta cephalotes (L., y el posible control de Alconeura sp. (Homoptera: Cicadellidae, insecto chupador que afecta la ceiba verde Pseudobombax septenatum (Jacq. Dugand

  1. Shell model Monte Carlo methods

    International Nuclear Information System (INIS)

    We review quantum Monte Carlo methods for dealing with large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; resultant path integral is evaluated stochastically. We first discuss the motivation, formalism, and implementation of such Shell Model Monte Carlo methods. There then follows a sampler of results and insights obtained from a number of applications. These include the ground state and thermal properties of pf-shell nuclei, thermal behavior of γ-soft nuclei, and calculation of double beta-decay matrix elements. Finally, prospects for further progress in such calculations are discussed. 87 refs

  2. Kinematics of multigrid Monte Carlo

    International Nuclear Information System (INIS)

    We study the kinematics of multigrid Monte Carlo algorithms by means of acceptance rates for nonlocal Metropolis update proposals. An approximation formula for acceptance rates is derived. We present a comparison of different coarse-to-fine interpolation schemes in free field theory, where the formula is exact. The predictions of the approximation formula for several interacting models are well confirmed by Monte Carlo simulations. The following rule is found: For a critical model with fundametal Hamiltonian Η(φ), absence of critical slowing down can only be expected if the expansion of (Η(φ+ψ)) in terms of the shift ψ contains no relevant (mass) term. We also introduce a multigrid update procedure for nonabelian lattice gauge theory and study the acceptance rates for gauge group SU(2) in four dimensions. (orig.)

  3. Asynchronous Anytime Sequential Monte Carlo

    OpenAIRE

    Paige, Brooks; Wood, Frank; Doucet, Arnaud; Teh, Yee Whye

    2014-01-01

    We introduce a new sequential Monte Carlo algorithm we call the particle cascade. The particle cascade is an asynchronous, anytime alternative to traditional particle filtering algorithms. It uses no barrier synchronizations which leads to improved particle throughput and memory efficiency. It is an anytime algorithm in the sense that it can be run forever to emit an unbounded number of particles while keeping within a fixed memory budget. We prove that the particle cascade is an unbiased mar...

  4. Neural Adaptive Sequential Monte Carlo

    OpenAIRE

    Gu, Shixiang; Ghahramani, Zoubin; Turner, Richard E

    2015-01-01

    Sequential Monte Carlo (SMC), or particle filtering, is a popular class of methods for sampling from an intractable target distribution using a sequence of simpler intermediate distributions. Like other importance sampling-based methods, performance is critically dependent on the proposal distribution: a bad proposal can lead to arbitrarily inaccurate estimates of the target distribution. This paper presents a new method for automatically adapting the proposal using an approximation of the Ku...

  5. Parallel Monte Carlo reactor neutronics

    International Nuclear Information System (INIS)

    The issues affecting implementation of parallel algorithms for large-scale engineering Monte Carlo neutron transport simulations are discussed. For nuclear reactor calculations, these include load balancing, recoding effort, reproducibility, domain decomposition techniques, I/O minimization, and strategies for different parallel architectures. Two codes were parallelized and tested for performance. The architectures employed include SIMD, MIMD-distributed memory, and workstation network with uneven interactive load. Speedups linear with the number of nodes were achieved

  6. Adaptive Multilevel Monte Carlo Simulation

    KAUST Repository

    Hoel, H

    2011-08-23

    This work generalizes a multilevel forward Euler Monte Carlo method introduced in Michael B. Giles. (Michael Giles. Oper. Res. 56(3):607–617, 2008.) for the approximation of expected values depending on the solution to an Itô stochastic differential equation. The work (Michael Giles. Oper. Res. 56(3):607– 617, 2008.) proposed and analyzed a forward Euler multilevelMonte Carlo method based on a hierarchy of uniform time discretizations and control variates to reduce the computational effort required by a standard, single level, Forward Euler Monte Carlo method. This work introduces an adaptive hierarchy of non uniform time discretizations, generated by an adaptive algorithmintroduced in (AnnaDzougoutov et al. Raùl Tempone. Adaptive Monte Carlo algorithms for stopped diffusion. In Multiscale methods in science and engineering, volume 44 of Lect. Notes Comput. Sci. Eng., pages 59–88. Springer, Berlin, 2005; Kyoung-Sook Moon et al. Stoch. Anal. Appl. 23(3):511–558, 2005; Kyoung-Sook Moon et al. An adaptive algorithm for ordinary, stochastic and partial differential equations. In Recent advances in adaptive computation, volume 383 of Contemp. Math., pages 325–343. Amer. Math. Soc., Providence, RI, 2005.). This form of the adaptive algorithm generates stochastic, path dependent, time steps and is based on a posteriori error expansions first developed in (Anders Szepessy et al. Comm. Pure Appl. Math. 54(10):1169– 1214, 2001). Our numerical results for a stopped diffusion problem, exhibit savings in the computational cost to achieve an accuracy of ϑ(TOL),from(TOL−3), from using a single level version of the adaptive algorithm to ϑ(((TOL−1)log(TOL))2).

  7. Monomial Gamma Monte Carlo Sampling

    OpenAIRE

    Zhang, Yizhe; Wang, Xiangyu; Chen, Changyou; Fan, Kai; Carin, Lawrence

    2016-01-01

    We unify slice sampling and Hamiltonian Monte Carlo (HMC) sampling by demonstrating their connection under the canonical transformation from Hamiltonian mechanics. This insight enables us to extend HMC and slice sampling to a broader family of samplers, called monomial Gamma samplers (MGS). We analyze theoretically the mixing performance of such samplers by proving that the MGS draws samples from a target distribution with zero-autocorrelation, in the limit of a single parameter. This propert...

  8. Extending canonical Monte Carlo methods

    Science.gov (United States)

    Velazquez, L.; Curilef, S.

    2010-02-01

    In this paper, we discuss the implications of a recently obtained equilibrium fluctuation-dissipation relation for the extension of the available Monte Carlo methods on the basis of the consideration of the Gibbs canonical ensemble to account for the existence of an anomalous regime with negative heat capacities C < 0. The resulting framework appears to be a suitable generalization of the methodology associated with the so-called dynamical ensemble, which is applied to the extension of two well-known Monte Carlo methods: the Metropolis importance sampling and the Swendsen-Wang cluster algorithm. These Monte Carlo algorithms are employed to study the anomalous thermodynamic behavior of the Potts models with many spin states q defined on a d-dimensional hypercubic lattice with periodic boundary conditions, which successfully reduce the exponential divergence of the decorrelation time τ with increase of the system size N to a weak power-law divergence \\tau \\propto N^{\\alpha } with α≈0.2 for the particular case of the 2D ten-state Potts model.

  9. Non statistical Monte-Carlo

    International Nuclear Information System (INIS)

    We have shown that the transport equation can be solved with particles, like the Monte-Carlo method, but without random numbers. In the Monte-Carlo method, particles are created from the source, and are followed from collision to collision until either they are absorbed or they leave the spatial domain. In our method, particles are created from the original source, with a variable weight taking into account both collision and absorption. These particles are followed until they leave the spatial domain, and we use them to determine a first collision source. Another set of particles is then created from this first collision source, and tracked to determine a second collision source, and so on. This process introduces an approximation which does not exist in the Monte-Carlo method. However, we have analyzed the effect of this approximation, and shown that it can be limited. Our method is deterministic, gives reproducible results. Furthermore, when extra accuracy is needed in some region, it is easier to get more particles to go there. It has the same kind of applications: rather problems where streaming is dominant than collision dominated problems

  10. Tafonomia y ambiente sedimentario del yacimiento de Huelago

    Directory of Open Access Journals (Sweden)

    Alberdi, M. T.

    2002-04-01

    situ. En los niveles detríticos asociados a paleocanales hay un porcentaje mayor de dientes aislados y esquirlas; y las mandíbulas y cuernas están asociadas a niveles limoso-margosos sin removilizar. Los agentes atmosféricos contribuyeron activamente a la fracturación de los huesos. La actividad de carroñeros-predadores en la superficie herbácea y encharcada del borde del lago ha sido reconocida. La gran diversidad de rumiantes, en particular los ramoneadores, indica áreas arboladas o arbustivas en los alrededores de Huélago, aunque no en el área inmediata del borde del lago. Se elaboró una matriz de datos con las variables medidas en cada resto fósil recuperado, que fue la base para el tratamiento gráfico y estadístico utilizado en el estudio del yacimiento.

  11. Análisis de la fragmentación en los montes de alto valor de conservación de ENCE de la provincia de Huelva desde el punto de vista de la ecología del paisaje

    OpenAIRE

    Fajardo Alcántara, M.; Dueñas López, M. A.; López Tirado, Javier; Carrasco Antelo, José María; Hidalgo Fernández, Pablo José

    2013-01-01

    La certificación FSC (Forest Stewardship Council) promueve la gestión forestal sostenible y, entre los principios aceptados, considera el paisaje como atributo para promover la biodiversidad y la funcionalidad ecológica de los montes. Define los Montes de Alto Valor de Conservación (MAVC) como unidades de gestión que tienen algún atributo interesante para la conservación de estas zonas, uno de ellos la identificación de hábitat de interés comunitario (HIC). La explotación intensiva de cultivo...

  12. Forward physics Monte Carlo (FPMC)

    Czech Academy of Sciences Publication Activity Database

    Boonekamp, M.; Juránek, Vojtěch; Kepka, Oldřich; Royon, C.

    Hamburg : Verlag Deutsches Elektronen-Synchrotron, 2009 - (Jung, H.; De Roeck, A.), s. 758-762 ISBN N. [HERA and the LHC workshop series on the implications of HERA for LHC physics. Geneve (CH), 26.05.2008-30.05.2008] R&D Projects: GA MŠk LC527; GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : forward physics * diffraction * two-photon * Monte Carlo Subject RIV: BF - Elementary Particles and High Energy Physics http://arxiv.org/PS_cache/arxiv/pdf/0903/0903.3861v2.pdf

  13. Monte Carlo techniques in radiation therapy

    CERN Document Server

    Verhaegen, Frank

    2013-01-01

    Modern cancer treatment relies on Monte Carlo simulations to help radiotherapists and clinical physicists better understand and compute radiation dose from imaging devices as well as exploit four-dimensional imaging data. With Monte Carlo-based treatment planning tools now available from commercial vendors, a complete transition to Monte Carlo-based dose calculation methods in radiotherapy could likely take place in the next decade. Monte Carlo Techniques in Radiation Therapy explores the use of Monte Carlo methods for modeling various features of internal and external radiation sources, including light ion beams. The book-the first of its kind-addresses applications of the Monte Carlo particle transport simulation technique in radiation therapy, mainly focusing on external beam radiotherapy and brachytherapy. It presents the mathematical and technical aspects of the methods in particle transport simulations. The book also discusses the modeling of medical linacs and other irradiation devices; issues specific...

  14. Monte Carlo primer for health physicists

    International Nuclear Information System (INIS)

    The basic ideas and principles of Monte Carlo calculations are presented in the form of a primer for health physicists. A simple integral with a known answer is evaluated by two different Monte Carlo approaches. Random number, which underlie Monte Carlo work, are discussed, and a sample table of random numbers generated by a hand calculator is presented. Monte Carlo calculations of dose and linear energy transfer (LET) from 100-keV neutrons incident on a tissue slab are discussed. The random-number table is used in a hand calculation of the initial sequence of events for a 100-keV neutron entering the slab. Some pitfalls in Monte Carlo work are described. While this primer addresses mainly the bare bones of Monte Carlo, a final section briefly describes some of the more sophisticated techniques used in practice to reduce variance and computing time

  15. Interacting Particle Markov Chain Monte Carlo

    OpenAIRE

    Rainforth, Tom; Naesseth, Christian A.; Lindsten, Fredrik; Paige, Brooks; van de Meent, Jan-Willem; Doucet, Arnaud; Wood, Frank

    2016-01-01

    We introduce interacting particle Markov chain Monte Carlo (iPMCMC), a PMCMC method that introduces a coupling between multiple standard and conditional sequential Monte Carlo samplers. Like related methods, iPMCMC is a Markov chain Monte Carlo sampler on an extended space. We present empirical results that show significant improvements in mixing rates relative to both non-interacting PMCMC samplers and a single PMCMC sampler with an equivalent total computational budget. An additional advant...

  16. Mean field simulation for Monte Carlo integration

    CERN Document Server

    Del Moral, Pierre

    2013-01-01

    In the last three decades, there has been a dramatic increase in the use of interacting particle methods as a powerful tool in real-world applications of Monte Carlo simulation in computational physics, population biology, computer sciences, and statistical machine learning. Ideally suited to parallel and distributed computation, these advanced particle algorithms include nonlinear interacting jump diffusions; quantum, diffusion, and resampled Monte Carlo methods; Feynman-Kac particle models; genetic and evolutionary algorithms; sequential Monte Carlo methods; adaptive and interacting Marko

  17. Aplicaciones SIG en proyectos de ordenación de montes

    OpenAIRE

    Fernández Morís, Iván

    2015-01-01

    Los objetivos del presente proyecto son conocer las posibles herramientas que Quantum GIS nos proporciona para su aplicación en el ámbito de la ordenación de montes y el uso de una tecnología GIS asequible para todo el mundo. Muchos son los beneficios que QGIS nos proporcionará en la gestión forestal y en el mundo empresarial: - Económico: El código abierto nos permite un ahorro de dinero para las empresas, ya que la mayoría de programas utilizados en el mundo del GIS ser rigen bajo lic...

  18. 1-D EQUILIBRIUM DISCRETE DIFFUSION MONTE CARLO

    Energy Technology Data Exchange (ETDEWEB)

    T. EVANS; ET AL

    2000-08-01

    We present a new hybrid Monte Carlo method for 1-D equilibrium diffusion problems in which the radiation field coexists with matter in local thermodynamic equilibrium. This method, the Equilibrium Discrete Diffusion Monte Carlo (EqDDMC) method, combines Monte Carlo particles with spatially discrete diffusion solutions. We verify the EqDDMC method with computational results from three slab problems. The EqDDMC method represents an incremental step toward applying this hybrid methodology to non-equilibrium diffusion, where it could be simultaneously coupled to Monte Carlo transport.

  19. Monte Carlo Application ToolKit (MCATK)

    International Nuclear Information System (INIS)

    Highlights: • Component-based Monte Carlo radiation transport parallel software library. • Designed to build specialized software applications. • Provides new functionality for existing general purpose Monte Carlo transport codes. • Time-independent and time-dependent algorithms with population control. • Algorithm verification and validation results are provided. - Abstract: The Monte Carlo Application ToolKit (MCATK) is a component-based software library designed to build specialized applications and to provide new functionality for existing general purpose Monte Carlo radiation transport codes. We will describe MCATK and its capabilities along with presenting some verification and validations results

  20. del Nim

    Directory of Open Access Journals (Sweden)

    Arturo Martínez Rodríguez

    2007-01-01

    Full Text Available Dado su uso específico como fuente de insecticidas naturales de fácil biodegradación, entre otras ventajas, el cultivo del árbol Nim ha sido mundialmente extendido en muchas regiones de Asia, África, Australia y América Latina, incluyendo Cuba. La cosecha del fruto del Nim se hace engorrosa debido a la altura que adquieren estos árboles a los pocos años de sembrados, siendo la cosecha mecánica mediante sacudidores de ramas o del tronco, una posible vía de solución práctica de esta problemática. En el presente trabajo se efectúa, mediante la simulación con el empleo de herramientas CAD-3D y programas de análisis por elementos finitos, un análisis modal abarcador de un número importante de modos de vibración del sistema fruto-pedúnculo del Nim. Como resultado del estudio se pudieron recomendar entornos de frecuencias de las vibraciones a aplicar con mejores expectativas durante la cosecha mecanizada de este producto.

  1. Multidimensional stochastic approximation Monte Carlo.

    Science.gov (United States)

    Zablotskiy, Sergey V; Ivanov, Victor A; Paul, Wolfgang

    2016-06-01

    Stochastic Approximation Monte Carlo (SAMC) has been established as a mathematically founded powerful flat-histogram Monte Carlo method, used to determine the density of states, g(E), of a model system. We show here how it can be generalized for the determination of multidimensional probability distributions (or equivalently densities of states) of macroscopic or mesoscopic variables defined on the space of microstates of a statistical mechanical system. This establishes this method as a systematic way for coarse graining a model system, or, in other words, for performing a renormalization group step on a model. We discuss the formulation of the Kadanoff block spin transformation and the coarse-graining procedure for polymer models in this language. We also apply it to a standard case in the literature of two-dimensional densities of states, where two competing energetic effects are present g(E_{1},E_{2}). We show when and why care has to be exercised when obtaining the microcanonical density of states g(E_{1}+E_{2}) from g(E_{1},E_{2}). PMID:27415383

  2. Single scatter electron Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Svatos, M.M. [Lawrence Livermore National Lab., CA (United States)|Wisconsin Univ., Madison, WI (United States)

    1997-03-01

    A single scatter electron Monte Carlo code (SSMC), CREEP, has been written which bridges the gap between existing transport methods and modeling real physical processes. CREEP simulates ionization, elastic and bremsstrahlung events individually. Excitation events are treated with an excitation-only stopping power. The detailed nature of these simulations allows for calculation of backscatter and transmission coefficients, backscattered energy spectra, stopping powers, energy deposits, depth dose, and a variety of other associated quantities. Although computationally intense, the code relies on relatively few mathematical assumptions, unlike other charged particle Monte Carlo methods such as the commonly-used condensed history method. CREEP relies on sampling the Lawrence Livermore Evaluated Electron Data Library (EEDL) which has data for all elements with an atomic number between 1 and 100, over an energy range from approximately several eV (or the binding energy of the material) to 100 GeV. Compounds and mixtures may also be used by combining the appropriate element data via Bragg additivity.

  3. Sísmica de reflexión de alta resolución en el estudio del Cuaternario de áreas de pie de monte Shallow, high-resolution seismic reflection in the study of the Quaternary in foothill areas

    OpenAIRE

    G. González Bonorino; J. I. Boyce; B. B. Koseoglu

    2003-01-01

    Se realizaron varias pruebas piloto con sísmica de reflexión de baja profundidad en depósitos de abanicos aluviales distales en la provincia de Salta, Argentina. Las pruebas incluyen dos áreas con características de subsuelo contrastantes. En el sector nororiental de la provincia, los depósitos del extenso abanico aluvial del Bermejo son arenosos y macizos, casi sin intercalaciones arcillosas; la napa se encontraba a más de 40 m de profundidad al tiempo del estudio. La otra zona de prueba se ...

  4. Regeneração e riqueza da formação arbustiva de Palmae em uma cronoseqüência pós-fogo na Restinga da Marambaia, Rio de Janeiro, RJ, Brasil The structure and diversity of three areas of shrubby restinga vegetation were analyzed 3, 12 and 84 months after fire in the Marambaia Restinga, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Luis Fernando Tavares de Menezes

    2004-12-01

    Full Text Available A estrutura e a riqueza da formação arbustiva de Palmae foram analisadas em três sítios numa cronoseqüência de regeneração (3, 12 e 84 meses após a última queimada na Restinga da Marambaia, registrando-se a presença de 29, 41 e 64 táxons, respectivamente. No sítio com maior tempo de regeneração, Allagoptera arenaria (Gomes Kuntze representou 79% da dominância relativa (DoR, seguida das nanofanerófitas Inga maritima Benth. e Manilkara subsericea (Mart. Dubard. Na área queimada há 12 meses, A. arenaria representou 88% da DoR, seguida de Inga maritima, Setaria setosa (Sw. P. Beauv. e Paspalum arenarium Schrad. No sítio com três meses de regeneração, a DoR de A. arenaria foi de 82%, acompanhada de Clitoria sp., Inga maritima e Portulaca mucronata Link. Nos três sítios estudados, a forma de vida mais importante foi geófita rizomatosa, devido à dominância de A. arenaria. Caméfita herbácea escaposa foi a forma de vida que apresentou maior número de espécies nos sítios com três e 12 meses de regeneração e no sítio queimado há 84 meses, as nanofanerófitas acompanharam as caméfitas herbáceas escaposas em número de espécies. Das 29 espécies registradas no sítio com três meses de regeneração, só Portulaca mucronata e Sebastiania corniculata (Vahl Müll. Arg. originaramse a partir de sementes, sendo que as demais rebrotaram ou se regeneraram. Sete dias após a queimada A. arenaria apresentou, em média, 8cm de sua parte vegetativa regenerada e com 180 dias apresentou as primeiras inflorescências.A total of 29, 41 and 64 taxa, respectively, were found. In the area sampled 84 months after fire, relative dominance of Allagoptera arenaria (Gomes Kuntze was 79%, followed by the nanophanerophytes Inga maritima Benth. and Manilkara subsericea (Mart. Dubard. In the area sampled 12 months after fire, relative dominance of A. arenaria was 88%, followed by Inga maritima, Setaria setosa (Sw. P. Beauv and Paspalum

  5. Caso exitoso energías renovables: Integración de sistemas solares en Faenadora Entre Montes

    OpenAIRE

    Banco Interamericano de Desarrollo (BID); Fundación Chile

    2012-01-01

    Este documento presenta el caso exitoso de implementación de la integración de sistemas solares en Faenadora Entre Montes. Esta empresa, mediante los aportes del BID-FOMIN - a través del "Programa de promoción de oportunidades de energías limpias" - ejecutado por Fundación Chile, logró ahorros anuales de $ 700 mil, un retorno de la inversión en cuatro años y ahorro de emisiones de CO2 de 5 toneladas al año. En el documento se explican los pormenores financieros y técnicos del proyecto....

  6. Diferencias en la flora herbácea y arbustiva entre claros y áreas bajo dosel en un bosque de Nothofagus pumilio en Argentina Differences in the herb and shrub flora growing under canopy gaps and under closed canopies in a Nothofagus pumilio forest of Argentina

    OpenAIRE

    M. ANGÉLICA DAMASCOS; EDUARDO H. RAPOPORT

    2002-01-01

    Se comparó la distribución de las hierbas y arbustos bajo el dosel y en dos tamaños de claros del bosque deciduo de Nothofagus pumilio de Argentina. La riqueza total y promedio de especies por cuadrado fueron similares bajo el dosel y en los claros pequeños (diámetro mayor < 5 m) y medianos (diámetro mayor entre 5-10 m). Las especies generalistas fueron las más numerosas (46 %), mientras que el 19 % correspondió a especies heliófobas y el 15 % a heliófilas obligadas y facultativas. La ausenci...

  7. Montes de Piedad eclesiásticos y particulares (S. XVIII-XIX: Usos monetarios

    Directory of Open Access Journals (Sweden)

    Muñoz Serrulla, María Teresa

    2009-12-01

    fronteras llegará a otras zonas europeas, entre ellas a la Península Ibérica. En el seno de la monarquía hispana en los inicios del siglo XVIII tiene lugar la fundación del Monte de Piedad de Madrid, obra del Padre Piquer que será heredero del espíritu y objetivos de los primitivos Montes italianos incluirá algunas novedades fruto de la devoción de su fundador y de las características propias de la época. Este Monte se constituye a su vez en modelo de otras instituciones similares tanto en la península como en los virreinatos americanos. Con el paso del tiempo, se producen una serie de fundaciones que coinciden en la denominación (todas llevarán por nombre Monte de Piedad, pero con importantes diferencias en sus constituciones y fines. Estas fundaciones surgen tanto en ámbito eclesiástico, como secular. El análisis de alguna de estas instituciones es el objetivo del presente estudio, diferenciando fundaciones eclesiásticas y seculares (en estas últimas se distinguen las fundadas por miembros de la nobleza. Partiendo de los textos fundacionales se analizan los objetivos particulares o generales, su espíritu benéfico, y diferentes aspectos relacionados con su puesta en marcha, pleitos, utilización para fines diferentes de los señalados en su fundación, etc.

  8. Variación estacional del uso y preferencia de los tipos vegetacionales por el venado cola blanca en un bosque tropical de Jalisco

    Directory of Open Access Journals (Sweden)

    S. Mandujano

    2004-01-01

    Full Text Available El venado cola blanca (Odocoileus virginianus habita el bosque tropical de Chamela en la costa Pacífica del estado de Jalisco, México. En esta región la vegetación dominante es el bosque tropical caducifolio el cual se establece en las colinas y se caracteriza porque en el estrato arbóreo y sotobosque dominan especies que pierden sus hojas durante seis a siete meses en la época seca. En contraste, la vegetación que se encuentra a lo largo de los arroyos y ríos es el bosque tropical subperennifolio en el cual dominan especies con hojas no caducifolias. Por lo tanto, en esta región existe un contraste notable en la disponibilidad de alimento, fuentes de agua, cobertura contra el clima y depredadores, tanto temporal como espacialmente. El objetivo del presente estudio fue analizarla variación estacional del uso y la preferencia que el venado cola blanca tiene por las dos principales comunidades o tipos vegetales en Chamela. Los resultados se discuten en función de dos hipótesis las cuales predicen mayor preferencia del bosque tropical caducifolio durante la época de lluvias, y mayor preferencia del bosque tropical subperennifolio durante la época de secas. El estudio se realizó de 1989 a 1993 y se emplearon los métodos de conteo directo de venados activos en el día a lo largo del año y el conteo de grupos fecales durante la época seca. Los sotobosques de ambos tipos vegetacionales fueron descritos para cada época del año(lluvias y seca cuantificando el número total de especies arbóreas, arbustivas y herbáceas, y se expresó como densidad promedio de número de especies por metro cuadrado; también se estimó la producción de biomasa foliar de las partes potencialmente consumibles por el venado como hojas y ramas tiernas, y se expresó como gramo de peso seco por metro cuadrado; finalmente se estimó la disponibilidad relativa de alimento a partir de datos de disponibilidad de las plantas que consume el venado en este sitio

  9. Potencial del agua del suelo

    OpenAIRE

    Bustamante Heliodoro

    2012-01-01

    La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es...

  10. Técnicas Monte Carlo aplicadas a la resolución de ecuaciones en derivadas parciales

    Directory of Open Access Journals (Sweden)

    Armando Serrano Lombillo

    2009-06-01

    Full Text Available En este trabajo se aplican las técnicas Monte Carlo a la resolución de ecuaciones en derivadas parciales, en concreto a la ecuación del calor. Si bien estas técnicas no mejoran las técnicas clásicas proporcionan una manera alternativa y más intuitiva de entender los métodos tradicionales. La última parte del trabajo se dedica al estudio estadístico de la importancia de cuatro factores en la precisión del método Monte Carlo. Para realizar el estudio se utilizó Statgraphics y Mathematica.

  11. General Monte Carlo code MONK

    International Nuclear Information System (INIS)

    The Monte Carlo code MONK is a general program written to provide a high degree of flexibility to the user. MONK is distinguished by its detailed representation of nuclear data in point form i.e., the cross-section is tabulated at specific energies instead of the more usual group representation. The nuclear data are unadjusted in the point form but recently the code has been modified to accept adjusted group data as used in fast and thermal reactor applications. The various geometrical handling capabilities and importance sampling techniques are described. In addition to the nuclear data aspects, the following features are also described; geometrical handling routines, tracking cycles, neutron source and output facilities. 12 references. (U.S.)

  12. Monte Carlo lattice program KIM

    International Nuclear Information System (INIS)

    The Monte Carlo program KIM solves the steady-state linear neutron transport equation for a fixed-source problem or, by successive fixed-source runs, for the eigenvalue problem, in a two-dimensional thermal reactor lattice. Fluxes and reaction rates are the main quantities computed by the program, from which power distribution and few-group averaged cross sections are derived. The simulation ranges from 10 MeV to zero and includes anisotropic and inelastic scattering in the fast energy region, the epithermal Doppler broadening of the resonances of some nuclides, and the thermalization phenomenon by taking into account the thermal velocity distribution of some molecules. Besides the well known combinatorial geometry, the program allows complex configurations to be represented by a discrete set of points, an approach greatly improving calculation speed

  13. Monte Carlo application tool-kit (MCATK)

    International Nuclear Information System (INIS)

    The Monte Carlo Application tool-kit (MCATK) is a C++ component-based software library designed to build specialized applications and to provide new functionality for existing general purpose Monte Carlo radiation transport codes such as MCNP. We will describe MCATK and its capabilities along with presenting some verification and validations results. (authors)

  14. Common misconceptions in Monte Carlo particle transport

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Thomas E., E-mail: teb@lanl.gov [LANL, XCP-7, MS F663, Los Alamos, NM 87545 (United States)

    2012-07-15

    Monte Carlo particle transport is often introduced primarily as a method to solve linear integral equations such as the Boltzmann transport equation. This paper discusses some common misconceptions about Monte Carlo methods that are often associated with an equation-based focus. Many of the misconceptions apply directly to standard Monte Carlo codes such as MCNP and some are worth noting so that one does not unnecessarily restrict future methods. - Highlights: Black-Right-Pointing-Pointer Adjoint variety and use from a Monte Carlo perspective. Black-Right-Pointing-Pointer Misconceptions and preconceived notions about statistical weight. Black-Right-Pointing-Pointer Reasons that an adjoint based weight window sometimes works well or does not. Black-Right-Pointing-Pointer Pulse height/probability of initiation tallies and 'the' transport equation. Black-Right-Pointing-Pointer Highlights unnecessary preconceived notions about Monte Carlo transport.

  15. Una alabarda procedente del valle del Manzanares (Madrid

    Directory of Open Access Journals (Sweden)

    Miguel Ángel de BLAS CORTINA

    2009-12-01

    Full Text Available RESUMEN: Se estudia una alabarda metálica procedente —sin datos precisos de su localización— del valle del Manzanares (Madrid. Posiblemente apareciera con otros materiales (¿puntas Palmela?, pero el hecho no pudo ser comprobado. Fundida en un molde monovalvo que proporciona un acabado homogéneo a una sola de las caras, se integra metalúrgicamente en el grupo E 01 (cobres arsenicales propio de la Península Ibérica durante el Calcolítico y el Bronce Antiguo. Tipológicamente puede ser clasificada como integrante del grupo Carrapatas al que pertenecen un conjunto de alabardas procedentes del N.E. de Portugal (Bragança y Tras os Montes del que se conocen escasos testimonios fuera del área característica. Especialmente significativo es el hallazgo de la finca de la Paloma (Pantoja, Toledo que muestra la asociación entre las alabardas Carrapatas y elementos propios del campaniforme tardío de España y Portugal, circunstancia que permite fechar el tipo entre el 1700-1500 a. de J.C., datación similar a las fechas admitidas para las alabardas irlandesas con las que algunos autores ven posibles relaciones. La existencia de alabardas grabadas en estelas más tardías o en rocas al aire libre plantea el problema de su perduración. No obstante, el carácter simbólico de las armas grabadas puede hacer que sea solamente la imagen representada la que superviva, aunque el arma como tal haya perdido vigencia. La alabarda del Manzanares, junto con las de Pantoja, señala la presencia en la Meseta Sur de elementos metalúrgicos propios del N.W. de la Península en un momento sincrónico con las fases finales del campaniforme.ABSTRACT: We study a metallic halberd found in an indeterminate place in the valley of the river Manzanares (Madrid. It might have appeared with other materials (Palmela Points?, although this fact could not be confirmed. Made in a single-faced mould which allows a homogeneous finish to only one of the sides, it belongs from

  16. Diagnóstico sociolingüístico del departamento del Amazonas

    OpenAIRE

    Pappenheim Murcia Ruth

    2000-01-01

    El Departamento de Lingüística de la Universidad Nacional de Colombia inició, en el segundo semestre de 1999, un estudio sociolingüístico del departamento del Amazonas, con el propósito de definir un perfil sociolingüístico de la región. Bajo la dirección de la profesora Olga Ardila y con la colaboración de las profesoras María Emilia Montes y Gabriele de Piñeros, como investigadoras principales, y la profesora Ruth Pappenheim, como asesora sociolingüista, se lleva a cabo en la actua...

  17. Culturas del Mundo

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger; Costa, Alberto; Waehle, Espen

    2006-01-01

    ’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39......’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39...

  18. DINÁMICA DEL CAMBIO DE USO DE LA TIERRA EN EL PARQUE NACIONAL HUMEDALES DEL OZAMA

    OpenAIRE

    Carmen Leticia Mendoza Gómez; Carmen Maritza Sánchez Pujols; Mayeline Gómez Espinal

    2011-01-01

    En este estudio se establecen y cuantifican los usos de la tierra actuales en el área protegida conocida como Parque Nacional "Humedales del Ozama", la cual forma parte del "Cinturón Verde de Santo Domingo" y está situada en las provincias de Santo Domingo y Monte Plata. Para ello se utilizaron fotos aéreas digitales de alta resolución de diferentes épocas, imágenes satelitales de alta resolución obtenidas a través de capturas de pantalla del visualizador en línea de Google Earth© con imágene...

  19. Use of Monte Carlo Methods in brachytherapy

    International Nuclear Information System (INIS)

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  20. Monte Carlo simulation for soot dynamics

    Directory of Open Access Journals (Sweden)

    Zhou Kun

    2012-01-01

    Full Text Available A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

  1. Monte carlo simulation for soot dynamics

    KAUST Repository

    Zhou, Kun

    2012-01-01

    A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

  2. Fast quantum Monte Carlo on a GPU

    CERN Document Server

    Lutsyshyn, Y

    2013-01-01

    We present a scheme for the parallelization of quantum Monte Carlo on graphical processing units, focusing on bosonic systems and variational Monte Carlo. We use asynchronous execution schemes with shared memory persistence, and obtain an excellent acceleration. Comparing with single core execution, GPU-accelerated code runs over x100 faster. The CUDA code is provided along with the package that is necessary to execute variational Monte Carlo for a system representing liquid helium-4. The program was benchmarked on several models of Nvidia GPU, including Fermi GTX560 and M2090, and the latest Kepler architecture K20 GPU. Kepler-specific optimization is discussed.

