WorldWideScience

Sample records for arbustiva del monte

  1. Uso de las leguminosas arbustivas en los sistemas de producción animal en el trópico

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    Jaime Olivares Pérez; Saúl Rojas Hernández;

    2005-05-01

    Full Text Available Este trabajo es una revisión bibliográfica del como podrían utilizarse las leguminosas arbustivas como un recurso natural en los sistemas de producción animal, con reportes del impacto en el recurso suelo, animal y de manera general en el medio ambiente, donde se han introducido estas especies vegetales.

  2. Las obras de acondicionamiento del Salto del Mont-Cenis

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    Vié, Georges

    1969-06-01

    Full Text Available The new dam at Mont Cenis has increased to water volume in the reservoir from 32 to 320 million m3 and provides a potential energy of 650.000 million Mp x m. This article describes the work involved in the construction of this project. Among other features, the water has been led to the reservoir along a network of varying cross-section, and of 28 km total length. The pressure conduit has been designed for a flow rate of 51 m3/s, its diameter varying between 4 and 5 m. The new power stations at Villarodin are fed by a pipe 3.6 km in length and 3 m in diameter. This conduit runs along a trench and is isolated from the ground, because of the gypsum and anhydrites contained in the soil. Its weight is 10.000 Mp, which is a European record. The power station comprises to vertical Pelton turbines of 195 MVA each, and a yearly output of 485 kWh.La capacidad de la nueva presa del Mont-Cenis ha aumentado con estas obras desde 32 hasta 320 millones de m3, permitiendo el abastecimiento de una energía potencial de 650.000 millones de Mp x m. En el artículo se describen las obras y operaciones necesarias para ello; entre otras, que las aguas captadas han sido llevadas al embalse por una red de galerías de sección variable de 28 km de longitud; y que la conducción forzada, de 18 km de longitud, fue dimensionada para un caudal de 51 m3/s, con un diámetro comprendido entre 4 y 5 metros. Las nuevas centrales de Villarodin están alimentadas por una desviación de 3,6 km de longitud y 3 m de diámetro. Este conducto, colocado en un foso inclinado para aislarlo del ter reno, en esa zona de yesos y anhidritas, principalmente, tiene un peso de 10.000 Mp, lo que constituye un récord europeo. La Central comprende dos grupos verticales de turbinas Pelton de 195 MVA cada uno, con una productividad de 485 millones de kWh.

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

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    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...

  4. en el desierto del Monte, Argentina

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    C.M. Campos

    2015-01-01

    Full Text Available Los bosques de Prosopis flexuosa proporcionan múltiples bienes y servicios. Actualmente, sufren una fuerte retracción debido a un uso histórico extractivistay se hace necesario promover la conservación y el manejo sostenible de los bosques como sistema. El objetivo del trabajo es sintetizarel conocimiento disponible acerca de las interacciones mutualistas y antagonistas entre mamíferos, frutos y semillas de P. flexuosa, comparandocon estudios realizados en otras especies de Prosopis de Argentina. Se considera a dos grupos de consumidores oportunistas de frutos: almacenadoresen cúmulos dispersos y frugívoros. Los roedores pequeños (como Eligmodontia typus y Microcavia australis son dispersores de semillasporque depredan pocas semillas y almacenan el resto en cúmulos sobre la superficie del suelo. Mamíferos frugívoros oportunistas silvestres (Dolichotispatagonum, Lepus europaeus, Lycalopex griseus, Lama guanicoe, etc. y domésticos (burro, caballo, vaca son dispersores endozoocóricosy proporcionan beneficios como el traslado de grandes cantidades de semillas, la eliminación de estructuras que mantienen la dormición y la desinfecciónde semillas atacadas por insectos. Sin embargo, la endozoocoria tiene costos sobre la viabilidad y la capacidad germinativa de las semillas.Ante un panorama de continuos cambios en el uso de la tierra y de cambio climático global, el conocimiento acerca del espectro diverso de animalesque proporcionan el beneficio de dispersión de semillas aporta bases científicas para considerar que la biodiversidad asociada a los bosques debeincluirse en la gestión y conservación de los mismos.

  5. 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

  6. 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.

  7. 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...

  8. 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)

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

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    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...

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

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    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...

  12. El peso del conejo de monte criado en jaula

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

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    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...

  14. Estudio de la micocenosis de macromicetos del Parque Natural del Monte Aloia (Pontevedra, España

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    Lorenzo, Purificación

    2009-12-01

    Full Text Available We study the composition of macrofungal communities in the Natural Reserve of Monte Aloia (Tui, Pontevedra and its relation with different biotopes in the selected area. The distribution of species in the selected mycotopes was analyzed using the Bray & Curtis similarity Index. (Cluster analysis. The mean values of similarity and dissimilarity among biotopes was determined using Multidimensional non-metric Scaling (MDS and the analysis of Porcentual Similarity (SIMPER. All biotopes were analyzed using the statistical program PRIMER (Plymouth Routines In Multivariate Ecological Research, version 6 for Windows.

    En este trabajo se estudia la composición de la comunidad macrofúngica del Parque Natural del Monte Aloia (Tui, Pontevedra, así como su relación con los distintos biotopos del área seleccionada. La distribución de las especies en los micotopos caracterizados se analizó empleando el índice de similitud de Bray & Curtis (análisis de conglomerado. La similitud y disimilitud promedio entre biotopos se ha determinado mediante los métodos de ordenación de Escalamiento Multidimensional no Métrico (MDS y de análisis de Similitud Porcentual (SIMPER. Todos fueron analizados utilizando el programa estadístico PRIMER (Plymouth Routines In Multivariate Ecological Research, versión 6 para Windows.

  15. 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...

  16. Herpetofauna del Parque Nacional de Monte Alén (Río Muni, Guinea Ecuatorial

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    Lasso, C. A.

    2002-12-01

    Full Text Available In the framework of a broad study of the vertebrate diversity at Monte Alen National Park (Río Muni, Equatorial Guinea, we identified 16 families, 47 genera, and 65 species of reptiles and seven families, 29 genera, and 56 species of amphibians. 21 species of reptiles and four species of amphibians represent new records for the Río Muni region. We present the preliminary inventory of the herpetofauna as well as some ecological comments. Monte Alén is considered one of the most diverse protected areas in central Africa from a herpetological standpoint.

    En el marco de un estudio general sobre de la diversidad de vertebrados del Parque Nacional de Monte Alén (Río Muni, Guinea Ecuatorial, se identificaron 16 familias, 47 géneros y 65 especies de reptiles, y 7 familias, 29 géneros y 56 especies de anfibios; 21 especies de reptiles y 4 de anfibios representan nuevos registros para la región de Río Muni. En el presente trabajo se expone el inventario preliminar de especies e información ecológica puntual sobre las mismas. Monte Alén puede ser considerada una de las áreas protegidas de mayor diversidad herpetológica de África central.

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

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    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...

  18. 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.

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

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    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...

  20. "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.

  1. 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...

  2. 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...

  3. 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...

  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

    2015-01-01

    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. Uso y transformación en espacio agrario del monte y del estrato arbóreo en la Ribeira Sacra durante los siglos XIV y XV.

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    López Sabatel, José Antonio

    2009-12-01

    Full Text Available This article wants to show the importance that the mountain played in a rural economy orientated as much to the utilization of its natural resources as to its transformation in agrarian space. As in case of the mountain, the exploitation of the wooded stratum, will allow an approximation to the agrarian landscape of the Ribeira Sacra during the XIVth and XVth centuries.

    Este artículo quiere mostrar la importancia que desempeñó el monte en una economía campesina orientada tanto al aprovechamiento de sus recursos naturales como a su transformación en espacio agrario. Al igual que en el caso del monte, la explotación del estrato arbóreo, permitirá un acercamiento al paisaje agrario de la Ribeira Sacra durante los siglos XIV y XV.

  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. Clethraceae endémicas del Perú

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    Blanca León

    2013-10-01

    Full Text Available La familia Clethraceae es reconocida en el Perú con un género, Clethra, y 11 especies (Brako & Zarucchi, 1993 arbóreas o arbustivas. En este trabajo reconocemos un endemismo, del cual no se conoce los requisitos de su hábitat, ni las condiciones de los ambientes que habita.

  8. 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

  9. 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...

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

    Directory of Open Access Journals (Sweden)

    Verónica Ovares Fallas

    2015-10-01

    Full Text Available 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 artículo, se muestra de manera resumida una investigación realizada con el objetivo de identificar aquellas características físicas y sociales del espacio público del Cantón de Montes de Oca que influyen en la percepción de inseguridad. Para ello se utilizó el Irvine Minnesota Inventory (Boarnet, Day, Alfonzo, Forsyth y Oakes, 2006 que fue adaptado al contexto del estudio y además la Escala de Inseguridad Percibida (Ovares y Quirós, 2013 desarrollada durante la investigación.

  11. 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)

  12. 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

  13. 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...

  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. 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...

  16. 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...

  17. 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

  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. 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

  20. 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.

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

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    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.

  2. Distribución espacial de los bosques nativos en el norte del Monte argentino, hacia mediados del siglo XIX

    Directory of Open Access Journals (Sweden)

    Facundo Rojas

    2014-12-01

    Full Text Available The objective of this investigation was to reconstruct the middle 19th century distribution of the native forest in the western valleys of the Monte Desert. The goal was to generate a baseline for understanding the status of algarrobales y retamales (Prosopis flexuosa y Bulnesia retama just prior to large-scale exploitation, first by mining activities and then the construction of the railway. The sources used were traveler’s diaries, business documents, descriptions by early naturalists, information provided by expeditions, scientific publications and government documents. Through the analysis of these data sources, the total surface area of native forests was estimated for 1850, as well as approximated limits of principal clusters of native forests. The study began with the assumption that the historic distribution of native forests would have had a high spatial correlation with the most densely populated and agricultural areas, where there would have been accentuated competition for use of the region’s land and natural resources.

  3. Paleolimnología de la Laguna Cerrillo del medio, Monte, provincia de Buenos Aires

    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.

  4. 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.

  5. 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

  6. 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

  7. 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)

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

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    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.

  9. 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...

  10. Study of the effect of usual heterogeneities in brachytherapy using Monte Carlo simulation; Estudio del efecto de heterogeneidades usuales en braquiterapia mediante simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Vera Sanchez, J. A.; Ruiz Morales, C.; Tobarra Gonzalez, B. M.

    2013-07-01

    The majority of current planning in brachytherapy systems don't count the composition of materials they form applicators, or the characteristics of the main interfaces present in the treatments. The objective of this study It is to compare the dosimetry distributions obtained by Monte Carlo simulations in geometric mannequins that they represent general features of the treatments that we find in our clinical practice, with results calculated according to the TG-43 formalism based on the existing consensus data for Ir-192 mHDR-v2 source. (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. Políticas agroambientales y ganadería en los montes de utilidad pública del País Vasco

    Directory of Open Access Journals (Sweden)

    Juan Cruz Alberdi Collantes

    2003-01-01

    Full Text Available Los terrenos y montes comunales han sido un recurso fundamental en la sociedad agraria vasca aportando toda una serie de aprovechamientos básicos para su funcionamiento como eran pastos, madera, helechales, agua, … Con su urbanización progresiva la explotación de muchos de sus recursos deja de tener sentido y estos espacios pasan a cumplir otras funciones, como áreas naturales, turísticas e incluso deportivas. Algunos aprovechamientos tradicionales perviven aunque han de adecuarse a las nuevas inquietudes sociales, como son las actividades ganaderas, que continúan cumpliendo una función básica en el mantenimiento del monte. Cambia su organización tradicional, antiguas prácticas de pastoreo son prohibidas y se recomiendan nuevas, los usos y áreas de aprovechamiento son delimitados. En definitiva, se incorporan conceptos medioambientales que contribuyen al correcto mantenimiento de estos espacios.

  13. 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)

  14. 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)

  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. Composición florística de las etapas de sucesión primaria sobre afloramientos rocosos del Parque Nacional Natural El Tuparro, Colombia

    Directory of Open Access Journals (Sweden)

    Rojas Zamora Óscar Andrés

    2007-12-01

    Full Text Available En un afloramiento granítico del PNN El Tuparro, en Vichada, Colombia, se investigaron los cambios en
    diversidad y composición florística en el proceso de sucesión vegetal primaria. Se evaluaron cinco etapas
    de sucesión (rasante, herbácea, arbustiva, Bosquecito de Syagrus y Bosque de Attalea. En la sucesión a largo plazo, la diversidad y riqueza vegetal aumentan desde la etapa de criptógamas (iniciales hasta los Bosques de Attalea (tardías; al avanzar el proceso, se presenta igualmente un aumento en la complejidad estructural. Se presenta un desarrollo y reemplazo gradual de nuevos estratos vegetales desde los inicios de la sucesión hasta las etapas tardías. Se registraron 238 especies distribuidos en 72 familias. Para la etapa de Criptógamas se encontró en total de siete especies donde los más importantes por su cobertura son líquenes rupícolas y Eleocharis ayacuchensis, 45 especies distribuidos en 28 familias para la etapa herbácea destacándose Vellozia lithophila y especies de Pepinia, 108 especies distribuidos en 45 familias en la etapa arbustiva destacándose Tibouchina sp. Pepinia patentiflora y Tabebuia orinocensis, 104 especies distribuidos en 44 familias para el Monte de Syagrus con predominio de Syagrus inajai, Myrcianthes sp. y Tabebuia barbata, 83 especies distribuidos en 37 familias para el Bosque de Attalea donde se destaca A. regia, Anaueria sp. y Bactris sp. A lo largo de la sucesión se destacan especies del género Pepinia (Bromeliaceae, Vellozia lithophila, Plumeria inodora y lianas como Malouetia sp. y especies de Ipomoea debido a su alta capacidad de reproducción vegetativa constituyendo la línea de avanzada de los parches de vegetación sobre la roca. Los mayores índices de diversidad se registran en las etapas intermedias debido a la variedad de microambientes presentes en los parches, así como por el sobrelapamiento de especies de las etapas tempranas y tardías. Los resultados obtenidos

  17. 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...

  18. 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)

  19. 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...

  20. Narrativas del pasado y literatura infantil: continuidades y rupturas en los planteos críticos de Graciela Montes y Ana Maria Machado

    Directory of Open Access Journals (Sweden)

    Laura Rafaela García

    2015-01-01

    Full Text Available Este trabajo propone continuar los estudios iniciados en otras instancias de investigación con el fin de explorar la literatura infanto - juvenil desde los estudios literarios y el impacto de la violencia política de las últimas dictaduras militares. El texto recorrerá l as miradas del pasado a partir de la experiencia de dos autoras claves para la literatura infantil de Argentina y de Brasil, como son Graciela Montes y Ana Maria Machado. Por un lado, este estudio pretende profundizar en los modos en los que la violencia p olítica de la última dictadura incidió en las prácticas intelectuales de estas autoras en los dos países. Esto nos permitirá establecer similitudes y diferencias entre ambos casos. Por otro lado, avanzaremos en el análisis de narrativas críticas entendidas como memorias fundamentales para la reconstrucción de las polémicas que definieron los principales planteos de la literatura para niños en los años noventa, dentro del contexto democrático. El posicionamiento crítico de las autoras con respecto a los movi mientos de su campo y las características del contexto de cada país contribuye a profundizar en los modos desde los cuales la literatura participa de la infancia.

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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

  6. Los equinodermos (Cystoidea. Homalozoa. Stelleroidea. Crinoidea del Paleozoico Inferior de los Montes de Toledo y Sierra Morena (España

    Directory of Open Access Journals (Sweden)

    Gutiérrez Marco, J. C.

    1984-12-01

    Full Text Available The presence of the cystoids Codiocystis and Phiyctocystis in the Llandeilo of Spain, associated to an undetermined Diploporite which may be a new genus, in confirmed. Several species of the genus Calix are described, some of them in open nomenclature, certain forms bearing a pentaradiated peristome. New samples of Homalozoa collected in the Middle Cambrian of Sierra Morena (Decacystis and the Lower Llanvirn of the Toledo Mountains (Mitrocystites are quotated, as well as an Asterozoa (Polaeura, found for the first time in Spain. The study of the echinoderm fauna collected in the "Tristani beds" (Llanvirn-Llandeilo of the Spanish Central-iberian zone allow to establish conclusions of biostratigraphic and paleobiogeographic interest.

    Se confirma la presencia de los cistideos Codlocystis y Phlyctocystis en el Llandeilo de España, junto a un Diploporito indeterminado que quizá corresponda a un nuevo género. Se describen diversas especies del género Calix, alguna de ellas en nomenclatura abierta, observándose en ciertas formas la existencia de un peristoma pentarradiado. Se citan nuevos ejemplares de Homalozoos procedentes del Cámbrico medio de Sierra Morena (Decocystls y del Llanvirn inferior de los Montes de Toledo (Mitrocystites, así como un Asterozoo, perteneciente al género Palaeura, descubierto por vez primera en España. El análisis de la fauna de equinodermos de las "capas con Tristani" (Llanvirn-Llandeilo de la zona Centro-ibérica española, perm ite, además, establecer diversas conclusiones de interés bioestratigráfico y paleobiogeográfico.

  7. 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

  8. 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

  9. 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 ...

  10. 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...

  11. Paisajes del despojo cotidiano: acaparamiento de tierra y agua en Montes de María, Colombia

    Directory of Open Access Journals (Sweden)

    Diana Ojeda

    2015-10-01

    Full Text Available The phenomena of landgrabbing and monopolizing of water sources have gained increasing attention in recent years. Nevertheless, very few studies have dealt with the problem of the grabbing and concentration of resources from an ethnographic perspective that would make it possible to illustrate the different ways in which dispossession takes place, as well as its concrete mechanisms and effects in particular historical, geographic and political contexts. This article makes a critical contribution to the relevant literature. Based on the specific case of the area of Montes de María, located in the Caribbean region of Colombia, it shows how the violent forms of dispossession are produced and maintained by everyday dynamics. Through the analysis of i the imagined geographies of the region, ii the implementation of development projects, iii the processes of privatization of water resources, and iv the configuration of spaces of fear, this study illustrates how the landscapes of everyday dispossession in the region are produced. In this way, it seeks to contribute to the research on socio-environmental conflicts and to break into the narrative of post-conflict in the region.

  12. Beyond habitat structure: Landscape heterogeneity explains the monito del monte (Dromiciops gliroides) occurrence and behavior at habitats dominated by exotic trees.

    Science.gov (United States)

    Salazar, Daniela A; Fontúrbel, Francisco E

    2016-09-01

    Habitat structure determines species occurrence and behavior. However, human activities are altering natural habitat structure, potentially hampering native species due to the loss of nesting cavities, shelter or movement pathways. The South American temperate rainforest is experiencing an accelerated loss and degradation, compromising the persistence of many native species, and particularly of the monito del monte (Dromiciops gliroides Thomas, 1894), an arboreal marsupial that plays a key role as seed disperser. Aiming to compare 2 contrasting habitats (a native forest and a transformed habitat composed of abandoned Eucalyptus plantations and native understory vegetation), we assessed D. gliroides' occurrence using camera traps and measured several structural features (e.g. shrub and bamboo cover, deadwood presence, moss abundance) at 100 camera locations. Complementarily, we used radio telemetry to assess its spatial ecology, aiming to depict a more complete scenario. Moss abundance was the only significant variable explaining D. gliroides occurrence between habitats, and no structural variable explained its occurrence at the transformed habitat. There were no differences in home range, core area or inter-individual overlapping. In the transformed habitats, tracked individuals used native and Eucalyptus-associated vegetation types according to their abundance. Diurnal locations (and, hence, nesting sites) were located exclusively in native vegetation. The landscape heterogeneity resulting from the vicinity of native and Eucalyptus-associated vegetation likely explains D. gliroides occurrence better than the habitat structure itself, as it may be use Eucalyptus-associated vegetation for feeding purposes but depend on native vegetation for nesting.

  13. 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.

  14. Novedades para la flora del Uruguay: nuevo registro de Agarista (Ericaceae Novidades para a flora do Uruguai: novo registro de Agarista (Ericaceae

    Directory of Open Access Journals (Sweden)

    Iván A. Grela

    2005-09-01

    Full Text Available Se reporta por primera vez la presencia de Agarista chlorantha (Cham. G. Don (Ericaceae para la flora del Uruguay. Esta especie arbustiva vive exclusivamente en el extremo noreste del país (Departamento de Rivera en las cimas y laderas de las elevaciones conocidas como "cerros chatos" formados por areniscas de edad jurásica. En este ambiente también crecen en forma casi exclusiva Agarista eucalyptoides (Cham. & Schltdl. D. Don, Ilex dumosa Reissek (Aquifoliaceae, Butia paraguayensis (Barb.-Rodr. L.H. Bailey (Arecaceae y Ocotea pulchella Mart. (Lauraceae, además de otras especies arbóreas y arbustivas de más amplia distribución en el país, en formaciones arbóreas abiertas asociadas a pastizales.A presença de Agarista chlorantha (Cham. G. Don (Ericaceae é mencionada pela primeira vez para a flora do Uruguai. Essa espécie arbustiva vive exclusivamente no extremo nordeste do país (Departamento de Rivera, nos topos e nas encostas das elevações conhecidas como "cerros chatos", formados por arenitos de idade jurássica. Nesse ambiente também crescem de forma quase exclusiva Agarista eucalyptoides (Cham. & Schltdl. D. Don, Ilex dumosa Reissek (Aquifoliaceae, Butia paraguayensis (Barb.-Rodr. L.H. Bailey (Arecaceae e Ocotea pulchella Mart. (Lauraceae, além de outras espécies arbóreas e arbustivas de distribuição mais ampla no país, em formações arbóreas abertas associadas a pastagens.

  15. 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

  16. Analysis of the dead layer of a detector of germanium with code ultrapure Monte Carlo SWORD-GEANT; Analisis del dead layer de un detector de germanio ultrapuro con el codigo de Monte Carlo SWORDS-GEANT

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, S.; Querol, A.; Ortiz, J.; Rodenas, J.; Verdu, G.

    2014-07-01

    In this paper the use of Monte Carlo code SWORD-GEANT is proposed to simulate an ultra pure germanium detector High Purity Germanium detector (HPGe) detector ORTEC specifically GMX40P4, coaxial geometry. (Author)

  17. The Capilla del Monte pluton, Sierras de Córdoba, Argentina: the easternmost Early Carboniferous magmatism in the pre-Andean SW Gondwana margin

    Science.gov (United States)

    Dahlquist, Juan A.; Pankhurst, Robert J.; Rapela, Carlos W.; Basei, Miguel A. S.; Alasino, Pablo H.; Saavedra, Julio; Baldo, Edgardo G.; Murra, Juan A.; da Costa Campos Neto, Mario

    2016-07-01

    New geochronological, geochemical, and isotopic data are reported for the Capilla del Monte two-mica granite pluton in the northeastern Sierras de Córdoba. An Early Carboniferous age is established by a U-Pb zircon concordia (336 ± 3 Ma) and a Rb-Sr whole-rock isochron (337 ± 2 Ma). Zircon saturation geothermometry indicates relatively high temperatures (735-800 °C). The granites have high average SiO2 (74.2 %), Na2O + K2O (7.8 %), and high field-strength elements, high K2O/Na2O (1.7) and FeO/MgO ratios (5.1), with low CaO content (0.71 %). REE patterns with marked negative Eu anomalies (Eu/Eu* 0.14-0.56) indicate crystal fractionation, dominantly of plagioclase and K-feldspar, from a peraluminous magma enriched in F. Isotope data (87Sr/86Srinitial = 0.7086, ɛ Nd336 = -5.5 to -4.4 with T DM = 1.5 Ga, zircon ɛ Hf336 +0.8 to -6.1; mean T DM = 1.5 Ga) suggest a Mesoproterozoic continental source, albeit with some younger or more juvenile material indicated by the Hf data. The pluton is the easternmost member of a Carboniferous A-type magmatic suite which shows an increase in juvenile input toward the west in this part of the pre-Andean margin. The petrological and geochemical data strongly suggest a similar intraplate geodynamic setting to that of the nearby but much larger, Late Devonian, Achala batholith, although Hf isotope signatures of zircon suggest a more uniformly crustal origin for the latter. Further studies are required to understand whether these bodies represent two independent magmatic episodes or more continuous activity.