  3. Importance iteration in MORSE Monte Carlo calculations

    International Nuclear Information System (INIS)

    An expression to calculate point values (the expected detector response of a particle emerging from a collision or the source) is derived and implemented in the MORSE-SGC/S Monte Carlo code. It is outlined how these point values can be smoothed as a function of energy and as a function of the optical thickness between the detector and the source. The smoothed point values are subsequently used to calculate the biasing parameters of the Monte Carlo runs to follow. The method is illustrated by an example, which shows that the obtained biasing parameters lead to a more efficient Monte Carlo calculation. (orig.)

  4. Advanced computers and Monte Carlo

    International Nuclear Information System (INIS)

    High-performance parallelism that is currently available is synchronous in nature. It is manifested in such architectures as Burroughs ILLIAC-IV, CDC STAR-100, TI ASC, CRI CRAY-1, ICL DAP, and many special-purpose array processors designed for signal processing. This form of parallelism has apparently not been of significant value to many important Monte Carlo calculations. Nevertheless, there is much asynchronous parallelism in many of these calculations. A model of a production code that requires up to 20 hours per problem on a CDC 7600 is studied for suitability on some asynchronous architectures that are on the drawing board. The code is described and some of its properties and resource requirements ae identified to compare with corresponding properties and resource requirements are identified to compare with corresponding properties and resource requirements are identified to compare with corresponding properties and resources of some asynchronous multiprocessor architectures. Arguments are made for programer aids and special syntax to identify and support important asynchronous parallelism. 2 figures, 5 tables

  5. Guideline for radiation transport simulation with the Monte Carlo method

    International Nuclear Information System (INIS)

    Today, the photon and neutron transport calculations with the Monte Carlo method have been progressed with advanced Monte Carlo codes and high-speed computers. Monte Carlo simulation is rather suitable expression than the calculation. Once Monte Carlo codes become more friendly and performance of computer progresses, most of the shielding problems will be solved by using the Monte Carlo codes and high-speed computers. As those codes prepare the standard input data for some problems, the essential techniques for solving the Monte Carlo method and variance reduction techniques of the Monte Carlo calculation might lose the interests to the general Monte Carlo users. In this paper, essential techniques of the Monte Carlo method and the variance reduction techniques, such as importance sampling method, selection of estimator, and biasing technique, are described to afford a better understanding of the Monte Carlo method and Monte Carlo code. (author)

  6. Diferencias en la flora herbácea y arbustiva entre claros y áreas bajo dosel en un bosque de Nothofagus pumilio en Argentina Differences in the herb and shrub flora growing under canopy gaps and under closed canopies in a Nothofagus pumilio forest of Argentina

    Directory of Open Access Journals (Sweden)

    M. ANGÉLICA DAMASCOS

    2002-09-01

    Full Text Available Se comparó la distribución de las hierbas y arbustos bajo el dosel y en dos tamaños de claros del bosque deciduo de Nothofagus pumilio de Argentina. La riqueza total y promedio de especies por cuadrado fueron similares bajo el dosel y en los claros pequeños (diámetro mayor The distribution of herbs and shrubs under closed canopies and in two canopy gaps of different size was compared in a Nothofagus pumilio deciduous forest of Argentina. The total and the average species richness per plot were similar between the areas under the canopy and in small (maximum diameter < 5 m and medium size gaps (maximum diameter 5-10 m. Generalist species were the most numerous (46 %, while obligate and facultatively shade-tolerant (heliophobous and intolerant (heliophilous species accounted for 19 and 15 % of the species, respectively. The absence of differences in species richness may be attributed to: (1 high frequency of generalist species (2 low effect of gap formation on shade-tolerant species distribution, (3 persistence of facultatively shade-tolerant species in small gaps, (4 gap invasion by obligate shade-intolerant species. The heterogeneity of light environment beneath the canopy and the effects on gap microclimate of edge trees and gap shrubs are possible causes of these patterns. Although with variations between the different biological groups, forest species are probably tolerant to the low level of disturbance generated by the natural forest dynamics

  7. 11th International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing

    CERN Document Server

    Nuyens, Dirk

    2016-01-01

    This book presents the refereed proceedings of the Eleventh International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing that was held at the University of Leuven (Belgium) in April 2014. These biennial conferences are major events for Monte Carlo and quasi-Monte Carlo researchers. The proceedings include articles based on invited lectures as well as carefully selected contributed papers on all theoretical aspects and applications of Monte Carlo and quasi-Monte Carlo methods. Offering information on the latest developments in these very active areas, this book is an excellent reference resource for theoreticians and practitioners interested in solving high-dimensional computational problems, arising, in particular, in finance, statistics and computer graphics.

  8. Monte Carlo simulations for plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, M.; Murakami, S.; Nakajima, N.; Wang, W.X. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-07-01

    Plasma behaviours are very complicated and the analyses are generally difficult. However, when the collisional processes play an important role in the plasma behaviour, the Monte Carlo method is often employed as a useful tool. For examples, in neutral particle injection heating (NBI heating), electron or ion cyclotron heating, and alpha heating, Coulomb collisions slow down high energetic particles and pitch angle scatter them. These processes are often studied by the Monte Carlo technique and good agreements can be obtained with the experimental results. Recently, Monte Carlo Method has been developed to study fast particle transports associated with heating and generating the radial electric field. Further it is applied to investigating the neoclassical transport in the plasma with steep gradients of density and temperatures which is beyong the conventional neoclassical theory. In this report, we briefly summarize the researches done by the present authors utilizing the Monte Carlo method. (author)

  9. Monte Carlo Treatment Planning for Advanced Radiotherapy

    DEFF Research Database (Denmark)

    Cronholm, Rickard

    validation of a Monte Carlo model of a medical linear accelerator (i), converting a CT scan of a patient to a Monte Carlo compliant phantom (ii) and translating the treatment plan parameters (including beam energy, angles of incidence, collimator settings etc) to a Monte Carlo input file (iii). A protocol...... more sophisticated than previous algorithms since it uses delineations of structures in order to include and/or exclude certain media in various anatomical regions. This method has the potential to reduce anatomically irrelevant media assignment. In house MATLAB scripts translating the treatment plan...... presented. Comparison between dose distribution for clinical treatment plans generated by a commercial Treatment Planning System and by the implemented Monte Carlo Treatment Planning workflow were conducted. Good agreement was generally found, but for regions involving large density gradients differences of...

  10. Experience with the Monte Carlo Method

    International Nuclear Information System (INIS)

    Monte Carlo simulation of radiation transport provides a powerful research and design tool that resembles in many aspects laboratory experiments. Moreover, Monte Carlo simulations can provide an insight not attainable in the laboratory. However, the Monte Carlo method has its limitations, which if not taken into account can result in misleading conclusions. This paper will present the experience of this author, over almost three decades, in the use of the Monte Carlo method for a variety of applications. Examples will be shown on how the method was used to explore new ideas, as a parametric study and design optimization tool, and to analyze experimental data. The consequences of not accounting in detail for detector response and the scattering of radiation by surrounding structures are two of the examples that will be presented to demonstrate the pitfall of condensed

  11. Frontiers of quantum Monte Carlo workshop: preface

    International Nuclear Information System (INIS)

    The introductory remarks, table of contents, and list of attendees are presented from the proceedings of the conference, Frontiers of Quantum Monte Carlo, which appeared in the Journal of Statistical Physics

  12. Monte Carlo methods for particle transport

    CERN Document Server

    Haghighat, Alireza

    2015-01-01

    The Monte Carlo method has become the de facto standard in radiation transport. Although powerful, if not understood and used appropriately, the method can give misleading results. Monte Carlo Methods for Particle Transport teaches appropriate use of the Monte Carlo method, explaining the method's fundamental concepts as well as its limitations. Concise yet comprehensive, this well-organized text: * Introduces the particle importance equation and its use for variance reduction * Describes general and particle-transport-specific variance reduction techniques * Presents particle transport eigenvalue issues and methodologies to address these issues * Explores advanced formulations based on the author's research activities * Discusses parallel processing concepts and factors affecting parallel performance Featuring illustrative examples, mathematical derivations, computer algorithms, and homework problems, Monte Carlo Methods for Particle Transport provides nuclear engineers and scientists with a practical guide ...

  13. Predator trapping on Monte Vista NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This letter is summarizing the status of predator trapping on Monte Vista National Wildlife refuge in light of the referendum passes in the State of Colorado...

  14. Avariide kiuste Monte Carlosse / Aare Arula

    Index Scriptorium Estoniae

    Arula, Aare

    2007-01-01

    Vt. ka Tehnika dlja Vsehh nr. 3, lk. 26-27. 26. jaanuaril 1937 Tallinnast Monte Carlo tähesõidule startinud Karl Siitanit ja tema meeskonda ootasid ees seiklused, mis oleksid neile peaaegu elu maksnud

  15. Monte Carlo simulation of granular fluids

    OpenAIRE

    Montanero, J. M.

    2003-01-01

    An overview of recent work on Monte Carlo simulations of a granular binary mixture is presented. The results are obtained numerically solving the Enskog equation for inelastic hard-spheres by means of an extension of the well-known direct Monte Carlo simulation (DSMC) method. The homogeneous cooling state and the stationary state reached using the Gaussian thermostat are considered. The temperature ratio, the fourth velocity moments and the velocity distribution functions are obtained for bot...

  16. Monte Carlo photon transport techniques

    International Nuclear Information System (INIS)

    The basis of Monte Carlo calculation of photon transport problems is the computer simulation of individual photon histories and their subsequent averaging to provide the quantities of interest. As the history of a photon is followed the values of variables are selected and decisions made by sampling known distributions using random numbers. The transport of photon is simulated by creation of particles from a defined source region, generally with a random initial orientation in space, with tracking of particles as they travel through the system, sampling the probability density functions for their interactions to evaluate their trajectories and energy deposition at different points in the system. The interactions determine the penetration and the motion of particles. The computational model, for radiation transport problems includes geometry and material specifications. Every computer code contains a database of experimentally obtained quantities, known as cross-sections that determine the probability of a particle interacting with the medium through which it is transported. Every cross-section is peculiar to the type and energy of the incident particle and to the kind of interaction it undergoes. These partial cross-sections are summed to form the total cross-section; the ratio of the partial cross-section to the total cross-section gives the probability of this particular interaction occurring. Cross-section data for the interaction types of interest must be supplied for each material present. The model also consists of algorithms used to compute the result of interactions (changes in particle energy, direction, etc.) based on the physical principles that describe the interaction of radiation with matter and the cross-section data provided

  17. Efecto del genotipo en la respuesta a fertilizantes en Chamaecyparis lawsoniana (A.Murr.) Parl. y Pseudotsuga menziesii (MIRB.) Franco.

    OpenAIRE

    Zas Arregui, Rafael; Pichel, F.

    2001-01-01

    6 páginas, 3 tablas -- Comunicación presentada al 3º Congreso Forestal Español, que se celebró en Granada del 25 al 28 de septiembre de 2001, bajo el lema “Montes para la Sociedad del nuevo milenio”, y con la denominación “Sierra Nevada 2001”.

  18. Perfil del visitante del parque nacional Desierto del Carmen

    OpenAIRE

    Elizabeth López Carré

    2007-01-01

    El artículo presenta los resultados obtenidos del proyecto de investigación titulado "Evaluación del potencial de comercialización y caracterización del visitante del Santo Desierto de Tenancingo", específicamente los correspondientes al perfil del visitante a dicho Parque Nacional. La metodología utilizada se sustenta en la investigación de mercados propuesta por Kinnear y Taylor. El resultado de dicha investigación permitió integrar el perfil del segmento de mercado religioso...

  19. Monte Carlo analysis of radiative transport in oceanographic lidar measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cupini, E.; Ferro, G. [ENEA, Divisione Fisica Applicata, Centro Ricerche Ezio Clementel, Bologna (Italy); Ferrari, N. [Bologna Univ., Bologna (Italy). Dipt. Ingegneria Energetica, Nucleare e del Controllo Ambientale

    2001-07-01

    The analysis of oceanographic lidar systems measurements is often carried out with semi-empirical methods, since there is only a rough understanding of the effects of many environmental variables. The development of techniques for interpreting the accuracy of lidar measurements is needed to evaluate the effects of various environmental situations, as well as of different experimental geometric configurations and boundary conditions. A Monte Carlo simulation model represents a tool that is particularly well suited for answering these important questions. The PREMAR-2F Monte Carlo code has been developed taking into account the main molecular and non-molecular components of the marine environment. The laser radiation interaction processes of diffusion, re-emission, refraction and absorption are treated. In particular are considered: the Rayleigh elastic scattering, produced by atoms and molecules with small dimensions with respect to the laser emission wavelength (i.e. water molecules), the Mie elastic scattering, arising from atoms or molecules with dimensions comparable to the laser wavelength (hydrosols), the Raman inelastic scattering, typical of water, the absorption of water, inorganic (sediments) and organic (phytoplankton and CDOM) hydrosols, the fluorescence re-emission of chlorophyll and yellow substances. PREMAR-2F is an extension of a code for the simulation of the radiative transport in atmospheric environments (PREMAR-2). The approach followed in PREMAR-2 was to combine conventional Monte Carlo techniques with analytical estimates of the probability of the receiver to have a contribution from photons coming back after an interaction in the field of view of the lidar fluorosensor collecting apparatus. This offers an effective mean for modelling a lidar system with realistic geometric constraints. The retrieved semianalytic Monte Carlo radiative transfer model has been developed in the frame of the Italian Research Program for Antarctica (PNRA) and it is

  20. Consumo de Carne de Monte de Armadillo (Dasypus novemcinctus) y sus Repercusiones en Salud Pública en Colombia

    OpenAIRE

    Laura Cristina Sánchez-Sáenz

    2015-01-01

    Objetivo: Hacer una revisión general del panorama nacional sobre consumo de carne de monte y zoonosis asociadas a fauna silvestre. Asimismo, citar como ejemplo uno de los reservorios zoonóticos consumidos con mayor frecuencia en Colombia debido a que existe poco conocimiento acerca de sus repercusiones en salud pública. Metodología: Mediante una revisión de literatura durante el segundo semestre del 2013, se identificaron los principales temas y subtemas asociados al consumo de carne de m...

  1. Successful vectorization - reactor physics Monte Carlo code

    International Nuclear Information System (INIS)

    Most particle transport Monte Carlo codes in use today are based on the ''history-based'' algorithm, wherein one particle history at a time is simulated. Unfortunately, the ''history-based'' approach (present in all Monte Carlo codes until recent years) is inherently scalar and cannot be vectorized. In particular, the history-based algorithm cannot take advantage of vector architectures, which characterize the largest and fastest computers at the current time, vector supercomputers such as the Cray X/MP or IBM 3090/600. However, substantial progress has been made in recent years in developing and implementing a vectorized Monte Carlo algorithm. This algorithm follows portions of many particle histories at the same time and forms the basis for all successful vectorized Monte Carlo codes that are in use today. This paper describes the basic vectorized algorithm along with descriptions of several variations that have been developed by different researchers for specific applications. These applications have been mainly in the areas of neutron transport in nuclear reactor and shielding analysis and photon transport in fusion plasmas. The relative merits of the various approach schemes will be discussed and the present status of known vectorization efforts will be summarized along with available timing results, including results from the successful vectorization of 3-D general geometry, continuous energy Monte Carlo. (orig.)

  2. Consumo de Carne de Monte de Armadillo (Dasypus novemcinctus y sus Repercusiones en Salud Pública en Colombia

    Directory of Open Access Journals (Sweden)

    Laura Cristina Sánchez-Sáenz

    2015-07-01

    Full Text Available Objetivo: Hacer una revisión general del panorama nacional sobre consumo de carne de monte y zoonosis asociadas a fauna silvestre. Asimismo, citar como ejemplo uno de los reservorios zoonóticos consumidos con mayor frecuencia en Colombia debido a que existe poco conocimiento acerca de sus repercusiones en salud pública. Metodología: Mediante una revisión de literatura durante el segundo semestre del 2013, se identificaron los principales temas y subtemas asociados al consumo de carne de monte y zoonosis, de los cuales se enfatizó la búsqueda en patógenos transmisibles por armadillos. Resultados: Existe un claro desconocimiento del posible desarrollo de zoonosis por consumo de carne de monte en Colombia. Los mamíferos son el grupo más consumido, de éstos los armadillos (Dasypus novemcinctus son una especie de valor comercial y de consumo en América del Sur, siendo objeto de investigación actual por su papel como reservorio de agentes zoonóticos, algunos de ellos con potencial transmisión a través de su carne. Conclusión: Dada la problemática sanitaria respecto a zoonosis transmitidas por fauna silvestre, así como la dinámica socio-cultural de consumo de carne de monte, es necesario adelantar estudios para determinar el estado de las enfermedades en la fauna silvestre de Colombia y sus repercusiones en salud pública. Igualmente, desarrollar alternativas para minimizar el tráfico de especies silvestres, mejorar la calidad de vida de las comunidades rurales y generar programas de vigilancia sanitaria para las mismas.

  3. Quantum Monte Carlo calculations of light nuclei

    International Nuclear Information System (INIS)

    Quantum Monte Carlo calculations using realistic two- and three-nucleon interactions are presented for nuclei with up to eight nucleons. We have computed the ground and a few excited states of all such nuclei with Greens function Monte Carlo (GFMC) and all of the experimentally known excited states using variational Monte Carlo (VMC). The GFMC calculations show that for a given Hamiltonian, the VMC calculations of excitation spectra are reliable, but the VMC ground-state energies are significantly above the exact values. We find that the Hamiltonian we are using (which was developed based on 3H, 4He, and nuclear matter calculations) underpredicts the binding energy of p-shell nuclei. However our results for excitation spectra are very good and one can see both shell-model and collective spectra resulting from fundamental many-nucleon calculations. Possible improvements in the three-nucleon potential are also be discussed

  4. Monte Carlo strategies in scientific computing

    CERN Document Server

    Liu, Jun S

    2008-01-01

    This paperback edition is a reprint of the 2001 Springer edition This book provides a self-contained and up-to-date treatment of the Monte Carlo method and develops a common framework under which various Monte Carlo techniques can be "standardized" and compared Given the interdisciplinary nature of the topics and a moderate prerequisite for the reader, this book should be of interest to a broad audience of quantitative researchers such as computational biologists, computer scientists, econometricians, engineers, probabilists, and statisticians It can also be used as the textbook for a graduate-level course on Monte Carlo methods Many problems discussed in the alter chapters can be potential thesis topics for masters’ or PhD students in statistics or computer science departments Jun Liu is Professor of Statistics at Harvard University, with a courtesy Professor appointment at Harvard Biostatistics Department Professor Liu was the recipient of the 2002 COPSS Presidents' Award, the most prestigious one for sta...

  5. Quantum Monte Carlo with Variable Spins

    CERN Document Server

    Melton, Cody A; Mitas, Lubos

    2016-01-01

    We investigate the inclusion of variable spins in electronic structure quantum Monte Carlo, with a focus on diffusion Monte Carlo with Hamiltonians that include spin-orbit interactions. Following our previous introduction of fixed-phase spin-orbit diffusion Monte Carlo (FPSODMC), we thoroughly discuss the details of the method and elaborate upon its technicalities. We present a proof for an upper-bound property for complex nonlocal operators, which allows for the implementation of T-moves to ensure the variational property. We discuss the time step biases associated with our particular choice of spin representation. Applications of the method are also presented for atomic and molecular systems. We calculate the binding energies and geometry of the PbH and Sn$_2$ molecules, as well as the electron affinities of the 6$p$ row elements in close agreement with experiments.

  6. SPQR: a Monte Carlo reactor kinetics code

    International Nuclear Information System (INIS)

    The SPQR Monte Carlo code has been developed to analyze fast reactor core accident problems where conventional methods are considered inadequate. The code is based on the adiabatic approximation of the quasi-static method. This initial version contains no automatic material motion or feedback. An existing Monte Carlo code is used to calculate the shape functions and the integral quantities needed in the kinetics module. Several sample problems have been devised and analyzed. Due to the large statistical uncertainty associated with the calculation of reactivity in accident simulations, the results, especially at later times, differ greatly from deterministic methods. It was also found that in large uncoupled systems, the Monte Carlo method has difficulty in handling asymmetric perturbations

  7. CosmoPMC: Cosmology Population Monte Carlo

    CERN Document Server

    Kilbinger, Martin; Cappe, Olivier; Cardoso, Jean-Francois; Fort, Gersende; Prunet, Simon; Robert, Christian P; Wraith, Darren

    2011-01-01

    We present the public release of the Bayesian sampling algorithm for cosmology, CosmoPMC (Cosmology Population Monte Carlo). CosmoPMC explores the parameter space of various cosmological probes, and also provides a robust estimate of the Bayesian evidence. CosmoPMC is based on an adaptive importance sampling method called Population Monte Carlo (PMC). Various cosmology likelihood modules are implemented, and new modules can be added easily. The importance-sampling algorithm is written in C, and fully parallelised using the Message Passing Interface (MPI). Due to very little overhead, the wall-clock time required for sampling scales approximately with the number of CPUs. The CosmoPMC package contains post-processing and plotting programs, and in addition a Monte-Carlo Markov chain (MCMC) algorithm. The sampling engine is implemented in the library pmclib, and can be used independently. The software is available for download at http://www.cosmopmc.info.

  8. Sísmica de reflexión de alta resolución en el estudio del Cuaternario de áreas de pie de monte Shallow, high-resolution seismic reflection in the study of the Quaternary in foothill areas

    Directory of Open Access Journals (Sweden)

    G. González Bonorino

    2003-03-01

    Full Text Available Se realizaron varias pruebas piloto con sísmica de reflexión de baja profundidad en depósitos de abanicos aluviales distales en la provincia de Salta, Argentina. Las pruebas incluyen dos áreas con características de subsuelo contrastantes. En el sector nororiental de la provincia, los depósitos del extenso abanico aluvial del Bermejo son arenosos y macizos, casi sin intercalaciones arcillosas; la napa se encontraba a más de 40 m de profundidad al tiempo del estudio. La otra zona de prueba se ubica al sur de la ciudad de Salta, donde coalescen abanicos aluviales pequeños que rellenan el valle de Lerma con depósitos de arena y grava, los cuales en los tramos distales se interdigitan con potentes capas arcillosas; la napa en esta área se hallaba a una profundidad mayor de 20 m al momento del estudio. La operación sísmica empleó un sismógrafo Geometrics R24 con 24 canales activos que se aumentaron a 48 mediante un "roll-over switch", alcanzando un máximo de cobertura de 1200%. Se probaron dos fuentes de sonido: una masa de 5 kg y una escopeta calibre 12. Principalmente por razones operativas se eligió como fuente la masa. Las pruebas en el abanico del Bermejo dieron registros de baja calidad, probablemente debido a la rápida pérdida de energía en las areas poco consolidadas y secas. Localmente, sin embargo, pudieron distinguirse tres unidades sísmicas y el techo del Terciario posiblemente fue detectado. Las pruebas en eje del valle de Lerma dieron registros sísmicos de excelente calidad. Se distinguieron cuatro unidades sísmicas. Un reflector débil a aproximadamente 220 mseg coincide con un cambio de las velocidades a unos 2500 m/seg y puede corresponder con el techo del sustrato terciario. Una potente capa de arcilla a una profundidad de 25 a 50 m puede claramente mapearse como un acuitardo. Los resultados de este estudio piloto demuestran que la sísmica de reflexión de poca profundidad puede ser aplicada con provecho en el

  9. Modelamiento y simulación de propiedades magnéticas y de transporte de bicapas del compuesto tipo manganita (La2/3Ca1/3MnO3/La1/3Ca2/3MnO3) utilizando el método de Monte Carlo

    OpenAIRE

    Ramírez García, Alejandro

    2009-01-01

    El material La1-XCaXMnO3 está clasificado como una manganita del tipo perovskita. Este clase de materiales responden a la fórmula A1-xBxMnO3, donde A es una tierra rara y B es un metal divalente (elementos ubicados en el grupo II de la tabla periódica). El número de investigaciones científicas dedicadas al estudio de las propiedades de las manganitas se ha incrementado en los últimos años. Este aumento se debe a que estos materiales exhiben un comportamiento interesante ante variaciones de...

  10. Aplicación del Método de Monte Carlo a la Planificación en Radioterapia y a la Reconstrucción de Espectros de Fotones de Aceleradores Lineales de Partículas (LinAc)

    OpenAIRE

    Juste Vidal, Belen Jeanine

    2011-01-01

    La radioterapia es uno de los tratamientos más generalizados aplicados a los pacientes que padecen determinados tipos de cáncer. Sin embargo, la efectividad de este tipo de tratamientos en la destrucción de las células cancerígenas lleva asociada la posibilidad de sufrir los efectos secundarios de la radiación sobre los tejidos sanos circundantes. El riesgo de lesión de las células sanas depende fundamentalmente de la orientación del haz emitido por la unidad de radioterapia y de la intensida...

  11. Geodesic Monte Carlo on Embedded Manifolds.

    Science.gov (United States)

    Byrne, Simon; Girolami, Mark

    2013-12-01

    Markov chain Monte Carlo methods explicitly defined on the manifold of probability distributions have recently been established. These methods are constructed from diffusions across the manifold and the solution of the equations describing geodesic flows in the Hamilton-Jacobi representation. This paper takes the differential geometric basis of Markov chain Monte Carlo further by considering methods to simulate from probability distributions that themselves are defined on a manifold, with common examples being classes of distributions describing directional statistics. Proposal mechanisms are developed based on the geodesic flows over the manifolds of support for the distributions, and illustrative examples are provided for the hypersphere and Stiefel manifold of orthonormal matrices. PMID:25309024

  12. Interaction picture density matrix quantum Monte Carlo

    International Nuclear Information System (INIS)

    The recently developed density matrix quantum Monte Carlo (DMQMC) algorithm stochastically samples the N-body thermal density matrix and hence provides access to exact properties of many-particle quantum systems at arbitrary temperatures. We demonstrate that moving to the interaction picture provides substantial benefits when applying DMQMC to interacting fermions. In this first study, we focus on a system of much recent interest: the uniform electron gas in the warm dense regime. The basis set incompleteness error at finite temperature is investigated and extrapolated via a simple Monte Carlo sampling procedure. Finally, we provide benchmark calculations for a four-electron system, comparing our results to previous work where possible

  13. Monte Carlo modeling of Tajoura reactor

    International Nuclear Information System (INIS)

    From neutronics point of view, reactor modeling is concerned with the determination of the reactor neutronic parameters which can be obtained through the solution of the neutron transport equation. The attractiveness of the Monte Carlo method is in its capability of handling geometrically complicated problems and due to the nature of the method a large number of particles can be tracked from birth to death before any statistically significant results can be obtained. In this paper the MCNP, a Monte Carlo code, is implemented in the modeling of the Tajoura reactor. (author)

  14. Monte Carlo dose computation for IMRT optimization*

    Science.gov (United States)

    Laub, W.; Alber, M.; Birkner, M.; Nüsslin, F.

    2000-07-01

    A method which combines the accuracy of Monte Carlo dose calculation with a finite size pencil-beam based intensity modulation optimization is presented. The pencil-beam algorithm is employed to compute the fluence element updates for a converging sequence of Monte Carlo dose distributions. The combination is shown to improve results over the pencil-beam based optimization in a lung tumour case and a head and neck case. Inhomogeneity effects like a broader penumbra and dose build-up regions can be compensated for by intensity modulation.

  15. Monte Carlo electron/photon transport

    International Nuclear Information System (INIS)

    A review of nonplasma coupled electron/photon transport using Monte Carlo method is presented. Remarks are mainly restricted to linerarized formalisms at electron energies from 1 keV to 1000 MeV. Applications involving pulse-height estimation, transport in external magnetic fields, and optical Cerenkov production are discussed to underscore the importance of this branch of computational physics. Advances in electron multigroup cross-section generation is reported, and its impact on future code development assessed. Progress toward the transformation of MCNP into a generalized neutral/charged-particle Monte Carlo code is described. 48 refs

  16. Monte Carlo simulation of neutron scattering instruments

    International Nuclear Information System (INIS)

    A library of Monte Carlo subroutines has been developed for the purpose of design of neutron scattering instruments. Using small-angle scattering as an example, the philosophy and structure of the library are described and the programs are used to compare instruments at continuous wave (CW) and long-pulse spallation source (LPSS) neutron facilities. The Monte Carlo results give a count-rate gain of a factor between 2 and 4 using time-of-flight analysis. This is comparable to scaling arguments based on the ratio of wavelength bandwidth to resolution width

  17. Monte Carlo applications to radiation shielding problems

    International Nuclear Information System (INIS)

    Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling of physical and mathematical systems to compute their results. However, basic concepts of MC are both simple and straightforward and can be learned by using a personal computer. Uses of Monte Carlo methods require large amounts of random numbers, and it was their use that spurred the development of pseudorandom number generators, which were far quicker to use than the tables of random numbers which had been previously used for statistical sampling. In Monte Carlo simulation of radiation transport, the history (track) of a particle is viewed as a random sequence of free flights that end with an interaction event where the particle changes its direction of movement, loses energy and, occasionally, produces secondary particles. The Monte Carlo simulation of a given experimental arrangement (e.g., an electron beam, coming from an accelerator and impinging on a water phantom) consists of the numerical generation of random histories. To simulate these histories we need an interaction model, i.e., a set of differential cross sections (DCS) for the relevant interaction mechanisms. The DCSs determine the probability distribution functions (pdf) of the random variables that characterize a track; 1) free path between successive interaction events, 2) type of interaction taking place and 3) energy loss and angular deflection in a particular event (and initial state of emitted secondary particles, if any). Once these pdfs are known, random histories can be generated by using appropriate sampling methods. If the number of generated histories is large enough, quantitative information on the transport process may be obtained by simply averaging over the simulated histories. The Monte Carlo method yields the same information as the solution of the Boltzmann transport equation, with the same interaction model, but is easier to implement. In particular, the simulation of radiation

  18. Monte Carlo dose distributions for radiosurgery

    International Nuclear Information System (INIS)

    The precision of Radiosurgery Treatment planning systems is limited by the approximations of their algorithms and by their dosimetrical input data. This fact is especially important in small fields. However, the Monte Carlo methods is an accurate alternative as it considers every aspect of particle transport. In this work an acoustic neurinoma is studied by comparing the dose distribution of both a planning system and Monte Carlo. Relative shifts have been measured and furthermore, Dose-Volume Histograms have been calculated for target and adjacent organs at risk. (orig.)

  19. Monte Carlo simulation of granular fluids

    CERN Document Server

    Montanero, J M

    2003-01-01

    An overview of recent work on Monte Carlo simulations of a granular binary mixture is presented. The results are obtained numerically solving the Enskog equation for inelastic hard-spheres by means of an extension of the well-known direct Monte Carlo simulation (DSMC) method. The homogeneous cooling state and the stationary state reached using the Gaussian thermostat are considered. The temperature ratio, the fourth velocity moments and the velocity distribution functions are obtained for both cases. The shear viscosity characterizing the momentum transport in the thermostatted case is calculated as well. The simulation results are compared with analytical predictions showing an excellent agreement.

  20. Fast sequential Monte Carlo methods for counting and optimization

    CERN Document Server

    Rubinstein, Reuven Y; Vaisman, Radislav

    2013-01-01

    A comprehensive account of the theory and application of Monte Carlo methods Based on years of research in efficient Monte Carlo methods for estimation of rare-event probabilities, counting problems, and combinatorial optimization, Fast Sequential Monte Carlo Methods for Counting and Optimization is a complete illustration of fast sequential Monte Carlo techniques. The book provides an accessible overview of current work in the field of Monte Carlo methods, specifically sequential Monte Carlo techniques, for solving abstract counting and optimization problems. Written by authorities in the

  1. Visita al Monte de Zaratán (Valladolid) el 26 de mayo de 1951

    OpenAIRE

    Valverde Gómez, José Antonio, 1926-2003

    2008-01-01

    Salida de campo al Monte de Zaratán (Zaratán, Valladolid) el día 26 de mayo de 1951, en la que se anotó una descripción de la vegetación del enclave, se observó un anifibio (posiblemente, un Gallipato, Pleurodeles waltl) y anotaron también observaciones sobre los siguientes mamíferos: Apodemus sp. (Ratón) y Oryctolagus cuniculus (Conejo), y aves: Alectoris rufa (Perdiz roja), Anthus campestris (Bisbita campestre), Apus apus (Vencejo común), Calandrella sp. (Terrera), Caprimulgus sp. (Chotac...

  2. Impact of Weather Conditions on the Construction of the Terminal - Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Tatjana Stanivuk

    2013-03-01

    Full Text Available A simulation model is developed for the potential planned Patagonia and Tierra del Fuego terminals. The purpose is to identify reliability and availability of loading operations at the terminal. The harsh weather conditions, technical reliability and concurrent traffic affect LNG (Liquefied Natural Gas Carriers during approaching or loading. Probabilistic simulation method is created and Monte Carlo simulations are carried out for several cases, with varied production, number of jetties and terminal storage. The results indicate high importance of weather restrictions and are used to present a recommendation with two loading jetties and a larger volume of storage capacity.

  3. Monte Carlo methods in AB initio quantum chemistry quantum Monte Carlo for molecules

    CERN Document Server

    Lester, William A; Reynolds, PJ

    1994-01-01

    This book presents the basic theory and application of the Monte Carlo method to the electronic structure of atoms and molecules. It assumes no previous knowledge of the subject, only a knowledge of molecular quantum mechanics at the first-year graduate level. A working knowledge of traditional ab initio quantum chemistry is helpful, but not essential.Some distinguishing features of this book are: Clear exposition of the basic theory at a level to facilitate independent study. Discussion of the various versions of the theory: diffusion Monte Carlo, Green's function Monte Carlo, and release n

  4. On the use of stochastic approximation Monte Carlo for Monte Carlo integration

    KAUST Repository

    Liang, Faming

    2009-03-01

    The stochastic approximation Monte Carlo (SAMC) algorithm has recently been proposed as a dynamic optimization algorithm in the literature. In this paper, we show in theory that the samples generated by SAMC can be used for Monte Carlo integration via a dynamically weighted estimator by calling some results from the literature of nonhomogeneous Markov chains. Our numerical results indicate that SAMC can yield significant savings over conventional Monte Carlo algorithms, such as the Metropolis-Hastings algorithm, for the problems for which the energy landscape is rugged. © 2008 Elsevier B.V. All rights reserved.

  5. Accelerating Hasenbusch's acceleration of hybrid Monte Carlo

    International Nuclear Information System (INIS)

    Hasenbusch has proposed splitting the pseudo-fermionic action into two parts, in order to speed-up Hybrid Monte Carlo simulations of QCD. We have tested a different splitting, also using clover-improved Wilson fermions. An additional speed-up between 5 and 20% over the original proposal was achieved in production runs. (orig.)

  6. A comparison of Monte Carlo generators

    CERN Document Server

    Golan, Tomasz

    2014-01-01

    A comparison of GENIE, NEUT, NUANCE, and NuWro Monte Carlo neutrino event generators is presented using a set of four observables: protons multiplicity, total visible energy, most energetic proton momentum, and $\\pi^+$ two-dimensional energy vs cosine distribution.

  7. Scalable Domain Decomposed Monte Carlo Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Matthew Joseph [Univ. of California, Davis, CA (United States)

    2013-12-05

    In this dissertation, we present the parallel algorithms necessary to run domain decomposed Monte Carlo particle transport on large numbers of processors (millions of processors). Previous algorithms were not scalable, and the parallel overhead became more computationally costly than the numerical simulation.

  8. Using CIPSI nodes in diffusion Monte Carlo

    CERN Document Server

    Caffarel, Michel; Giner, Emmanuel; Scemama, Anthony

    2016-01-01

    Several aspects of the recently proposed DMC-CIPSI approach consisting in using selected Configuration Interaction (SCI) approaches such as CIPSI (Configuration Interaction using a Perturbative Selection done Iteratively) to build accurate nodes for diffusion Monte Carlo (DMC) calculations are presented and discussed. The main ideas are illustrated with a number of calculations for diatomics molecules and for the benchmark G1 set.

  9. Coded aperture optimization using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Coded apertures using Uniformly Redundant Arrays (URA) have been unsuccessfully evaluated for two-dimensional and three-dimensional imaging in Nuclear Medicine. The images reconstructed from coded projections contain artifacts and suffer from poor spatial resolution in the longitudinal direction. We introduce a Maximum-Likelihood Expectation-Maximization (MLEM) algorithm for three-dimensional coded aperture imaging which uses a projection matrix calculated by Monte Carlo simulations. The aim of the algorithm is to reduce artifacts and improve the three-dimensional spatial resolution in the reconstructed images. Firstly, we present the validation of GATE (Geant4 Application for Emission Tomography) for Monte Carlo simulations of a coded mask installed on a clinical gamma camera. The coded mask modelling was validated by comparison between experimental and simulated data in terms of energy spectra, sensitivity and spatial resolution. In the second part of the study, we use the validated model to calculate the projection matrix with Monte Carlo simulations. A three-dimensional thyroid phantom study was performed to compare the performance of the three-dimensional MLEM reconstruction with conventional correlation method. The results indicate that the artifacts are reduced and three-dimensional spatial resolution is improved with the Monte Carlo-based MLEM reconstruction.

  10. Monte Carlo methods beyond detailed balance

    NARCIS (Netherlands)

    Schram, Raoul D.; Barkema, Gerard T.

    2015-01-01

    Monte Carlo algorithms are nearly always based on the concept of detailed balance and ergodicity. In this paper we focus on algorithms that do not satisfy detailed balance. We introduce a general method for designing non-detailed balance algorithms, starting from a conventional algorithm satisfying

  11. Monte Carlo Renormalization Group: a review

    International Nuclear Information System (INIS)

    The logic and the methods of Monte Carlo Renormalization Group (MCRG) are reviewed. A status report of results for 4-dimensional lattice gauge theories derived using MCRG is presented. Existing methods for calculating the improved action are reviewed and evaluated. The Gupta-Cordery improved MCRG method is described and compared with the standard one. 71 refs., 8 figs

  12. Monte Carlo simulation of the microcanonical ensemble

    International Nuclear Information System (INIS)

    We consider simulating statistical systems with a random walk on a constant energy surface. This combines features of deterministic molecular dynamics techniques and conventional Monte Carlo simulations. For discrete systems the method can be programmed to run an order of magnitude faster than other approaches. It does not require high quality random numbers and may also be useful for nonequilibrium studies. 10 references

  13. Extending canonical Monte Carlo methods: II

    International Nuclear Information System (INIS)

    We have previously presented a methodology for extending canonical Monte Carlo methods inspired by a suitable extension of the canonical fluctuation relation C = β2(δE2) compatible with negative heat capacities, C α, as is shown in the particular case of the 2D seven-state Potts model where the exponent α = 0.14–0.18

  14. A Monte Carlo simulation of photomultiplier resolution

    International Nuclear Information System (INIS)

    A Monte Carlo simulation of dynode statistics has been used to generate multiphotoelectron distributions to compare with actual photomultiplier resolution results. In place of Poission of Polya statistics, in this novel approach, the basis for the simulation is an experimentally determined single electron response. The relevance of this method to the study of intrinsic line widths of scintillators is discussed

  15. Parallel processing Monte Carlo radiation transport codes

    International Nuclear Information System (INIS)

    Issues related to distributed-memory multiprocessing as applied to Monte Carlo radiation transport are discussed. Measurements of communication overhead are presented for the radiation transport code MCNP which employs the communication software package PVM, and average efficiency curves are provided for a homogeneous virtual machine

  16. A note on simultaneous Monte Carlo tests

    DEFF Research Database (Denmark)

    Hahn, Ute

    In this short note, Monte Carlo tests of goodness of fit for data of the form X(t), t ∈ I are considered, that reject the null hypothesis if X(t) leaves an acceptance region bounded by an upper and lower curve for some t in I. A construction of the acceptance region is proposed that complies to a...

  17. del cambio

    Directory of Open Access Journals (Sweden)

    Alejandro Canales

    2006-01-01

    Full Text Available El artículo analiza las propuestas y los compromisos en materia de cobertura y de financiamiento en el periodo 2000-2006. En particular, revisa las modificaciones y los ajustes de los tres principales documentos en los que se expresaron las iniciativas: el de la Asociación Nacional de Universidades e Instituciones de Educación Superior, el del equipo de la transición y el programa sectorial. Los resultados muestran que las cifras de atención a la demanda educativa e inversión quedaron lejos de las metas autoimpuestas por el gobierno federal y que será necesario realizar mayores esfuerzos para atender tales desafíos.

  18. Development of Monte Carlo machine for particle transport problem

    International Nuclear Information System (INIS)

    Monte Carlo machine, Monte-4 has been developed to realize high performance computing of Monte Carlo codes for particle transport. The calculation for particle tracking in a complex geometry requires (1) classification of particles by the region types using multi-way conditional branches, and (2) determination whether intersections of particle paths with surfaces of the regions are on the boundaries of the regions or not, using nests of conditional branches. However, these procedures require scalar operations or unusual vector operations. Thus the speedup ratios have been low, i.e. nearly two times, in vector processing of Monte Carlo codes for particle transport on conventional vector processors. The Monte Carlo machine Monte-4 has been equipped with the special hardware called Monte Carlo pipelines to process these procedures with high performance. Additionally Monte-4 has been equipped with enhanced load/store pipelines to realize fast transfer of indirectly addressed data for the purpose of resolving imbalances between the performance of data transfers and arithmetic operations in vector processing of Monte Carlo codes on conventional vector processors. Finally, Monte-4 has a parallel processing capability with four processors to multiply the performance of vector processing. We have evaluated the effective performance of Monte-4 using production-level Monte Carlo codes such as vectorized KENO-IV and MCNP. In the performance evaluation, nearly ten times speedup ratios have been obtained, compared with scalar processing of the original codes. (author)

  19. Avaliação do uso de medicamentos pela população idosa em Montes Claros, Minas Gerais, Brasil Evaluación del uso de los medicamentos por la población anciana Evaluation of medication use among elderly population

    Directory of Open Access Journals (Sweden)

    Carla Silvana Oliveira Silva

    2010-12-01

    Full Text Available Inserido no universo do cuidado de enfermagem à pessoa idosa, o estudo descreve o perfil sociodemográfico e verifica o uso de medicação segundo gênero em idosos cadastrados em um PSF. MÉTODO: Estudo quantitativo, descritivo, transversal com pesquisa de campo. Utilizou-se o questionário semiestruturado, possibilitando identificar o perfil desses usuários, as principais morbidades, os medicamentos utilizados e as dificuldades relatadas por eles quanto ao uso dos medicamentos. O universo foi de 211 idosos. Na análise dos dados utilizou-se o programa SPSS, priorizando a associação estatística de forma analítica. RESULTADOS: Entre os idosos em uso de medicamentos, verificou-se predominância feminina, renda familiar e escolaridade baixas, idosos vivendo com familiares e sem dificuldades no uso de medicamentos. Uso de medicamentos foi comum em mais de 90% dos idosos. Verificou-se associação para "ausência de dificuldades no uso do medicamento" e "orientações do PSF" (PInserido en el universo del cuidado de enfermería al anciano, el estudio describe el perfil sociodemográfico y verifica el uso de medicación según género en acianos asistidos en una unidad del Programa de Salud Familiar. MÉTODO: Estudio cuantitativo, descriptivo y transversal con trabajo de campo. Fue utilizado cuestionario seme-estructurado, posibilitando identificar el perfil de los usuarios, las principales morbilidades, los medicamentos utilizados y las dificultades relatadas por ellos en relación al uso de los medicamentos. En el análisis de los dados, fue utilizado el programa SPSS, priorizando la asociación estadística de forma analítica. RESULTADOS: Entre los ancianos con uso de medicamentos, fue verificado predominancia femenina, renda familiar y escolaridad bajas, ancianos viviendo con los familiares y sin dificultades en uso de los medicamentos. El uso de medicamento fue común en más de 90% de los ancianos. Fue verificado asociación para

  20. Micromamíferos del Pleistoceno Superior del yacimiento de PRERESA en el valle del Manzanares y su contribución a la reconstrucción paleoambiental de la cuenca de Madrid durante el Pleistoceno

    Directory of Open Access Journals (Sweden)

    Sesé, C.

    2011-12-01

    ubica el yacimiento, excepto Cricetulus (Allocricetus bursae que se extinguió en la Península Ibérica al final del Pleistoceno Superior. Las observaciones realizadas sobre el material indican que la acumulación de restos de micromamíferos en el yacimiento es debida, en su mayor parte, a la acción de predadores, muy posiblemente a egagrópilas de aves rapaces. La asociación de micromamíferos de PRERESA indica unas condiciones de clima templado con cierta humedad y un desarrollo de la vegetación con algunas zonas boscosas y fundamentalmente áreas abiertas pero con vegetación arbustiva, herbácea, praderas secas y húmedas, y ribereña. En una comparación de los micromamíferos del yacimiento de PRERESA con los de los yacimientos del Pleistoceno Medio de Áridos 1 y Valdocarros, los datos indican que en los tramos bajos de los ríos Manzanares y Jarama hubo unas condiciones climáticas y paisajísticas similares en los momentos que representan estos yacimientos (Pleistoceno Medio avanzado y primer tercio del Pleistoceno Superior. Sin embargo, y al igual que sucede en la actualidad, estas condiciones fueron algo diferentes en el valle del Lozoya en la Sierra de Guadarrama durante el primer tercio del Pleistoceno Superior, según indica la asociación de micromamíferos de la Cueva del Camino (Pinilla del Valle, Madrid, que sugiere un clima relativamente más húmedo y un medio con una mayor variedad de biotopos. La asociación de micromamíferos del Pleistoceno Superior de PRERESA, en el tramo bajo del Manzanares, comparada con la de la Cueva del Camino que tiene una cronología similar, y con otras del Norte de Madrid del Pleistoceno Superior, pone de manifiesto según nuestras observaciones una diferenciación biogeográfica y paleoclimática ya durante este periodo entre unas y otras, de las que la zona limitante serían más o menos las estribaciones meridionales y centro-orientales del Sistema Central.

  1. Monte Carlo calculations on the magnetization profile and domain wall structure in bulk systems and nanoconstricitons

    Energy Technology Data Exchange (ETDEWEB)

    Serena, P. A. [Instituto de Ciencias de Materiales de Madrid, Madrid (Spain); Costa-Kraemer, J. L. [Instituto de Microelectronica de Madrid, Madrid (Spain)

    2001-03-01

    A Monte Carlo algorithm suitable to study systems described by an anisotropic Heisenberg Hamiltonian is presented. This technique has been tested successfully with 3D and 2D systems, illustrating how magnetic properties depend on the dimensionality and the coordination number. We have found that magnetic properties of constrictions differ from those appearing in bulk. In particular, spin fluctuations are considerable larger than those calculated for bulk materials. In addition, domain walls are strongly modified when a constriction is present, with a decrease of the domain-wall width. This decrease is explained in terms of previous theoretical works. [Spanish] Se presenta un algoritmo de Monte Carlo para estudiar sistemas discritos por un hamiltoniano anisotropico de Heisenburg. Esta tecnica ha sido probada exitosamente con sistemas de dos y tres dimensiones, ilustrado con las propiedades magneticas dependen de la dimensionalidad y el numero de coordinacion. Hemos encontrado que las propiedades magneticas de constricciones difieren de aquellas del bulto. En particular, las fluctuaciones de espin son considerablemente mayores. Ademas, las paredes de dominio son fuertemente modificadas cuando una construccion esta presente, originando un decrecimiento del ancho de la pared de dominio. Damos cuenta de este decrecimiento en terminos de un trabajo teorico previo.

  2. Monte Carlo study of real time dynamics

    CERN Document Server

    Alexandru, Andrei; Bedaque, Paulo F; Vartak, Sohan; Warrington, Neill C

    2016-01-01

    Monte Carlo studies involving real time dynamics are severely restricted by the sign problem that emerges from highly oscillatory phase of the path integral. In this letter, we present a new method to compute real time quantities on the lattice using the Schwinger-Keldysh formalism via Monte Carlo simulations. The key idea is to deform the path integration domain to a complex manifold where the phase oscillations are mild and the sign problem is manageable. We use the previously introduced "contraction algorithm" to create a Markov chain on this alternative manifold. We substantiate our approach by analyzing the quantum mechanical anharmonic oscillator. Our results are in agreement with the exact ones obtained by diagonalization of the Hamiltonian. The method we introduce is generic and in principle applicable to quantum field theory albeit very slow. We discuss some possible improvements that should speed up the algorithm.

  3. Monte Carlo Simulation for Particle Detectors

    CERN Document Server

    Pia, Maria Grazia

    2012-01-01

    Monte Carlo simulation is an essential component of experimental particle physics in all the phases of its life-cycle: the investigation of the physics reach of detector concepts, the design of facilities and detectors, the development and optimization of data reconstruction software, the data analysis for the production of physics results. This note briefly outlines some research topics related to Monte Carlo simulation, that are relevant to future experimental perspectives in particle physics. The focus is on physics aspects: conceptual progress beyond current particle transport schemes, the incorporation of materials science knowledge relevant to novel detection technologies, functionality to model radiation damage, the capability for multi-scale simulation, quantitative validation and uncertainty quantification to determine the predictive power of simulation. The R&D on simulation for future detectors would profit from cooperation within various components of the particle physics community, and synerg...

  4. Multilevel Monte Carlo Approaches for Numerical Homogenization

    KAUST Repository

    Efendiev, Yalchin R.

    2015-10-01

    In this article, we study the application of multilevel Monte Carlo (MLMC) approaches to numerical random homogenization. Our objective is to compute the expectation of some functionals of the homogenized coefficients, or of the homogenized solutions. This is accomplished within MLMC by considering different sizes of representative volumes (RVEs). Many inexpensive computations with the smallest RVE size are combined with fewer expensive computations performed on larger RVEs. Likewise, when it comes to homogenized solutions, different levels of coarse-grid meshes are used to solve the homogenized equation. We show that, by carefully selecting the number of realizations at each level, we can achieve a speed-up in the computations in comparison to a standard Monte Carlo method. Numerical results are presented for both one-dimensional and two-dimensional test-cases that illustrate the efficiency of the approach.

  5. Coevolution Based Adaptive Monte Carlo Localization (CEAMCL

    Directory of Open Access Journals (Sweden)

    Luo Ronghua

    2008-11-01

    Full Text Available An adaptive Monte Carlo localization algorithm based on coevolution mechanism of ecological species is proposed. Samples are clustered into species, each of which represents a hypothesis of the robot's pose. Since the coevolution between the species ensures that the multiple distinct hypotheses can be tracked stably, the problem of premature convergence when using MCL in highly symmetric environments can be solved. And the sample size can be adjusted adaptively over time according to the uncertainty of the robot's pose by using the population growth model. In addition, by using the crossover and mutation operators in evolutionary computation, intra-species evolution can drive the samples move towards the regions where the desired posterior density is large. So a small size of samples can represent the desired density well enough to make precise localization. The new algorithm is termed coevolution based adaptive Monte Carlo localization (CEAMCL. Experiments have been carried out to prove the efficiency of the new localization algorithm.

  6. Monte Carlo simulation of gas Cerenkov detectors

    International Nuclear Information System (INIS)

    Theoretical study of selected gamma-ray and electron diagnostic necessitates coupling Cerenkov radiation to electron/photon cascades. A Cerenkov production model and its incorporation into a general geometry Monte Carlo coupled electron/photon transport code is discussed. A special optical photon ray-trace is implemented using bulk optical properties assigned to each Monte Carlo zone. Good agreement exists between experimental and calculated Cerenkov data in the case of a carbon-dioxide gas Cerenkov detector experiment. Cerenkov production and threshold data are presented for a typical carbon-dioxide gas detector that converts a 16.7 MeV photon source to Cerenkov light, which is collected by optics and detected by a photomultiplier

  7. No-compromise reptation quantum Monte Carlo

    International Nuclear Information System (INIS)

    Since its publication, the reptation quantum Monte Carlo algorithm of Baroni and Moroni (1999 Phys. Rev. Lett. 82 4745) has been applied to several important problems in physics, but its mathematical foundations are not well understood. We show that their algorithm is not of typical Metropolis-Hastings type, and we specify conditions required for the generated Markov chain to be stationary and to converge to the intended distribution. The time-step bias may add up, and in many applications it is only the middle of a reptile that is the most important. Therefore, we propose an alternative, 'no-compromise reptation quantum Monte Carlo' to stabilize the middle of the reptile. (fast track communication)

  8. Fast Lattice Monte Carlo Simulations of Polymers

    Science.gov (United States)

    Wang, Qiang; Zhang, Pengfei

    2014-03-01

    The recently proposed fast lattice Monte Carlo (FLMC) simulations (with multiple occupancy of lattice sites (MOLS) and Kronecker δ-function interactions) give much faster/better sampling of configuration space than both off-lattice molecular simulations (with pair-potential calculations) and conventional lattice Monte Carlo simulations (with self- and mutual-avoiding walk and nearest-neighbor interactions) of polymers.[1] Quantitative coarse-graining of polymeric systems can also be performed using lattice models with MOLS.[2] Here we use several model systems, including polymer melts, solutions, blends, as well as confined and/or grafted polymers, to demonstrate the great advantages of FLMC simulations in the study of equilibrium properties of polymers.

  9. Status of Monte Carlo at Los Alamos

    International Nuclear Information System (INIS)

    Four papers were presented by Group X-6 on April 22, 1980, at the Oak Ridge Radiation Shielding Information Center (RSIC) Seminar-Workshop on Theory and Applications of Monte Carlo Methods. These papers are combined into one report for convenience and because they are related to each other. The first paper (by Thompson and Cashwell) is a general survey about X-6 and MCNP and is an introduction to the other three papers. It can also serve as a resume of X-6. The second paper (by Godfrey) explains some of the details of geometry specification in MCNP. The third paper (by Cashwell and Schrandt) illustrates calculating flux at a point with MCNP; in particular, the once-more-collided flux estimator is demonstrated. Finally, the fourth paper (by Thompson, Deutsch, and Booth) is a tutorial on some variance-reduction techniques. It should be required for a fledging Monte Carlo practitioner

  10. Composite biasing in Monte Carlo radiative transfer

    CERN Document Server

    Baes, Maarten; Lunttila, Tuomas; Bianchi, Simone; Camps, Peter; Juvela, Mika; Kuiper, Rolf

    2016-01-01

    Biasing or importance sampling is a powerful technique in Monte Carlo radiative transfer, and can be applied in different forms to increase the accuracy and efficiency of simulations. One of the drawbacks of the use of biasing is the potential introduction of large weight factors. We discuss a general strategy, composite biasing, to suppress the appearance of large weight factors. We use this composite biasing approach for two different problems faced by current state-of-the-art Monte Carlo radiative transfer codes: the generation of photon packages from multiple components, and the penetration of radiation through high optical depth barriers. In both cases, the implementation of the relevant algorithms is trivial and does not interfere with any other optimisation techniques. Through simple test models, we demonstrate the general applicability, accuracy and efficiency of the composite biasing approach. In particular, for the penetration of high optical depths, the gain in efficiency is spectacular for the spe...

  11. Hybrid Monte Carlo with Chaotic Mixing

    CERN Document Server

    Kadakia, Nirag

    2016-01-01

    We propose a hybrid Monte Carlo (HMC) technique applicable to high-dimensional multivariate normal distributions that effectively samples along chaotic trajectories. The method is predicated on the freedom of choice of the HMC momentum distribution, and due to its mixing properties, exhibits sample-to-sample autocorrelations that decay far faster than those in the traditional hybrid Monte Carlo algorithm. We test the methods on distributions of varying correlation structure, finding that the proposed technique produces superior covariance estimates, is less reliant on step-size tuning, and can even function with sparse or no momentum re-sampling. The method presented here is promising for more general distributions, such as those that arise in Bayesian learning of artificial neural networks and in the state and parameter estimation of dynamical systems.

  12. Monte Carlo Shell Model Mass Predictions

    International Nuclear Information System (INIS)

    The nuclear mass calculation is discussed in terms of large-scale shell model calculations. First, the development and limitations of the conventional shell model calculations are mentioned. In order to overcome the limitations, the Quantum Monte Carlo Diagonalization (QMCD) method has been proposed. The basic formulation and features of the QMCD method are presented as well as its application to the nuclear shell model, referred to as Monte Carlo Shell Model (MCSM). The MCSM provides us with a breakthrough in shell model calculations: the structure of low-lying states can be studied with realistic interactions for a nearly unlimited variety of nuclei. Thus, the MCSM can contribute significantly to the study of nuclear masses. An application to N∼20 unstable nuclei far from the β-stability line is mentioned

  13. Quantum Monte Carlo calculations for carbon nanotubes

    Science.gov (United States)

    Luu, Thomas; Lähde, Timo A.

    2016-04-01

    We show how lattice quantum Monte Carlo can be applied to the electronic properties of carbon nanotubes in the presence of strong electron-electron correlations. We employ the path-integral formalism and use methods developed within the lattice QCD community for our numerical work. Our lattice Hamiltonian is closely related to the hexagonal Hubbard model augmented by a long-range electron-electron interaction. We apply our method to the single-quasiparticle spectrum of the (3,3) armchair nanotube configuration, and consider the effects of strong electron-electron correlations. Our approach is equally applicable to other nanotubes, as well as to other carbon nanostructures. We benchmark our Monte Carlo calculations against the two- and four-site Hubbard models, where a direct numerical solution is feasible.

  14. Status of Monte Carlo at Los Alamos

    International Nuclear Information System (INIS)

    At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time

  15. A Monte Carlo solution to skyshine radiation

    International Nuclear Information System (INIS)

    A Monte Carlo method was used to calculate the skyshine doses from 2-ft exposure cell ceiling of an accelerator. Modifications were made to the Monte Carlo program MORSE code to perform this analysis. Adjoint mode calculations provided optimum Russian roulette and splitting parameters which were later used in the forward mode calculations. Russian roulette and splitting were used at the collision sites and at boundary crossings. Exponential transform was used for particle pathlength stretching. The TIGER code was used to generate the anisotropic source term and P5 Legendre expansion was used to compute the cross sections. Where negative fluxes occured at detector locations due to large angle scatterings, a macroscopic cross section data bank was used to make Klein-Nishina and pair production flux estimates. With the above modifications, sixty detectors at locations ranging from 10 to 300 ft from the cell wall showed good statistical responses (5 to 10% fsd)

  16. del discurso

    Directory of Open Access Journals (Sweden)

    Alexander Mosquera

    2006-01-01

    Full Text Available En varios comunicados quedó reflejada la tensión de la reciente crisis entre Colombia y Venezuela, suscitada a raíz de la captura en diciembre de 2004 de un guerrillero de la FARC en Caracas (Rodrigo Granda. El presente trabajo es un avance de un proyecto de investigación, que persigue como objetivos: 1 describir el discurso implícito en dichos comunicados; 2 identificar los aspectos semánticos y pragmáticos presentes en la confrontación discursiva; y 3 delinear el componente ideológico reflejado en los comunicados. Para el respectivo análisis se siguieron algunos aspectos teóricos y metodológicos de Colle (2000, Bolívar (1998 yMolero de Cabeza (1985. Entre las conclusiones preliminares de este avance se tiene que, con el caso Granda, Colombia recurrió a la vieja política del "fin justifica los medios", a la vez que puso en entredicho el papel de Venezuela en la lucha contra el terrorismo, quizás como respuesta a su política exterior de estrechos vínculos con el gobierno estadounidense

  17. The lund Monte Carlo for jet fragmentation

    International Nuclear Information System (INIS)

    We present a Monte Carlo program based on the Lund model for jet fragmentation. Quark, gluon, diquark and hadron jets are considered. Special emphasis is put on the fragmentation of colour singlet jet systems, for which energy, momentum and flavour are conserved explicitly. The model for decays of unstable particles, in particular the weak decay of heavy hadrons, is described. The central part of the paper is a detailed description on how to use the FORTRAN 77 program. (Author)

  18. New Dynamic Monte Carlo Renormalization Group Method

    OpenAIRE

    Lacasse, Martin-D.; Vinals, Jorge; Grant, Martin

    1992-01-01

    The dynamical critical exponent of the two-dimensional spin-flip Ising model is evaluated by a Monte Carlo renormalization group method involving a transformation in time. The results agree very well with a finite-size scaling analysis performed on the same data. The value of $z = 2.13 \\pm 0.01$ is obtained, which is consistent with most recent estimates.

  19. Autocorrelations in hybrid Monte Carlo simulations

    International Nuclear Information System (INIS)

    Simulations of QCD suffer from severe critical slowing down towards the continuum limit. This problem is known to be prominent in the topological charge, however, all observables are affected to various degree by these slow modes in the Monte Carlo evolution. We investigate the slowing down in high statistics simulations and propose a new error analysis method, which gives a realistic estimate of the contribution of the slow modes to the errors. (orig.)

  20. Monte Carlo methods for preference learning

    DEFF Research Database (Denmark)

    Viappiani, P.

    2012-01-01

    Utility elicitation is an important component of many applications, such as decision support systems and recommender systems. Such systems query the users about their preferences and give recommendations based on the system’s belief about the utility function. Critical to these applications is th...... is the acquisition of prior distribution about the utility parameters and the possibility of real time Bayesian inference. In this paper we consider Monte Carlo methods for these problems....

  1. The Moment Guided Monte Carlo Method

    OpenAIRE

    Degond, Pierre; Dimarco, Giacomo; Pareschi, Lorenzo

    2009-01-01

    In this work we propose a new approach for the numerical simulation of kinetic equations through Monte Carlo schemes. We introduce a new technique which permits to reduce the variance of particle methods through a matching with a set of suitable macroscopic moment equations. In order to guarantee that the moment equations provide the correct solutions, they are coupled to the kinetic equation through a non equilibrium term. The basic idea, on which the method relies, consists in guiding the p...

  2. Handbook of Markov chain Monte Carlo

    CERN Document Server

    Brooks, Steve

    2011-01-01

    ""Handbook of Markov Chain Monte Carlo"" brings together the major advances that have occurred in recent years while incorporating enough introductory material for new users of MCMC. Along with thorough coverage of the theoretical foundations and algorithmic and computational methodology, this comprehensive handbook includes substantial realistic case studies from a variety of disciplines. These case studies demonstrate the application of MCMC methods and serve as a series of templates for the construction, implementation, and choice of MCMC methodology.

  3. Simulated Annealing using Hybrid Monte Carlo

    OpenAIRE

    Salazar, Rafael; Toral, Raúl

    1997-01-01

    We propose a variant of the simulated annealing method for optimization in the multivariate analysis of differentiable functions. The method uses global actualizations via the hybrid Monte Carlo algorithm in their generalized version for the proposal of new configurations. We show how this choice can improve upon the performance of simulated annealing methods (mainly when the number of variables is large) by allowing a more effective searching scheme and a faster annealing schedule.

  4. Coevolution Based Adaptive Monte Carlo Localization (CEAMCL)

    OpenAIRE

    Luo Ronghua; Hong Bingrong

    2004-01-01

    An adaptive Monte Carlo localization algorithm based on coevolution mechanism of ecological species is proposed. Samples are clustered into species, each of which represents a hypothesis of the robot's pose. Since the coevolution between the species ensures that the multiple distinct hypotheses can be tracked stably, the problem of premature convergence when using MCL in highly symmetric environments can be solved. And the sample size can be adjusted adaptively over time according to the unce...

  5. Monte Carlo modeling of liquid scinttilation spectra

    Czech Academy of Sciences Publication Activity Database

    Šimek, Ondřej; Šídlová, V.; Světlík, Ivo; Tomášková, Lenka

    Praha : ČVUT v Praze, 2007, s. 90-93. ISBN 978-80-01-03901-4. [Dny radiační ochrany /29./. Kouty nad Desnou, Hrubý Jeseník (CZ), 05.11.2007-09.11.2007] Institutional research plan: CEZ:AV0Z10480505 Keywords : Monte Carlo modelling * liquid scintillation spectra * energy deposition Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  6. Monte Carlo Simulations of Star Clusters

    CERN Document Server

    Giersz, M

    2000-01-01

    A revision of Stod\\'o{\\l}kiewicz's Monte Carlo code is used to simulate evolution of large star clusters. The survey on the evolution of multi-mass N-body systems influenced by the tidal field of a parent galaxy and by stellar evolution is discussed. For the first time, the simulation on the "star-by-star" bases of evolution of 1,000,000 body star cluster is presented. \\

  7. Replica Exchange for Reactive Monte Carlo Simulations

    Czech Academy of Sciences Publication Activity Database

    Turner, C.H.; Brennan, J.K.; Lísal, Martin

    2007-01-01

    Roč. 111, č. 43 (2007), s. 15706-15715. ISSN 1932-7447 R&D Projects: GA ČR GA203/05/0725; GA AV ČR 1ET400720409; GA AV ČR 1ET400720507 Institutional research plan: CEZ:AV0Z40720504 Keywords : monte carlo * simulation * reactive system Subject RIV: CF - Physical ; Theoretical Chemistry

  8. A Ballistic Monte Carlo Approximation of {\\pi}

    CERN Document Server

    Dumoulin, Vincent

    2014-01-01

    We compute a Monte Carlo approximation of {\\pi} using importance sampling with shots coming out of a Mossberg 500 pump-action shotgun as the proposal distribution. An approximated value of 3.136 is obtained, corresponding to a 0.17% error on the exact value of {\\pi}. To our knowledge, this represents the first attempt at estimating {\\pi} using such method, thus opening up new perspectives towards computing mathematical constants using everyday tools.

  9. Topological zero modes in Monte Carlo simulations

    International Nuclear Information System (INIS)

    We present an improvement of global Metropolis updating steps, the instanton hits, used in a hybrid Monte Carlo simulation of the two-flavor Schwinger model with staggered fermions. These hits are designed to change the topological sector of the gauge field. In order to match these hits to an unquenched simulation with pseudofermions, the approximate zero mode structure of the lattice Dirac operator has to be considered explicitly. (orig.)

  10. On adaptive Markov chain Monte Carlo algorithms

    OpenAIRE

    Atchadé, Yves F.; Rosenthal, Jeffrey S.

    2005-01-01

    We look at adaptive Markov chain Monte Carlo algorithms that generate stochastic processes based on sequences of transition kernels, where each transition kernel is allowed to depend on the history of the process. We show under certain conditions that the stochastic process generated is ergodic, with appropriate stationary distribution. We use this result to analyse an adaptive version of the random walk Metropolis algorithm where the scale parameter σ is sequentially adapted using a Robbins-...

  11. Introduction to the Monte Carlo methods

    International Nuclear Information System (INIS)

    Codes illustrating the use of Monte Carlo methods in high energy physics such as the inverse transformation method, the ejection method, the particle propagation through the nucleus, the particle interaction with the nucleus, etc. are presented. A set of useful algorithms of random number generators is given (the binomial distribution, the Poisson distribution, β-distribution, γ-distribution and normal distribution). 5 figs., 1 tab

  12. Tracklength biassing in Monte Carlo radiation transport

    International Nuclear Information System (INIS)

    Tracklength stretching is employed in deep penetration Monte Carlo studies for variance reduction. Incorporating a dependence of the biassing on the angular disposition of the track improves the procedure. Linear and exponential forms for this dependence are investigated here, using Spanier's self-learning technique. Suitable biassing parameters are worked out for representative shield systems, for use in practical simulations. Of the two, we find that the exponential scheme performs better. (orig.)