  18. 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

  19. 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.

  20. 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...

  1. 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)

  2. 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.

  3. 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)

  4. 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

  5. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    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. 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...

  10. 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.

  11. 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.

  12. Evaluación del espesor de capas delgadas mediante análisis EDS y simulación de Monte Carlo

    Directory of Open Access Journals (Sweden)

    García, J. C.

    2010-12-01

    Full Text Available This work shows a method to evaluate the thin layer thickness by the X ray dispersive energy (EDS technique. The analytical measures of the area of characteristic peaks carried out with this technique are complemented with electron trajectories on the interaction volume byMonte Carlo simulation. These together with the estimations obtained for the characteristic peaks intensities according to Bethe, Joy&Luo algorithm makes possible to estimate the thickness of samples.En este trabajo se presenta un método de evaluación de espesores de capas delgadas mediante la técnica de energías dispersivas de rayos X (EDS. Las medidas analíticas de las áreas de los picos característicos de los elementos detectados en las capas, obtenidas mediante esta técnica, se complementan con simulaciones de Monte Carlo de las trayectorias de los electrones en el volumen de interacción. Esto, junto con las estimaciones de la intensidad de los picos característicos obtenidos mediante el algoritmo de Bethe, Joy & Luo, posibilita realizar la estimación de los espesores de las muestras analizadas.

  13. 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

  14. 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

  15. El colegio de teólogos y juristas «San Dionisio Aeropagita del Sacro-Monte de Granada» (1752-1800

    Directory of Open Access Journals (Sweden)

    Francisco MARTÍN ZUÑIGA

    2010-03-01

    Full Text Available RESUMEN: Los ocho siglos de vida islámica condicionan la plena integración de Granada en la sociedad española, y muy especialmente en el ámbito religioso: «carecía de una historia eclesiástica propiamente dicha, y aun los pocos datos existentes sobre la iglesia mozárabe de Ilíberis se desconocían entonces. Esta falta de datos ocasionó un vacío que pesaba mucho en los granadinos...Hasta las noticias del patrono —San Cecilio— caían prácticamente en la categoría de leyendas».

  16. Monte Carlo simulation of the dose distribution around the {sup 125}I model 6711 seed as function of radius of the silver cylinder using the Penelope code; Simulacion por el Metodo de Monte Carlo de la distribucion de dosis alrededor de la semilla de {sup 125}I modelo 6711 en funcion del radio del cilindro de plata usando el codigo Penelope

    Energy Technology Data Exchange (ETDEWEB)

    Nerio, U. [Universidad de Cordoba, Monteria (Colombia); Instituto Nacional de Cancerologia, Bogota (Colombia); Chica, L. [Universidad Nacional de Colombia, Bogota (Colombia); Paul, A. [Universite de la Mediterranee, Marseille (France)

    2004-07-01

    The Monte Carlo method is applied to find the dose rates distribution in tissue around {sup 125} I seeds model 6711 as a function of the silver cylinder radius, R{sub sc} (0.017, 0.021, 0.025, 0.029 and 0.033) cm are used as radius values. It is found here that the dose rate at any point within the tissue decreases as R{sub sc} increases. The relative difference of dose rate that produced by the standard R{sub sc} seed, is less than 5%, for seeds with Rsc between 0.017 and 0.033 cm. (author)

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. 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)

  3. 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)

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. The Virtual Monte Carlo

    CERN Document Server

    Hrivnacova, I; Berejnov, V V; Brun, R; Carminati, F; Fassò, A; Futo, E; Gheata, A; Caballero, I G; Morsch, Andreas

    2003-01-01

    The concept of Virtual Monte Carlo (VMC) has been developed by the ALICE Software Project to allow different Monte Carlo simulation programs to run without changing the user code, such as the geometry definition, the detector response simulation or input and output formats. Recently, the VMC classes have been integrated into the ROOT framework, and the other relevant packages have been separated from the AliRoot framework and can be used individually by any other HEP project. The general concept of the VMC and its set of base classes provided in ROOT will be presented. Existing implementations for Geant3, Geant4 and FLUKA and simple examples of usage will be described.

  9. 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

  10. 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...

  11. 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

  12. 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...

  13. Monte Carlo and nonlinearities

    CERN Document Server

    Dauchet, Jérémi; Blanco, Stéphane; Caliot, Cyril; Charon, Julien; Coustet, Christophe; Hafi, Mouna El; Eymet, Vincent; Farges, Olivier; Forest, Vincent; Fournier, Richard; Galtier, Mathieu; Gautrais, Jacques; Khuong, Anaïs; Pelissier, Lionel; Piaud, Benjamin; Roger, Maxime; Terrée, Guillaume; Weitz, Sebastian

    2016-01-01

    The Monte Carlo method is widely used to numerically predict systems behaviour. However, its powerful incremental design assumes a strong premise which has severely limited application so far: the estimation process must combine linearly over dimensions. Here we show that this premise can be alleviated by projecting nonlinearities on a polynomial basis and increasing the configuration-space dimension. Considering phytoplankton growth in light-limited environments, radiative transfer in planetary atmospheres, electromagnetic scattering by particles and concentrated-solar-power-plant productions, we prove the real world usability of this advance on four test-cases that were so far regarded as impracticable by Monte Carlo approaches. We also illustrate an outstanding feature of our method when applied to sharp problems with interacting particles: handling rare events is now straightforward. Overall, our extension preserves the features that made the method popular: addressing nonlinearities does not compromise o...

  14. 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.

  15. 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 ...

  16. ¿''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

  17. 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.

  18. Gestión de Emisiones de Gases de Efecto Invernadero como parte de la Estrategia de Sostenibilidad de la Escuela Técnica Superior de Ingeniería de Montes, Forestal y del Medio Natural

    OpenAIRE

    Rodríguez Cuesta, Carla

    2015-01-01

    Las consecuencias ambientales, sociales y económicas que conlleva el cambio climático, enfatizan la creciente preocupación por desarrollar estrategias, medidas y acciones de prevención, adaptación y mitigación del mismo. La aplicación de buenas prácticas integradas en el modelo de gestión de las organizaciones bajo los criterios de responsabilidad social y sostenibilidad permite: tener un mayor control de riesgos, identificar nuevas oportunidades, mejorar relaciones con los grupos de interés,...

  19. 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...

  20. 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!

  1. 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.

  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. Una nueva especie de Musaraña del género Cryptotis Pomel 1848 (Mammalia: Soricomorpha: Soricidae de Ecuador y estatus taxonomico de Cryptotis equatoris Thomas (1912

    Directory of Open Access Journals (Sweden)

    Pablo A. Moreno Cárdenas

    2014-01-01

    Full Text Available En este estudio se reportan cuatro especies de musarañas del género Cryptotis para el Ecuador, y una especie descrita aquí como Cryptotis niausa sp. nov., nueva para la ciencia la cual está distribuida para las zonas altoandinas del norte del Ecuador y es distinta de Cryptotis montivagus, que habita los páramos y zonas arbustivas del sur del Ecuador. La especie nueva se caracteriza por su gran tamaño para el género, pelo largo y de color café-grisáceo contrastando con una tonalidad amarillenta, principalmente en la garganta. Los análisis de este estudio demuestran que Cryptotis equatoris osgoodi, es distinta de Cryptotis equatoris equatoris, por lo que se consideran a estos clados como especies distintas. Cryptotis equatoris, es de mediano tamaño y de coloración negruzca, y se halla distribuida en las zonas boscosas templadas y frías, de las estribaciones occidentales de los Andes; y Cryptotis osgoodi, habita, principalmente en los bosques nublados de las estribaciones orientales de los Andes.

  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. Monte Carlo methods for electromagnetics

    CERN Document Server

    Sadiku, Matthew NO

    2009-01-01

    Until now, novices had to painstakingly dig through the literature to discover how to use Monte Carlo techniques for solving electromagnetic problems. Written by one of the foremost researchers in the field, Monte Carlo Methods for Electromagnetics provides a solid understanding of these methods and their applications in electromagnetic computation. Including much of his own work, the author brings together essential information from several different publications.Using a simple, clear writing style, the author begins with a historical background and review of electromagnetic theory. After addressing probability and statistics, he introduces the finite difference method as well as the fixed and floating random walk Monte Carlo methods. The text then applies the Exodus method to Laplace's and Poisson's equations and presents Monte Carlo techniques for handing Neumann problems. It also deals with whole field computation using the Markov chain, applies Monte Carlo methods to time-varying diffusion problems, and ...

  7. 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

  8. 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.

  9. 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

  10. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras Soil litter stock and fertility after planting leguminous shrubs and forage trees on degraded signal grass pasture

    Directory of Open Access Journals (Sweden)

    André Barbosa Silva

    2013-04-01

    Full Text Available As pastagens formam a base da pecuária brasileira; essas sofrem degradação em larga escala por deficiência de nitrogênio (N. O consórcio com leguminosas, além de fixar N, pode apresentar outros efeitos na fertilidade do solo como acidificação ou retirada de nutrientes de camadas mais profundas para as mais superficiais. Este trabalho objetivou avaliar o estoque de serapilheira e a fertilidade do solo em pastagens degradadas de braquiária (Brachiaria decumbens, após implantar leguminosas arbustivas e arbóreas forrageiras. Para isso, uma amostragem foi realizada em março de 2010 em um experimento no campo, introduzindo pastagem degradada de Brachiaria decumbens, em julho de 2008, com sabiá (Mimosa caesalpiniifolia, leucena (Leucaena leucocephala, mororó (Bauhinia cheilantha e gliricídia (Gliricidia sepium, além de braquiária adubada e não adubada com N. As amostras de solo e serapilheira foram coletadas aos 0-10, 10-20 e 20-40 cm de profundidade, em três transectos, alternando pontos cobertos por gramíneas e leguminosas, totalizando sete amostras compostas por parcela para determinar pH, P, K, Ca, Mg e Al no solo, enquanto SB, t e m foram calculados. A serapilheira foi separada visualmente em leguminosas, gramíneas e materiais não identificados, em que foram utilizados para quantificação de matéria seca, matéria orgânica, N, P, C, fibra detergente ácido e lignina. A introdução das leguminosas aumentou os teores de N total na serapilheira e reduziu as relações C:N, com destaque para gliricídia e sabiá; entretanto, essa última apresentou elevados teores de lignina. Houve efeito significativo da cobertura por leguminosas, sem diferenças entre essas, para pH e K, na profundidade de 0-10 cm, e para Al e m, aos 10-20 cm de profundidade.Pastures are the fodder supply of Brazilian livestock, and are exhaustively degraded by nitrogen (N deficiency. Intercropping with legumes, aside from nitrogen fixation, may have

  11. 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

  12. 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....

  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. Mineralogy of Libya Montes, Mars

    Science.gov (United States)

    Perry, K. A.; Bishop, J. L.; McKeown, N. K.

    2009-12-01

    Observations by CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) have revealed a range of minerals in Libya Montes including olivine, pyroxene, and phyllosilicate [1]. Here we extend our spectral analyses of CRISM images in Libya Montes to identify carbonates. We have also performed detailed characterization of the spectral signature of the phyllosilicate- and carbonate-bearing outcrops in order to constrain the types of phyllosilicates and carbonates present. Phyllosilicate-bearing rocks in Libya Montes have spectral bands at 1.42, 2.30 and 2.39 µm, consistent with Fe- and Mg- bearing smectites. The mixture of Fe and Mg in Libya Montes may be within the clay mineral structure or within the CRISM pixel. Because the pixels have 18 meter/pixel spatial resolution, it is possible that the bands observed are due to the mixing of nontronite and saponite rather than a smectite with both Fe and Mg. Carbonates found in Libya Montes are similar to those found in Nili Fossae [2]. The carbonates have bands centered at 2.30 and 2.52 µm. Libya Montes carbonates most closely resemble the Mg-carbonate, magnesite. Olivine spectra are seen throughout Libya Montes, characterized by a positive slope from 1.2-1.8 µm. Large outcrops of olivine are relatively rare on Mars [3]. This implies that fresh bedrock has been recently exposed because olivine weathers readily compared to pyroxene and feldspar. Pyroxene in Libya Montes resembles an Fe-bearing orthopyroxene with a broad band centered at 1.82 µm. The lowermost unit identified in Libya Montes is a clay-bearing unit. Overlying this is a carbonate-bearing unit with a clear unit division visible in at least one CRISM image. An olivine-bearing unit unconformably overlies these two units and may represent a drape related to the Isidis impact, as suggested for Nili Fossae [2]. However, it appears that the carbonate in Libya Montes is an integral portion of the rock underlying the olivine-bearing unit rather than an

  15. Synchronous Parallel Kinetic Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Mart?nez, E; Marian, J; Kalos, M H

    2006-12-14

    A novel parallel kinetic Monte Carlo (kMC) algorithm formulated on the basis of perfect time synchronicity is presented. The algorithm provides an exact generalization of any standard serial kMC model and is trivially implemented in parallel architectures. We demonstrate the mathematical validity and parallel performance of the method by solving several well-understood problems in diffusion.

  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. 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.

  18. 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.

  19. 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

  20. 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.)

  1. 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...

  2. 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).

  3. 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...

  4. 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

  5. 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

  6. 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...

  7. 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

  8. Monte Carlo Treatment Planning for Advanced Radiotherapy

    DEFF Research Database (Denmark)

    Cronholm, Rickard

    for commissioning of a Monte Carlo model of a medical linear accelerator, ensuring agreement with measurements within 1% for a range of situations, is presented. The resulting Monte Carlo model was validated against measurements for a wider range of situations, including small field output factors, and agreement...... modulating the intensity of the field during the irradiation. The workflow described has the potential to fully model the dynamic delivery, including gantry rotation during irradiation, of modern radiotherapy. Three corner stones of Monte Carlo Treatment Planning are identified: Building, commissioning...... and 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...

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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 ...

  16. 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.

  17. 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

  18. 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.)

  19. 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.

  20. Challenges of Monte Carlo Transport

    Energy Technology Data Exchange (ETDEWEB)

    Long, Alex Roberts [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational Physics and Methods (CCS-2)

    2016-06-10

    These are slides from a presentation for Parallel Summer School at Los Alamos National Laboratory. Solving discretized partial differential equations (PDEs) of interest can require a large number of computations. We can identify concurrency to allow parallel solution of discrete PDEs. Simulated particles histories can be used to solve the Boltzmann transport equation. Particle histories are independent in neutral particle transport, making them amenable to parallel computation. Physical parameters and method type determine the data dependencies of particle histories. Data requirements shape parallel algorithms for Monte Carlo. Then, Parallel Computational Physics and Parallel Monte Carlo are discussed and, finally, the results are given. The mesh passing method greatly simplifies the IMC implementation and allows simple load-balancing. Using MPI windows and passive, one-sided RMA further simplifies the implementation by removing target synchronization. The author is very interested in implementations of PGAS that may allow further optimization for one-sided, read-only memory access (e.g. Open SHMEM). The MPICH_RMA_OVER_DMAPP option and library is required to make one-sided messaging scale on Trinitite - Moonlight scales poorly. Interconnect specific libraries or functions are likely necessary to ensure performance. BRANSON has been used to directly compare the current standard method to a proposed method on idealized problems. The mesh passing algorithm performs well on problems that are designed to show the scalability of the particle passing method. BRANSON can now run load-imbalanced, dynamic problems. Potential avenues of improvement in the mesh passing algorithm will be implemented and explored. A suite of test problems that stress DD methods will elucidate a possible path forward for production codes.

  1. Challenges of Monte Carlo Transport

    Energy Technology Data Exchange (ETDEWEB)

    Long, Alex Roberts [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational Physics and Methods (CCS-2)

    2016-06-10

    These are slides from a presentation for Parallel Summer School at Los Alamos National Laboratory. Solving discretized partial differential equations (PDEs) of interest can require a large number of computations. We can identify concurrency to allow parallel solution of discrete PDEs. Simulated particles histories can be used to solve the Boltzmann transport equation. Particle histories are independent in neutral particle transport, making them amenable to parallel computation. Physical parameters and method type determine the data dependencies of particle histories. Data requirements shape parallel algorithms for Monte Carlo. Then, Parallel Computational Physics and Parallel Monte Carlo are discussed and finally the results are given. The mesh passing method greatly simplifies the IMC implementation and allows simple load-balancing. Using MPI windows and passive, one-sided RMA further simplifies the implementation by removing target synchronization. The author is very interested in implementations of PGAS that may allow further optimization for one-sided, read-only memory access (e.g. Open SHMEM). The MPICH_RMA_OVER_DMAPP option and library is required to make one-sided messaging scale on Trinitite - Moonlight scales poorly. Interconnect specific libraries or functions are likely necessary to ensure performance. BRANSON has been used to directly compare the current standard method to a proposed method on idealized problems. The mesh passing algorithm performs well on problems that are designed to show the scalability of the particle passing method. BRANSON can now run load-imbalanced, dynamic problems. Potential avenues of improvement in the mesh passing algorithm will be implemented and explored. A suite of test problems that stress DD methods will elucidate a possible path forward for production codes.

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Aasta film - joonisfilm "Mont Blanc" / Verni Leivak

    Index Scriptorium Estoniae

    Leivak, Verni, 1966-

    2002-01-01

    Eesti Filmiajakirjanike Ühing andis aasta 2001 parima filmi tiitli Priit Tenderi joonisfilmile "Mont Blanc" : Eesti Joonisfilm 2001.Ka filmikriitikute eelistused kinodes ja televisioonis 2001. aastal näidatud filmide osas

  11. 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 ...

  12. 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

  13. Simulation and the Monte Carlo method

    CERN Document Server

    Rubinstein, Reuven Y

    2016-01-01

    Simulation and the Monte Carlo Method, Third 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 more than a quarter of a century 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, such as engineering, statistics, computer science, mathematics, and the physical and life sciences. The book begins with a modernized introduction that addresses the basic concepts of probability, Markov processes, and convex optimization. Subsequent chapters discuss the dramatic changes that have occurred in the field of the Monte Carlo method, with coverage of many modern topics including: Markov Chain Monte Carlo, variance reduction techniques such as the transform likelihood ratio...

  14. Smart detectors for Monte Carlo radiative transfer

    CERN Document Server

    Baes, Maarten

    2008-01-01

    Many optimization techniques have been invented to reduce the noise that is inherent in Monte Carlo radiative transfer simulations. As the typical detectors used in Monte Carlo simulations do not take into account all the information contained in the impacting photon packages, there is still room to optimize this detection process and the corresponding estimate of the surface brightness distributions. We want to investigate how all the information contained in the distribution of impacting photon packages can be optimally used to decrease the noise in the surface brightness distributions and hence to increase the efficiency of Monte Carlo radiative transfer simulations. We demonstrate that the estimate of the surface brightness distribution in a Monte Carlo radiative transfer simulation is similar to the estimate of the density distribution in an SPH simulation. Based on this similarity, a recipe is constructed for smart detectors that take full advantage of the exact location of the impact of the photon pack...

  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. 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...

  17. 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

  18. 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”.

  19. Development of Monte Carlo depletion code MCDEP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. S.; Kim, K. Y.; Lee, J. C.; Ji, S. K. [KAERI, Taejon (Korea, Republic of)

    2003-07-01

    Monte Carlo neutron transport calculation has been used to obtain a reference solution in reactor physics analysis. The typical and widely-used Monte Carlo transport code is MCNP (Monte Carlo N-Particle Transport Code) developed in Los Alamos National Laboratory. The drawbacks of Monte-Carlo transport codes are the lacks of the capacities for the depletion and temperature dependent calculations. In this research we developed MCDEP (Monte Carlo Depletion Code Package) using MCNP with the capacity of the depletion calculation. This code package is the integration of MCNP and depletion module of ORIGEN-2 using the matrix exponential method. This code package enables the automatic MCNP and depletion calculations only with the initial MCNP and MCDEP inputs prepared by users. Depletion chains were simplified for the efficiency of computing time and the treatment of short-lived nuclides without cross section data. The results of MCDEP showed that the reactivity and pin power distributions for the PWR fuel pins and assemblies are consistent with those of CASMO-3 and HELIOS.

  20. Approaching Chemical Accuracy with Quantum Monte Carlo

    CERN Document Server

    Petruzielo, F R; Umrigar, C J

    2012-01-01

    A quantum Monte Carlo study of the atomization energies for the G2 set of molecules is presented. Basis size dependence of diffusion Monte Carlo atomization energies is studied with a single determinant Slater-Jastrow trial wavefunction formed from Hartree-Fock orbitals. With the largest basis set, the mean absolute deviation from experimental atomization energies for the G2 set is 3.0 kcal/mol. Optimizing the orbitals within variational Monte Carlo improves the agreement between diffusion Monte Carlo and experiment, reducing the mean absolute deviation to 2.1 kcal/mol. Moving beyond a single determinant Slater-Jastrow trial wavefunction, diffusion Monte Carlo with a small complete active space Slater-Jastrow trial wavefunction results in near chemical accuracy. In this case, the mean absolute deviation from experimental atomization energies is 1.2 kcal/mol. It is shown from calculations on systems containing phosphorus that the accuracy can be further improved by employing a larger active space.

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. Monte carlo simulations of organic photovoltaics.

    Science.gov (United States)

    Groves, Chris; Greenham, Neil C

    2014-01-01

    Monte Carlo simulations are a valuable tool to model the generation, separation, and collection of charges in organic photovoltaics where charges move by hopping in a complex nanostructure and Coulomb interactions between charge carriers are important. We review the Monte Carlo techniques that have been applied to this problem, and describe the results of simulations of the various recombination processes that limit device performance. We show how these processes are influenced by the local physical and energetic structure of the material, providing information that is useful for design of efficient photovoltaic systems.

  10. Monte Carlo dose distributions for radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Perucha, M.; Leal, A.; Rincon, M.; Carrasco, E. [Sevilla Univ. (Spain). Dept. Fisiologia Medica y Biofisica; Sanchez-Doblado, F. [Sevilla Univ. (Spain). Dept. Fisiologia Medica y Biofisica]|[Hospital Univ. Virgen Macarena, Sevilla (Spain). Servicio de Oncologia Radioterapica; Nunez, L. [Clinica Puerta de Hierro, Madrid (Spain). Servicio de Radiofisica; Arrans, R.; Sanchez-Calzado, J.A.; Errazquin, L. [Hospital Univ. Virgen Macarena, Sevilla (Spain). Servicio de Oncologia Radioterapica; Sanchez-Nieto, B. [Royal Marsden NHS Trust (United Kingdom). Joint Dept. of Physics]|[Inst. of Cancer Research, Sutton, Surrey (United Kingdom)

    2001-07-01

    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.)

  11. 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

  12. 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.)

  13. 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.

  14. 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

  15. 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...

  16. 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...

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.)

  3. 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.

  4. Advances in Monte Carlo computer simulation

    Science.gov (United States)

    Swendsen, Robert H.

    2011-03-01

    Since the invention of the Metropolis method in 1953, Monte Carlo methods have been shown to provide an efficient, practical approach to the calculation of physical properties in a wide variety of systems. In this talk, I will discuss some of the advances in the MC simulation of thermodynamics systems, with an emphasis on optimization to obtain a maximum of useful information.