  13. A Monte Carlo for BFKL Physics

    OpenAIRE

    Orr, Lynne H.; Stirling, W. J.

    2000-01-01

    Virtual photon scattering in e^+e^- collisions can result in events with the electron-positron pair at large rapidity separation with hadronic activity in between. The BFKL equation resums large logarithms that dominate the cross section for this process. We report here on a Monte Carlo method for solving the BFKL equation that allows kinematic constraints to be taken into account. The application to e^+e^- collisions is in progress.

  14. Lookahead Strategies for Sequential Monte Carlo

    OpenAIRE

    Lin, Ming; Chen, Rong; Liu, Jun

    2013-01-01

    Based on the principles of importance sampling and resampling, sequential Monte Carlo (SMC) encompasses a large set of powerful techniques dealing with complex stochastic dynamic systems. Many of these systems possess strong memory, with which future information can help sharpen the inference about the current state. By providing theoretical justification of several existing algorithms and introducing several new ones, we study systematically how to construct efficient SMC algorithms to take ...

  15. Archimedes, the Free Monte Carlo simulator

    OpenAIRE

    Sellier, Jean Michel D.

    2012-01-01

    Archimedes is the GNU package for Monte Carlo simulations of electron transport in semiconductor devices. The first release appeared in 2004 and since then it has been improved with many new features like quantum corrections, magnetic fields, new materials, GUI, etc. This document represents the first attempt to have a complete manual. Many of the Physics models implemented are described and a detailed description is presented to make the user able to write his/her own input deck. Please, fee...

  16. Monte Carlo simulation and numerical integration

    OpenAIRE

    Geweke, John F.

    1995-01-01

    This is a survey of simulation methods in economics, with a specific focus on integration problems. It describes acceptance methods, importance sampling procedures, and Markov chain Monte Carlo methods for simulation from univariate and multivariate distributions and their application to the approximation of integrals. The exposition gives emphasis to combinations of different approaches and assessment of the accuracy of numerical approximations to integrals and expectations. The survey illus...

  17. jTracker and Monte Carlo Comparison

    Science.gov (United States)

    Selensky, Lauren; SeaQuest/E906 Collaboration

    2015-10-01

    SeaQuest is designed to observe the characteristics and behavior of `sea-quarks' in a proton by reconstructing them from the subatomic particles produced in a collision. The 120 GeV beam from the main injector collides with a fixed target and then passes through a series of detectors which records information about the particles produced in the collision. However, this data becomes meaningful only after it has been processed, stored, analyzed, and interpreted. Several programs are involved in this process. jTracker (sqerp) reads wire or hodoscope hits and reconstructs the tracks of potential dimuon pairs from a run, and Geant4 Monte Carlo simulates dimuon production and background noise from the beam. During track reconstruction, an event must meet the criteria set by the tracker to be considered a viable dimuon pair; this ensures that relevant data is retained. As a check, a comparison between a new version of jTracker and Monte Carlo was made in order to see how accurately jTracker could reconstruct the events created by Monte Carlo. In this presentation, the results of the inquest and their potential effects on the programming will be shown. This work is supported by U.S. DOE MENP Grant DE-FG02-03ER41243.

  18. Monte Carlo dose mapping on deforming anatomy

    Science.gov (United States)

    Zhong, Hualiang; Siebers, Jeffrey V.

    2009-10-01

    This paper proposes a Monte Carlo-based energy and mass congruent mapping (EMCM) method to calculate the dose on deforming anatomy. Different from dose interpolation methods, EMCM separately maps each voxel's deposited energy and mass from a source image to a reference image with a displacement vector field (DVF) generated by deformable image registration (DIR). EMCM was compared with other dose mapping methods: energy-based dose interpolation (EBDI) and trilinear dose interpolation (TDI). These methods were implemented in EGSnrc/DOSXYZnrc, validated using a numerical deformable phantom and compared for clinical CT images. On the numerical phantom with an analytically invertible deformation map, EMCM mapped the dose exactly the same as its analytic solution, while EBDI and TDI had average dose errors of 2.5% and 6.0%. For a lung patient's IMRT treatment plan, EBDI and TDI differed from EMCM by 1.96% and 7.3% in the lung patient's entire dose region, respectively. As a 4D Monte Carlo dose calculation technique, EMCM is accurate and its speed is comparable to 3D Monte Carlo simulation. This method may serve as a valuable tool for accurate dose accumulation as well as for 4D dosimetry QA.

  19. Quantum Monte Carlo for vibrating molecules

    International Nuclear Information System (INIS)

    Quantum Monte Carlo (QMC) has successfully computed the total electronic energies of atoms and molecules. The main goal of this work is to use correlation function quantum Monte Carlo (CFQMC) to compute the vibrational state energies of molecules given a potential energy surface (PES). In CFQMC, an ensemble of random walkers simulate the diffusion and branching processes of the imaginary-time time dependent Schroedinger equation in order to evaluate the matrix elements. The program QMCVIB was written to perform multi-state VMC and CFQMC calculations and employed for several calculations of the H2O and C3 vibrational states, using 7 PES's, 3 trial wavefunction forms, two methods of non-linear basis function parameter optimization, and on both serial and parallel computers. In order to construct accurate trial wavefunctions different wavefunctions forms were required for H2O and C3. In order to construct accurate trial wavefunctions for C3, the non-linear parameters were optimized with respect to the sum of the energies of several low-lying vibrational states. In order to stabilize the statistical error estimates for C3 the Monte Carlo data was collected into blocks. Accurate vibrational state energies were computed using both serial and parallel QMCVIB programs. Comparison of vibrational state energies computed from the three C3 PES's suggested that a non-linear equilibrium geometry PES is the most accurate and that discrete potential representations may be used to conveniently determine vibrational state energies

  20. Monte Carlo small-sample perturbation calculations

    International Nuclear Information System (INIS)

    Two different Monte Carlo methods have been developed for benchmark computations of small-sample-worths in simplified geometries. The first is basically a standard Monte Carlo perturbation method in which neutrons are steered towards the sample by roulette and splitting. One finds, however, that two variance reduction methods are required to make this sort of perturbation calculation feasible. First, neutrons that have passed through the sample must be exempted from roulette. Second, neutrons must be forced to undergo scattering collisions in the sample. Even when such methods are invoked, however, it is still necessary to exaggerate the volume fraction of the sample by drastically reducing the size of the core. The benchmark calculations are then used to test more approximate methods, and not directly to analyze experiments. In the second method the flux at the surface of the sample is assumed to be known. Neutrons entering the sample are drawn from this known flux and tracking by Monte Carlo. The effect of the sample or the fission rate is then inferred from the histories of these neutrons. The characteristics of both of these methods are explored empirically

  1. A new species of Nebria Latreille, 1802 from the Montes de León, north-west Spain (Coleoptera, Carabidae, Nebriinae

    Directory of Open Access Journals (Sweden)

    Zaballos, J. P.

    2000-12-01

    Full Text Available Nebria leonensis sp. n. from the Sierras de la Cabrera Baja and del Teleno (southern Montes de León is described. This species, related to N. lafresnayei Serville, 1821, is characterised by its slender body, long and light brown extremities, the form of its pronotum, and evenly rounded elytra, which are conspicuously flattened on the discus. The differentiating characters and the habitat are described. A determination key to the species and subspecies of the group to which the new species belongs is presented.Se describe Nebria leonensis sp. n. de las sierras de la Cabrera Baja y del Teleno (sur de los Montes de León. Esta especie, relacionada con Nebria lafresnayei Serville, 1821, se caracteriza especialmente por su cuerpo delgado, largas extremidades de color marrón claro, forma del pronoto, y élitros uniformemente redondeados y claramente deprimidos en el disco. Además de describir los caracteres que la definen y el hábitat, se presentan unas breves notas sobre la historia faunística de los montes de León, y una clave de determinación de las especies y subespecies del grupo al que pertenece la nueva especie.

  2. El abandono del manejo tradicional aumenta la diversidad arbórea en los sabinares albares.

    OpenAIRE

    Olano Mendoza, J. M.; Rozas Ortiz, Vicente Fernando; Zavala, Miguel A.; Sanz Crespo, A.; Yagüe De Miguel, L.; Ruiz Benito, P.; Pinillos Herrero, F.

    2009-01-01

    13 páginas, 2 figuras, 2 tablas / 12 diapositivas -- Comunicación presentada al 5º Congreso Forestal Español que se celebró del 21 y 25 de septiembre de 2009 en Ávila, bajo el lema “Montes y sociedad: saber qué hacer”.

  3. Landscape changes and human activity in Monte Penide (Redondela, Pontevedra: a methodological approach

    Directory of Open Access Journals (Sweden)

    Martínez Cortizas, Antonio

    2000-06-01

    Full Text Available We have surveyed two areas with open air rock art in Monte Penide, finding in the process several artefact scatters near the petro glyphs of roughly the same age. Also, we have undertaken a soil analysis of a section already exposed in one of those places (Coto da Fenteira, looking for occurrences of enrichment in certain trace elements (Ti, Zr, Hg or Br along the sequence. As a result of this studies in combination with 14C dating of charcoal and organic matter, we have been able to define two main erosive episodes, resulting from human activity: one in the first half of the third millennium BC and a second, less violent one, from the start of the second millennium BC. These episodes have to do mostly with the spread of a farming economy during the Chalcolithic and its consolidation along the Earlier Bronze Age, thus rejecting the notion of a socioeconomic crisis during the latter and showing, instead, a progressive interference with the environment by human groups up to the second Iron Age.

    Hemos prospectado dos áreas con manifestaciones de arte rupestre en Monte Penide, descubriendo en su cercanía concentraciones de material cerámico y lítico de cronología semejante. Uno de los lugares examinados (Coto da Fenteira fue objeto de un análisis edafológico sobre un corte abierto por obras recientes. La combinación de estudios sobre elementos traza (Ti, Zr, Hg o Br y de dataciones C-14 ha permitido definir un suelo policíclico que se extiende a lo largo del Holoceno y en el que se diferencian dos grandes episodios erosivos vinculados a la acción antrópica: uno a partir de la primera mitad del III milenio AC y otro menos violento desde inicios del II milenio, coincidentes grosso modo con la expansión del sistema agropastoril durante el Calcolítico y su continuación a lo largo del Bronce inicial/medio regional, desmintiendo así la noción de una crisis socioeconómica durante el segundo período y apoyando, en cambio, la

  4. Tecnolog??as del cuidado del mundo

    OpenAIRE

    Higuera Esp??n, Javier de la

    2011-01-01

    Desde la ??ptica de la ontolog??a de la actualidad, este texto pretende pensar en la posibilidad de unas ???tecnolog??as del mundo??? que, en correlaci??n con las ???tecnolog??as del yo???, sean responsables del cuidado del acontecer singular que define nuestro presente, amenazado por fuertes tendencias homogeneizadoras capaces de cerrar o compactar el mundo. Por el contrario, el mundo s??lo es mundo si ???en ??l puede abrirse un afuera??? (J.-L. Nancy). Para ello analiza la naturaleza de es...

  5. El Banco del Sur

    OpenAIRE

    Espejo, Silvana

    2012-01-01

    En este trabajo abordaremos las características principales del Banco del Sur como una institución financiera sudamericana. Primero presentaremos sus principales características y explicaremos las características de un banco de desarrollo regional. Luego, expondremos el proceso de conformación del mismo haciendo un recorrido por sus principales antecedentes. Por último, cerraremos con una evaluación sobre el estado actual del Banco del Sur. (Párrafo extraído del texto a modo de resumen)...

  6. Belo Monte hydropower project: actual studies; AHE Belo Monte: os estudos atuais

    Energy Technology Data Exchange (ETDEWEB)

    Figueira Netto, Carlos Alberto de Moya [CNEC Engenharia S.A., Sao Paulo, SP (Brazil); Rezende, Paulo Fernando Vieira Souto [Centrais Eletricas Brasileiras S.A. (ELETROBRAS), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This article presents the evolution of the studies of Belo Monte Hydro Power Project (HPP) since the initial inventory studies of the Xingu River in 1979 until the current studies for conclusion of the Technical, Economic and Environmental Feasibility Studies the Belo Monte Hydro Power Project, as authorized by Brazilian National Congress. The current studies characterize the Belo Monte HPP with an installed capacity of 11,181.3 MW (20 units of 550 MW in the main power house and 7 units of 25.9 MW in the additional power house), connected to the Brazilian Interconnected Power Grid, allowing to generate 4,796 mean MW of firm energy, without depending on any flow rate regularization of the upstream Xingu river flooding only 441 k m2, of which approximately 200 k m2, correspond to the normal annual wet season flooding of the Xingu River. (author)

  7. Guideline of Monte Carlo calculation. Neutron/gamma ray transport simulation by Monte Carlo method

    CERN Document Server

    2002-01-01

    This report condenses basic theories and advanced applications of neutron/gamma ray transport calculations in many fields of nuclear energy research. Chapters 1 through 5 treat historical progress of Monte Carlo methods, general issues of variance reduction technique, cross section libraries used in continuous energy Monte Carlo codes. In chapter 6, the following issues are discussed: fusion benchmark experiments, design of ITER, experiment analyses of fast critical assembly, core analyses of JMTR, simulation of pulsed neutron experiment, core analyses of HTTR, duct streaming calculations, bulk shielding calculations, neutron/gamma ray transport calculations of the Hiroshima atomic bomb. Chapters 8 and 9 treat function enhancements of MCNP and MVP codes, and a parallel processing of Monte Carlo calculation, respectively. An important references are attached at the end of this report.

  8. Monte Carlo simulations in medical technology- II. Application of Monte Carlo procedure to medical technology

    International Nuclear Information System (INIS)

    Methods for Monte Carlo procedure in radiation measurement by SPECT (single photon emission computed tomography) and 3-D PET (3-dimensional positron emission tomography) are described together with its application to develop and optimize the scattering correction method in 201Tl-SPECT. In the medical technology, the Monte Carlo simulation makes it possible to quantify the behavior of a photon like scattering and absorption, and which can be performed by the use of EGS4 simulation code consisting from Step A - E. With the method, data collection procedures of the diagnostic equipments for nuclear medicine and application to develop the transmission radiation source for SPECT are described. Precision of the scattering correction method is also evaluated in the SPECT by the Monte Carlo simulation. The simulation is a useful tool for evaluating the behavior of radiation in the human body which can not be actually measured. (K.H.)

  9. Accesibilidad del sitio web del CONAPRED

    OpenAIRE

    Luján Mora, Sergio

    2012-01-01

    Accesibilidad del sitio web del CONAPRED (Consejo Nacional para Prevenir la Discriminación) de México. Más información: - http://accesibilidadweb.dlsi.ua.es - http://desarrolloweb.dlsi.ua.es Autor: Sergio Luján Mora, profesor de la Universidad de Alicante (http://www.ua.es).

  10. Monte Carlo modelling for individual monitoring

    International Nuclear Information System (INIS)

    Full text: Individual monitoring techniques provide suitable tools for the estimate of personal dose equivalent Hp(d), representative of the effective dose, in case of external irradiation, or the evaluation of the committed effective dose by inference from activity measurements, in case of internal contamination. In both these fields Monte Carlo techniques play a crucial role: they can provide a series of parameters that are usually difficult, sometimes impossible, to be assessed experimentally. The aim of this paper is to give a panoramic view of Monte Carlo studies in external exposures individual monitoring field; internal dosimetry applications are briefly summarized in another paper. The operative practice in the field of occupational exposure relies on the employment of personal dosemeters to be worn appropriately on the body in order to guarantee a reliable estimate of the radiation protection quantities (i.e. effective dose or equivalent dose). Personal dosemeters are calibrated in terms of the ICRU operational quantity personal dose equivalent, Hp(d), that should, in principle, represent a reasonably conservative approximation of the radiation protection quantity (this condition is not fulfilled in a specific neutron energy range). All the theoretical and practical implementation of photon individual monitoring relies on two main aspects: the definition of the operational quantities and the calculation of the corresponding conversion coefficients for the field quantities (fluence and air kerma); the characterization of individual dosemeters in terms of these operational quantities with the associated energy and angular type test evaluations carried out on suitable calibration phantoms. For the first aspect (evaluation of conversion coefficients) rather exhaustive tabulations of Monte Carlo evaluated conversion coefficients has been published in ICRP and ICRU reports as well as in the open literature. For the second aspect (type test and calibration

  11. Quantum Monte Carlo for vibrating molecules

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.R. [Univ. of California, Berkeley, CA (United States). Chemistry Dept.]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

    1996-08-01

    Quantum Monte Carlo (QMC) has successfully computed the total electronic energies of atoms and molecules. The main goal of this work is to use correlation function quantum Monte Carlo (CFQMC) to compute the vibrational state energies of molecules given a potential energy surface (PES). In CFQMC, an ensemble of random walkers simulate the diffusion and branching processes of the imaginary-time time dependent Schroedinger equation in order to evaluate the matrix elements. The program QMCVIB was written to perform multi-state VMC and CFQMC calculations and employed for several calculations of the H{sub 2}O and C{sub 3} vibrational states, using 7 PES`s, 3 trial wavefunction forms, two methods of non-linear basis function parameter optimization, and on both serial and parallel computers. In order to construct accurate trial wavefunctions different wavefunctions forms were required for H{sub 2}O and C{sub 3}. In order to construct accurate trial wavefunctions for C{sub 3}, the non-linear parameters were optimized with respect to the sum of the energies of several low-lying vibrational states. In order to stabilize the statistical error estimates for C{sub 3} the Monte Carlo data was collected into blocks. Accurate vibrational state energies were computed using both serial and parallel QMCVIB programs. Comparison of vibrational state energies computed from the three C{sub 3} PES`s suggested that a non-linear equilibrium geometry PES is the most accurate and that discrete potential representations may be used to conveniently determine vibrational state energies.

  12. A Monte Carlo approach to water management

    Science.gov (United States)

    Koutsoyiannis, D.

    2012-04-01

    Common methods for making optimal decisions in water management problems are insufficient. Linear programming methods are inappropriate because hydrosystems are nonlinear with respect to their dynamics, operation constraints and objectives. Dynamic programming methods are inappropriate because water management problems cannot be divided into sequential stages. Also, these deterministic methods cannot properly deal with the uncertainty of future conditions (inflows, demands, etc.). Even stochastic extensions of these methods (e.g. linear-quadratic-Gaussian control) necessitate such drastic oversimplifications of hydrosystems that may make the obtained results irrelevant to the real world problems. However, a Monte Carlo approach is feasible and can form a general methodology applicable to any type of hydrosystem. This methodology uses stochastic simulation to generate system inputs, either unconditional or conditioned on a prediction, if available, and represents the operation of the entire system through a simulation model as faithful as possible, without demanding a specific mathematical form that would imply oversimplifications. Such representation fully respects the physical constraints, while at the same time it evaluates the system operation constraints and objectives in probabilistic terms, and derives their distribution functions and statistics through Monte Carlo simulation. As the performance criteria of a hydrosystem operation will generally be highly nonlinear and highly nonconvex functions of the control variables, a second Monte Carlo procedure, implementing stochastic optimization, is necessary to optimize system performance and evaluate the control variables of the system. The latter is facilitated if the entire representation is parsimonious, i.e. if the number of control variables is kept at a minimum by involving a suitable system parameterization. The approach is illustrated through three examples for (a) a hypothetical system of two reservoirs

  13. Geologia del Baix Ter

    OpenAIRE

    Mas-Pla, Josep

    1986-01-01

    Article que analitza el valor i la singularitat de les zones humides del Baix Ter, tenint en compte la descripció de les característiques geològiques de la Plana del Ter i dels diferents ambients morfodinàmics que s' hi troben

  14. Il dono del racconto

    DEFF Research Database (Denmark)

    Polito, Paola

    1998-01-01

    L'articolo indaga a vari livelli strutturali del romanzo "Il coraggio del pettirosso" (rete metaforica, dialogismo diegetico, dialogismo come fenomeno di voce, strategie discorsive messe in atto dalla voce narrante, stile colloquiale) la complessa realizzazione testuale del genere narrativo /racc...

  15. Modulated pulse bathymetric lidar Monte Carlo simulation

    Science.gov (United States)

    Luo, Tao; Wang, Yabo; Wang, Rong; Du, Peng; Min, Xia

    2015-10-01

    A typical modulated pulse bathymetric lidar system is investigated by simulation using a modulated pulse lidar simulation system. In the simulation, the return signal is generated by Monte Carlo method with modulated pulse propagation model and processed by mathematical tools like cross-correlation and digital filter. Computer simulation results incorporating the modulation detection scheme reveal a significant suppression of the water backscattering signal and corresponding target contrast enhancement. More simulation experiments are performed with various modulation and reception variables to investigate the effect of them on the bathymetric system performance.

  16. Monte Carlo Simulation of an American Option

    Directory of Open Access Journals (Sweden)

    Gikiri Thuo

    2007-04-01

    Full Text Available We implement gradient estimation techniques for sensitivity analysis of option pricing which can be efficiently employed in Monte Carlo simulation. Using these techniques we can simultaneously obtain an estimate of the option value together with the estimates of sensitivities of the option value to various parameters of the model. After deriving the gradient estimates we incorporate them in an iterative stochastic approximation algorithm for pricing an option with early exercise features. We illustrate the procedure using an example of an American call option with a single dividend that is analytically tractable. In particular we incorporate estimates for the gradient with respect to the early exercise threshold level.

  17. Monte-Carlo simulations: FLUKA vs. MCNPX

    Czech Academy of Sciences Publication Activity Database

    Oden, M.; Krása, Antonín; Majerle, Mitja; Svoboda, Ondřej; Wagner, Vladimír

    Melville : AMER INST PHYSICS, 2007 - (Granja, C.; Leroy, C.; Štekl, I.), s. 219-221 ISBN 978-0-7354-0472-4. ISSN 0094-243X. - (AIP Conference Proceedings. 958). [4th International Summer School on Nuclear Physics Methods and Accelerators in Biology and Medicine . Praha (CZ), 08.07.2007-19.07.2007] R&D Projects: GA MŠk(CZ) LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutron production * spallation reaction * Monte-Carlo simulation Subject RIV: BG - Nuclear , Atomic and Molecular Physics, Colliders

  18. The Moment Guided Monte Carlo Method

    CERN Document Server

    Degond, Pierre; Pareschi, Lorenzo

    2009-01-01

    In this work we propose a new approach for the numerical simulation of kinetic equations through Monte Carlo schemes. We introduce a new technique which permits to reduce the variance of particle methods through a matching with a set of suitable macroscopic moment equations. In order to guarantee that the moment equations provide the correct solutions, they are coupled to the kinetic equation through a non equilibrium term. The basic idea, on which the method relies, consists in guiding the particle positions and velocities through moment equations so that the concurrent solution of the moment and kinetic models furnishes the same macroscopic quantities.

  19. Markov chains analytic and Monte Carlo computations

    CERN Document Server

    Graham, Carl

    2014-01-01

    Markov Chains: Analytic and Monte Carlo Computations introduces the main notions related to Markov chains and provides explanations on how to characterize, simulate, and recognize them. Starting with basic notions, this book leads progressively to advanced and recent topics in the field, allowing the reader to master the main aspects of the classical theory. This book also features: Numerous exercises with solutions as well as extended case studies.A detailed and rigorous presentation of Markov chains with discrete time and state space.An appendix presenting probabilistic notions that are nec

  20. Discovering correlated fermions using quantum Monte Carlo.

    Science.gov (United States)

    Wagner, Lucas K; Ceperley, David M

    2016-09-01

    It has become increasingly feasible to use quantum Monte Carlo (QMC) methods to study correlated fermion systems for realistic Hamiltonians. We give a summary of these techniques targeted at researchers in the field of correlated electrons, focusing on the fundamentals, capabilities, and current status of this technique. The QMC methods often offer the highest accuracy solutions available for systems in the continuum, and, since they address the many-body problem directly, the simulations can be analyzed to obtain insight into the nature of correlated quantum behavior. PMID:27518859

  1. Exascale Monte Carlo R&D

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Ryan C. [Los Alamos National Laboratory

    2012-07-24

    Overview of this presentation is (1) Exascale computing - different technologies, getting there; (2) high-performance proof-of-concept MCMini - features and results; and (3) OpenCL toolkit - Oatmeal (OpenCL Automatic Memory Allocation Library) - purpose and features. Despite driver issues, OpenCL seems like a good, hardware agnostic tool. MCMini demonstrates the possibility for GPGPU-based Monte Carlo methods - it shows great scaling for HPC application and algorithmic equivalence. Oatmeal provides a flexible framework to aid in the development of scientific OpenCL codes.

  2. Monte Carlo methods for applied scientists

    CERN Document Server

    Dimov, Ivan T

    2007-01-01

    The Monte Carlo method is inherently parallel and the extensive and rapid development in parallel computers, computational clusters and grids has resulted in renewed and increasing interest in this method. At the same time there has been an expansion in the application areas and the method is now widely used in many important areas of science including nuclear and semiconductor physics, statistical mechanics and heat and mass transfer. This book attempts to bridge the gap between theory and practice concentrating on modern algorithmic implementation on parallel architecture machines. Although

  3. Variation After Response in Quantum Monte Carlo

    CERN Document Server

    Neuscamman, Eric

    2016-01-01

    We present a new method for modeling electronically excited states that overcomes a key failing of linear response theory by allowing the underlying ground state ansatz to relax in the presence of an excitation. The method is variational, has a cost similar to ground state variational Monte Carlo, and admits both open and periodic boundary conditions. We present preliminary numerical results showing that, when paired with the Jastrow antisymmetric geminal power ansatz, the variation-after-response formalism delivers accuracies for valence and charge transfer single excitations on par with equation of motion coupled cluster, while surpassing even this very high-level method's accuracy for excitations with significant doubly excited character.

  4. Monte Carlo method in radiation transport problems

    International Nuclear Information System (INIS)

    In neutral radiation transport problems (neutrons, photons), two values are important: the flux in the phase space and the density of particles. To solve the problem with Monte Carlo method leads to, among other things, build a statistical process (called the play) and to provide a numerical value to a variable x (this attribution is called score). Sampling techniques are presented. Play biasing necessity is proved. A biased simulation is made. At last, the current developments (rewriting of programs for instance) are presented due to several reasons: two of them are the vectorial calculation apparition and the photon and neutron transport in vacancy media

  5. Introduction to Monte-Carlo method

    International Nuclear Information System (INIS)

    We recall first some well known facts about random variables and sampling. Then we define the Monte-Carlo method in the case where one wants to compute a given integral. Afterwards, we ship to discrete Markov chains for which we define random walks, and apply to finite difference approximations of diffusion equations. Finally we consider Markov chains with continuous state (but discrete time), transition probabilities and random walks, which are the main piece of this work. The applications are: diffusion and advection equations, and the linear transport equation with scattering

  6. Monte Carlo simulation of block copolymer brushes

    International Nuclear Information System (INIS)

    We studied a simplified model of a polymer brush formed by linear chains, which were restricted to a simple cubic lattice. The chain macromolecules consisted of a sequence of two kinds of segment, arranged in a specific sequence. The chains were grafted to an impenetrable surface, i.e. they were terminally attached to the surface at one end. The number of chains was varied from low to high grafting density. The model system was studied under different solvent quality, from good to poor solvent. The properties of this model system were studied by means of Monte Carlo simulations. The sampling algorithm was based on local changes of the chain's conformations

  7. Discovering correlated fermions using quantum Monte Carlo

    Science.gov (United States)

    Wagner, Lucas K.; Ceperley, David M.

    2016-09-01

    It has become increasingly feasible to use quantum Monte Carlo (QMC) methods to study correlated fermion systems for realistic Hamiltonians. We give a summary of these techniques targeted at researchers in the field of correlated electrons, focusing on the fundamentals, capabilities, and current status of this technique. The QMC methods often offer the highest accuracy solutions available for systems in the continuum, and, since they address the many-body problem directly, the simulations can be analyzed to obtain insight into the nature of correlated quantum behavior.

  8. Monte Carlo modelling for neutron guide losses

    International Nuclear Information System (INIS)

    In modern research reactors, neutron guides are commonly used for beam conducting. The neutron guide is a well polished or equivalently smooth glass tube covered inside by sputtered or evaporated film of natural Ni or 58Ni isotope where the neutrons are totally reflected. A Monte Carlo calculation was carried out to establish the real efficiency and the spectral as well as spatial distribution of the neutron beam at the end of a glass mirror guide. The losses caused by mechanical inaccuracy and mirror quality were considered and the effects due to the geometrical arrangement were analyzed. (author) 2 refs.; 2 figs

  9. Kinetic Monte Carlo simulation of dislocation dynamics

    International Nuclear Information System (INIS)

    A kinetic Monte Carlo simulation of dislocation motion is introduced. The dislocations are assumed to be composed of pure edge and screw segments confined to a fixed lattice. The stress and temperature dependence of the dislocation velocity is studied, and finite-size effects are discussed. It is argued that surfaces and boundaries may play a significant role in the velocity of dislocations. The simulated dislocations are shown to display kinetic roughening according to the exponents predicted by the Kardar-Parisi-Zhang equation. copyright 1999 The American Physical Society

  10. Monte Carlo Simulation of Quantum Computation

    OpenAIRE

    Cerf, N. J.; Koonin, S. E.

    1997-01-01

    The many-body dynamics of a quantum computer can be reduced to the time evolution of non-interacting quantum bits in auxiliary fields by use of the Hubbard-Stratonovich representation of two-bit quantum gates in terms of one-bit gates. This makes it possible to perform the stochastic simulation of a quantum algorithm, based on the Monte Carlo evaluation of an integral of dimension polynomial in the number of quantum bits. As an example, the simulation of the quantum circuit for the Fast Fouri...

  11. Monte Carlo simulation for Kaonic deuterium studies

    International Nuclear Information System (INIS)

    Full text: The SIDDHARTA experiment at the DAFNE collider measured the shift and with of the ground level in kaonic hydrogen caused by the strong interaction between the kaons and protons. The measurement of the X-ray transitions to the 1s level in kaonic deuterium will allow, together with the available results from kaonic hydrogen, to extract the isospin- dependent antikaon-nucleon scattering lengths. I will present the Monte Carlo simulation of the SIDDHARTA-2 setup, in the framework of GEANT4. The program is used to optimize the critical parameters of the setup in order to perform the kaonic deuterium measurement. (author)

  12. Monte Carlo simulations for heavy ion dosimetry

    OpenAIRE

    Geithner, Oksana

    2006-01-01

    Water-to-air stopping power ratio ( ) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used which is a substantially modified version of its predecessor SHIELD-HIT v1. The code was partially rewritten, replacing formerly used single precision variables with double precision variabl...

  13. by means of FLUKA Monte Carlo method

    Directory of Open Access Journals (Sweden)

    Ermis Elif Ebru

    2015-01-01

    Full Text Available Calculations of gamma-ray mass attenuation coefficients of various detector materials (crystals were carried out by means of FLUKA Monte Carlo (MC method at different gamma-ray energies. NaI, PVT, GSO, GaAs and CdWO4 detector materials were chosen in the calculations. Calculated coefficients were also compared with the National Institute of Standards and Technology (NIST values. Obtained results through this method were highly in accordance with those of the NIST values. It was concluded from the study that FLUKA MC method can be an alternative way to calculate the gamma-ray mass attenuation coefficients of the detector materials.

  14. Archimedes, the Free Monte Carlo simulator

    CERN Document Server

    Sellier, Jean Michel D

    2012-01-01

    Archimedes is the GNU package for Monte Carlo simulations of electron transport in semiconductor devices. The first release appeared in 2004 and since then it has been improved with many new features like quantum corrections, magnetic fields, new materials, GUI, etc. This document represents the first attempt to have a complete manual. Many of the Physics models implemented are described and a detailed description is presented to make the user able to write his/her own input deck. Please, feel free to contact the author if you want to contribute to the project.

  15. Conocimiento campesino, el "monte santiagueño" como recurso forrajero Peasant knowledge, the "monte santiagueño" as fodder resource

    Directory of Open Access Journals (Sweden)

    Patricia Riat

    2012-12-01

    Full Text Available El conocimiento campesino sobre el entorno natural puede ser interpretado a través de su relación cotidiana con el monte, donde gran parte de sus necesidades de subsistencia están abastecidas por este. A modo de aproximación se toma el conocimiento sobre el uso de las plantas nativas, y teniendo en cuenta el principal modo de subsistencia, la ganadería, se analiza el conocimiento de plantas alimenticias para el ganado. La zona de estudio se encuentra en la región fitogeográfica chaqueña. Abarca el norte del Pueblo Los Juríes, entre el departamento General Taboada y el departamento Brigadier Felipe Ibarra, al centro-este de la Provincia de Santiago del Estero. La producción ganadera se hace en pequeña escala y en forma extensiva, siendo los sistemas ganaderos netamente de subsistencia. Durante un año se efectuaron tres viajes de campaña en la zona. En el primer viaje fue presentado el proyecto ante la comunidad y se obtuvo el consentimiento informado para el desarrollo del mismo y publicación de los resultados. Los datos fueron obtenidos a través de técnicas etnobotánicas cualitativas a fin de relevar el conocimiento y prácticas acerca de los recursos vegetales. Se relevaron treinta y cinco plantas reconocidas y usadas localmente como forrajeras y el tipo de ganado asociado. Los resultados expuestos demuestran la importancia de los saberes locales concernientes a especies vegetales nativas útiles en la alimentación del ganado. A pesar del relativamente corto tiempo de asentamiento de la población campesina en la zona, sus conocimientos, provenientes de regiones lindantes y adquiridos in situ, demuestran un alto grado de observación y comprensión del ecosistema en el cual se hallan inmersos.Peasant knowledge about natural environment could be interpreted through their daily relationship with the "monte", where a big part of their needs of subsistence are supplied by it. Considering the primary mode of subsistence, animal

  16. Ordenación de un monte vecinal en mano común para la producción de madera de eucalipto

    OpenAIRE

    Boado Sánchez, Isabel; Riesco Muñoz, Guillermo

    2006-01-01

    Se presenta la ordenación del monte vecinal en mano común de Coto Redondo (Lousame, A Coruña). El monte presenta clima atlántico, con un régimen pluviométrico de transición entre el atlántico y el mediterráneo, con un período vegetativo que dura 12 meses. Por tanto, en ninguna época del año existe parada vegetativa debida a la temperatura y tampoco se produce parada vegetativa por limitación hídrica. En el vuelo arbóreo aparece Eucalyptus globulus Labill., Pinus pinaster Ait. y diversas frond...