  5. 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

  6. 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.

  7. 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...

  8. 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

  9. 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.

  10. Micromamíferos del Pleistoceno Medio y Pleistoceno Superior en el Valle del Jarama: yacimientos de Valdocarros y HAT (Madrid, España

    Directory of Open Access Journals (Sweden)

    Sesé, C.

    2011-06-01

    >Oryctolagus cuniculus; y en HAT: soricomorfos: Soricidae indet.; roedores: Eliomys quercinus, Apodemus sp., Arvi cola aff. sapidus y Microtus cf. cabrerae; y lagomorfos: cf. Oryctolagus sp. La asociación del yacimiento de Valdocarros, por su composición y por el estadio evolutivo de Microtus brecciensis, se sitúa en el Pleistoceno Medio avanzado pero no final. La presencia de Microtus cf. cabrerae en el yacimiento de HAT hace que se adscriba al Pleistoceno Superior. Ambas asociaciones indican unas condiciones paleo- ambientales de clima templado y un buen desarrollo de la cobertura vegetal con zonas boscosas y zonas abiertas con vegetación arbustiva, ribereña y praderas.

  11. Monimiaceae endémicas del Perú

    Directory of Open Access Journals (Sweden)

    Blanca León

    2013-10-01

    Full Text Available La familia Monimiaceae es reconocida en el Perú por presentar dos géneros y casi 50 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004; Renner & Hausner, 2005, arbustivas y arbóreas. En este trabajo reconocemos dos especies endémicas en dos géneros, las que habitan las regiones Bosques Muy Húmedos Premontanos y Bosques Húmedos Amazónicos, entre los 140 y 1800 m de altitud. Ninguna especie endémica está representada en el Sistema Nacional de Áreas Naturales Protegidas por el Estado.

  12. Monte Carlo simulations of fluid vesicles

    Science.gov (United States)

    Sreeja, K. K.; Ipsen, John H.; Kumar, P. B. Sunil

    2015-07-01

    Lipid vesicles are closed two dimensional fluid surfaces that are studied extensively as model systems for understanding the physical properties of biological membranes. Here we review the recent developments in the Monte Carlo techniques for simulating fluid vesicles and discuss some of their applications. The technique, which treats the membrane as an elastic sheet, is most suitable for the study of large scale conformations of membranes. The model can be used to study vesicles with fixed and varying topologies. Here we focus on the case of multi-component membranes with the local lipid and protein composition coupled to the membrane curvature leading to a variety of shapes. The phase diagram is more intriguing in the case of fluid vesicles having an in-plane orientational order that induce anisotropic directional curvatures. Methods to explore the steady state morphological structures due to active flux of materials have also been described in the context of Monte Carlo simulations.

  13. 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.

  14. 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...

  15. PHOTOS Monte Carlo and its theoretical accuracy

    CERN Document Server

    Was, Z; Nanava, G

    2008-01-01

    Because of properties of QED, the bremsstrahlung corrections to decays of particles or resonances can be calculated, with a good precision, separately from other effects. Thanks to the widespread use of event records such calculations can be embodied into a separate module of Monte Carlo simulation chains, as used in High Energy Experiments of today. The PHOTOS Monte Carlo program is used for this purpose since nearly 20 years now. In the following talk let us review the main ideas and constraints which shaped the program version of today and enabled it widespread use. Finally, we will underline importance of aspects related to reliability of program results: event record contents and implementation of channel specific matrix elements.

  16. 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...

  17. 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)

  18. 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

  19. Status of Monte Carlo at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, W.L.; Cashwell, E.D.; Godfrey, T.N.K.; Schrandt, R.G.; Deutsch, O.L.; Booth, T.E.

    1980-05-01

    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.

  20. 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.

  1. 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

  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. Livestock grazing, habitat protection and diversity of bees and wasps in the Central Monte desert

    Directory of Open Access Journals (Sweden)

    Diego P. VÁZQUEZ

    2008-01-01

    Full Text Available 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 a lo largo de varios años antes que estos resultados puedan ser aplicados como guía de decisiones de manejo.

  4. 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)

  5. 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.)

  6. 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.

  7. 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.

  8. 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. \\

  9. 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.

  10. 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 ...

  11. 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.

  12. 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....

  13. 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...

  14. 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

  15. 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.

  16. A Valley in the Libya Montes

    Science.gov (United States)

    2000-01-01

    [figure removed for brevity, see original site] (A) [figure removed for brevity, see original site] (B) [figure removed for brevity, see original site] (C)This Mars Global Surveyor Mars Orbiter Camera narrow angle image (top) shows an intermountain valley floor in the Libya Montes region of Mars. Its regional setting is seen in the wide angle color mosaic (Figure A). The Libya Montes were formed by the giant impact that created the ancient Isidis basin. The Libya Mountains and valleys--like the one shown here--were subsequently modified and eroded by other processes, including wind, impact cratering, and flow of liquid water to make the small valley that runs across the middle of the scene. Until the mission was canceled, the Libya Montes region was among the top two candidates for the Mars Surveyor 2001 Lander. This image, illuminated by sunlight from the left, covers an area 3 kilometers (1.9 miles) wide and 19 kilometers (11.8 miles) long. The scene is located near 1.5oN, 278.4oW and was acquired on June 27, 1999. The high resolution color view (top) was created by combining the colors derived from Mars Orbiter Camera Wide Angle views of the region obtained in May 1999 (Figures A and B) with the high resolution view obtained in June 1999 (Figure C).

  17. 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.

  18. 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

  19. 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

  20. 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)

  1. 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.

  2. 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.

  3. 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”.

  4. Conocimiento de seis especies arbustivas utilizadas como plantas nodrizas en el occidente de Guatemala

    Directory of Open Access Journals (Sweden)

    José Vicente Martínez-Arévalo

    2015-11-01

    Full Text Available En la restauración de ecosistemas, una técnica es utilizar arbustos de la sucesión como nodriza. En la parte alta de San Marcos, Guatemala, se ha recurrido al menos a seis de ellos en el establecimiento de pino y pinabete: arrayán (Baccharis vaccinoides Kunth, salvia (Buddleia megalocephala Donn. Sm., mozote (Acaena elongata L., chicajol (Stevia polycephala Bertol, mora (Rubus trilobus Ser. y malacate (Symphoricarpos microphyllus Kunth. Se carece de la documentación de su comportamiento y características que puedan servir para utilizarlas ampliamente como plantas protectoras. En esta investigación se estudió características in situ y reproductivas de estas especies. Entre los principales resultados está que la altura de plantas es de 1.17 a 2.64 m y cobertura de 0.34 a 2.77 m2, con una amplia variación entre y dentro de especies. La cantidad de frutos/planta va desde 90 en S. microphyllus a 59,400 en B. vaccinioides. La propagación vegetativa en campo estuvo entre 48 a 92 %, mayor que cuando se realizó en vivero, donde B. vaccinoides, S. microphyllus y R. trilobus tuvieron mejor respuesta. La propagación por semilla muestra que las seis especies pueden reproducirse adecuadamente. Estos resultados permiten su reproducción en viveros para su uso en restauración ecológica.

  5. 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

  6. 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...

  7. 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.

  8. 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

  9. 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)...

  10. 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.

  11. 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.

  12. 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

  13. A Monte Carlo algorithm for degenerate plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Turrell, A.E., E-mail: a.turrell09@imperial.ac.uk; Sherlock, M.; Rose, S.J.

    2013-09-15

    A procedure for performing Monte Carlo calculations of plasmas with an arbitrary level of degeneracy is outlined. It has possible applications in inertial confinement fusion and astrophysics. Degenerate particles are initialised according to the Fermi–Dirac distribution function, and scattering is via a Pauli blocked binary collision approximation. The algorithm is tested against degenerate electron–ion equilibration, and the degenerate resistivity transport coefficient from unmagnetised first order transport theory. The code is applied to the cold fuel shell and alpha particle equilibration problem of inertial confinement fusion.

  14. 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

  15. 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

  16. Hybrid Monte Carlo simulation of polymer chains

    CERN Document Server

    Irbäck, A

    1993-01-01

    We develop the hybrid Monte Carlo method for simulations of single off-lattice polymer chains. We discuss implementation and choice of simulation parameters in some detail. The performance of the algorithm is tested on models for homopolymers with short- or long-range self-repulsion, using chains with $16\\le N\\le 512$ monomers. Without excessive fine tuning, we find that the computational cost grows as $N^{2+z^\\prime}$ with $0.64

  17. 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.

  18. 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.

  19. 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.

  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.

  1. 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...

  2. 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

  3. State-of-the-art Monte Carlo 1988

    Energy Technology Data Exchange (ETDEWEB)

    Soran, P.D.

    1988-06-28

    Particle transport calculations in highly dimensional and physically complex geometries, such as detector calibration, radiation shielding, space reactors, and oil-well logging, generally require Monte Carlo transport techniques. Monte Carlo particle transport can be performed on a variety of computers ranging from APOLLOs to VAXs. Some of the hardware and software developments, which now permit Monte Carlo methods to be routinely used, are reviewed in this paper. The development of inexpensive, large, fast computer memory, coupled with fast central processing units, permits Monte Carlo calculations to be performed on workstations, minicomputers, and supercomputers. The Monte Carlo renaissance is further aided by innovations in computer architecture and software development. Advances in vectorization and parallelization architecture have resulted in the development of new algorithms which have greatly reduced processing times. Finally, the renewed interest in Monte Carlo has spawned new variance reduction techniques which are being implemented in large computer codes. 45 refs.

  4. Monte Carlo simulations in theoretical physic; Simulations Monte Carlo en physique theorique

    Energy Technology Data Exchange (ETDEWEB)

    Billoire, A.

    1991-12-31

    After a presentation of the MONTE CARLO method principle, the method is applied, first to the critical exponents calculations in the three dimensions ISING model, and secondly to the discrete quantum chromodynamic with calculation times in function of computer power. 28 refs., 4 tabs.

  5. 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

  6. 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...

  7. 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.

  8. 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)

  9. 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.

  10. 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...

  11. 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 ...

  12. 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.

  13. 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

  14. 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.

  15. 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...

  16. Quantum Monte Carlo Calculations of Neutron Matter

    CERN Document Server

    Carlson, J; Ravenhall, D G

    2003-01-01

    Uniform neutron matter is approximated by a cubic box containing a finite number of neutrons, with periodic boundary conditions. We report variational and Green's function Monte Carlo calculations of the ground state of fourteen neutrons in a periodic box using the Argonne $\\vep $ two-nucleon interaction at densities up to one and half times the nuclear matter density. The effects of the finite box size are estimated using variational wave functions together with cluster expansion and chain summation techniques. They are small at subnuclear densities. We discuss the expansion of the energy of low-density neutron gas in powers of its Fermi momentum. This expansion is strongly modified by the large nn scattering length, and does not begin with the Fermi-gas kinetic energy as assumed in both Skyrme and relativistic mean field theories. The leading term of neutron gas energy is ~ half the Fermi-gas kinetic energy. The quantum Monte Carlo results are also used to calibrate the accuracy of variational calculations ...

  17. 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)

  18. 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).

  19. 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

  20. 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...

  1. 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

  2. Intervención humana y transformación de los paisajes forestales en la cuenca del Duero durante la edad moderna

    Directory of Open Access Journals (Sweden)

    José María Ramos Santos

    2005-01-01

    Full Text Available La actuación humana ejercida sobre los montes durante la Edad Moderna constituye un claro exponente de la posición central que ocupaban los montes en el espacio agrario, no sólo pinares, sino también encinares y quejigares, responden a este interés humano por el monte. De esta manera se manifi esta cómo el conjunto de los montes adquiere su verdadera fi sonomía a través de esta actuación humana, sostenida en el tiempo a través de auténticos programas plasmados en las Ordenanzas Montes y en las Ordenanzas Municipales. Esta intervención adquiere distintas características en función de los intereses de cada comunidad rural y en relación con distintos momentos históricos. De esta manera junto a algunas constantes vinculadas con la intervención en los montes pueden señalarse grandes diferencias, pues mientras en unas zonas el monte se reduce en favor de las tierras cultivadas, en otras se conserva y se amplia. Estas diferencias, así pues, constituyen un efecto del prestigio del monte o de su olvido como soporte o equilibrio de la actividad rural.

  3. Del territorio del sujeto al emplazamiento del Común

    Directory of Open Access Journals (Sweden)

    Mariano Adrían Ferretti

    2016-01-01

    Full Text Available La construcción de lo público abarca una variedad de dinámicas que condicionan el resultado físico de los espacios donde actúan los individuos en sus necesidades de habitar, modificando su realidad desde la diferenciación y la singularización subjetiva del entorno que derivan en nuevas formas de territorialidad de lo público a partir de la dialéctica entre lo público y lo privado. Sin embargo, los resultados de tales representaciones entendidas como acciones colectivas –y por tanto comunes- no siempre explican los valores que desde lo simbólico partiendo del sujeto constituyan un estatus diferente de lo público en los procesos de territorialización. Se propone una aproximación que aborde de manera teórica cuestiones tales como: los vínculos del individuo con los procesos de acumulación material y transformación del territorio y las implicaciones que dichos fenómenos tienen en la posibilidad de constitución de un sujeto que trascendiendo al individuo sea capaz de conformar un nuevo estatus del sujeto o, dicho de otro modo, un emplazamiento del Común.

  4. 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)

  5. Monte Carlo Implementation of Polarized Hadronization

    CERN Document Server

    Matevosyan, Hrayr H; Thomas, Anthony W

    2016-01-01

    We study the polarized quark hadronization in a Monte Carlo (MC) framework based on the recent extension of the quark-jet framework, where a self-consistent treatment of the quark polarization transfer in a sequential hadronization picture has been presented. Here, we first adopt this approach for MC simulations of hadronization process with finite number of produced hadrons, expressing the relevant probabilities in terms of the eight leading twist quark-to-quark transverse momentum dependent (TMD) splitting functions (SFs) for elementary $q \\to q'+h$ transition. We present explicit expressions for the unpolarized and Collins fragmentation functions (FFs) of unpolarized hadrons emitted at rank two. Further, we demonstrate that all the current spectator-type model calculations of the leading twist quark-to-quark TMD SFs violate the positivity constraints, and propose quark model based ansatz for these input functions that circumvents the problem. We validate our MC framework by explicitly proving the absence o...

  6. 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.

  7. 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...

  8. 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.

  9. Nuclear reactions in Monte Carlo codes

    CERN Document Server

    Ferrari, Alfredo

    2002-01-01

    The physics foundations of hadronic interactions as implemented in most Monte Carlo codes are presented together with a few practical examples. The description of the relevant physics is presented schematically split into the major steps in order to stress the different approaches required for the full understanding of nuclear reactions at intermediate and high energies. Due to the complexity of the problem, only a few semi-qualitative arguments are developed in this paper. The description will be necessarily schematic and somewhat incomplete, but hopefully it will be useful for a first introduction into this topic. Examples are shown mostly for the high energy regime, where all mechanisms mentioned in the paper are at work and to which perhaps most of the readers are less accustomed. Examples for lower energies can be found in the references. (43 refs) .

  10. 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

  11. 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.

  12. 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.

  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. QWalk: A Quantum Monte Carlo Program for Electronic Structure

    CERN Document Server

    Wagner, Lucas K; Mitas, Lubos

    2007-01-01

    We describe QWalk, a new computational package capable of performing Quantum Monte Carlo electronic structure calculations for molecules and solids with many electrons. We describe the structure of the program and its implementation of Quantum Monte Carlo methods. It is open-source, licensed under the GPL, and available at the web site http://www.qwalk.org

  15. Recent Developments in Quantum Monte Carlo: Methods and Applications

    Science.gov (United States)

    Aspuru-Guzik, Alan; Austin, Brian; Domin, Dominik; Galek, Peter T. A.; Handy, Nicholas; Prasad, Rajendra; Salomon-Ferrer, Romelia; Umezawa, Naoto; Lester, William A.

    2007-12-01

    The quantum Monte Carlo method in the diffusion Monte Carlo form has become recognized for its capability of describing the electronic structure of atomic, molecular and condensed matter systems to high accuracy. This talk will briefly outline the method with emphasis on recent developments connected with trial function construction, linear scaling, and applications to selected systems.

  16. 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

  17. 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)

  18. 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.

  19. 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

  20. Practical schemes for accurate forces in quantum Monte Carlo

    NARCIS (Netherlands)

    Moroni, S.; Saccani, S.; Filippi, C.

    2014-01-01

    While the computation of interatomic forces has become a well-established practice within variational Monte Carlo (VMC), the use of the more accurate Fixed-Node Diffusion Monte Carlo (DMC) method is still largely limited to the computation of total energies on structures obtained at a lower level of

  1. 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.

  2. 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

  3. 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)

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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)

  9. 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.

  10. 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)

  11. 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 ...

  12. 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.

  13. 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)

  14. 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.

  15. Projection effects on the FP thickness: a Monte-Carlo exploration

    CERN Document Server

    Lanzoni, B

    2003-01-01

    We study the contribution of projection effects to the intrinsic thickness of the Fundamental Plane (FP) of elliptical galaxies. The Monte-Carlo mapping technique between model properties and observed quantities, introduced by Bertin, Ciotti, and Del Principe (2002), is extended to oblate, two-integrals galaxy models, with non-homologous density profiles, adjustable flattening, variable amount of ordered rotational support, and for which all the relevant projected dynamical quantities can be expressed in fully analytical way. In agreement with previous works, it is found that projection effects move models not exactly parallel to the edge-on FP, by an amount that can be as large as the observed FP thickness. The statistical contribution of projection effects to the FP thickness is however marginal, and the estimated physical FP rms thickness is ~90% of the observed one (when corrected for measurement errors).

  16. 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

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Psicodrama del duelo.

    Directory of Open Access Journals (Sweden)

    José Antonio Espina Barrio

    1997-01-01

    Full Text Available La pérdida de rituales agrava y alarga la reacción del duelo. Se define el Psicodrama Antropológico y su intervención en el proceso del duelo. El Psicodrama Focal del Duelo es una psicoterapia breve centrada en el proceso de Duelo. Se comentan varios casos y resultados. Se concluye con un programa sencillo para el duelo en Atención Primaria.

  4. Fractura triple del complejo suspensorio del hombro

    Directory of Open Access Journals (Sweden)

    Eraclio Delgado Rifá

    2015-06-01

    Full Text Available El complejo suspensorio del hombro es una estructura sumamente importante, compuesta por un anillo de huesos y tejidos blandos. Las lesiones aisladas de este complejo anatómico son frecuentes y no afectan su estabilidad. La interrupción doble conduce a la inestabilidad de esta estructura y usualmente requiere tratamiento quirúrgico. La triple interrupción, por su parte, es sumamente rara y es encontrada en casos de trauma de alta energía a menudo en asociación con otras lesiones. Se presenta una triple lesión del complejo suspensorio del hombro en un paciente de 46 años de edad, con una fractura de la glenoides, del acromion tipo III de Kuhn y de la coracoides tipo II de Ogawa. En este caso, la fractura del acromion fue tratada con fijación percutánea con alambres de Kirschner, por tener asociado lesiones de partes blandas que contraindicaron la reducción abierta. La fractura de la glenoides y de la apófisis coracoides fueron tratadas conservadoramente. Después de 6 meses de evolución, el paciente tuvo un resultado funcional aceptable, con una abducción de 90 grados, los 30 grados de rotación externa y 70 de rotación interna, además asintomático y consolidación de todas las fracturas. A pesar de ser catalogada de una lesión grave del cinturón escapular y estar asociada a otras lesiones se obtuvo un resultado satisfactorio al final del tratamiento.

  5. 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...

  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. 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

  8. 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...

  9. 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...

  10. 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.

  11. 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)

  12. 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)

  13. Diffusion Monte Carlo in internal coordinates.

    Science.gov (United States)

    Petit, Andrew S; McCoy, Anne B

    2013-08-15

    An internal coordinate extension of diffusion Monte Carlo (DMC) is described as a first step toward a generalized reduced-dimensional DMC approach. The method places no constraints on the choice of internal coordinates other than the requirement that they all be independent. Using H(3)(+) and its isotopologues as model systems, the methodology is shown to be capable of successfully describing the ground state properties of molecules that undergo large amplitude, zero-point vibrational motions. Combining the approach developed here with the fixed-node approximation allows vibrationally excited states to be treated. Analysis of the ground state probability distribution is shown to provide important insights into the set of internal coordinates that are less strongly coupled and therefore more suitable for use as the nodal coordinates for the fixed-node DMC calculations. In particular, the curvilinear normal mode coordinates are found to provide reasonable nodal surfaces for the fundamentals of H(2)D(+) and D(2)H(+) despite both molecules being highly fluxional.

  14. Commensurabilities between ETNOs: a Monte Carlo survey

    Science.gov (United States)

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

    2016-07-01

    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 Nine hypothesis; in particular, a number of objects may be trapped in the 5:3 and 3:1 mean motion resonances with a putative Planet Nine with semimajor axis ˜700 au.

  15. 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.)

  16. 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.

  17. 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.

  18. Monte Carlo Simulation of River Meander Modelling

    Science.gov (United States)

    Posner, A. J.; Duan, J. G.

    2010-12-01

    This study first compares the first order analytical solutions for flow field by Ikeda et. al. (1981) and Johanesson and Parker (1989b). Ikeda et. al.’s (1981) linear bank erosion model was implemented to predict the rate of bank erosion in which the bank erosion coefficient is treated as a stochastic variable that varies with physical properties of the bank (e.g. cohesiveness, stratigraphy, vegetation density). The developed model was used to predict the evolution of meandering planforms. Then, the modeling results were analyzed and compared to the observed data. Since the migration of meandering channel consists of downstream translation, lateral expansion, and downstream or upstream rotations. Several measures are formulated in order to determine which of the resulting planform is closest to the experimental measured one. Results from the deterministic model highly depend on the calibrated erosion coefficient. Since field measurements are always limited, the stochastic model yielded more realistic predictions of meandering planform evolutions. Due to the random nature of bank erosion coefficient, the meandering planform evolution is a stochastic process that can only be accurately predicted by a stochastic model. Quasi-2D Ikeda (1989) flow solution with Monte Carlo Simulation of Bank Erosion Coefficient.

  19. Markov Chain Monte Carlo and Irreversibility

    Science.gov (United States)

    Ottobre, Michela

    2016-06-01

    Markov Chain Monte Carlo (MCMC) methods are statistical methods designed to sample from a given measure π by constructing a Markov chain that has π as invariant measure and that converges to π. Most MCMC algorithms make use of chains that satisfy the detailed balance condition with respect to π; such chains are therefore reversible. On the other hand, recent work [18, 21, 28, 29] has stressed several advantages of using irreversible processes for sampling. Roughly speaking, irreversible diffusions converge to equilibrium faster (and lead to smaller asymptotic variance as well). In this paper we discuss some of the recent progress in the study of nonreversible MCMC methods. In particular: i) we explain some of the difficulties that arise in the analysis of nonreversible processes and we discuss some analytical methods to approach the study of continuous-time irreversible diffusions; ii) most of the rigorous results on irreversible diffusions are available for continuous-time processes; however, for computational purposes one needs to discretize such dynamics. It is well known that the resulting discretized chain will not, in general, retain all the good properties of the process that it is obtained from. In particular, if we want to preserve the invariance of the target measure, the chain might no longer be reversible. Therefore iii) we conclude by presenting an MCMC algorithm, the SOL-HMC algorithm [23], which results from a nonreversible discretization of a nonreversible dynamics.