  17. Monte Carlo Hamiltonian: Generalization to Quantum Field Theory

    OpenAIRE

    Luo, Xiang-Qian; Jirari, H.; Kroger, H; Moriarty, K.

    2001-01-01

    Monte Carlo techniques with importance sampling have been extensively applied to lattice gauge theory in the Lagrangian formulation. Unfortunately, it is extremely difficult to compute the excited states using the conventional Monte Carlo algorithm. Our recently developed approach: the Monte Carlo Hamiltonian method, has been designed to overcome the difficulties of the conventional approach. In this paper, we extend the method to many body systems and quantum field theory. The Klein-Gordon f...

  18. Alternative Monte Carlo Approach for General Global Illumination

    Institute of Scientific and Technical Information of China (English)

    徐庆; 李朋; 徐源; 孙济洲

    2004-01-01

    An alternative Monte Carlo strategy for the computation of global illumination problem was presented.The proposed approach provided a new and optimal way for solving Monte Carlo global illumination based on the zero variance importance sampling procedure. A new importance driven Monte Carlo global illumination algorithm in the framework of the new computing scheme was developed and implemented. Results, which were obtained by rendering test scenes, show that this new framework and the newly derived algorithm are effective and promising.

  19. Unbiased combinations of nonanalog Monte Carlo techniques and fair games

    International Nuclear Information System (INIS)

    Historically, Monte Carlo variance reduction techniques have developed one at a time in response to calculational needs. This paper provides the theoretical basis for obtaining unbiased Monte Carlo estimates from all possible combinations of variance reduction techniques. Hitherto, the techniques have not been proven to be unbiased in arbitrary combinations. The authors are unaware of any Monte Carlo techniques (in any linear process) that are not treated by the theorem herein. (author)

  20. Temperature variance study in Monte-Carlo photon transport theory

    International Nuclear Information System (INIS)

    We study different Monte-Carlo methods for solving radiative transfer problems, and particularly Fleck's Monte-Carlo method. We first give the different time-discretization schemes and the corresponding stability criteria. Then we write the temperature variance as a function of the variances of temperature and absorbed energy at the previous time step. Finally we obtain some stability criteria for the Monte-Carlo method in the stationary case

  1. The computation of Greeks with multilevel Monte Carlo

    OpenAIRE

    Burgos, Sylvestre Jean-Baptiste Louis; Michael B. Giles

    2014-01-01

    In mathematical finance, the sensitivities of option prices to various market parameters, also known as the “Greeks”, reflect the exposure to different sources of risk. Computing these is essential to predict the impact of market moves on portfolios and to hedge them adequately. This is commonly done using Monte Carlo simulations. However, obtaining accurate estimates of the Greeks can be computationally costly. Multilevel Monte Carlo offers complexity improvements over standard Monte Carl...

  2. Monte Carlo likelihood inference for missing data models

    OpenAIRE

    Sung, Yun Ju; Geyer, Charles J.

    2007-01-01

    We describe a Monte Carlo method to approximate the maximum likelihood estimate (MLE), when there are missing data and the observed data likelihood is not available in closed form. This method uses simulated missing data that are independent and identically distributed and independent of the observed data. Our Monte Carlo approximation to the MLE is a consistent and asymptotically normal estimate of the minimizer θ* of the Kullback–Leibler information, as both Monte Carlo and observed data sa...

  3. Validation of Compton Scattering Monte Carlo Simulation Models

    CERN Document Server

    Weidenspointner, Georg; Hauf, Steffen; Hoff, Gabriela; Kuster, Markus; Pia, Maria Grazia; Saracco, Paolo

    2014-01-01

    Several models for the Monte Carlo simulation of Compton scattering on electrons are quantitatively evaluated with respect to a large collection of experimental data retrieved from the literature. Some of these models are currently implemented in general purpose Monte Carlo systems; some have been implemented and evaluated for possible use in Monte Carlo particle transport for the first time in this study. Here we present first and preliminary results concerning total and differential Compton scattering cross sections.

  4. Combinatorial nuclear level density by a Monte Carlo method

    OpenAIRE

    Cerf, N.

    1993-01-01

    We present a new combinatorial method for the calculation of the nuclear level density. It is based on a Monte Carlo technique, in order to avoid a direct counting procedure which is generally impracticable for high-A nuclei. The Monte Carlo simulation, making use of the Metropolis sampling scheme, allows a computationally fast estimate of the level density for many fermion systems in large shell model spaces. We emphasize the advantages of this Monte Carlo approach, particularly concerning t...

  5. Discrete diffusion Monte Carlo for frequency-dependent radiative transfer

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, Jeffrey D [Los Alamos National Laboratory; Kelly, Thompson G [Los Alamos National Laboratory; Urbatish, Todd J [Los Alamos National Laboratory

    2010-11-17

    Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Implicit Monte Carlo radiative-transfer simulations. In this paper, we develop an extension of DDMC for frequency-dependent radiative transfer. We base our new DDMC method on a frequency-integrated diffusion equation for frequencies below a specified threshold. Above this threshold we employ standard Monte Carlo. With a frequency-dependent test problem, we confirm the increased efficiency of our new DDMC technique.

  6. Neutron transport calculations using Quasi-Monte Carlo methods

    Energy Technology Data Exchange (ETDEWEB)

    Moskowitz, B.S.

    1997-07-01

    This paper examines the use of quasirandom sequences of points in place of pseudorandom points in Monte Carlo neutron transport calculations. For two simple demonstration problems, the root mean square error, computed over a set of repeated runs, is found to be significantly less when quasirandom sequences are used ({open_quotes}Quasi-Monte Carlo Method{close_quotes}) than when a standard Monte Carlo calculation is performed using only pseudorandom points.

  7. Simulación Monte Carlo de circuitos electrónicos mediante una aplicación P2P

    OpenAIRE

    Eugenio García Moreno; Rodrigo Picos Gayà; Miquel Roca Adrover; Aitor Lapeña Gutierrez

    2011-01-01

    El diseño de circuitos integrados requiere evaluar los efectos de las tolerancias del proceso de fabricación sobre sus características eléctricas mediante un análisis estadístico. Habitualmente se emplea el método de Monte Carlo. Éste consiste en realizar múltiples simulaciones eléctricas del circuito, variando de manera aleatoria aquellos parámetros que se ven afectados por la fabricación. Esto requiere gran potencia de cálculo y mucho tiempo de proceso. En este trabajo proponemos una soluci...

  8. Monte Carlo techniques for analyzing deep-penetration problems

    International Nuclear Information System (INIS)

    Current methods and difficulties in Monte Carlo deep-penetration calculations are reviewed, including statistical uncertainty and recent adjoint optimization of splitting, Russian roulette, and exponential transformation biasing. Other aspects of the random walk and estimation processes are covered, including the relatively new DXANG angular biasing technique. Specific items summarized are albedo scattering, Monte Carlo coupling techniques with discrete ordinates and other methods, adjoint solutions, and multigroup Monte Carlo. The topic of code-generated biasing parameters is presented, including the creation of adjoint importance functions from forward calculations. Finally, current and future work in the area of computer learning and artificial intelligence is discussed in connection with Monte Carlo applications

  9. Le Comte de Monte Cristo: da literatura ao cinema

    OpenAIRE

    Caravela, Natércia Murta Silva

    2008-01-01

    A presente dissertação discute o diálogo estabelecido entre literatura e cinema no tratamento da personagem principal – um homem traído que se vinga de forma cruel dos seus inimigos – na obra literária Le Comte de Monte-Cristo, de Alexandre Dumas, e nas três adaptações fílmicas escolhidas: Le Comte de Monte-Cristo de Robert Vernay (1943); The count of Monte Cristo de David Greene (1975) e The count of Monte Cristo de Kevin Reynolds (2002). O projecto centra-se na análise da ...

  10. Information Geometry and Sequential Monte Carlo

    CERN Document Server

    Sim, Aaron; Stumpf, Michael P H

    2012-01-01

    This paper explores the application of methods from information geometry to the sequential Monte Carlo (SMC) sampler. In particular the Riemannian manifold Metropolis-adjusted Langevin algorithm (mMALA) is adapted for the transition kernels in SMC. Similar to its function in Markov chain Monte Carlo methods, the mMALA is a fully adaptable kernel which allows for efficient sampling of high-dimensional and highly correlated parameter spaces. We set up the theoretical framework for its use in SMC with a focus on the application to the problem of sequential Bayesian inference for dynamical systems as modelled by sets of ordinary differential equations. In addition, we argue that defining the sequence of distributions on geodesics optimises the effective sample sizes in the SMC run. We illustrate the application of the methodology by inferring the parameters of simulated Lotka-Volterra and Fitzhugh-Nagumo models. In particular we demonstrate that compared to employing a standard adaptive random walk kernel, the SM...

  11. Quantum Monte Carlo for atoms and molecules

    International Nuclear Information System (INIS)

    The diffusion quantum Monte Carlo with fixed nodes (QMC) approach has been employed in studying energy-eigenstates for 1--4 electron systems. Previous work employing the diffusion QMC technique yielded energies of high quality for H2, LiH, Li2, and H2O. Here, the range of calculations with this new approach has been extended to include additional first-row atoms and molecules. In addition, improvements in the previously computed fixed-node energies of LiH, Li2, and H2O have been obtained using more accurate trial functions. All computations were performed within, but are not limited to, the Born-Oppenheimer approximation. In our computations, the effects of variation of Monte Carlo parameters on the QMC solution of the Schroedinger equation were studied extensively. These parameters include the time step, renormalization time and nodal structure. These studies have been very useful in determining which choices of such parameters will yield accurate QMC energies most efficiently. Generally, very accurate energies (90--100% of the correlation energy is obtained) have been computed with single-determinant trail functions multiplied by simple correlation functions. Improvements in accuracy should be readily obtained using more complex trial functions

  12. High performance computing&Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Brown, F. B. (Forrest B.); Martin, W. R. (William R.)

    2004-01-01

    High performance computing (HPC), used for the most demanding computational problems, has evolved from single processor custom systems in the 1960s and 1970s, to vector processors in the 1980s, to parallel processors in the 1990s, to clusters of commodity processors in the 2000s. Performance/price has increased by a factor of more than I million over that time, so that today's desktop PC is more powerful than yesterday's supercomputer. With the introduction of inexpensive Linux clusters and the standardization of parallel software through MPI and OpenMP, parallel computing is now widespread and available to everyone. Monte Carlo codes for particle transport are especially well-positioned to take advantage of accessible parallel computing, due to the inherently parallel nature of the computational algorithm. We review Monte Carlo particle parallelism, including the basic algorithm, load-balancing, fault tolerance, and scaling, using MCNP5 as an example. Due to memory limitations, especially on single nodes of Linux clusters, domain decomposition has been tried, with partial success. We conclude with a new scheme, data decomposition, which holds promise for very large problems.

  13. Monte Carlo generators in ATLAS software

    International Nuclear Information System (INIS)

    This document describes how Monte Carlo (MC) generators can be used in the ATLAS software framework (Athena). The framework is written in C++ using Python scripts for job configuration. Monte Carlo generators that provide the four-vectors describing the results of LHC collisions are written in general by third parties and are not part of Athena. These libraries are linked from the LCG Generator Services (GENSER) distribution. Generators are run from within Athena and the generated event output is put into a transient store, in HepMC format, using StoreGate. A common interface, implemented via inheritance of a GeneratorModule class, guarantees common functionality for the basic generation steps. The generator information can be accessed and manipulated by helper packages like TruthHelper. The ATLAS detector simulation as well access the truth information from StoreGate1. Steering is done through specific interfaces to allow for flexible configuration using ATLAS Python scripts. Interfaces to most general purpose generators, including: Pythia6, Pythia8, Herwig, Herwig++ and Sherpa are provided, as well as to more specialized packages, for example Phojet and Cascade. A second type of interface exist for the so called Matrix Element generators that only generate the particles produced in the hard scattering process and write events in the Les Houches event format. A generic interface to pass these events to Pythia6 and Herwig for parton showering and hadronisation has been written.

  14. Monte Carlo calculations in lattice gauge theories

    International Nuclear Information System (INIS)

    This paper covers the following: a few words of motivation for numerical simulations, and a description of the Monte Carlo method as applied to lattice gauge theories. This is followed by a discussion of systems that contain bosonic degrees of freedom only. The authors review Monte Carlo results for pure gauge systems, illustrating the determination of a variety of observables - the string tension, the potential, the temperature at which quarks become deconfined, and attempts to calculate the mass gap of the theory, also called the glue-ball mass. They try to explain what happens if one considers various types of the action, how one verifies universality in the passage to the continuum limit and we mention briefly simulations applied to systems that go beyond just gauge fields and include other bosonic fields, known in general as Higgs scalars. Finally they consider fermions on the lattice, pointing out conceptual problems in the formulation of the Dirac equation on the lattice, and then discussing the difficulties that arise in attempting to apply the same kind of numerical methods to fermionic systems, the approximations and the techniques that are used to overcome these problems and some of the numerical results

  15. Feedback-optimized parallel tempering Monte Carlo

    Science.gov (United States)

    Katzgraber, Helmut G.; Trebst, Simon; Huse, David A.; Troyer, Matthias

    2006-03-01

    We introduce an algorithm for systematically improving the efficiency of parallel tempering Monte Carlo simulations by optimizing the simulated temperature set. Our approach is closely related to a recently introduced adaptive algorithm that optimizes the simulated statistical ensemble in generalized broad-histogram Monte Carlo simulations. Conventionally, a temperature set is chosen in such a way that the acceptance rates for replica swaps between adjacent temperatures are independent of the temperature and large enough to ensure frequent swaps. In this paper, we show that by choosing the temperatures with a modified version of the optimized ensemble feedback method we can minimize the round-trip times between the lowest and highest temperatures which effectively increases the efficiency of the parallel tempering algorithm. In particular, the density of temperatures in the optimized temperature set increases at the 'bottlenecks' of the simulation, such as phase transitions. In turn, the acceptance rates are now temperature dependent in the optimized temperature ensemble. We illustrate the feedback-optimized parallel tempering algorithm by studying the two-dimensional Ising ferromagnet and the two-dimensional fully frustrated Ising model, and briefly discuss possible feedback schemes for systems that require configurational averages, such as spin glasses.

  16. The MCNPX Monte Carlo Radiation Transport Code

    International Nuclear Information System (INIS)

    MCNPX (Monte Carlo N-Particle eXtended) is a general-purpose Monte Carlo radiation transport code with three-dimensional geometry and continuous-energy transport of 34 particles and light ions. It contains flexible source and tally options, interactive graphics, and support for both sequential and multi-processing computer platforms. MCNPX is based on MCNP4c and has been upgraded to most MCNP5 capabilities. MCNP is a highly stable code tracking neutrons, photons and electrons, and using evaluated nuclear data libraries for low-energy interaction probabilities. MCNPX has extended this base to a comprehensive set of particles and light ions, with heavy ion transport in development. Models have been included to calculate interaction probabilities when libraries are not available. Recent additions focus on the time evolution of residual nuclei decay, allowing calculation of transmutation and delayed particle emission. MCNPX is now a code of great dynamic range, and the excellent neutronics capabilities allow new opportunities to simulate devices of interest to experimental particle physics, particularly calorimetry. This paper describes the capabilities of the current MCNPX version 2.6.C, and also discusses ongoing code development

  17. THE MCNPX MONTE CARLO RADIATION TRANSPORT CODE

    Energy Technology Data Exchange (ETDEWEB)

    WATERS, LAURIE S. [Los Alamos National Laboratory; MCKINNEY, GREGG W. [Los Alamos National Laboratory; DURKEE, JOE W. [Los Alamos National Laboratory; FENSIN, MICHAEL L. [Los Alamos National Laboratory; JAMES, MICHAEL R. [Los Alamos National Laboratory; JOHNS, RUSSELL C. [Los Alamos National Laboratory; PELOWITZ, DENISE B. [Los Alamos National Laboratory

    2007-01-10

    MCNPX (Monte Carlo N-Particle eXtended) is a general-purpose Monte Carlo radiation transport code with three-dimensional geometry and continuous-energy transport of 34 particles and light ions. It contains flexible source and tally options, interactive graphics, and support for both sequential and multi-processing computer platforms. MCNPX is based on MCNP4B, and has been upgraded to most MCNP5 capabilities. MCNP is a highly stable code tracking neutrons, photons and electrons, and using evaluated nuclear data libraries for low-energy interaction probabilities. MCNPX has extended this base to a comprehensive set of particles and light ions, with heavy ion transport in development. Models have been included to calculate interaction probabilities when libraries are not available. Recent additions focus on the time evolution of residual nuclei decay, allowing calculation of transmutation and delayed particle emission. MCNPX is now a code of great dynamic range, and the excellent neutronics capabilities allow new opportunities to simulate devices of interest to experimental particle physics; particularly calorimetry. This paper describes the capabilities of the current MCNPX version 2.6.C, and also discusses ongoing code development.

  18. Reactor perturbation calculations by Monte Carlo methods

    International Nuclear Information System (INIS)

    Whilst Monte Carlo methods are useful for reactor calculations involving complicated geometry, it is difficult to apply them to the calculation of perturbation worths because of the large amount of computing time needed to obtain good accuracy. Various ways of overcoming these difficulties are investigated in this report, with the problem of estimating absorbing control rod worths particularly in mind. As a basis for discussion a method of carrying out multigroup reactor calculations by Monte Carlo methods is described. Two methods of estimating a perturbation worth directly, without differencing two quantities of like magnitude, are examined closely but are passed over in favour of a third method based on a correlation technique. This correlation method is described, and demonstrated by a limited range of calculations for absorbing control rods in a fast reactor. In these calculations control rod worths of between 1% and 7% in reactivity are estimated to an accuracy better than 10% (3 standard errors) in about one hour's computing time on the English Electric KDF.9 digital computer. (author)

  19. Quantum Monte Carlo Endstation for Petascale Computing

    Energy Technology Data Exchange (ETDEWEB)

    Lubos Mitas

    2011-01-26

    NCSU research group has been focused on accomplising the key goals of this initiative: establishing new generation of quantum Monte Carlo (QMC) computational tools as a part of Endstation petaflop initiative for use at the DOE ORNL computational facilities and for use by computational electronic structure community at large; carrying out high accuracy quantum Monte Carlo demonstration projects in application of these tools to the forefront electronic structure problems in molecular and solid systems; expanding the impact of QMC methods and approaches; explaining and enhancing the impact of these advanced computational approaches. In particular, we have developed quantum Monte Carlo code (QWalk, www.qwalk.org) which was significantly expanded and optimized using funds from this support and at present became an actively used tool in the petascale regime by ORNL researchers and beyond. These developments have been built upon efforts undertaken by the PI's group and collaborators over the period of the last decade. The code was optimized and tested extensively on a number of parallel architectures including petaflop ORNL Jaguar machine. We have developed and redesigned a number of code modules such as evaluation of wave functions and orbitals, calculations of pfaffians and introduction of backflow coordinates together with overall organization of the code and random walker distribution over multicore architectures. We have addressed several bottlenecks such as load balancing and verified efficiency and accuracy of the calculations with the other groups of the Endstation team. The QWalk package contains about 50,000 lines of high quality object-oriented C++ and includes also interfaces to data files from other conventional electronic structure codes such as Gamess, Gaussian, Crystal and others. This grant supported PI for one month during summers, a full-time postdoc and partially three graduate students over the period of the grant duration, it has resulted in 13

  20. Biodiversidad del margen continental del Caribe colombiano.

    OpenAIRE

    2010-01-01

    Incluye valiosa información producto de varios años de investigación marina de las aguas profundas, la plataforma continental y el talud superior del Caribe colombiano, llevada a cabo por un grupo multidisciplinario de investigadores en áreas de taxonomía, geología, ecología, cartografía y conservación del Invemar. Dentro de los resultados más destacados se encuentra el haber colectado e identificado más de 1600 especies, de las cuales alrededor del 35% se constituyeron en primeros registr...

  1. Flora vascular acompañante en masas de monte bajo de castaño en Asturias

    OpenAIRE

    García, Andrés; Díaz-, T.; Majada, Juan; Ciordia, Marta

    2014-01-01

    En Asturias, las zonas forestales ocupan un total de 762.329 hectáreas, es decir, el 72,2% de la superficie del Principado es monte. De éstas, 453.700 hectáreas son arboladas, siendo los bosques de caducifolios (hoja caduca) los más abundantes y que representan en torno al 20% de la superficie asturiana. En estos bosques encontramos, por ejemplo, especies arbóreas como el roble (Quercus spp.), el abedul (Betula celtiberica Rothm. & Vasc.) o el haya (Fagus sylv...

  2. El bosque invisible bajo el monte bajo : una mirada al sistema radical de las cepas de encina.

    OpenAIRE

    Serrada Hierro, Rafael; Bravo Fernandez, Jose Alfredo; Otero de Irizar, Javier; Ruiz-peinado Gertrudix, R.; Mutke Regneri, Sven; Roig Gómez, Sonia

    2013-01-01

    La extensa superficie ocupada en la cuenca mediterránea por tallares de Quercus antiguamente explotados en monte bajo y su preocupante situación como consecuencia del abandono de la gestión han justificado en los últimos años el análisis de su estado actual y de posibles tratamientos. Sin embargo, en muy pocos casos se aborda el estudio de los sistemas radicales debido a la obvia dificultad de acceder a ellos. Este trabajo presenta la metodología y resultados preliminares de la caracterizació...

  3. Morse Monte Carlo Radiation Transport Code System

    Energy Technology Data Exchange (ETDEWEB)

    Emmett, M.B.

    1975-02-01

    The report contains sections containing descriptions of the MORSE and PICTURE codes, input descriptions, sample problems, deviations of the physical equations and explanations of the various error messages. The MORSE code is a multipurpose neutron and gamma-ray transport Monte Carlo code. Time dependence for both shielding and criticality problems is provided. General three-dimensional geometry may be used with an albedo option available at any material surface. The PICTURE code provide aid in preparing correct input data for the combinatorial geometry package CG. It provides a printed view of arbitrary two-dimensional slices through the geometry. By inspecting these pictures one may determine if the geometry specified by the input cards is indeed the desired geometry. 23 refs. (WRF)

  4. Computation cluster for Monte Carlo calculations

    International Nuclear Information System (INIS)

    Two computation clusters based on Rocks Clusters 5.1 Linux distribution with Intel Core Duo and Intel Core Quad based computers were made at the Department of the Nuclear Physics and Technology. Clusters were used for Monte Carlo calculations, specifically for MCNP calculations applied in Nuclear reactor core simulations. Optimization for computation speed was made on hardware and software basis. Hardware cluster parameters, such as size of the memory, network speed, CPU speed, number of processors per computation, number of processors in one computer were tested for shortening the calculation time. For software optimization, different Fortran compilers, MPI implementations and CPU multi-core libraries were tested. Finally computer cluster was used in finding the weighting functions of neutron ex-core detectors of VVER-440. (authors)

  5. Atomistic Monte Carlo simulation of lipid membranes

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Sklenar, Heinz

    2014-01-01

    molecule, as assessed by calculation of molecular energies and entropies. We also show transition from a crystalline-like to a fluid DPPC bilayer by the CBC local-move MC method, as indicated by the electron density profile, head group orientation, area per lipid, and whole-lipid displacements. We discuss......Biological membranes are complex assemblies of many different molecules of which analysis demands a variety of experimental and computational approaches. In this article, we explain challenges and advantages of atomistic Monte Carlo (MC) simulation of lipid membranes. We provide an introduction...... into the various move sets that are implemented in current MC methods for efficient conformational sampling of lipids and other molecules. In the second part, we demonstrate for a concrete example, how an atomistic local-move set can be implemented for MC simulations of phospholipid monomers and...

  6. Monte Carlo modeling and meteor showers

    International Nuclear Information System (INIS)

    Prediction of short lived increases in the cosmic dust influx, the concentration in lower thermosphere of atoms and ions of meteor origin and the determination of the frequency of micrometeor impacts on spacecraft are all of scientific and practical interest and all require adequate models of meteor showers at an early stage of their existence. A Monte Carlo model of meteor matter ejection from a parent body at any point of space was worked out by other researchers. This scheme is described. According to the scheme, the formation of ten well known meteor streams was simulated and the possibility of genetic affinity of each of them with the most probable parent comet was analyzed. Some of the results are presented

  7. Monte Carlo modeling and meteor showers

    Science.gov (United States)

    Kulikova, N. V.

    1987-08-01

    Prediction of short lived increases in the cosmic dust influx, the concentration in lower thermosphere of atoms and ions of meteor origin and the determination of the frequency of micrometeor impacts on spacecraft are all of scientific and practical interest and all require adequate models of meteor showers at an early stage of their existence. A Monte Carlo model of meteor matter ejection from a parent body at any point of space was worked out by other researchers. This scheme is described. According to the scheme, the formation of ten well known meteor streams was simulated and the possibility of genetic affinity of each of them with the most probable parent comet was analyzed. Some of the results are presented.

  8. Helminthiases in Montes Claros. Preliminary survey

    Directory of Open Access Journals (Sweden)

    Rina Girard Kaminsky

    1976-04-01

    Full Text Available A preliminary survey was conducted for the presence of helminths in the city of Montes Claros, M. G., Brazil. Three groups of persons were examined by the direct smear, Kato thick film and MIFC techniques; one group by direct smear and Kato only. General findings were: a high prevalence of hookworm, followed by ascariasis, S. mansoni, S. stercoralis and very light infections with T. trichiurá. E. vermicularis and H. nana were ranking parasites at an orphanage, with some hookworm and S. mansoni infections as well. At a pig slaughter house, the dominant parasites were hookworm and S. mansoni. Pig cysticercosis was an incidental finding worth mentioning for the health hazard it represents for humans as well as an economic loss. From the comparative results between the Kato and the MIF the former proved itself again as a more sensitive and reliable concentration method for helminth eggs, of low cost and easy performance.

  9. The reporting on the Mont Louis shipwrecking

    International Nuclear Information System (INIS)

    Offensive information policy during the first hours following the accident ought to have determined the course of journalistic presentation. Instead, information was put forth and directed by Grenpeace who exploited the issue politically. In Germany as well as in other countries there are hardly any special editors who can actually handle such an issue from their own knowledge. It is only newspapers, radio and TV stations who have scientific editors. Reporting on events like the Mont Louis shipwreck took place mainly on the news pages or even miscellaneous, the latter requiring slogan-like, concise and popular style. Thus, we encounter an enormous collision of interests between the requirement of illustrative style and adequate scientific precision. (orig./HP)

  10. Monte Carlo Exploration of Warped Higgsless Models

    CERN Document Server

    Hewett, J L; Rizzo, T G

    2004-01-01

    We have performed a detailed Monte Carlo exploration of the parameter space for a warped Higgsless model of electroweak symmetry breaking in 5 dimensions. This model is based on the $SU(2)_L\\times SU(2)_R\\times U(1)_{B-L}$ gauge group in an AdS$_5$ bulk with arbitrary gauge kinetic terms on both the Planck and TeV branes. Constraints arising from precision electroweak measurements and collider data are found to be relatively easy to satisfy. We show, however, that the additional requirement of perturbative unitarity up to the cut-off, $\\simeq 10$ TeV, in $W_L^+W_L^-$ elastic scattering in the absence of dangerous tachyons eliminates all models. If successful models of this class exist, they must be highly fine-tuned.

  11. MORSE Monte Carlo radiation transport code system

    International Nuclear Information System (INIS)

    This report is an addendum to the MORSE report, ORNL-4972, originally published in 1975. This addendum contains descriptions of several modifications to the MORSE Monte Carlo Code, replacement pages containing corrections, Part II of the report which was previously unpublished, and a new Table of Contents. The modifications include a Klein Nishina estimator for gamma rays. Use of such an estimator required changing the cross section routines to process pair production and Compton scattering cross sections directly from ENDF tapes and writing a new version of subroutine RELCOL. Another modification is the use of free form input for the SAMBO analysis data. This required changing subroutines SCORIN and adding new subroutine RFRE. References are updated, and errors in the original report have been corrected

  12. Monte Carlo and detector simulation in OOP

    International Nuclear Information System (INIS)

    Object-Oriented Programming techniques are explored with an eye towards applications in High Energy Physics codes. Two prototype examples are given: MCOOP (a particle Monte Carlo generator) and GISMO (a detector simulation/analysis package). The OOP programmer does no explicit or detailed memory management nor other bookkeeping chores; hence, the writing, modification, and extension of the code is considerably simplified. Inheritance can be used to simplify the class definitions as well as the instance variables and action methods of each class; thus the work required to add new classes, parameters, or new methods is minimal. The software industry is moving rapidly to OOP since it has been proven to improve programmer productivity, and promises even more for the future by providing truly reusable software. The High Energy Physics community clearly needs to follow this trend

  13. Variable length trajectory compressible hybrid Monte Carlo

    CERN Document Server

    Nishimura, Akihiko

    2016-01-01

    Hybrid Monte Carlo (HMC) generates samples from a prescribed probability distribution in a configuration space by simulating Hamiltonian dynamics, followed by the Metropolis (-Hastings) acceptance/rejection step. Compressible HMC (CHMC) generalizes HMC to a situation in which the dynamics is reversible but not necessarily Hamiltonian. This article presents a framework to further extend the algorithm. Within the existing framework, each trajectory of the dynamics must be integrated for the same amount of (random) time to generate a valid Metropolis proposal. Our generalized acceptance/rejection mechanism allows a more deliberate choice of the integration time for each trajectory. The proposed algorithm in particular enables an effective application of variable step size integrators to HMC-type sampling algorithms based on reversible dynamics. The potential of our framework is further demonstrated by another extension of HMC which reduces the wasted computations due to unstable numerical approximations and corr...

  14. Monte Carlo stratified source-sampling

    International Nuclear Information System (INIS)

    In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo open-quotes eigenvalue of the worldclose quotes problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. The original test-problem was treated by a special code designed specifically for that purpose. Recently ANL started work on a method for dealing with more realistic eigenvalue of the world configurations, and has been incorporating this method into VIM. The original method has been modified to take into account real-world statistical noise sources not included in the model problem. This paper constitutes a status report on work still in progress

  15. Response decomposition with Monte Carlo correlated coupling

    International Nuclear Information System (INIS)

    Particle histories that contribute to a detector response are categorized according to whether they are fully confined inside a source-detector enclosure or cross and recross the same enclosure. The contribution from the confined histories is expressed using a forward problem with the external boundary condition on the source-detector enclosure. The contribution from the crossing and recrossing histories is expressed as the surface integral at the same enclosure of the product of the directional cosine and the fluxes in the foregoing forward problem and the adjoint problem for the whole spatial domain. The former contribution can be calculated by a standard forward Monte Carlo. The latter contribution can be calculated by correlated coupling of forward and adjoint histories independently of the former contribution. We briefly describe the computational method and discuss its application to perturbation analysis for localized material changes. (orig.)

  16. Hybrid algorithms in quantum Monte Carlo

    International Nuclear Information System (INIS)

    With advances in algorithms and growing computing powers, quantum Monte Carlo (QMC) methods have become a leading contender for high accuracy calculations for the electronic structure of realistic systems. The performance gain on recent HPC systems is largely driven by increasing parallelism: the number of compute cores of a SMP and the number of SMPs have been going up, as the Top500 list attests. However, the available memory as well as the communication and memory bandwidth per element has not kept pace with the increasing parallelism. This severely limits the applicability of QMC and the problem size it can handle. OpenMP/MPI hybrid programming provides applications with simple but effective solutions to overcome efficiency and scalability bottlenecks on large-scale clusters based on multi/many-core SMPs. We discuss the design and implementation of hybrid methods in QMCPACK and analyze its performance on current HPC platforms characterized by various memory and communication hierarchies.

  17. Commensurabilities between ETNOs: a Monte Carlo survey

    CERN Document Server

    Marcos, C de la Fuente

    2016-01-01

    Many asteroids in the main and trans-Neptunian belts are trapped in mean motion resonances with Jupiter and Neptune, respectively. As a side effect, they experience accidental commensurabilities among themselves. These commensurabilities define characteristic patterns that can be used to trace the source of the observed resonant behaviour. Here, we explore systematically the existence of commensurabilities between the known ETNOs using their heliocentric and barycentric semimajor axes, their uncertainties, and Monte Carlo techniques. We find that the commensurability patterns present in the known ETNO population resemble those found in the main and trans-Neptunian belts. Although based on small number statistics, such patterns can only be properly explained if most, if not all, of the known ETNOs are subjected to the resonant gravitational perturbations of yet undetected trans-Plutonian planets. We show explicitly that some of the statistically significant commensurabilities are compatible with the Planet Nin...

  18. Quantum Monte Carlo Simulations : Algorithms, Limitations and Applications

    NARCIS (Netherlands)

    Raedt, H. De

    1992-01-01

    A survey is given of Quantum Monte Carlo methods currently used to simulate quantum lattice models. The formalisms employed to construct the simulation algorithms are sketched. The origin of fundamental (minus sign) problems which limit the applicability of the Quantum Monte Carlo approach is shown

  19. CERN Summer Student Report 2016 Monte Carlo Data Base Improvement

    CERN Document Server

    Caciulescu, Alexandru Razvan

    2016-01-01

    During my Summer Student project I worked on improving the Monte Carlo Data Base and MonALISA services for the ALICE Collaboration. The project included learning the infrastructure for tracking and monitoring of the Monte Carlo productions as well as developing a new RESTful API for seamless integration with the JIRA issue tracking framework.

  20. Adjoint electron-photon transport Monte Carlo calculations with ITS

    International Nuclear Information System (INIS)

    A general adjoint coupled electron-photon Monte Carlo code for solving the Boltzmann-Fokker-Planck equation has recently been created. It is a modified version of ITS 3.0, a coupled electronphoton Monte Carlo code that has world-wide distribution. The applicability of the new code to radiation-interaction problems of the type found in space environments is demonstrated

  1. Neutron point-flux calculation by Monte Carlo

    International Nuclear Information System (INIS)

    A survey of the usual methods for estimating flux at a point is given. The associated variance-reducing techniques in direct Monte Carlo games are explained. The multigroup Monte Carlo codes MC for critical systems and PUNKT for point source-point detector-systems are represented, and problems in applying the codes to practical tasks are discussed. (author)

  2. Monte Carlo simulations of single polymer force-extension relations

    International Nuclear Information System (INIS)

    We present Monte Carlo simulations for studying the statistical mechanics of arbitrarily long single molecules under stretching. In many cases in which the thermodynamic limit is not satisfied, different statistical ensembles yield different macroscopic force-displacement curves. In this work we provide a description of the Monte Carlo simulations and discuss in details the assumptions adopted.

  3. Nuclear data treatment for SAM-CE Monte Carlo calculations

    International Nuclear Information System (INIS)

    The treatment of nuclear data by the SAM-CE Monte Carlo code system is presented. The retrieval of neutron, gamma production, and photon data from the ENDF/B fils is described. Integral cross sections as well as differential data are utilized in the Monte Carlo calculations, and the processing procedures for the requisite data are summarized

  4. Monte Carlo approaches to effective field theories

    International Nuclear Information System (INIS)

    In this paper, we explore the application of continuum Monte Carlo methods to effective field theory models. Effective field theories, in this context, are those in which a Fock space decomposition of the state is useful. These problems arise both in nuclear and condensed matter physica. In nuclear physics, much work has been done on effective field theories of mesons and baryons. While the theories are not fundamental, they should be able to describe nuclear properties at low energy and momentum scales. After describing the methods, we solve two simple scalar field theory problems; the polaron and two nucleons interacting through scalar meson exchange. The methods presented here are rather straightforward extensions of methods used to solve quantum mechanics problems. Monte Carlo methods are used to avoid the truncation inherent in a Tamm-Dancoff approach and its associated difficulties. Nevertheless, the methods will be most valuable when the Fock space decomposition of the states is useful. Hence, while they are not intended for ab initio studies of QCD, they may prove valuable in studies of light nuclei, or for systems of interacting electrons and phonons. In these problems a Fock space decomposition can be used to reduce the number of degrees of freedom and to retain the rotational symmetries exactly. The problems we address here are comparatively simple, but offer useful initial tests of the method. We present results for the polaron and two non-relativistic nucleons interacting through scalar meson exchange. In each case, it is possible to integrate out the boson degrees of freedom exactly, and obtain a retarded form of the action that depends only upon the fermion paths. Here we keep the explicit bosons, though, since we would like to retain information about the boson components of the states and it will be necessary to keep these components in order to treat non-scalar of interacting bosonic fields

  5. Monte Carlo modelling of TRIGA research reactor

    Energy Technology Data Exchange (ETDEWEB)

    El Bakkari, B., E-mail: bakkari@gmail.co [Reactor Operating Unit (UCR), National Centre of Sciences, Energy and Nuclear Techniques (CNESTEN/CENM), POB 1382, Rabat (Morocco); ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); Nacir, B. [Reactor Operating Unit (UCR), National Centre of Sciences, Energy and Nuclear Techniques (CNESTEN/CENM), POB 1382, Rabat (Morocco); El Bardouni, T. [ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); El Younoussi, C. [Reactor Operating Unit (UCR), National Centre of Sciences, Energy and Nuclear Techniques (CNESTEN/CENM), POB 1382, Rabat (Morocco); ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); Merroun, O. [ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); Htet, A. [Reactor Technology Unit (UTR), National Centre of Sciences, Energy and Nuclear Techniques (CNESTEN/CENM), POB 1382, Rabat (Morocco); Boulaich, Y. [Reactor Operating Unit (UCR), National Centre of Sciences, Energy and Nuclear Techniques (CNESTEN/CENM), POB 1382, Rabat (Morocco); ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); Zoubair, M.; Boukhal, H. [ERSN-LMR, Department of Physics, Faculty of Sciences, POB 2121, Tetuan (Morocco); Chakir, M. [EPTN-LPMR, Faculty of Sciences, Kenitra (Morocco)

    2010-10-15

    The Moroccan 2 MW TRIGA MARK II research reactor at Centre des Etudes Nucleaires de la Maamora (CENM) achieved initial criticality on May 2, 2007. The reactor is designed to effectively implement the various fields of basic nuclear research, manpower training, and production of radioisotopes for their use in agriculture, industry, and medicine. This study deals with the neutronic analysis of the 2-MW TRIGA MARK II research reactor at CENM and validation of the results by comparisons with the experimental, operational, and available final safety analysis report (FSAR) values. The study was prepared in collaboration between the Laboratory of Radiation and Nuclear Systems (ERSN-LMR) from Faculty of Sciences of Tetuan (Morocco) and CENM. The 3-D continuous energy Monte Carlo code MCNP (version 5) was used to develop a versatile and accurate full model of the TRIGA core. The model represents in detailed all components of the core with literally no physical approximation. Continuous energy cross-section data from the more recent nuclear data evaluations (ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1, and JENDL-3.3) as well as S({alpha}, {beta}) thermal neutron scattering functions distributed with the MCNP code were used. The cross-section libraries were generated by using the NJOY99 system updated to its more recent patch file 'up259'. The consistency and accuracy of both the Monte Carlo simulation and neutron transport physics were established by benchmarking the TRIGA experiments. Core excess reactivity, total and integral control rods worth as well as power peaking factors were used in the validation process. Results of calculations are analysed and discussed.

  6. Monte Carlo modelling of TRIGA research reactor

    International Nuclear Information System (INIS)

    The Moroccan 2 MW TRIGA MARK II research reactor at Centre des Etudes Nucleaires de la Maamora (CENM) achieved initial criticality on May 2, 2007. The reactor is designed to effectively implement the various fields of basic nuclear research, manpower training, and production of radioisotopes for their use in agriculture, industry, and medicine. This study deals with the neutronic analysis of the 2-MW TRIGA MARK II research reactor at CENM and validation of the results by comparisons with the experimental, operational, and available final safety analysis report (FSAR) values. The study was prepared in collaboration between the Laboratory of Radiation and Nuclear Systems (ERSN-LMR) from Faculty of Sciences of Tetuan (Morocco) and CENM. The 3-D continuous energy Monte Carlo code MCNP (version 5) was used to develop a versatile and accurate full model of the TRIGA core. The model represents in detailed all components of the core with literally no physical approximation. Continuous energy cross-section data from the more recent nuclear data evaluations (ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1, and JENDL-3.3) as well as S(α, β) thermal neutron scattering functions distributed with the MCNP code were used. The cross-section libraries were generated by using the NJOY99 system updated to its more recent patch file 'up259'. The consistency and accuracy of both the Monte Carlo simulation and neutron transport physics were established by benchmarking the TRIGA experiments. Core excess reactivity, total and integral control rods worth as well as power peaking factors were used in the validation process. Results of calculations are analysed and discussed.

  7. Accelerated GPU based SPECT Monte Carlo simulations.

    Science.gov (United States)

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: (99m) Tc, (111)In and (131)I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational

  8. Accelerated GPU based SPECT Monte Carlo simulations

    Science.gov (United States)

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: 99m Tc, 111In and 131I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational efficiency

  9. Monte Carlo modelling of TRIGA research reactor

    Science.gov (United States)

    El Bakkari, B.; Nacir, B.; El Bardouni, T.; El Younoussi, C.; Merroun, O.; Htet, A.; Boulaich, Y.; Zoubair, M.; Boukhal, H.; Chakir, M.

    2010-10-01

    The Moroccan 2 MW TRIGA MARK II research reactor at Centre des Etudes Nucléaires de la Maâmora (CENM) achieved initial criticality on May 2, 2007. The reactor is designed to effectively implement the various fields of basic nuclear research, manpower training, and production of radioisotopes for their use in agriculture, industry, and medicine. This study deals with the neutronic analysis of the 2-MW TRIGA MARK II research reactor at CENM and validation of the results by comparisons with the experimental, operational, and available final safety analysis report (FSAR) values. The study was prepared in collaboration between the Laboratory of Radiation and Nuclear Systems (ERSN-LMR) from Faculty of Sciences of Tetuan (Morocco) and CENM. The 3-D continuous energy Monte Carlo code MCNP (version 5) was used to develop a versatile and accurate full model of the TRIGA core. The model represents in detailed all components of the core with literally no physical approximation. Continuous energy cross-section data from the more recent nuclear data evaluations (ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1, and JENDL-3.3) as well as S( α, β) thermal neutron scattering functions distributed with the MCNP code were used. The cross-section libraries were generated by using the NJOY99 system updated to its more recent patch file "up259". The consistency and accuracy of both the Monte Carlo simulation and neutron transport physics were established by benchmarking the TRIGA experiments. Core excess reactivity, total and integral control rods worth as well as power peaking factors were used in the validation process. Results of calculations are analysed and discussed.

  10. Criticality benchmarking of ANET Monte Carlo code

    International Nuclear Information System (INIS)

    In this work the new Monte Carlo code ANET is tested on criticality calculations. ANET is developed based on the high energy physics code GEANT of CERN and aims at progressively satisfying several requirements regarding both simulations of GEN II/III reactors, as well as of innovative nuclear reactor designs such as the Accelerator Driven Systems (ADSs). Here ANET is applied on three different nuclear configurations, including a subcritical assembly, a Material Testing Reactor and the conceptual configuration of an ADS. In the first case, calculation of the effective multiplication factor (keff) are performed for the Training Nuclear Reactor of the Aristotle University of Thessaloniki, while in the second case keff is computed for the fresh fueled core of the Portuguese research reactor (RPJ) just after its conversion to Low Enriched Uranium, considering the control rods at the position that renders the reactor critical. In both cases ANET computations are compared with corresponding results obtained by three different well established codes, including both deterministic (XSDRNPM/CITATION) and Monte Carlo (TRIPOLI, MCNP). In the RPI case, keff computations are also compared with observations during the reactor core commissioning since the control rods are considered at criticality position. The above verification studies show ANET to produce reasonable results since they are satisfactorily compared with other models as well as with observations. For the third case (ADS), preliminary ANET computations of keff for various intensities of the proton beam are presented, showing also a reasonable code performance concerning both the order of magnitude and the relative variation of the computed parameter. (author)

  11. Monte Carlo scatter correction for SPECT

    Science.gov (United States)

    Liu, Zemei

    The goal of this dissertation is to present a quantitatively accurate and computationally fast scatter correction method that is robust and easily accessible for routine applications in SPECT imaging. A Monte Carlo based scatter estimation method is investigated and developed further. The Monte Carlo simulation program SIMIND (Simulating Medical Imaging Nuclear Detectors), was specifically developed to simulate clinical SPECT systems. The SIMIND scatter estimation (SSE) method was developed further using a multithreading technique to distribute the scatter estimation task across multiple threads running concurrently on multi-core CPU's to accelerate the scatter estimation process. An analytical collimator that ensures less noise was used during SSE. The research includes the addition to SIMIND of charge transport modeling in cadmium zinc telluride (CZT) detectors. Phenomena associated with radiation-induced charge transport including charge trapping, charge diffusion, charge sharing between neighboring detector pixels, as well as uncertainties in the detection process are addressed. Experimental measurements and simulation studies were designed for scintillation crystal based SPECT and CZT based SPECT systems to verify and evaluate the expanded SSE method. Jaszczak Deluxe and Anthropomorphic Torso Phantoms (Data Spectrum Corporation, Hillsborough, NC, USA) were used for experimental measurements and digital versions of the same phantoms employed during simulations to mimic experimental acquisitions. This study design enabled easy comparison of experimental and simulated data. The results have consistently shown that the SSE method performed similarly or better than the triple energy window (TEW) and effective scatter source estimation (ESSE) methods for experiments on all the clinical SPECT systems. The SSE method is proven to be a viable method for scatter estimation for routine clinical use.

  12. Kontrola tačnosti rezultata u simulacijama Monte Karlo / Accuracy control in Monte Carlo simulations

    Directory of Open Access Journals (Sweden)

    Nebojša V. Nikolić

    2010-04-01

    Full Text Available U radu je demonstrirana primena metode automatizovanog ponavljanja nezavisnih simulacionih eksperimenata sa prikupljanjem statistike slučajnih procesa, u dostizanju i kontroli tačnosti simulacionih rezultata u simulaciji sistema masovnog opsluživanja Monte Karlo. Metoda se zasniva na primeni osnovnih stavova i teorema matematičke statistike i teorije verovatnoće. Tačnost simulacionih rezultata dovedena je u direktnu vezu sa brojem ponavljanja simulacionih eksperimenata. / The paper presents an application of the Automated Independent Replication with Gathering Statistics of the Stochastic Processes Method in achieving and controlling the accuracy of simulation results in the Monte Carlo queuing simulations. The method is based on the application of the basic theorems of the theory of probability and mathematical statistics. The accuracy of the simulation results is linked with a number of independent replications of simulation experiments.

  13. Fission Matrix Capability for MCNP Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Carney, Sean E. [Los Alamos National Laboratory; Brown, Forrest B. [Los Alamos National Laboratory; Kiedrowski, Brian C. [Los Alamos National Laboratory; Martin, William R. [Los Alamos National Laboratory

    2012-09-05

    In a Monte Carlo criticality calculation, before the tallying of quantities can begin, a converged fission source (the fundamental eigenvector of the fission kernel) is required. Tallies of interest may include powers, absorption rates, leakage rates, or the multiplication factor (the fundamental eigenvalue of the fission kernel, k{sub eff}). Just as in the power iteration method of linear algebra, if the dominance ratio (the ratio of the first and zeroth eigenvalues) is high, many iterations of neutron history simulations are required to isolate the fundamental mode of the problem. Optically large systems have large dominance ratios, and systems containing poor neutron communication between regions are also slow to converge. The fission matrix method, implemented into MCNP[1], addresses these problems. When Monte Carlo random walk from a source is executed, the fission kernel is stochastically applied to the source. Random numbers are used for: distances to collision, reaction types, scattering physics, fission reactions, etc. This method is used because the fission kernel is a complex, 7-dimensional operator that is not explicitly known. Deterministic methods use approximations/discretization in energy, space, and direction to the kernel. Consequently, they are faster. Monte Carlo directly simulates the physics, which necessitates the use of random sampling. Because of this statistical noise, common convergence acceleration methods used in deterministic methods do not work. In the fission matrix method, we are using the random walk information not only to build the next-iteration fission source, but also a spatially-averaged fission kernel. Just like in deterministic methods, this involves approximation and discretization. The approximation is the tallying of the spatially-discretized fission kernel with an incorrect fission source. We address this by making the spatial mesh fine enough that this error is negligible. As a consequence of discretization we get a

  14. Quantum Monte Carlo methods algorithms for lattice models

    CERN Document Server

    Gubernatis, James; Werner, Philipp

    2016-01-01

    Featuring detailed explanations of the major algorithms used in quantum Monte Carlo simulations, this is the first textbook of its kind to provide a pedagogical overview of the field and its applications. The book provides a comprehensive introduction to the Monte Carlo method, its use, and its foundations, and examines algorithms for the simulation of quantum many-body lattice problems at finite and zero temperature. These algorithms include continuous-time loop and cluster algorithms for quantum spins, determinant methods for simulating fermions, power methods for computing ground and excited states, and the variational Monte Carlo method. Also discussed are continuous-time algorithms for quantum impurity models and their use within dynamical mean-field theory, along with algorithms for analytically continuing imaginary-time quantum Monte Carlo data. The parallelization of Monte Carlo simulations is also addressed. This is an essential resource for graduate students, teachers, and researchers interested in ...

  15. Hybrid SN/Monte Carlo research and results

    International Nuclear Information System (INIS)

    The neutral particle transport equation is solved by a hybrid method that iteratively couples regions where deterministic (SN) and stochastic (Monte Carlo) methods are applied. The Monte Carlo and SN regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid method has been successfully applied to realistic shielding problems. The vectorized Monte Carlo algorithm in the hybrid method has been ported to the massively parallel architecture of the Connection Machine. Comparisons of performance on a vector machine (Cray Y-MP) and the Connection Machine (CM-2) show that significant speedups are obtainable for vectorized Monte Carlo algorithms on massively parallel machines, even when realistic problems requiring variance reduction are considered. However, the architecture of the Connection Machine does place some limitations on the regime in which the Monte Carlo algorithm may by expected to perform well. (author)

  16. Reconstruction of Monte Carlo replicas from Hessian parton distributions

    CERN Document Server

    Hou, Tie-Jiun; Huston, Joey; Nadolsky, Pavel; Schmidt, Carl; Stump, Daniel; Wang, Bo-Ting; Xie, Ke-Ping; Dulat, Sayipjamal; Pumplin, Jon; Yuan, C -P

    2016-01-01

    We explore connections between two common methods for quantifying the uncertainty in parton distribution functions (PDFs), based on the Hessian error matrix and Monte-Carlo sampling. CT14 parton distributions in the Hessian representation are converted into Monte-Carlo replicas by a numerical method that reproduces important properties of CT14 Hessian PDFs: the asymmetry of CT14 uncertainties and positivity of individual parton distributions. The ensembles of CT14 Monte-Carlo replicas constructed this way at NNLO and NLO are suitable for various collider applications, such as cross section reweighting. Master formulas for computation of asymmetric standard deviations in the Monte-Carlo representation are derived. A numerical program is made available for conversion of Hessian PDFs into Monte-Carlo replicas according to normal, log-normal, and Watt-Thorne sampling procedures.

  17. Problems in radiation shielding calculations with Monte Carlo methods

    International Nuclear Information System (INIS)

    The Monte Carlo method is a very useful tool for solving a large class of radiation transport problem. In contrast with deterministic method, geometric complexity is a much less significant problem for Monte Carlo calculations. However, the accuracy of Monte Carlo calculations is of course, limited by statistical error of the quantities to be estimated. In this report, we point out some typical problems to solve a large shielding system including radiation streaming. The Monte Carlo coupling technique was developed to settle such a shielding problem accurately. However, the variance of the Monte Carlo results using the coupling technique of which detectors were located outside the radiation streaming, was still not enough. So as to bring on more accurate results for the detectors located outside the streaming and also for a multi-legged-duct streaming problem, a practicable way of ''Prism Scattering technique'' is proposed in the study. (author)

  18. Facies del subfondo del canal Beagle, Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Gustavo Bujalesky

    2004-03-01

    Full Text Available El canal Beagle conecta los océanos Pacífico y Atlántico en el extremo meridional de Sudamérica y se ubica en el ambiente subantártico. Conforma una cuenca de unos 300 m de profundidad máxima y está separada del océano Atlántico por un umbral de 30 m de profundidad. El canal es un valle tectónico que fue completamente cubierto por el hielo glacial durante la última glaciación. Posteriormente, el canal fue ocupado por un lago glacial desde los 12.000 a los 8.000 años A.P., cuando fue invadido por el mar que alcanzó un nivel máximo entre los 6.000 y 5.000 años A.P. Con el objetivo de analizar las facies sedimentarias superficiales y del subfondo del canal se realizó un relevamiento geofísico con sonar de barrido lateral y un perfilador de 3,5 kHz. Sobre un basamento constituido por rocas metamórficas del Mesozoico, se identificaron depósitos de till y secuencias granodecrecientes que representan distintos estadios del retroceso glaciar, evidenciando hacia la sección superior facies lacustres y por encima depósitos de la transgresión marina del Holoceno. Además, se han identificado paleocauces y secuencias fluviales cubiertas por sedimentos marinos transgresivos.

  19. Monte Carlo 2000 Conference : Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications

    CERN Document Server

    Baräo, Fernando; Nakagawa, Masayuki; Távora, Luis; Vaz, Pedro

    2001-01-01

    This book focusses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications, the latter involving in particular, the use and development of electron--gamma, neutron--gamma and hadronic codes. Besides the basic theory and the methods employed, special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields ranging from particle to medical physics.

  20. Monte Carlo simulation for fragment mass and kinetic energy distributions from the neutron-induced fission of 235U

    OpenAIRE

    Montoya, M.; E. Saettone; Rojas, J.

    2007-01-01

    Mediante la simulación con el método Monte Carlo, fue estudiada la distribución de masas y energía cinética de los fragmentos de la fisión inducida por neutrones térmicos del 235U. Además de reproducir el ensanchamiento pronunciado en la desviación estándar de la distribución de la energía cinética de los fragmentos finales (¾e(m)) alrededor del número másico m = 109, nuestra simulación también produce un segundo ensanchamiento alrededor de m = 125, en concordancia con los datos expe...

  1. Estudio del proceso de crecimiento del cultivo del tomate

    OpenAIRE

    Barraza, Fernando V.; Fischer, Gerhard; Cardona, Carlos E.

    2010-01-01

    Para conocer la densidad poblacional óptimay obtener el mayor rendimiento en el cultivo deltomate en el Valle del Sinú medio, se hizo una investigaciónmediante diseño completamente al azar con cuatrotratamientos (densidades poblacionales de 20.000,25.000, 33.333 y 50.000 plantas∙ha -1) y tres repeticiones.Se tomaron las medidas directas: altura de planta, númerode hojas, área foliar, número de frutos y rendimiento.También se calcularon los índices de crecimiento: tasa decrecimiento del cultiv...

  2. A hybrid Monte Carlo and response matrix Monte Carlo method in criticality calculation

    International Nuclear Information System (INIS)

    Full core calculations are very useful and important in reactor physics analysis, especially in computing the full core power distributions, optimizing the refueling strategies and analyzing the depletion of fuels. To reduce the computing time and accelerate the convergence, a method named Response Matrix Monte Carlo (RMMC) method based on analog Monte Carlo simulation was used to calculate the fixed source neutron transport problems in repeated structures. To make more accurate calculations, we put forward the RMMC method based on non-analog Monte Carlo simulation and investigate the way to use RMMC method in criticality calculations. Then a new hybrid RMMC and MC (RMMC+MC) method is put forward to solve the criticality problems with combined repeated and flexible geometries. This new RMMC+MC method, having the advantages of both MC method and RMMC method, can not only increase the efficiency of calculations, also simulate more complex geometries rather than repeated structures. Several 1-D numerical problems are constructed to test the new RMMC and RMMC+MC method. The results show that RMMC method and RMMC+MC method can efficiently reduce the computing time and variations in the calculations. Finally, the future research directions are mentioned and discussed at the end of this paper to make RMMC method and RMMC+MC method more powerful. (authors)

  3. 欧式期权定价的Monte-Carlo方法%Monte-Carlo methods for Pricing European-style options

    Institute of Scientific and Technical Information of China (English)

    张丽虹

    2015-01-01

    讨论各种欧式期权价格的Monte-Carlo方法。根据Black-Scholes期权定价模型以及风险中性理论,首先详细地讨论如何利用Monte-Carlo方法来计算标准欧式期权价格;然后讨论如何引入控制变量以及对称变量来提高Monte-Carlo方法的精确性;最后用Monte-Carlo方法来计算标准欧式期权、欧式—两值期权、欧式—回望期权以及欧式—亚式期权的价格,并讨论相关方法的优缺点。%We discuss Monte-Carlo methods for pricing European options.Based on the famous Black-Scholes model,we first discuss the Monte-Carlo simulation method to pricing standard European options according to Risk neutral theory.Methods to improve the Monte-Carlo simulation performance including introducing control variates and antithetic variates are also discussed.Finally we apply the proposed Monte-Carlo methods to price the European binary options,European lookback options and European Asian options.

  4. Marketing Mix del Software.

    OpenAIRE

    Yudith del Carmen Rodríguez Pérez

    2006-01-01

    La ingeniería del software y los modelos de calidad del software han consolidado sus esfuerzos en el proceso de producción del mismo, sin embargo son pocos sus aportes en el proceso de comercialización. Es esencial en la ciencia de la computación desarrollar un modelo de comercialización para las organizaciones productoras de software con el fin de elevar la productividad de las mismas. Sin embargo, es preciso primero conocer las características del producto software que los diferencian de ot...

  5. Los sentimientos del Cid

    OpenAIRE

    Aurelio González

    2007-01-01

    Un recorrido por los sentimientos que se han plasmado en la caracterización del personaje del Cid conlleva el análisis de las formas expresivas, que se utilizan para que estos sentimientos sean verosímiles, sin entrar en contradicción con la condición heroica y épica del personaje. La consideración de las expresiones de tristeza, alegría, devoción o gratitud de Rodrigo permite identificar estrategias discursivas del poema que intentan acercar al receptor a una valoración positiva de la baja n...

  6. Estado nutricional de mujeres con sobrepeso y obesidad del área de cobertura del Programa de Atención Integral en Salud (PAIS) 2006

    OpenAIRE

    Viviana Esquivel Solís; Marco Vinicio Alvarado

    2009-01-01

    Objetivo: El objetivo de la presente investigación fue evaluar el estado nutricional de mujeres con sobrepeso y obesidad del área de atracción del Programa de Atención Integral en Salud, PAIS. Métodos: Se trabajó con un total de 90 mujeres, 30 mujeres de cada uno de los distritos que conforman el área de cobertura PAIS (Curridabat, La Unión y Montes de Oca), con edades comprendidas entre los 18-53 años, diagnosticadas todas con sobrepeso y obesidad. Las variables estudiadas fueron característ...

  7. Estudio del léxico del Ecuador

    OpenAIRE

    Estrella Santos, Ana Teresa

    2008-01-01

    El presente trabajo de investigación pretende proporcionar una descripción del léxico del español del Ecuador, a partir de materiales de la lengua hablada. Hemos llevado a cabo un análisis contrastivo del léxico de las provincias de Pichincha y Guayas, una recopilación del léxico general del Ecuador y un análisis de los quichuismos presentes en nuestro corpus.

  8. Riesgos laborales en trabajadores del sector informal del Cauca, Colombia

    OpenAIRE

    Augusto Muñoz-Caicedo; Pilar Mirely Chois-Lenis

    2014-01-01

    Antecedentes. Un estudio a nivel nacional permitió establecer los riesgos a los cuales estaban expuestos los trabajadores del sector informal del comercio. Sin embargo, no fue incluido el Departamento del Cauca. Objetivo. Describirlos riesgos laborales de las personas ocupadas en el sector informal del comercio, en cinco municipios del departamento del Cauca, durante el 2011. Materiales y métodos. Estudio descriptivo, transversal, desarrollado con 223 sujetos a quienes se les aplicó una encue...

  9. Biodiversity of Myxomycetes from the Monte Desert of Argentina

    Directory of Open Access Journals (Sweden)

    Lado, C.

    2011-06-01

    Full Text Available A biodiversity survey for myxomycetes was carried out in the Monte Desert (Argentina and surrounding areas in November 2006 and late February and March 2007. Specimens were collected in seven different provinces (Catamarca, Jujuy, La Rioja, Salta, San Juan, San Luis and Tucumán, between 23º and 33º S latitude, and a total of 105 localities were sampled. Cacti and succulent plants were the most common type of substrate investigated, but shrubs and herbs characteristic of this biome were also included in the survey. Almost six hundred specimens of myxomycetes from 72 different species in 22 genera were collected either in the field, or from moist chamber cultures prepared with samples of plant material obtained from the same collecting sites. The results include 1 species new to science, Macbrideola andina three more species recently described based on material from this survey, 5 species cited for the first time for the Neotropics, 11 new records for South America and 38 new records for Argentina. Taxonomic comments on rare or unusual species are included and illustrated with photographs by LM and SEM. Data are presented on the development of some species and microenvironmental factors are discussed. An analysis of the biodiversity of myxomycetes in this area, and a comparison with other desert areas, are included.

    Con el objetivo de estudiar la biodiversidad de Myxomycetes en el Desierto de Monte (Argentina y áreas circundantes, se realizó un muestreo en los meses de noviembre de 2006 y febrero y marzo de 2007. Se recolectaron especímenes en un total de 105 localidades pertenecientes a siete provincias (Catamarca, Jujuy, La Rioja, Salta, San Juan, San Luis y Tucumán, situadas entre los paralelos 23º y 33º de latitud sur. Los cactus y plantas suculentas fueron los tipos de sustratos más estudiados, pero también se analizaron arbustos y plantas herbáceas características de este bioma. Casi 600 especímenes de mixomicetes

  10. Recent advances and future prospects for Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B [Los Alamos National Laboratory

    2010-01-01

    The history of Monte Carlo methods is closely linked to that of computers: The first known Monte Carlo program was written in 1947 for the ENIAC; a pre-release of the first Fortran compiler was used for Monte Carlo In 1957; Monte Carlo codes were adapted to vector computers in the 1980s, clusters and parallel computers in the 1990s, and teraflop systems in the 2000s. Recent advances include hierarchical parallelism, combining threaded calculations on multicore processors with message-passing among different nodes. With the advances In computmg, Monte Carlo codes have evolved with new capabilities and new ways of use. Production codes such as MCNP, MVP, MONK, TRIPOLI and SCALE are now 20-30 years old (or more) and are very rich in advanced featUres. The former 'method of last resort' has now become the first choice for many applications. Calculations are now routinely performed on office computers, not just on supercomputers. Current research and development efforts are investigating the use of Monte Carlo methods on FPGAs. GPUs, and many-core processors. Other far-reaching research is exploring ways to adapt Monte Carlo methods to future exaflop systems that may have 1M or more concurrent computational processes.

  11. Iterative acceleration methods for Monte Carlo and deterministic criticality calculations

    International Nuclear Information System (INIS)

    If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors

  12. Iterative acceleration methods for Monte Carlo and deterministic criticality calculations

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, T.J.

    1995-11-01

    If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors.

  13. Helminthiases in Montes Claros. Preliminary survey

    Directory of Open Access Journals (Sweden)

    Rina Girard Kaminsky

    1976-04-01

    Full Text Available A preliminary survey was conducted for the presence of helminths in the city of Montes Claros, M. G., Brazil. Three groups of persons were examined by the direct smear, Kato thick film and MIFC techniques; one group by direct smear and Kato only. General findings were: a high prevalence of hookworm, followed by ascariasis, S. mansoni, S. stercoralis and very light infections with T. trichiurá. E. vermicularis and H. nana were ranking parasites at an orphanage, with some hookworm and S. mansoni infections as well. At a pig slaughter house, the dominant parasites were hookworm and S. mansoni. Pig cysticercosis was an incidental finding worth mentioning for the health hazard it represents for humans as well as an economic loss. From the comparative results between the Kato and the MIF the former proved itself again as a more sensitive and reliable concentration method for helminth eggs, of low cost and easy performance.Um estudo preliminar sobre helmintos foi feito na cidade de Montes Claros, MG, Brasil. Três grupos de pessoas foram examinados pelos métodos direto, de Kato e do MIF e um grupo pelos métodos direto e Kato exclusivamente. Encontrou-se uma alta prevalência de necatorose, seguindo-se ascaríase, S. mansoni, S. stercoralis, e infecções leves pelo T. trichiura. E. vermicularis e H. nana foram osparasitos mais prevalentes num orfanato, com alguns casos de infecção pelo Necator e S. mansoni. Cisticercose dos suinos foi achado incidental e é importante ser mencionada devido ao perigo que representa no plano da Saúde Pública, bem como pela perda econômica que produz. Discutiu-se brevemente a importância do solo na transmissão dos helmintos num clima quente e seco. Da comparação dos métodos de Kato e MIF, o primeiro demonstrou ser o método mais sensível para ovos de helmintos, de baixo custo e fácil preparo.

  14. Evidencias del ciclo Pampeano en el basamento del sector noroccidental de la sierra de San Luis

    Directory of Open Access Journals (Sweden)

    GI Vujovich

    2003-12-01

    Full Text Available Se presenta una edad preliminar U-Pb sobre circones de un gneis biotítico feldespático perteneciente al Complejo Nogolí aflorante en las cercanías de San Francisco del Monte de Oro, sierra de San Luis. Los resultados indican una edad de cristalización para el mismo de 554 ± 4,8 Ma, representando un interesante hallazgo del ciclo Pampeano en el marco geológico considerado. Se postula además la existencia de un proceso de pérdida episódica de Pb durante el Cretácico inferior (112 ± 23 Ma, reflejado en la intersección inferior de la recta de discordia. Esta edad inferior podría asociarse con gradientes térmicos anómalos relacionados con los procesos distensivos generalizados que afectaron al Gondwana durante la apertura del océano Atlántico Sur.

  15. Cartas del Observatorio N° 2

    OpenAIRE

    Castell, Edmon; Torres Carreño, Guillermo Andrés; Diazgranados, Carlos Nicolás; Mora, Yaneth

    2011-01-01

    El boletín del OAN, "Cartas del Observatorio", es una pieza de comunicación desarrollada entre el Observatorio Astronómico Nacional (OAN) y el Área de Comunicación del SPM. El boletín periódico forma parte de los aportes del SPM al Bicentenario de la Independencia (2010) de Colombia. Este segundo número de Cartas del Observatorio, describe la construcción del edificio, el plan museológico por parte del SPM, una de las piezas importante del OAN, la publicación de la infografía y la partici...