  20. Hot Dog and Butterfly, Nereidum Montes

    Science.gov (United States)

    1999-01-01

    Some of the pictures returned from Mars by the Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) spacecraft show features that--at a glance--resemble familiar, non-geological objects on Earth. For example, the picture above at the left shows several low, relatively flat-topped hills (mesas) on the floor of a broad valley among the mountains of the Nereidum Montes region, northeast of Argyre Planitia. One of the mesas seen here looks like half of a butterfly (upper subframe on right). Another hill looks something like a snail or a hot dog wrapped and baked in a croissant roll (lower subframe on right). These mesas were formed by natural processes and are most likely the eroded remnants of a formerly more extensive layer of bedrock. In the frame on the left, illumination is from the upper left and the scene covers an area 2.7 km (1.7 miles) wide by 6.8 km (4.2 miles) high. The 'butterfly' is about 800 meters (875 yards) in length and the 'hot dog' is about 1 km (0.62 miles) long. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  1. 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.

  2. 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...

  3. 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...

  4. 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)

  5. 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. ...

  6. 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.

  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. LA POLITICA SOCIAL DEL "GOBIERNO DEL CAMBIO"

    Directory of Open Access Journals (Sweden)

    Laura Mota Díaz

    2002-01-01

    Full Text Available El artículo se centra en la política social del actual sexenio foxista , la cual se ha definido como incluyente y equitativa dentro del marco de un gobierno autodenominado del cambio, no sólo por lo que se refiere a la alternancia política del poder, sino porque además pretende ser un gobierno con una visión más amplia del desarrollo. Todo ello se traduce en “nuevas” estrategias para alcanzar la democracia, la equidad, la justicia social y el bienestar general de la población. El objetivo es analizar las posibilidades y limitaciones de un verdadero cambio que contribuya a mejorar la calidad de vida de la población en su sentido más amplio, pues los retos son cada vez mayores dado el incremento en los niveles de pobreza, el creciente desempleo y la constante violación a los derechos humanos.

  9. 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.

  10. 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.

  11. 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...

  12. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1988

    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 1988 calendar year. The report begins with a...

  13. 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

  14. 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...

  15. Monte Carlo techniques for analyzing deep penetration problems

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, S.N.; Gonnord, J.; Hendricks, J.S.

    1985-01-01

    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. 1990 waterfowl production on Alamosa-Monte Vista NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is data on waterfowl production on Alamosa National Wildlife Refuge and Monte Vista National Wildlife Refuge in Colorado. Data are summaries from...

  17. 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...

  18. 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...

  19. 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...

  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 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...

  2. 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)

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. Monte Vista National Wildlife Refuge : Narrative Report : Calendar Year 1971

    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 1971 calendar year. The report begins by...

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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

  13. 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:...

  14. 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 ...

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. Monte Carlo Simulation of Optical Properties of Wake Bubbles

    Institute of Scientific and Technical Information of China (English)

    CAO Jing; WANG Jiang-An; JIANG Xing-Zhou; SHI Sheng-Wei

    2007-01-01

    Based on Mie scattering theory and the theory of multiple light scattering, the light scattering properties of air bubbles in a wake are analysed by Monte Carlo simulation. The results show that backscattering is enhanced obviously due to the existence of bubbles, especially with the increase of bubble density, and that it is feasible to use the Monte Carlo method to study the properties of light scattering by air bubbles.

  4. 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

  5. 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.

  6. Monte Carlo simulation of large electron fields

    Science.gov (United States)

    Faddegon, Bruce A.; Perl, Joseph; Asai, Makoto

    2008-03-01

    Two Monte Carlo systems, EGSnrc and Geant4, the latter with two different 'physics lists,' were used to calculate dose distributions in large electron fields used in radiotherapy. Source and geometry parameters were adjusted to match calculated results to measurement. Both codes were capable of accurately reproducing the measured dose distributions of the six electron beams available on the accelerator. Depth penetration matched the average measured with a diode and parallel-plate chamber to 0.04 cm or better. Calculated depth dose curves agreed to 2% with diode measurements in the build-up region, although for the lower beam energies there was a discrepancy of up to 5% in this region when calculated results are compared to parallel-plate measurements. Dose profiles at the depth of maximum dose matched to 2-3% in the central 25 cm of the field, corresponding to the field size of the largest applicator. A 4% match was obtained outside the central region. The discrepancy observed in the bremsstrahlung tail in published results that used EGS4 is no longer evident. Simulations with the different codes and physics lists used different source energies, incident beam angles, thicknesses of the primary foils, and distance between the primary and secondary foil. The true source and geometry parameters were not known with sufficient accuracy to determine which parameter set, including the energy of the source, was closest to the truth. These results underscore the requirement for experimental benchmarks of depth penetration and electron scatter for beam energies and foils relevant to radiotherapy.

  7. 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.

  8. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.

    2015-12-01

    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single forces, making the nonlinear inversion computationally reasonable. We apply this method to very-long-period (VLP) seismic events that accompany minor eruptions at Fuego volcano, Guatemala. The library of single force Green's functions is computed with a 3D finite-difference modeling algorithm through a homogeneous velocity-density model that includes topography, for a 3D grid of nodes, spaced 40 m apart, within the summit region. The homogenous velocity and density model is justified by long wavelength of VLP data. The nonlinear inversion reveals well resolved model features and informs the interpretation through a better understanding of the possible models. This approach can also be used to evaluate possible station geometries in order to optimize networks prior to deployment.

  9. 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 ...

  10. Desarrollo del lenguaje

    Directory of Open Access Journals (Sweden)

    Silva Villena Omer

    2004-06-01

    Full Text Available

    E. Owens Robert (2003. Desarrollo del lenguaje. Madrid: Pearson Education, S.A. , 2003, (463 páginas. Estamos ante un texto destinado a entender el dominio o ámbito de la "psicolingüística del desarrollo" en el que terapeutas del lenguaje, psicólogos, profesores y lingüistas encontrarán información actualizada y amplia en lo que respecta a los avances que este campo ha experimentado en las dos últimas décadas. Tanto en las cinco ediciones en lengua inglesa desde 1998 a esta esperada edición en español, el propósito del autor es entregar una visión profunda de los procesos de adquisición y desarrollo del lenguaje.

  11. Implications of Monte Carlo Statistical Errors in Criticality Safety Assessments

    Energy Technology Data Exchange (ETDEWEB)

    Pevey, Ronald E.

    2005-09-15

    Most criticality safety calculations are performed using Monte Carlo techniques because of Monte Carlo's ability to handle complex three-dimensional geometries. For Monte Carlo calculations, the more histories sampled, the lower the standard deviation of the resulting estimates. The common intuition is, therefore, that the more histories, the better; as a result, analysts tend to run Monte Carlo analyses as long as possible (or at least to a minimum acceptable uncertainty). For Monte Carlo criticality safety analyses, however, the optimization situation is complicated by the fact that procedures usually require that an extra margin of safety be added because of the statistical uncertainty of the Monte Carlo calculations. This additional safety margin affects the impact of the choice of the calculational standard deviation, both on production and on safety. This paper shows that, under the assumptions of normally distributed benchmarking calculational errors and exact compliance with the upper subcritical limit (USL), the standard deviation that optimizes production is zero, but there is a non-zero value of the calculational standard deviation that minimizes the risk of inadvertently labeling a supercritical configuration as subcritical. Furthermore, this value is shown to be a simple function of the typical benchmarking step outcomes--the bias, the standard deviation of the bias, the upper subcritical limit, and the number of standard deviations added to calculated k-effectives before comparison to the USL.

  12. Adecuación y análisis de sensibilidad de un modelo para la estimación de la capacidad de carga del hábitat de venado cola blanca Fitness and sensitivity analysis of a model to estimate carrying capacity in the habitat from white-tailed deer

    Directory of Open Access Journals (Sweden)

    FX Plata

    2011-01-01

    Full Text Available Se adecuó un modelo para estimar la capacidad de carga (K de venados de cola blanca y se realizó un análisis de sensibilidad utilizando datos de un rancho cinegético localizado en la región semiárida de Aguascalientes, México. El modelo está compuesto por dos componentes, el primero estima la energía metabolizable disponible en un área dada a partir de la disponibilidad de materia vegetal por estratos (gramíneas, herbáceas, arbustivas, arbóreas y la biomasa total y el segundo estima el gasto energético del venado basado en su estado fisiológico, sexo, peso vivo aproximado y época del año. El análisis de sensibilidad reveló que las variables con mayor impacto en el valor de cambio de K (> 5 son la digestibilidad del alimento, la biomasa total disponible y el peso vivo del animal. El menor impacto sobre K (The aim of this study was to fit a model to estimate the carrying capacity (K for white-tailed deer and to perform a sensitivity analysis using data of a hunting ranch located in the semi-arid region of Aguascalientes, Mexico. The model had two main components, the first one calculates the metabolizable energy available in a given area from the accessibility of vegetal matter by strata (forbs, grasses, shrubs, trees and the total biomass, and the second component considered the energetic cost of the deer based on its physiological state, sex, approximated live weight and time of the year. The sensitivity analysis revealed that the variables with a higher impact on the value of change of K (> 5% are the digestibility of the food, the total available biomass and the live weight of the animal. The lower impact on K (< 5% is caused by the type of plant, their proportion in the site and the sex or the physiological state of the animal. It was possible to observe that the increase in the plant variables improves the carrying capacity whereas the increase in the animal energy requirements reduces it.

  13. Alexander von Humboldt und Carlos Montúfar als Reisegefährten: ein Vergleich ihrer Tagebücher zum Chimborazo-Aufstieg

    Directory of Open Access Journals (Sweden)

    Reinhard Andress

    2011-03-01

    Full Text Available ZusammenfassungAls Alexander von Humboldt im Juni 1802 von Quito aus zum Rest seiner lateinamerikanischen Forschungsreise aufbrach, begleitete ihn, abgesehen von Aimé Bonpland, Carlos Montúfar bis nach Europa zurück begleitet, u.a. auch auf beim Versuch, den Chimborazo zu ersteigen. Bis kurz vor der Stadt Cajamarca im heutigen Peru schrieb Montúfar ein relativ unbekanntes Tagebuch zur Reise. Nach einem kurzen Ausflug in das Leben von Humboldts Begleiter steht im Zentrum der weiteren Ausführungen die Frage, ob sein Tagebuch ein anderes Licht auf Humboldt und speziell auf den Aufstiegsversuch wirft. Das läuft auf einen Vergleich der Tagebücher der beiden Reisegefährten hinaus und auf den Versuch, die scheinbaren Widersprüche aufzulösen.AbstractWhen Alexander von Humboldt left Quito in June 1802 in order to undertake the rest of his Latin-American trip of exploration, he was accompanied, aside from Aimé Bonpland, by Carlos Montúfar all the way back to Europe, including the attempt to scale the Chimborazo. Up to shortly before the city of Cajamarca in today’s Peru, Montúfar wrote an relatively unknown diary account of their travels. After a brief excursion into the life of Humboldt’s companion, the question is considered whether his diary sheds a different light on Humboldt and specifically on the mountain climb. That amounts to a comparison of the diaries of the two travel companions and to an attempt to explain the apparent contradictions.ResumenCuando Alexander von Humboldt salió de Quito en junio de 1802 para continuar con el resto de su viaje de exploración por la América Latina, fue acompañado por Carlos Montúfar además de Aimé Bonpland hasta que volvieron a Europa. Este trayecto incluía la tentativa de llegar a la cima del Chimborazo. Hasta un poco antes de la cuidad de Cajamarca que está en el Perú de hoy día, Montúfar mantenía un diario relativamente no conocido del viaje. Después de una breve excursión por

  14. 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.

  15. Elementos del sistema electoral del Congreso Mexicano

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    Aldo Medina García

    2013-07-01

    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.

  16. OBJETIVO DEL DESARROLLO DEL MILENIO 7

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    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.

  17. 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.

  18. 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.