  16. La luz del origen del universo

    Directory of Open Access Journals (Sweden)

    Casas, Alberto

    2015-10-01

    Full Text Available Penzias and Wilson discovered the cosmic microwave background, a luminous echo of the Big Bang, in 1965. The amount of information encoded in this relic of the early universe is truly extraordinary. At present, the most precise data about the origin and structure of the universe comes from the study of this primordial light, the full potential of which has yet to be explored.En 1965 se descubrió el fondo de radiación de microondas, un eco luminoso de la Gran Explosión (Big Bang. La cantidad de información contenida en esta reliquia del universo primitivo es verdaderamente extraordinaria. En la actualidad los datos más precisos sobre el origen y estructura del universo provienen del estudio de esta luz primigenia, que aún no ha sido explorada en todo su potencial.

  17. El equilibrio del consumidor

    OpenAIRE

    León Rodríguez, Mª Dolores; Fernández Pérez, Ana Mª

    2008-01-01

    Obtencin de la recta presupuestaria de un consumidor. Definición y características de las Curvas de indiferencia. Concepto de relación marginal de sustitución. Obtención del equilibrio del consumidor

  18. Variance reduction in Monte Carlo analysis of rarefied gas diffusion.

    Science.gov (United States)

    Perlmutter, M.

    1972-01-01

    The problem of rarefied diffusion between parallel walls is solved using the Monte Carlo method. The diffusing molecules are evaporated or emitted from one of the two parallel walls and diffuse through another molecular species. The Monte Carlo analysis treats the diffusing molecule as undergoing a Markov random walk, and the local macroscopic properties are found as the expected value of the random variable, the random walk payoff. By biasing the transition probabilities and changing the collision payoffs, the expected Markov walk payoff is retained but its variance is reduced so that the Monte Carlo result has a much smaller error.

  19. Status of vectorized Monte Carlo for particle transport analysis

    International Nuclear Information System (INIS)

    The conventional particle transport Monte Carlo algorithm is ill suited for modern vector supercomputers because the random nature of the particle transport process in the history based algorithm inhibits construction of vectors. An alternative, event-based algorithm is suitable for vectorization and has been used recently to achieve impressive gains in performance on vector supercomputers. This review describes the event-based algorithm and several variations of it. Implementations of this algorithm for applications in particle transport are described, and their relative merits are discussed. The implementation of Monte Carlo methods on multiple vector parallel processors is considered, as is the potential of massively parallel processors for Monte Carlo particle transport simulations

  20. Simulation and the Monte Carlo Method, Student Solutions Manual

    CERN Document Server

    Rubinstein, Reuven Y

    2012-01-01

    This accessible new edition explores the major topics in Monte Carlo simulation Simulation and the Monte Carlo Method, Second Edition reflects the latest developments in the field and presents a fully updated and comprehensive account of the major topics that have emerged in Monte Carlo simulation since the publication of the classic First Edition over twenty-five years ago. While maintaining its accessible and intuitive approach, this revised edition features a wealth of up-to-date information that facilitates a deeper understanding of problem solving across a wide array of subject areas, suc

  1. The Monte Carlo method the method of statistical trials

    CERN Document Server

    Shreider, YuA

    1966-01-01

    The Monte Carlo Method: The Method of Statistical Trials is a systematic account of the fundamental concepts and techniques of the Monte Carlo method, together with its range of applications. Some of these applications include the computation of definite integrals, neutron physics, and in the investigation of servicing processes. This volume is comprised of seven chapters and begins with an overview of the basic features of the Monte Carlo method and typical examples of its application to simple problems in computational mathematics. The next chapter examines the computation of multi-dimensio

  2. Los reptiles del Delta del Orinoco, Venezuela

    OpenAIRE

    Molina, César; Señaris, josefa; Rivas, Gilson

    2004-01-01

    Como resultado de cinco años (1992-1997) de exploraciones herpetológicas, revisiones bibliográficas y examen de museos nacionales, se presenta un análisis taxonómico, ecológico y biogeográfico preliminar de los reptiles del delta del río Orinoco, Estado Delta Amacuro. Se reconocen 70 especies de reptiles agrupados en tres órdenes, 22 familias y 53 géneros. El orden Squamata es el más diverso, con dominancia de las serpientes de la familias Colubridae y Boidae, y los lagartos de las familias G...

  3. Las cosas del quehacer

    OpenAIRE

    Sergio C. Staude

    2010-01-01

    El psicoanálisis es una praxis y no una práctica especulativa que solo busca afianzar un saber. Esta praxis encuentra su eje central en la noción de acto que es la invitación —y el sostén— a una experiencia y no a la acumulación de información. Ese acto da cuenta del tiempo de un pasaje, y el artículo destaca dos: el del momento inaugural del psicoanálisis y el de la función del psicoanalista en el devenir del análisis. A ambas las une la responsabilidad ...

  4. Monte Carlo simulations for focusing elliptical guides

    Energy Technology Data Exchange (ETDEWEB)

    Valicu, Roxana [FRM2 Garching, Muenchen (Germany); Boeni, Peter [E20, TU Muenchen (Germany)

    2009-07-01

    The aim of the Monte Carlo simulations using McStas Programme was to improve the focusing of the neutron beam existing at PGAA (FRM II) by prolongation of the existing elliptic guide (coated now with supermirrors with m=3) with a new part. First we have tried with an initial length of the additional guide of 7,5cm and coatings for the neutron guide of supermirrors with m=4,5 and 6. The gain (calculated by dividing the intensity in the focal point after adding the guide by the intensity at the focal point with the initial guide) obtained for this coatings indicated that a coating with m=5 would be appropriate for a first trial. The next step was to vary the length of the additional guide for this m value and therefore choosing the appropriate length for the maximal gain. With the m value and the length of the guide fixed we have introduced an aperture 1 cm before the focal point and we have varied the radius of this aperture in order to obtain a focused beam. We have observed a dramatic decrease in the size of the beam in the focal point after introducing this aperture. The simulation results, the gains obtained and the evolution of the beam size will be presented.

  5. Finding Planet Nine: a Monte Carlo approach

    CERN Document Server

    Marcos, C de la Fuente

    2016-01-01

    Planet Nine is a hypothetical planet located well beyond Pluto that has been proposed in an attempt to explain the observed clustering in physical space of the perihelia of six extreme trans-Neptunian objects or ETNOs. The predicted approximate values of its orbital elements include a semimajor axis of 700 au, an eccentricity of 0.6, an inclination of 30 degrees, and an argument of perihelion of 150 degrees. Searching for this putative planet is already under way. Here, we use a Monte Carlo approach to create a synthetic population of Planet Nine orbits and study its visibility statistically in terms of various parameters and focusing on the aphelion configuration. Our analysis shows that, if Planet Nine exists and is at aphelion, it might be found projected against one out of four specific areas in the sky. Each area is linked to a particular value of the longitude of the ascending node and two of them are compatible with an apsidal antialignment scenario. In addition and after studying the current statistic...

  6. Measuring Berry curvature with quantum Monte Carlo

    CERN Document Server

    Kolodrubetz, Michael

    2014-01-01

    The Berry curvature and its descendant, the Berry phase, play an important role in quantum mechanics. They can be used to understand the Aharonov-Bohm effect, define topological Chern numbers, and generally to investigate the geometric properties of a quantum ground state manifold. While Berry curvature has been well-studied in the regimes of few-body physics and non-interacting particles, its use in the regime of strong interactions is hindered by the lack of numerical methods to solve it. In this paper we fill this gap by implementing a quantum Monte Carlo method to solve for the Berry curvature, based on interpreting Berry curvature as a leading correction to imaginary time ramps. We demonstrate our algorithm using the transverse-field Ising model in one and two dimensions, the latter of which is non-integrable. Despite the fact that the Berry curvature gives information about the phase of the wave function, we show that our algorithm has no sign or phase problem for standard sign-problem-free Hamiltonians...

  7. The Monts d'Arree CLI

    International Nuclear Information System (INIS)

    This document gathers numerous reports published by the CLI (Local Commission of Information) associated with the basic nuclear installation located in Brennilis, and also documents concerning this installation published by other actors (notably ASN, EDF). After a presentation of the CLI members, documents are gathered by themes: News (10 documents: reports of CLI sessions from January to October 2012, presentations by EDF and ASN), CLI operation (7 documents: creation order, members, internal regulation, site presentation, activity reports for 2009, 2010 and 2011), Works during consultation and public inquiry in 2009 (10 documents: mails exchanged between the CLI and different authorities, technical reports, report, opinion and conclusion of the inquiry commission, public meeting), consultation of the ASN on technical requirement project (notably with respect to water sampling and to releases by the power station), information on the Monts d'Arree site (22 documents: technical reports, information reports, radio-ecological investigation, environmental survey, mails by the different actors, i.e., the CLI, EDF, ASN), and reports of CLI plenary sessions (17 documents: reports from January 2009 to October 2012)

  8. Monte Carlo study of nanowire magnetic properties

    Institute of Scientific and Technical Information of China (English)

    R.Masrour; L.Bahmad; A.Benyoussef

    2013-01-01

    In this work,we use Monte Carlo simulations to study the magnetic properties of a nanowire system based on a honeycomb lattice,in the absence as well as in the presence of both an external magnetic field and crystal field.The system is formed with NL layers having spins that can take the values σ =+1/2 and S =+1,0.The blocking temperature is deduced,for each spin configuration,depending on the crystal field A.The effect of the exchange interaction coupling Jp between the spin configurations σ and S is studied for different values of temperature at fixed crystal field.The established ground-state phase diagram,in the plane (Jp,A),shows that the only stable configurations are:(1/2,0),(1/2,+1),and (1/2,-1).The thermal magnetization and susceptibility are investigated for the two spin configurations,in the absence as well as in the presence of a crystal field.Finally,we establish the hysteresis cycle for different temperature values,showing that there is almost no remaining magnetization in the absence of the external magnetic field,and that the studied system exhibits a super-paramagnetic behavior.

  9. Extending canonical Monte Carlo methods: II

    Science.gov (United States)

    Velazquez, L.; Curilef, S.

    2010-04-01

    We have previously presented a methodology for extending canonical Monte Carlo methods inspired by a suitable extension of the canonical fluctuation relation C = β2langδE2rang compatible with negative heat capacities, C < 0. Now, we improve this methodology by including the finite size effects that reduce the precision of a direct determination of the microcanonical caloric curve β(E) = ∂S(E)/∂E, as well as by carrying out a better implementation of the MC schemes. We show that, despite the modifications considered, the extended canonical MC methods lead to an impressive overcoming of the so-called supercritical slowing down observed close to the region of the temperature driven first-order phase transition. In this case, the size dependence of the decorrelation time τ is reduced from an exponential growth to a weak power-law behavior, \\tau (N)\\propto N^{\\alpha } , as is shown in the particular case of the 2D seven-state Potts model where the exponent α = 0.14-0.18.

  10. Monte Carlo Production Management at CMS

    Science.gov (United States)

    Boudoul, G.; Franzoni, G.; Norkus, A.; Pol, A.; Srimanobhas, P.; Vlimant, J.-R.

    2015-12-01

    The analysis of the LHC data at the Compact Muon Solenoid (CMS) experiment requires the production of a large number of simulated events. During the RunI of LHC (20102012), CMS has produced over 12 Billion simulated events, organized in approximately sixty different campaigns each emulating specific detector conditions and LHC running conditions (pile up). In order to aggregate the information needed for the configuration and prioritization of the events production, assure the book-keeping of all the processing requests placed by the physics analysis groups, and to interface with the CMS production infrastructure, the web- based service Monte Carlo Management (McM) has been developed and put in production in 2013. McM is based on recent server infrastructure technology (CherryPy + AngularJS) and relies on a CouchDB database back-end. This contribution covers the one and half year of operational experience managing samples of simulated events for CMS, the evolution of its functionalities and the extension of its capability to monitor the status and advancement of the events production.

  11. A continuation multilevel Monte Carlo algorithm

    KAUST Repository

    Collier, Nathan

    2014-09-05

    We propose a novel Continuation Multi Level Monte Carlo (CMLMC) algorithm for weak approximation of stochastic models. The CMLMC algorithm solves the given approximation problem for a sequence of decreasing tolerances, ending when the required error tolerance is satisfied. CMLMC assumes discretization hierarchies that are defined a priori for each level and are geometrically refined across levels. The actual choice of computational work across levels is based on parametric models for the average cost per sample and the corresponding variance and weak error. These parameters are calibrated using Bayesian estimation, taking particular notice of the deepest levels of the discretization hierarchy, where only few realizations are available to produce the estimates. The resulting CMLMC estimator exhibits a non-trivial splitting between bias and statistical contributions. We also show the asymptotic normality of the statistical error in the MLMC estimator and justify in this way our error estimate that allows prescribing both required accuracy and confidence in the final result. Numerical results substantiate the above results and illustrate the corresponding computational savings in examples that are described in terms of differential equations either driven by random measures or with random coefficients. © 2014, Springer Science+Business Media Dordrecht.

  12. Monte Carlo simulation framework for TMT

    Science.gov (United States)

    Vogiatzis, Konstantinos; Angeli, George Z.

    2008-07-01

    This presentation describes a strategy for assessing the performance of the Thirty Meter Telescope (TMT). A Monte Carlo Simulation Framework has been developed to combine optical modeling with Computational Fluid Dynamics simulations (CFD), Finite Element Analysis (FEA) and controls to model the overall performance of TMT. The framework consists of a two year record of observed environmental parameters such as atmospheric seeing, site wind speed and direction, ambient temperature and local sunset and sunrise times, along with telescope azimuth and elevation with a given sampling rate. The modeled optical, dynamic and thermal seeing aberrations are available in a matrix form for distinct values within the range of influencing parameters. These parameters are either part of the framework parameter set or can be derived from them at each time-step. As time advances, the aberrations are interpolated and combined based on the current value of their parameters. Different scenarios can be generated based on operating parameters such as venting strategy, optical calibration frequency and heat source control. Performance probability distributions are obtained and provide design guidance. The sensitivity of the system to design, operating and environmental parameters can be assessed in order to maximize the % of time the system meets the performance specifications.

  13. Accelerated Monte Carlo Methods for Coulomb Collisions

    Science.gov (United States)

    Rosin, Mark; Ricketson, Lee; Dimits, Andris; Caflisch, Russel; Cohen, Bruce

    2014-03-01

    We present a new highly efficient multi-level Monte Carlo (MLMC) simulation algorithm for Coulomb collisions in a plasma. The scheme, initially developed and used successfully for applications in financial mathematics, is applied here to kinetic plasmas for the first time. The method is based on a Langevin treatment of the Landau-Fokker-Planck equation and has a rich history derived from the works of Einstein and Chandrasekhar. The MLMC scheme successfully reduces the computational cost of achieving an RMS error ɛ in the numerical solution to collisional plasma problems from (ɛ-3) - for the standard state-of-the-art Langevin and binary collision algorithms - to a theoretically optimal (ɛ-2) scaling, when used in conjunction with an underlying Milstein discretization to the Langevin equation. In the test case presented here, the method accelerates simulations by factors of up to 100. We summarize the scheme, present some tricks for improving its efficiency yet further, and discuss the method's range of applicability. Work performed for US DOE by LLNL under contract DE-AC52- 07NA27344 and by UCLA under grant DE-FG02-05ER25710.

  14. Monte Carlo Production Management at CMS

    CERN Document Server

    Boudoul, G.; Pol, A; Srimanobhas, P; Vlimant, J R; Franzoni, Giovanni

    2015-01-01

    The analysis of the LHC data at the Compact Muon Solenoid (CMS) experiment requires the production of a large number of simulated events.During the runI of LHC (2010-2012), CMS has produced over 12 Billion simulated events,organized in approximately sixty different campaigns each emulating specific detector conditions and LHC running conditions (pile up).In order toaggregate the information needed for the configuration and prioritization of the events production,assure the book-keeping and of all the processing requests placed by the physics analysis groups,and to interface with the CMS production infrastructure,the web-based service Monte Carlo Management (McM) has been developed and put in production in 2012.McM is based on recent server infrastructure technology (CherryPy + java) and relies on a CouchDB database back-end.This contribution will coverthe one and half year of operational experience managing samples of simulated events for CMS,the evolution of its functionalitiesand the extension of its capabi...

  15. The Monte Carlo calculation of gamma family

    International Nuclear Information System (INIS)

    The method of the Monte Carlo calculation for gamma family was investigated. The effects of the variation of values or terms of parameters on observed quantities were studied. The terms taken for the standard calculation are the scaling law for the model, simple proton spectrum for primary cosmic ray, a constant cross section of interaction, zero probability of neutral pion production, and the bending of the curve of primary energy spectrum. This is called S model. Calculations were made by changing one of above mentioned parameters. The chamber size, the mixing of gamma and hadrons, and the family size were fitted to the practical ECC data. When the model was changed from the scaling law to the CKP model, the energy spectrum of the family was able to be expressed by the CKP model better than the scaling law. The scaling law was better in the symmetry around the family center. It was denied that primary cosmic ray mostly consists of heavy particles. The increase of the interaction cross section was necessary in view of the frequency of the families. (Kato, T.)

  16. Monte Carlo Simulation of Critical Casimir Forces

    Science.gov (United States)

    Vasilyev, Oleg A.

    2015-03-01

    In the vicinity of the second order phase transition point long-range critical fluctuations of the order parameter appear. The second order phase transition in a critical binary mixture in the vicinity of the demixing point belongs to the universality class of the Ising model. The superfluid transition in liquid He belongs to the universality class of the XY model. The confinement of long-range fluctuations causes critical Casimir forces acting on confining surfaces or particles immersed in the critical substance. Last decade critical Casimir forces in binary mixtures and liquid helium were studied experimentally. The critical Casimir force in a film of a given thickness scales as a universal scaling function of the ratio of the film thickness to the bulk correlation length divided over the cube of the film thickness. Using Monte Carlo simulations we can compute critical Casimir forces and their scaling functions for lattice Ising and XY models which correspond to experimental results for the binary mixture and liquid helium, respectively. This chapter provides the description of numerical methods for computation of critical Casimir interactions for lattice models for plane-plane, plane-particle, and particle-particle geometries.

  17. Biofilm growth: a lattice Monte Carlo model

    Science.gov (United States)

    Tao, Yuguo; Slater, Gary

    2011-03-01

    Biofilms are complex colonies of bacteria that grow in contact with a wall, often in the presence of a flow. In the current work, biofilm growth is investigated using a new two-dimensional lattice Monte Carlo algorithm based on the Bond-Fluctuation Algorithm (BFA). One of the distinguishing characteristics of biofilms, the synthesis and physical properties of the extracellular polymeric substance (EPS) in which the cells are embedded, is explicitly taken into account. Cells are modelled as autonomous closed loops with well-defined mechanical and thermodynamic properties, while the EPS is modelled as flexible polymeric chains. This BFA model allows us to add biologically relevant features such as: the uptake of nutrients; cell growth, division and death; the production of EPS; cell maintenance and hibernation; the generation of waste and the impact of toxic molecules; cell mutation and evolution; cell motility. By tuning the structural, interactional and morphologic parameters of the model, the cell shapes as well as the growth and maturation of various types of biofilm colonies can be controlled.

  18. Monte Carlo simulations for heavy ion dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Geithner, O.

    2006-07-26

    Water-to-air stopping power ratio (s{sub w,air}) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used which is a substantially modified version of its predecessor SHIELD-HIT v1. The code was partially rewritten, replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe- Bloch formula, thus widening its range for medical dosimetry applications. Optional MSTAR and ICRU-73 stopping power data were included. The fragmentation model was verified using all available experimental data and some parameters were adjusted. The present code version shows excellent agreement with experimental data. Additional to the calculations of stopping power ratios, s{sub w,air}, the influence of fragments and I-values on s{sub w,air} for carbon ion beams was investigated. The value of s{sub w,air} deviates as much as 2.3% at the Bragg peak from the recommended by TRS-398 constant value of 1.130 for an energy of 50 MeV/u. (orig.)

  19. Linear Scaling Quantum Monte Carlo Calculations

    Science.gov (United States)

    Williamson, Andrew

    2002-03-01

    New developments to the quantum Monte Carlo approach are presented that improve the scaling of the time required to calculate the total energy of a configuration of electronic coordinates from N^3 to nearly linear[1]. The first factor of N is achieved by applying a unitary transform to the set of single particle orbitals used to construct the Slater determinant, creating a set of maximally localized Wannier orbitals. These localized functions are then truncated beyond a given cutoff radius to introduce sparsity into the Slater determinant. The second factor of N is achieved by evaluating the maximally localized Wannier orbitals on a cubic spline grid, which removes the size dependence of the basis set (e.g. plane waves, Gaussians) typically used to expand the orbitals. Application of this method to the calculation of the binding energy of carbon fullerenes and silicon nanostructures will be presented. An extension of the approach to deal with excited states of systems will also be presented in the context of the calculation of the excitonic gap of a variety of systems. This work was performed under the auspices of the U.S. Dept. of Energy at the University of California/LLNL under contract no. W-7405-Eng-48. [1] A.J. Williamson, R.Q. Hood and J.C. Grossman, Phys. Rev. Lett. 87 246406 (2001)

  20. SERPENT Monte Carlo reactor physics code

    International Nuclear Information System (INIS)

    SERPENT is a three-dimensional continuous-energy Monte Carlo reactor physics burnup calculation code, developed at VTT Technical Research Centre of Finland since 2004. The code is specialized in lattice physics applications, but the universe-based geometry description allows transport simulation to be carried out in complicated three-dimensional geometries as well. The suggested applications of SERPENT include generation of homogenized multi-group constants for deterministic reactor simulator calculations, fuel cycle studies involving detailed assembly-level burnup calculations, validation of deterministic lattice transport codes, research reactor applications, educational purposes and demonstration of reactor physics phenomena. The Serpent code has been publicly distributed by the OECD/NEA Data Bank since May 2009 and RSICC in the U. S. since March 2010. The code is being used in some 35 organizations in 20 countries around the world. This paper presents an overview of the methods and capabilities of the Serpent code, with examples in the modelling of WWER-440 reactor physics. (Author)

  1. Rare event simulation using Monte Carlo methods

    CERN Document Server

    Rubino, Gerardo

    2009-01-01

    In a probabilistic model, a rare event is an event with a very small probability of occurrence. The forecasting of rare events is a formidable task but is important in many areas. For instance a catastrophic failure in a transport system or in a nuclear power plant, the failure of an information processing system in a bank, or in the communication network of a group of banks, leading to financial losses. Being able to evaluate the probability of rare events is therefore a critical issue. Monte Carlo Methods, the simulation of corresponding models, are used to analyze rare events. This book sets out to present the mathematical tools available for the efficient simulation of rare events. Importance sampling and splitting are presented along with an exposition of how to apply these tools to a variety of fields ranging from performance and dependability evaluation of complex systems, typically in computer science or in telecommunications, to chemical reaction analysis in biology or particle transport in physics. ...

  2. Monte Carlo simulations for heavy ion dosimetry

    International Nuclear Information System (INIS)

    Water-to-air stopping power ratio (sw,air) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used which is a substantially modified version of its predecessor SHIELD-HIT v1. The code was partially rewritten, replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe- Bloch formula, thus widening its range for medical dosimetry applications. Optional MSTAR and ICRU-73 stopping power data were included. The fragmentation model was verified using all available experimental data and some parameters were adjusted. The present code version shows excellent agreement with experimental data. Additional to the calculations of stopping power ratios, sw,air, the influence of fragments and I-values on sw,air for carbon ion beams was investigated. The value of sw,air deviates as much as 2.3% at the Bragg peak from the recommended by TRS-398 constant value of 1.130 for an energy of 50 MeV/u. (orig.)

  3. Finding Planet Nine: a Monte Carlo approach

    Science.gov (United States)

    de la Fuente Marcos, C.; de la Fuente Marcos, R.

    2016-06-01

    Planet Nine is a hypothetical planet located well beyond Pluto that has been proposed in an attempt to explain the observed clustering in physical space of the perihelia of six extreme trans-Neptunian objects or ETNOs. The predicted approximate values of its orbital elements include a semimajor axis of 700 au, an eccentricity of 0.6, an inclination of 30°, and an argument of perihelion of 150°. Searching for this putative planet is already under way. Here, we use a Monte Carlo approach to create a synthetic population of Planet Nine orbits and study its visibility statistically in terms of various parameters and focusing on the aphelion configuration. Our analysis shows that, if Planet Nine exists and is at aphelion, it might be found projected against one out of the four specific areas in the sky. Each area is linked to a particular value of the longitude of the ascending node and two of them are compatible with an apsidal anti-alignment scenario. In addition and after studying the current statistics of ETNOs, a cautionary note on the robustness of the perihelia clustering is presented.

  4. Monte Carlo Simulations of the Photospheric Process

    CERN Document Server

    Santana, Rodolfo; Hernandez, Roberto A; Kumar, Pawan

    2015-01-01

    We present a Monte Carlo (MC) code we wrote to simulate the photospheric process and to study the photospheric spectrum above the peak energy. Our simulations were performed with a photon to electron ratio $N_{\\gamma}/N_{e} = 10^{5}$, as determined by observations of the GRB prompt emission. We searched an exhaustive parameter space to determine if the photospheric process can match the observed high-energy spectrum of the prompt emission. If we do not consider electron re-heating, we determined that the best conditions to produce the observed high-energy spectrum are low photon temperatures and high optical depths. However, for these simulations, the spectrum peaks at an energy below 300 keV by a factor $\\sim 10$. For the cases we consider with higher photon temperatures and lower optical depths, we demonstrate that additional energy in the electrons is required to produce a power-law spectrum above the peak-energy. By considering electron re-heating near the photosphere, the spectrum for these simulations h...

  5. Parallel Monte Carlo simulation of aerosol dynamics

    KAUST Repository

    Zhou, K.

    2014-01-01

    A highly efficient Monte Carlo (MC) algorithm is developed for the numerical simulation of aerosol dynamics, that is, nucleation, surface growth, and coagulation. Nucleation and surface growth are handled with deterministic means, while coagulation is simulated with a stochastic method (Marcus-Lushnikov stochastic process). Operator splitting techniques are used to synthesize the deterministic and stochastic parts in the algorithm. The algorithm is parallelized using the Message Passing Interface (MPI). The parallel computing efficiency is investigated through numerical examples. Near 60% parallel efficiency is achieved for the maximum testing case with 3.7 million MC particles running on 93 parallel computing nodes. The algorithm is verified through simulating various testing cases and comparing the simulation results with available analytical and/or other numerical solutions. Generally, it is found that only small number (hundreds or thousands) of MC particles is necessary to accurately predict the aerosol particle number density, volume fraction, and so forth, that is, low order moments of the Particle Size Distribution (PSD) function. Accurately predicting the high order moments of the PSD needs to dramatically increase the number of MC particles. 2014 Kun Zhou et al.

  6. Monte Carlo method application to shielding calculations

    International Nuclear Information System (INIS)

    CANDU spent fuel discharged from the reactor core contains Pu, so it must be stressed in two directions: tracing for the fuel reactivity in order to prevent critical mass formation and personnel protection during the spent fuel manipulation. The basic tasks accomplished by the shielding calculations in a nuclear safety analysis consist in dose rates calculations in order to prevent any risks both for personnel protection and impact on the environment during the spent fuel manipulation, transport and storage. To perform photon dose rates calculations the Monte Carlo MORSE-SGC code incorporated in SAS4 sequence from SCALE system was used. The paper objective was to obtain the photon dose rates to the spent fuel transport cask wall, both in radial and axial directions. As source of radiation one spent CANDU fuel bundle was used. All the geometrical and material data related to the transport cask were considered according to the shipping cask type B model, whose prototype has been realized and tested in the Institute for Nuclear Research Pitesti. (authors)

  7. FORMAS Y MODOS DEL TRABAJO EN LA HACIENDA TRADICIONAL MONTEMARIANA (1930-1960

    Directory of Open Access Journals (Sweden)

    Javier Hernández García

    2008-08-01

    Full Text Available Se explicitan en este artículo algunos aspectos específicos del ordenamiento social de la hacienda tradicional montemariana en la primera parte del siglo XX (1930-1960, en lo atinente a las relaciones de control, sujeción, subalternidad, confrontación, alianza y exclusión, asociadas a las formas del trabajo campesino, tal como fueron descritas y significadas por los propios actores. Se reelaboran aquí, en este respecto, algunos de los principales hallazgos que arrojó el proceso de organización e interpretación de información testimonial que forma parte del informe de investigación “Aspectos de la Vida Cotidiana en la hacienda Tradicional en Épocas de Auge y de Crisis en Montes de María (Sucre 1930-1960”, (Javier Hernández, Universidad de Cartagena, 2008.

  8. Elementos del sistema electoral del Congreso Mexicano

    Directory of Open Access Journals (Sweden)

    Aldo Medina García

    2013-08-01

    Full Text Available El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuerzas minoritarias en la integración del Senado y de la Cámara de Diputados, la división que se hace del territorio en circunscripciones electorales, la barrera electoral que se fija a los partidos políticos para acceder a la representación en el Parlamento, la fórmula de asignación que se aplica a la votación obtenida, para finalmente concluir que el sistema electoral mexicano es esencialmente mayoritario aun cuando se vista de proporcional.

  9. OBJETIVO DEL DESARROLLO DEL MILENIO 7

    Directory of Open Access Journals (Sweden)

    Margarita M. Pérez O.

    2013-10-01

    Full Text Available Los Objetivos de Desarrollo del Milenio, también conocidos como los Objetivos del Milenio, constituyeron las metas finales que aprobaron los dirigentes mundiales, 189 jefes de estado y de gobierno en la Cumbre del Milenio de las Naciones Unidas celebrada en Nueva York en el año 2000, en la cual los Estados miembros de la organización reafirmaron su compromiso de luchar por un mundo en el que el desarrollo sostenible y la eliminación de la pobreza tuvieran máxima prioridad1 . En la cumbre se definió la Declaración del Milenio, la cual detalla los objetivos, principios, valores, metas y acciones para erradicar la pobreza Mundial hacia el año 2015, todos ellos ratificados con alto interés y acción estratégica de carácter global, como marco para la medición de los progresos en materia de desarrollo.

  10. La crisi del diritto del lavoro

    Directory of Open Access Journals (Sweden)

    Alessandro Garilli

    2012-01-01

    Full Text Available Riassunto - L’Autore ripercorre in chiave critica l’evoluzione delle politiche legislative in materia di lavoro, alla luce dell’attuale fase di crisi economico finanziaria. Nell’esaminare i principali interventi normativi attuati da inizio secolo, l’Autore mette in evidenza le scelte di metodo e gli elementi di continuità che accomunano i vari provvedimenti, individuandoli nell’affannosa ricerca del punto di equilibrio tra flessibilità e garantismo. La riflessione si chiude con alcuni interrogativi sulle ultime linee di riforma del mercato del lavoro e con l’auspicio che, anche al cospetto delle imprescindibili ragioni dell’economia, il diritto del lavoro possa continuare a svolgere il proprio tradizionale ruolo di disciplina di tutela della persona.   Abstract - The author analyzes, with a critically oriented approach, the development of the employment law, in the light of the current economic and financial crisis. In examining the main regulatory measures implemented since the beginning of the century, the author highlights the methodological choices and the elements of continuity that unite the various measures, focusing them in a hard research of a point of balance between flexibility and security. The discussion concludes with some questions about the last lines of the reform of the labor market and with the hope that, even in the face of compelling reasons of economy, labor law can continue to play its traditional role of governing the protection of person.

  11. Monte Vista National Wildlife Refuge [Refuge boundary map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map is of the Monte Vista National Wildlife Refuge in Rio Grande and Alamosa counties, Colorado. It depicts the refuge boundary, water features and major roads.

  12. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1987 calendar year. The report begins with a...

  13. On the Markov Chain Monte Carlo (MCMC) method

    Indian Academy of Sciences (India)

    Rajeeva L Karandikar

    2006-04-01

    Markov Chain Monte Carlo (MCMC) is a popular method used to generate samples from arbitrary distributions, which may be specified indirectly. In this article, we give an introduction to this method along with some examples.

  14. [Monte Vista National Wildlife Refuge livestock grazing lawsuit : Information packet

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Packet of information from the Colorado Cattlemen's Association concerning the 1992 lawsuit filed against the Monte Vista National Wildlife Refuge. The suit was...

  15. Suppression of the initial transient in Monte Carlo criticality simulations

    International Nuclear Information System (INIS)

    Criticality Monte Carlo calculations aim at estimating the effective multiplication factor (k-effective) for a fissile system through iterations simulating neutrons propagation (making a Markov chain). Arbitrary initialization of the neutron population can deeply bias the k-effective estimation, defined as the mean of the k-effective computed at each iteration. A simplified model of this cycle k-effective sequence is built, based on characteristics of industrial criticality Monte Carlo calculations. Statistical tests, inspired by Brownian bridge properties, are designed to discriminate stationarity of the cycle k-effective sequence. The initial detected transient is, then, suppressed in order to improve the estimation of the system k-effective. The different versions of this methodology are detailed and compared, firstly on a plan of numerical tests fitted on criticality Monte Carlo calculations, and, secondly on real criticality calculations. Eventually, the best methodologies observed in these tests are selected and allow to improve industrial Monte Carlo criticality calculations. (author)

  16. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1982 calendar year. The report begins with a...

  17. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1981 calendar year. The report begins with a...

  18. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1983 calendar year. The report begins with a...

  19. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1964

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1964 calendar year. The report begins by...

  20. Bayesian phylogeny analysis via stochastic approximation Monte Carlo

    KAUST Repository

    Cheon, Sooyoung

    2009-11-01

    Monte Carlo methods have received much attention in the recent literature of phylogeny analysis. However, the conventional Markov chain Monte Carlo algorithms, such as the Metropolis-Hastings algorithm, tend to get trapped in a local mode in simulating from the posterior distribution of phylogenetic trees, rendering the inference ineffective. In this paper, we apply an advanced Monte Carlo algorithm, the stochastic approximation Monte Carlo algorithm, to Bayesian phylogeny analysis. Our method is compared with two popular Bayesian phylogeny software, BAMBE and MrBayes, on simulated and real datasets. The numerical results indicate that our method outperforms BAMBE and MrBayes. Among the three methods, SAMC produces the consensus trees which have the highest similarity to the true trees, and the model parameter estimates which have the smallest mean square errors, but costs the least CPU time. © 2009 Elsevier Inc. All rights reserved.

  1. Monte Carlo computations of the hadronic mass spectrum

    International Nuclear Information System (INIS)

    This paper summarizes two talks presented at the Orbis Scientiae Meeting, 1982. Monte Carlo results on the mass gap (or glueball mass) and on the masses of the lightest quark-model hadrons are illustrated

  2. 1993 farming and grazing program plans for Monte Vista NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Plans for farming and grazing at Monte Vista National Wildlife Refuge for 1993. This program will use rotations of small grain, field peas, and legumes as a farming...

  3. Monte Carlo methods for the self-avoiding walk

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J [Department of Mathematics and Statistics, York University, Toronto, ON M3J 1P3 (Canada)], E-mail: rensburg@yorku.ca

    2009-08-14

    The numerical simulation of self-avoiding walks remains a significant component in the study of random objects in lattices. In this review, I give a comprehensive overview of the current state of Monte Carlo simulations of models of self-avoiding walks. The self-avoiding walk model is revisited, and the motivations for Monte Carlo simulations of this model are discussed. Efficient sampling of self-avoiding walks remains an elusive objective, but significant progress has been made over the last three decades. The model still poses challenging numerical questions however, and I review specific Monte Carlo methods for improved sampling including general Monte Carlo techniques such as Metropolis sampling, umbrella sampling and multiple Markov Chain sampling. In addition, specific static and dynamic algorithms for walks are presented, and I give an overview of recent innovations in this field, including algorithms such as flatPERM, flatGARM and flatGAS. (topical review)

  4. Monte Carlo methods for the self-avoiding walk

    International Nuclear Information System (INIS)

    The numerical simulation of self-avoiding walks remains a significant component in the study of random objects in lattices. In this review, I give a comprehensive overview of the current state of Monte Carlo simulations of models of self-avoiding walks. The self-avoiding walk model is revisited, and the motivations for Monte Carlo simulations of this model are discussed. Efficient sampling of self-avoiding walks remains an elusive objective, but significant progress has been made over the last three decades. The model still poses challenging numerical questions however, and I review specific Monte Carlo methods for improved sampling including general Monte Carlo techniques such as Metropolis sampling, umbrella sampling and multiple Markov Chain sampling. In addition, specific static and dynamic algorithms for walks are presented, and I give an overview of recent innovations in this field, including algorithms such as flatPERM, flatGARM and flatGAS. (topical review)

  5. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1976

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1976 calendar year. The report begins with an introduction...

  6. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1993 calendar year. The report begins with a...

  7. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1977

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1977 calendar year. The report begins with an introduction...

  8. An Introduction to Multilevel Monte Carlo for Option Valuation

    CERN Document Server

    Higham, Desmond J

    2015-01-01

    Monte Carlo is a simple and flexible tool that is widely used in computational finance. In this context, it is common for the quantity of interest to be the expected value of a random variable defined via a stochastic differential equation. In 2008, Giles proposed a remarkable improvement to the approach of discretizing with a numerical method and applying standard Monte Carlo. His multilevel Monte Carlo method offers an order of speed up given by the inverse of epsilon, where epsilon is the required accuracy. So computations can run 100 times more quickly when two digits of accuracy are required. The multilevel philosophy has since been adopted by a range of researchers and a wealth of practically significant results has arisen, most of which have yet to make their way into the expository literature. In this work, we give a brief, accessible, introduction to multilevel Monte Carlo and summarize recent results applicable to the task of option evaluation.

  9. Using Supervised Learning to Improve Monte Carlo Integral Estimation

    CERN Document Server

    Tracey, Brendan; Alonso, Juan J

    2011-01-01

    Monte Carlo (MC) techniques are often used to estimate integrals of a multivariate function using randomly generated samples of the function. In light of the increasing interest in uncertainty quantification and robust design applications in aerospace engineering, the calculation of expected values of such functions (e.g. performance measures) becomes important. However, MC techniques often suffer from high variance and slow convergence as the number of samples increases. In this paper we present Stacked Monte Carlo (StackMC), a new method for post-processing an existing set of MC samples to improve the associated integral estimate. StackMC is based on the supervised learning techniques of fitting functions and cross validation. It should reduce the variance of any type of Monte Carlo integral estimate (simple sampling, importance sampling, quasi-Monte Carlo, MCMC, etc.) without adding bias. We report on an extensive set of experiments confirming that the StackMC estimate of an integral is more accurate than ...

  10. [1994 duck production on the Monte Vista National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memorandum is a summary of 1994 duck production on the Monte Vista National Wildlife refuge. Nest density, nest success, species composition, nesting cover,...

  11. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1990 calendar year. The report begins with a...

  12. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1986 calendar year. The report begins with a...

  13. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1992 calendar year. The report begins with a...

  14. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with a...

  15. Monte Carlo techniques for analyzing deep penetration problems

    International Nuclear Information System (INIS)

    A review of current methods and difficulties in Monte Carlo deep-penetration calculations is presented. Statistical uncertainty is discussed, and recent adjoint optimization of splitting, Russian roulette, and exponential transformation biasing is reviewed. Other aspects of the random walk and estimation processes are covered, including the relatively new DXANG angular biasing technique. Specific items summarized are albedo scattering, Monte Carlo coupling techniques with discrete ordinates and other methods, adjoint solutions, and multi-group Monte Carlo. The topic of code-generated biasing parameters is presented, including the creation of adjoint importance functions from forward calculations. Finally, current and future work in the area of computer learning and artificial intelligence is discussed in connection with Monte Carlo applications. 29 refs

  16. Monte Carlo techniques for analyzing deep penetration problems

    International Nuclear Information System (INIS)

    A review of current methods and difficulties in Monte Carlo deep-penetration calculations is presented. Statistical uncertainty is discussed, and recent adjoint optimization of splitting, Russian roulette, and exponential transformation biasing is reviewed. Other aspects of the random walk and estimation processes are covered, including the relatively new DXANG angular biasing technique. Specific items summarized are albedo scattering, Monte Carlo coupling techniques with discrete ordinates and other methods, adjoint solutions, and multi-group Monte Carlo. The topic of code-generated biasing parameters is presented, including the creation of adjoint importance functions from forward calculations. Finally, current and future work in the area of computer learning and artificial intelligence is discussed in connection with Monte Carlo applications

  17. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Monte Vista National Wildlife Refuge outlines Refuge accomplishments during the 1965 calendar year. The report begins by...

  18. Monte Carlo variance reduction approaches for non-Boltzmann tallies

    International Nuclear Information System (INIS)

    Quantities that depend on the collective effects of groups of particles cannot be obtained from the standard Boltzmann transport equation. Monte Carlo estimates of these quantities are called non-Boltzmann tallies and have become increasingly important recently. Standard Monte Carlo variance reduction techniques were designed for tallies based on individual particles rather than groups of particles. Experience with non-Boltzmann tallies and analog Monte Carlo has demonstrated the severe limitations of analog Monte Carlo for many non-Boltzmann tallies. In fact, many calculations absolutely require variance reduction methods to achieve practical computation times. Three different approaches to variance reduction for non-Boltzmann tallies are described and shown to be unbiased. The advantages and disadvantages of each of the approaches are discussed

  19. Efecto hepatoprotector y antioxidante del extracto y los principios activos de Geranium shiedeanum

    OpenAIRE

    Vargas Mendoza, Nancy

    2013-01-01

    El uso de plantas medicinales se ha reportado en todo el mundo para el tratamiento de múltiples enfermedades desde épocas ancestrales, sin embargo la mayoría de ellas no cuentan con estudios científicos suficientes que sustenten su uso. El Geranium shiedenum, es una especie que crece en los bosques de Mineral del Monte y Mineral del chico en el Estado de Hidalgo, México, de este, se ha descrito un uso en la medicina tradicional como antiséptico y antipirético, sin embargo tampo...

  20. La actividad agraria en el Aguilar del s. XVIII. Los cultivos y aprovechamientos

    OpenAIRE

    Naranjo-Ramírez, J.

    1998-01-01

    Utilizando la información (vaciada en su totalidad) contenida en los Libros de Haciendas del Catastro de Ensenada, se presenta una radiografía de la actividad agraria en el Aguilar del s. XVIII. Son objeto de estudio y análisis desde la superficie inculta, las distintas modalidades de sembradura de secano, el olivar, los espacios ocupados por vegetación natural y monte, el viñedo y las tierras regadas. Se dedica igualmente un espacio a la consideración de la actividad ganadera.

  1. Monte Carlo simulation techniques : The development of a general framework

    OpenAIRE

    Nilsson, Emma

    2009-01-01

    Algorithmica Research AB develops software application for the financial markets. One of their products is Quantlab that is a tool for quantitative analyses. An effective method to value several financial instruments is Monte Carlo simulation. Since it is a common method Algorithmica is interesting in investigating if it is possible to create a Monte Carlo framework. A requirement from Algorithmica is that the framework is general and this is the main problem to solve. It is difficult to gene...

  2. Quantum Monte Carlo with Coupled-Cluster wave functions

    OpenAIRE

    Roggero, Alessandro; Mukherjee, Abhishek; Pederiva, Francesco

    2013-01-01

    We introduce a novel many body method which combines two powerful many body techniques, viz., quantum Monte Carlo and coupled cluster theory. Coupled cluster wave functions are introduced as importance functions in a Monte Carlo method designed for the configuration interaction framework to provide rigorous upper bounds to the ground state energy. We benchmark our method on the homogeneous electron gas in momentum space. The importance function used is the coupled cluster doubles wave functio...

  3. Measuring the reliability of MCMC inference with bidirectional Monte Carlo

    OpenAIRE

    Grosse, Roger B.; Ancha, Siddharth; Roy, Daniel M.

    2016-01-01

    Markov chain Monte Carlo (MCMC) is one of the main workhorses of probabilistic inference, but it is notoriously hard to measure the quality of approximate posterior samples. This challenge is particularly salient in black box inference methods, which can hide details and obscure inference failures. In this work, we extend the recently introduced bidirectional Monte Carlo technique to evaluate MCMC-based posterior inference algorithms. By running annealed importance sampling (AIS) chains both ...

  4. Monte Carlo method for solving a parabolic problem

    Directory of Open Access Journals (Sweden)

    Tian Yi

    2016-01-01

    Full Text Available In this paper, we present a numerical method based on random sampling for a parabolic problem. This method combines use of the Crank-Nicolson method and Monte Carlo method. In the numerical algorithm, we first discretize governing equations by Crank-Nicolson method, and obtain a large sparse system of linear algebraic equations, then use Monte Carlo method to solve the linear algebraic equations. To illustrate the usefulness of this technique, we apply it to some test problems.

  5. Public Infrastructure for Monte Carlo Simulation: publicMC@BATAN

    CERN Document Server

    Waskita, A A; Akbar, Z; Handoko, L T; 10.1063/1.3462759

    2010-01-01

    The first cluster-based public computing for Monte Carlo simulation in Indonesia is introduced. The system has been developed to enable public to perform Monte Carlo simulation on a parallel computer through an integrated and user friendly dynamic web interface. The beta version, so called publicMC@BATAN, has been released and implemented for internal users at the National Nuclear Energy Agency (BATAN). In this paper the concept and architecture of publicMC@BATAN are presented.

  6. Computing Functionals of Multidimensional Diffusions via Monte Carlo Methods

    OpenAIRE

    Jan Baldeaux; Eckhard Platen

    2012-01-01

    We discuss suitable classes of diffusion processes, for which functionals relevant to finance can be computed via Monte Carlo methods. In particular, we construct exact simulation schemes for processes from this class. However, should the finance problem under consideration require e.g. continuous monitoring of the processes, the simulation algorithm can easily be embedded in a multilevel Monte Carlo scheme. We choose to introduce the finance problems under the benchmark approach, and find th...

  7. On the inner workings of Monte Carlo codes

    OpenAIRE

    Dubbeldam, D.; Torres Knoop, A.; Walton, K.S.

    2013-01-01

    We review state-of-the-art Monte Carlo (MC) techniques for computing fluid coexistence properties (Gibbs simulations) and adsorption simulations in nanoporous materials such as zeolites and metal-organic frameworks. Conventional MC is discussed and compared to advanced techniques such as reactive MC, configurational-bias Monte Carlo and continuous fractional MC. The latter technique overcomes the problem of low insertion probabilities in open systems. Other modern methods are (hyper-)parallel...

  8. Monte Carlo maximum likelihood estimation for discretely observed diffusion processes

    OpenAIRE

    Beskos, Alexandros; Papaspiliopoulos, Omiros; Roberts, Gareth

    2009-01-01

    This paper introduces a Monte Carlo method for maximum likelihood inference in the context of discretely observed diffusion processes. The method gives unbiased and a.s.\\@ continuous estimators of the likelihood function for a family of diffusion models and its performance in numerical examples is computationally efficient. It uses a recently developed technique for the exact simulation of diffusions, and involves no discretization error. We show that, under regularity conditions, the Monte C...

  9. Data-driven Sequential Monte Carlo in Probabilistic Programming

    OpenAIRE

    Perov, Yura N.; Le, Tuan Anh; Wood, Frank

    2015-01-01

    Most of Markov Chain Monte Carlo (MCMC) and sequential Monte Carlo (SMC) algorithms in existing probabilistic programming systems suboptimally use only model priors as proposal distributions. In this work, we describe an approach for training a discriminative model, namely a neural network, in order to approximate the optimal proposal by using posterior estimates from previous runs of inference. We show an example that incorporates a data-driven proposal for use in a non-parametric model in t...

  10. HISTORY AND TERRITORY HEURISTICS FOR MONTE CARLO GO

    OpenAIRE

    BRUNO BOUZY

    2006-01-01

    Recently, the Monte Carlo approach has been applied to computer go with promising success. INDIGO uses such an approach which can be enhanced with specific heuristics. This paper assesses two heuristics within the 19 × 19 Monte Carlo go framework of INDIGO: the territory heuristic and the history heuristic, both in their internal and external versions. The external territory heuristic is more effective, leading to a 40-point improvement on 19 × 19 boards. The external history heuristic brings...

  11. Benchmarking Monte Carlo codes for criticality safety using subcritical measurements

    International Nuclear Information System (INIS)

    Monte Carlo codes that are used for criticality safety evaluations are typically validated using critical experiments in which the neutron multiplication factor is unity. However, the conditions for most fissile material operations do not coincide to those of the critical experiments. This paper demonstrates that Monte Carlo methods and nuclear data can be validated using subcritical measurements whose conditions may coincide more closely to actual configurations of fissile material. (orig.)

  12. Confidence and efficiency scaling in Variational Quantum Monte Carlo calculations

    CERN Document Server

    Delyon, François; Holzmann, Markus

    2016-01-01

    Based on the central limit theorem, we discuss the problem of evaluation of the statistical error of Monte Carlo calculations using a time discretized diffusion process. We present a robust and practical method to determine the effective variance of general observables and show how to verify the equilibrium hypothesis by the Kolmogorov-Smirnov test. We then derive scaling laws of the efficiency illustrated by Variational Monte Carlo calculations on the two dimensional electron gas.

  13. Excited states and transition metal compounds with quantum Monte Carlo

    OpenAIRE

    Bande, Annika

    2007-01-01

    To the most challenging electron structure calculations belong weak interactions, excited state calculations, transition metals and properties. In this work the performance of variational (VMC) and fixed-node diffusion quantum Monte Carlo (FN-DMC) is tested for challenging electron structure problems using the quantum Monte Carlo amolqc code by Lüchow et al. The transition metal compounds under consideration are vanadium oxides. Here excitation, ionization, oxygen atom and molecule abstractio...

  14. Computing Greeks with Multilevel Monte Carlo Methods using Importance Sampling

    OpenAIRE

    Euget, Thomas

    2012-01-01

    This paper presents a new efficient way to reduce the variance of an estimator of popular payoffs and greeks encounter in financial mathematics. The idea is to apply Importance Sampling with the Multilevel Monte Carlo recently introduced by M.B. Giles. So far, Importance Sampling was proved successful in combination with standard Monte Carlo method. We will show efficiency of our approach on the estimation of financial derivatives prices and then on the estimation of Greeks (i.e. sensitivitie...

  15. Herwig: The Evolution of a Monte Carlo Simulation

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Monte Carlo event generation has seen significant developments in the last 10 years starting with preparation for the LHC and then during the first LHC run. I will discuss the basic ideas behind Monte Carlo event generators and then go on to discuss these developments, focussing on the developments in Herwig(++) event generator. I will conclude by presenting the current status of event generation together with some results of the forthcoming new version of Herwig, Herwig 7.

  16. Adaptive Hamiltonian and Riemann Manifold Monte Carlo Samplers

    OpenAIRE

    Wang, Ziyu; MOHAMED, SHAKIR; De Freitas, Nando

    2013-01-01

    In this paper we address the widely-experienced difficulty in tuning Hamiltonian-based Monte Carlo samplers. We develop an algorithm that allows for the adaptation of Hamiltonian and Riemann manifold Hamiltonian Monte Carlo samplers using Bayesian optimization that allows for infinite adaptation of the parameters of these samplers. We show that the resulting sampling algorithms are ergodic, and that the use of our adaptive algorithms makes it easy to obtain more efficient samplers, in some ca...

  17. Monte Carlo methods and applications in nuclear physics

    International Nuclear Information System (INIS)

    Monte Carlo methods for studying few- and many-body quantum systems are introduced, with special emphasis given to their applications in nuclear physics. Variational and Green's function Monte Carlo methods are presented in some detail. The status of calculations of light nuclei is reviewed, including discussions of the three-nucleon-interaction, charge and magnetic form factors, the coulomb sum rule, and studies of low-energy radiative transitions. 58 refs., 12 figs

  18. A New Method for Parallel Monte Carlo Tree Search

    OpenAIRE

    Mirsoleimani, S. Ali; Plaat, Aske; Herik, Jaap van den; Vermaseren, Jos

    2016-01-01

    In recent years there has been much interest in the Monte Carlo tree search algorithm, a new, adaptive, randomized optimization algorithm. In fields as diverse as Artificial Intelligence, Operations Research, and High Energy Physics, research has established that Monte Carlo tree search can find good solutions without domain dependent heuristics. However, practice shows that reaching high performance on large parallel machines is not so successful as expected. This paper proposes a new method...

  19. Design of shielding of LILW containers by Monte Carlo codes

    International Nuclear Information System (INIS)

    Accurate prediction of dose rates from containers with radioactive waste is becoming more important regarding more rigorous regulative in this area. The usual approach to the problem consists in combining numerical and measuring methods. In this paper a Monte Carlo calculations were used for calculating doses from a standard 200 liter drum which contains the intermediate level radioactive waste. Two different Monte Carlo codes were applied and compared, for the same combination of parameters. (author)

  20. Reliability of QCD Monte-Carlo event generators

    International Nuclear Information System (INIS)

    The author examines the extent to which Monte-Carlo simulations reproduce the predictions of perturbative QCD especially in the case of very high energy hadron-hadron scattering. Although the Monte-Carlos have great success in reproducing most of the qualitative features of the theory, they do not fully incorporate even the leading logarithmic approximation. Work is needed to give a systematic method for inclusion of both leading and non-leading effects

  1. Proton therapy Monte Carlo SRNA-VOX code

    OpenAIRE

    Ilić Radovan D.

    2012-01-01

    The most powerful feature of the Monte Carlo method is the possibility of simulating all individual particle interactions in three dimensions and performing numerical experiments with a preset error. These facts were the motivation behind the development of a general-purpose Monte Carlo SRNA program for proton transport simulation in technical systems described by standard geometrical forms (plane, sphere, cone, cylinder, cube). Some of the possible applications of the SRNA program are:...

  2. Identification of Logical Errors through Monte-Carlo Simulation

    CERN Document Server

    Emmett, Hilary L

    2010-01-01

    The primary focus of Monte Carlo simulation is to identify and quantify risk related to uncertainty and variability in spreadsheet model inputs. The stress of Monte Carlo simulation often reveals logical errors in the underlying spreadsheet model that might be overlooked during day-to-day use or traditional "what-if" testing. This secondary benefit of simulation requires a trained eye to recognize warning signs of poor model construction.

  3. A Particle Population Control Method for Dynamic Monte Carlo

    Science.gov (United States)

    Sweezy, Jeremy; Nolen, Steve; Adams, Terry; Zukaitis, Anthony

    2014-06-01

    A general particle population control method has been derived from splitting and Russian Roulette for dynamic Monte Carlo particle transport. A well-known particle population control method, known as the particle population comb, has been shown to be a special case of this general method. This general method has been incorporated in Los Alamos National Laboratory's Monte Carlo Application Toolkit (MCATK) and examples of it's use are shown for both super-critical and sub-critical systems.

  4. Ruptura del projecte parental i disposici?? dels preembrions

    OpenAIRE

    Farn??s Amor??s, Esther

    2010-01-01

    La tesi doctoral "Ruptura del projecte parental i disposici?? dels preembrions" analitza els efectes del consentiment a les t??cniques de reproducci?? assistida prestat en el marc d'un projecte parental. La tesi ofereix una resposta als conflictes que enfronten exesposos o exconvivents en relaci?? al dest?? dels preembrions sobrants d'un cicle de fecundaci?? "in vitro" iniciat durant la relaci??. Aquests conflictes constitueixen un grup de casos al voltant del qual no hi ha solucions legislat...

  5. Lattice Monte Carlo simulations of polymer melts

    Science.gov (United States)

    Hsu, Hsiao-Ping

    2014-12-01

    We use Monte Carlo simulations to study polymer melts consisting of fully flexible and moderately stiff chains in the bond fluctuation model at a volume fraction 0.5. In order to reduce the local density fluctuations, we test a pre-packing process for the preparation of the initial configurations of the polymer melts, before the excluded volume interaction is switched on completely. This process leads to a significantly faster decrease of the number of overlapping monomers on the lattice. This is useful for simulating very large systems, where the statistical properties of the model with a marginally incomplete elimination of excluded volume violations are the same as those of the model with strictly excluded volume. We find that the internal mean square end-to-end distance for moderately stiff chains in a melt can be very well described by a freely rotating chain model with a precise estimate of the bond-bond orientational correlation between two successive bond vectors in equilibrium. The plot of the probability distributions of the reduced end-to-end distance of chains of different stiffness also shows that the data collapse is excellent and described very well by the Gaussian distribution for ideal chains. However, while our results confirm the systematic deviations between Gaussian statistics for the chain structure factor Sc(q) [minimum in the Kratky-plot] found by Wittmer et al. [EPL 77, 56003 (2007)] for fully flexible chains in a melt, we show that for the available chain length these deviations are no longer visible, when the chain stiffness is included. The mean square bond length and the compressibility estimated from collective structure factors depend slightly on the stiffness of the chains.

  6. Monte Carlo study of microdosimetric diamond detectors

    International Nuclear Information System (INIS)

    Ion-beam therapy provides a high dose conformity and increased radiobiological effectiveness with respect to conventional radiation-therapy. Strict constraints on the maximum uncertainty on the biological weighted dose and consequently on the biological weighting factor require the determination of the radiation quality, defined as the types and energy spectra of the radiation at a specific point. However the experimental determination of radiation quality, in particular for an internal target, is not simple and the features of ion interactions and treatment delivery require dedicated and optimized detectors. Recently chemical vapor deposition (CVD) diamond detectors have been suggested as ion-beam therapy microdosimeters. Diamond detectors can be manufactured with small cross sections and thin shapes, ideal to cope with the high fluence rate. However the sensitive volume of solid state detectors significantly deviates from conventional microdosimeters, with a diameter that can be up to 1000 times the height. This difference requires a redefinition of the concept of sensitive thickness and a deep study of the secondary to primary radiation, of the wall effects and of the impact of the orientation of the detector with respect to the radiation field. The present work intends to study through Monte Carlo simulations the impact of the detector geometry on the determination of radiation quality quantities, in particular on the relative contribution of primary and secondary radiation. The dependence of microdosimetric quantities such as the unrestricted linear energy L and the lineal energy y are investigated for different detector cross sections, by varying the particle type (carbon ions and protons) and its energy. (paper)

  7. Investigations on Monte Carlo based coupled core calculations

    International Nuclear Information System (INIS)

    The present trend in advanced and next generation nuclear reactor core designs is towards increased material heterogeneity and geometry complexity. The continuous energy Monte Carlo method has the capability of modeling such core environments with high accuracy. This paper presents results from feasibility studies being performed at the Pennsylvania State University (PSU) on both accelerating Monte Carlo criticality calculations by using hybrid nodal diffusion Monte Carlo schemes and thermal-hydraulic feedback modeling in Monte Carlo core calculations. The computation process is greatly accelerated by calculating the three-dimensional (3D) distributions of fission source and thermal-hydraulics parameters with the coupled NEM/COBRA-TF code and then using coupled MCNP5/COBRA-TF code to fine tune the results to obtain an increased accuracy. The PSU NEM code employs cross-sections generated by MCNP5 for pin-cell based nodal compositions. The implementation of different code modifications facilitating coupled calculations are presented first. Then the coupled hybrid Monte Carlo based code system is applied to a 3D 2*2 pin array extracted from a Boiling Water Reactor (BWR) assembly with reflective radial boundary conditions. The obtained results are discussed and it is showed that performing Monte-Carlo based coupled core steady state calculations are feasible. (authors)

  8. Sociedad abierta del conocimiento

    OpenAIRE

    Echeverría, Javier

    2007-01-01

    En las sociedades del conocimiento hay dos modelos opuestos de gestión: conocimiento libre y conocimiento propietario. Ambos generan desarrollos tecnológicos e innovaciones, pero el primero favorece la emergencia de sociedades abiertas del conocimiento. Aplicando las propuestas de von Hippel, este artículo muestra que la contraposición entre ambos modelos no sólo afecta a la producción y distribución del conocimiento, también a su almacenamiento y uso. Los usuarios son la principal fuente de ...

  9. Secretos del test extraterrestre

    OpenAIRE

    Hybris, Profesor

    2016-01-01

    Por el parasicólogo y astrólogo Profesor Hybris La prensa mundial ha revelado recientemente los detalles del extraño caso de Asdrúbal Carrasquilla, el camionero chileno que desapareciera misteriosamente en su país, ante el asombro de varios automovilistas que lo vieron desvanecerse en el aire, junto con su camión, en la muy transitada vía entre Las Fraguas y San Venancio, en la provincia chilena de Valverde. El hecho ocurrió a las 16.55 del 15 de diciembre de 1981. A las 16.58 del mismo día, ...

  10. La muerte del mito

    OpenAIRE

    Sánchez-Biosca, Vicente

    1990-01-01

    Habría de ser de nuevo John Ford quien sentenciará la defunción del western en cuanto mito, su imposibilidad de construirse en el vacío de la historia. Y habría de ser en uno de los más lúcidos films de la historia del cine: The Man who shot Liberty Valance (El hombre que mató a Liberty Valance, 1962). Todo en este film posee un reverso: un viaje en ferrocarril abre paso al pueblecito de Shinbone. Pero, en el interior del relato, otro emprendido por el antes pionero y ho...

  11. La escritura del mundo

    OpenAIRE

    Martínez García-Posada, Ángel

    2010-01-01

    El mapa de un arquitecto es un paisaje alternativo, una representación intencionada del medio que se aleja del documento impuesto y apunta la posibilidad de transformarlo, así comienza el proyecto; el sentido inverso, llevar al territorio los signos del plano, remite a la esencia de la arquitectura y su capacidad de alterar el mundo. Nuestras representaciones describen una realidad y a su vez son otra distinta, entre ambos campos se produce un flujo que los liga y los condiciona. La cartograf...

  12. LA ESCRITURA DEL MUNDO

    OpenAIRE

    Ángel Martínez García-Posada

    2010-01-01

    RESUMEN El mapa de un arquitecto es un paisaje alternativo, una representación intencionada del medio que se aleja del documento impuesto y apunta la posibilidad de transformarlo, así comienza el proyecto; el sentido inverso, llevar al territorio los signos del plano, remite a la esencia de la arquitectura y su capacidad de alterar el mundo. Nuestras representaciones describen una realidad y a su vez son otra distinta, entre ambos campos se produce un flujo que los liga y los condiciona. La c...

  13. ¿Morirán mis hijos o las frutas del monte se secarán si no canto y uso mi amuleto cada noche? Mujeres tobas (qom) y Misioneros Anglicanos en el Chaco Centro occidental (Argentina) Will my children die or the fruit from the bush dry up if I don't sing or use my amulet every night? Toba women and anglican missionaries in mid-western Chaco (Argentina) in the 1930's and 1940's

    OpenAIRE

    Mariana Daniela Gómez

    2011-01-01

    En este artículo abordo cómo fueron observadas y representadas las mujeres tobas del oeste (qom) por los misioneros anglicanos de la South American Missionary Society (SAMS) durante su labor en la Misión El Toba, en el Chaco centro occidental, en la provincia de Formosa (Argentina). También analizo algunas actividades promovidas por la misión durante las décadas de 1930 y de 1940 que buscaban generar cambios culturales en los roles, en las identidades y en los espacios de las mujeres y los ho...

  14. Actividad del virus del oeste del Nilo y otros flavivirus en cinco departamentos del Caribe colombiano

    Directory of Open Access Journals (Sweden)

    Jaime Álvarez

    2010-04-01

    Full Text Available El virus del oeste del Nilo (VON y el virus de la encefalitis de San Luis (VESL pertenece a la familia Flaviviridae, género Flavivirus y hacen parte del serocomplejo de la encefalitis japonesa (1. Estos virus se encuentran distribuidos en Estados Unidos, centro América y suramerica (2. Son mantenidos en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Humanos, équidos y otros vertebrados se infectan por la picadura de mosquitos del genero Culex principalmente (1,2. En humanos se han identificado y descrito nuevos modos de transmisión de VON incluyendo infección a través de productos sanguíneos contaminados (3, transplante de órganos (4, transmisión a través de la leche materna (5, transmisión intrauterina (6, y exposición ocupacional (7.

  15. El vicio del amor

    OpenAIRE

    Zaietz, Patricia

    2007-01-01

    “Si alguien entre nosotros no conoce el arte de amar, que lea este poema y, adoctrinado por su lectura, ame”. Con generoso didactismo, comienza Ovidio, poeta romano (43 a.C.-17 d.C), su libro Arte de Amar, texto clásico bien conocido por el clérigo Guillaume de Lorris al momento de escribir la primera parte del Roman de la Rose. (Párrafo extraído del texto a modo de resumen)

  16. Il problema del litio.

    Science.gov (United States)

    D'Antona, F.

    1995-03-01

    Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.

  17. La política de los Montes Protectores y su relación con los riesgos naturales en la provincia de Granada

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Mesa

    2015-01-01

    Full Text Available Ante el problema secular de deforestación que se padecía en la Península Ibérica y el relativofracaso de las políticas forestales que intentaron la restauración del arbolado, la administraciónmoderna intentó resolverlo sobre todo por sus repercusiones en los desastres naturales, medianteuna nueva fórmula. Esta consistió en la implantación de la figura de Monte Protector, mediantela Ley 24 de Junio de 1908 de Conservación de Montes y Repoblación Forestal. Esta figura finalmentesólo se implantaría en cuatro provincias, entre las que se encontraba la provincia de Granada.Su importancia radica en que marcará un hito en la consideración de los espacios públicosy privados como objeto de la ausencia de arbolado y lo que posteriormente significaría las políticasde repoblación de montes. En este trabajo se analizan las políticas de Montes Protectores enla provincia de Granada y su incidencia territorial, así como su relación con los riesgos naturales.

  18. el Valle del Cauca

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Ortiz

    2007-01-01

    Full Text Available Este artículo se enfoca en la identi- ficación de aquellos factores estructurales que explican la pérdida de dinamismo económico de largo plazo en Colombia y, en particular, en el Valle del Cauca. Se examina la competitividad del Valle en relación con Colombia y con el resto del mundo. Se cuestiona la insistencia en una estrategia exportadora como dinamizadora del desarrollo económico. Se identifica que una gran parte de la población está excluida de los beneficios del desarrollo económico. Para construir un modelo de desarrollo que incluya a esta población se recomienda recuperar la senda de la industrialización, invertir en el capital humano (educación de alta calidad, salud, salubridad y nutrición, e invertir en infraestructura. La participación del Estado en estas inversiones sociales es necesaria para disminuir la desigualdad y aumentar el crecimiento económico.

  19. pensiones del ISSSTE

    Directory of Open Access Journals (Sweden)

    Alejandro Villagómez Amezcua

    2005-01-01

    Full Text Available El análisis en este estudio ofrece una valoración sobre el problema de viabilidad financiera del programa de pensiones del ISSSTE y la urgente necesidad de modificarlo, no sólo por el costo fiscal que implica, sino porque este costo será creciente. Actualmente las aportaciones no son suficientes para cubrir las pensiones vigentes por lo que se recibe una transferencia de recursos del ramo XIX que en 2001 superó 0.20% del PIB. Utilizando supuestos moderados para el comportamiento futuro de la economía y de este programa, estimamos que de no reformarse el costo fiscal oscilará entre 22 y 39% del PIB. Si se realiza una reforma menor que sólo afecte algunos de los parámetros del esquema actual como contribuciones y edad de retiro, este costo puede reducirse en casi 50%. Sin embargo, no deben descartarse alternativas mixtas que permitan mitigar este costo aún más al tiempo que el programa cumpla con su objetivo final que es el de garantizar pensiones a los trabajadores.

  20. Espectroscopia del Cometa Halley

    Science.gov (United States)

    Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.