  19. Noticia del hallazgo de un epígrafe altoimperial en el lugar de Pelou, Grandas de Salime (Asturias

    Directory of Open Access Journals (Sweden)

    Villa Valdés, Ángel

    2005-12-01

    Full Text Available The present paper reports the discovery at Monte Castrelo de Pelou (Asturias, Spain of an epigraphic inscription dated at the first Century AD. Monte Castrelo is a little hillfort located in the vicinity of Grandas de Salime township, in the western area of Asturias, in northern Spain. This site was traditionally considered a Roman mining settlement, but current archaeological research unveiled the existence of much older occupation strata underlying the Imperial Roman context where the described inscription was located. The new archaeological data reveal that the site was a fortified settlement already during the Iron Age, being reoccupied, again with a military function, during the fourth century AD. The inscription is engraved in cursives on a slate panel. It contains a list of probably 45 to 50 names, although just around 35 of them are still legible to some extent. It is tentatively interpreted as an administrative document reflecting the census of population under control of the hillfort's garrison.El texto recoge la noticia del descubrimiento de un epígrafe del siglo I d.C. en el Monte Cástrelo de Pelou, en Grandas de Salime, un pequeño castro del occidente de Asturias tradicionalmente interpretado como establecimiento minero de filiación romana. Además del horizonte altoimperial del que procede la pieza, las excavaciones arqueológicas han revelado la existencia de un asentamiento subyacente, fortificado durante la Edad del Hierro, y una reocupación posterior, también de carácter militar, datada en el siglo IV d.C. El epígrafe, grabado sobre pizarra en letra cursiva, pudo contener en origen un listado de 45-50 individuos de los que aún son legibles, en distinto grado, unos 35 nombres. Se trata, probablemente, del censo establecido en el territorio subordinado a la guarnición del castro.

  20. Influencia del manejo del riego en el rendimiento del cafeto

    Directory of Open Access Journals (Sweden)

    Enrique Cisneros Z.

    2006-01-01

    Full Text Available El trabajo trata sobre una investigación de manejo del riego en el cafeto (Coffea Arábica Lin Var. Caturra Rojo de 12 años de edad en la provincia de Pinar del Rió, plantado sobre un suelo Ferralítico Amarillento Lixiviado Cuarcitico. Fueron estudiados 6 tratamientos con un diseño experimental de bloques al azar, el momento de riego y el volumen de aplicación se controló por el método gravimétrico. La técnica de riego empleada fue la microaspersión bajo el principio de cobertura total (no localizada. Como promedio de los cuatro años de estudio se obtuvo que el mejor tratamiento fue el de regar todo el año al 85 % del límite superior de agua disponible, donde fue necesario aplicar 21 riegos con norma parcial neta de 355 m3/ha y norma total neta de 7 455 m3/ha, esta variante produjo 17,94 t/ha de café cereza para un incremento de 3,98 t/ha (29 % con respecto al secano. La rentabilidad más alta se detectó en el tratamiento de riego todo el año (Tratamiento 1 con 236,93 % en comparación con el testigo (Tratamiento 6

  1. 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.

  2. 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...

  3. Zamiaceae endémicas del Perú

    Directory of Open Access Journals (Sweden)

    Blanca León

    2013-06-01

    Full Text Available La familia Zamiaceae es reconocida en el Perú por presentar un género, Zamia, y cuatro especies (Brako & Zarucchi, 1993; Stevenson, 2004, todas arbustivas, con tallos cortos menores de 2 m de alto o desde un tallo subterráneo. En este trabajo reconocemos dos endemismos, los cuales constituyen adiciones a la flora desde 1993 (Ulloa Ulloa et al., 2004. Estas especies endémicas han sido encontradas en bosques de las regiones de Bosques Muy Húmedos Premontanos y Húmedo Amazónico, entre los 100 y 700 m de altitud. Una de ellas se encuentra representada en una de las áreas naturales protegidas. Por lo atractivo de su follaje y valor ornamental, plantas en algunas poblaciones son extraídas ilegalmente para su comercialización.

  4. Zamiaceae endémicas del Perú

    Directory of Open Access Journals (Sweden)

    Blanca León

    2013-10-01

    Full Text Available La familia Zamiaceae es reconocida en el Perú por presentar un género, Zamia, y cuatro especies (Brako & Zarucchi, 1993; Stevenson, 2004, todas arbustivas, con tallos cortos menores de 2 m de alto o desde un tallo subterráneo. En este trabajo reconocemos dos endemismos, los cuales constituyen adiciones a la flora desde 1993 (Ulloa Ulloa et al., 2004. Estas especies endémicas han sido encontradas en bosques de las regiones de Bosques Muy Húmedos Premontanos y Húmedo Amazónico, entre los 100 y 700 m de altitud. Una de ellas se encuentra representada en una de las áreas naturales protegidas. Por lo atractivo de su follaje y valor ornamental, plantas en algunas poblaciones son extraídas ilegalmente para su comercialización.

  5. 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 ...

  6. 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, ...

  7. Hipertrofia del proceso coronoideo

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    E. Moretti

    2014-06-01

    Full Text Available Entre las principales causas de la reducción progresiva y sin dolor de la apertura bucal en pacientes jóvenes, se encuentra la denominada hipertrofia del proceso coronoideo. Se trata de una patología secundaria a la elongación anormal del proceso coronoideo por el crecimiento del hueso que provoca una alteración mecánica al abrir la boca. Presentamos nuestra experiencia con la recogida de 5 casos clínicos.

  8. 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...

  9. 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.

  10. MONTE: An automated Monte Carlo based approach to nuclear magnetic resonance assignment of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Hitchens, T. Kevin; Lukin, Jonathan A.; Zhan Yiping; McCallum, Scott A.; Rule, Gordon S. [Carnegie Mellon University, Department of Biological Sciences (United States)], E-mail: rule@andrew.cmu.edu

    2003-01-15

    A general-purpose Monte Carlo assignment program has been developed to aid in the assignment of NMR resonances from proteins. By virtue of its flexible data requirements the program is capable of obtaining assignments of both heavily deuterated and fully protonated proteins. A wide variety of source data, such as inter-residue scalar connectivity, inter-residue dipolar (NOE) connectivity, and residue specific information, can be utilized in the assignment process. The program can also use known assignments from one form of a protein to facilitate the assignment of another form of the protein. This attribute is useful for assigning protein-ligand complexes when the assignments of the unliganded protein are known. The program can be also be used as an interactive research tool to assist in the choice of additional experimental data to facilitate completion of assignments. The assignment of a deuterated 45 kDa homodimeric Glutathione-S-transferase illustrates the principal features of the program.

  11. Caracterización del hábitat del Pico dorsiblanco (Dendrocopos leucotos) y propuesta de gestión en los hayedos del monte Mortua (Navarra)

    OpenAIRE

    BARNARD BELENGUER, BARRY JAMES

    2015-01-01

    [EN] This Work is part of a larger project of the company Bioma Forestal. It takes place in the beech forests at the watershed between Mediterranean and Atlantic basins in the transition arch between the Cantabric Mountains and the Pyrenees. The studied species, Dendrocopos leucotos, is classified as endangered in Spain, so a detailed knowledge and a management proposal could help to its preservation. In the Mortua forest, 9 territories were found for the white-backed woodpecker (Dendroco...

  12. Brainworkers: Trabajadores del conocimiento

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    Óscar Abellón García

    2004-02-01

    Full Text Available Los trabajadores del conocimiento realizan trabajos que requieren el empleo de la inteligencia, de la facultad de entender: son intelectuales. Se crecen ante los problemas complejos, aprecian la dificultad de la abstracción simplificada, juegan con modelos de realidades virtuales, razonan con transversalidad e intuición, son creativos e innovadores, transfieren informaciones y conceptos, en redes que vinculan conocimientos y amistades; manifiestan, en ese sentido, un espíritu renacentista. La mejor novedad que aporta el trabajador del conocimiento es su alto estado de alerta, su buen manejo de la información y por lo mismo es un guía en adaptación a los cambios del entorno. Las crisis de sectores son precisamente una prueba del funcionamiento ecosistémico de los procesos de cambio.

  13. Los muertos del Floreanismo

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    Enrique Ayala Mora

    2008-06-01

    Full Text Available El artículo analiza el crimen político durante las primeras décadas de vida de la República del Ecuador. Específicamente centra su estudio en el período dominado por la figura de Juan José Flores, primer presidente del Ecuador. La inestabilidad política, la precariedad de las alianzas entre las élites regionales, la crisis económica generada por las guerras de Independencia, las conspiraciones y la violencia que caracterizaron al período de surgimiento de las repúblicas andinas hicieron del crimen político un “vicio de nacimiento”. El asesinato del general Antonio José de Sucre, la muerte de los miembros de la sociedad El Quiteño Libre, el homicidio de Juan Otamendi, entre otros, hicieron patente esta característica.

  14. Preferencias del Turista

    Directory of Open Access Journals (Sweden)

    Jose Luis Leiva Olivencia

    2015-01-01

    Full Text Available Actualmente existen aplicaciones orientadas al turismo basadas en realidad aumentada, pero no integran técnicas de recomendación. Este articulo describe RAMCAT (Realidad Aumentada Móvil Contextual Aplicada al Turismo un modelo de guía turística, que recomienda puntos de interés, teniendo en cuenta factores como preferencias personales y atributos contextuales. Se presentan los componentes teóricos de la arquitectura propuesta, así como sus características, destacando la integración de diferentes sistemas de recomendación, que permiten añadir nuevos motores en el futuro. El articulo se centra en describir sus funcionalidades y el modulo correspondiente al sistema de recomendación basado en el perfil del turista. Otra característica importante del sistema propuesto es la retroalimentación del mismo mediante calificaciones del turista y su trazabilidad.

  15. Monte Carlo treatment planning for photon and electron beams

    Science.gov (United States)

    Reynaert, N.; van der Marck, S. C.; Schaart, D. R.; Van der Zee, W.; Van Vliet-Vroegindeweij, C.; Tomsej, M.; Jansen, J.; Heijmen, B.; Coghe, M.; De Wagter, C.

    2007-04-01

    During the last few decades, accuracy in photon and electron radiotherapy has increased substantially. This is partly due to enhanced linear accelerator technology, providing more flexibility in field definition (e.g. the usage of computer-controlled dynamic multileaf collimators), which led to intensity modulated radiotherapy (IMRT). Important improvements have also been made in the treatment planning process, more specifically in the dose calculations. Originally, dose calculations relied heavily on analytic, semi-analytic and empirical algorithms. The more accurate convolution/superposition codes use pre-calculated Monte Carlo dose "kernels" partly accounting for tissue density heterogeneities. It is generally recognized that the Monte Carlo method is able to increase accuracy even further. Since the second half of the 1990s, several Monte Carlo dose engines for radiotherapy treatment planning have been introduced. To enable the use of a Monte Carlo treatment planning (MCTP) dose engine in clinical circumstances, approximations have been introduced to limit the calculation time. In this paper, the literature on MCTP is reviewed, focussing on patient modeling, approximations in linear accelerator modeling and variance reduction techniques. An overview of published comparisons between MC dose engines and conventional dose calculations is provided for phantom studies and clinical examples, evaluating the added value of MCTP in the clinic. An overview of existing Monte Carlo dose engines and commercial MCTP systems is presented and some specific issues concerning the commissioning of a MCTP system are discussed.

  16. An unbiased Hessian representation for Monte Carlo PDFs

    Energy Technology Data Exchange (ETDEWEB)

    Carrazza, Stefano; Forte, Stefano [Universita di Milano, TIF Lab, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano (Italy); Kassabov, Zahari [Universita di Milano, TIF Lab, Dipartimento di Fisica, Milan (Italy); Universita di Torino, Dipartimento di Fisica, Turin (Italy); INFN, Sezione di Torino (Italy); Latorre, Jose Ignacio [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia, Barcelona (Spain); Rojo, Juan [University of Oxford, Rudolf Peierls Centre for Theoretical Physics, Oxford (United Kingdom)

    2015-08-15

    We develop a methodology for the construction of a Hessian representation of Monte Carlo sets of parton distributions, based on the use of a subset of the Monte Carlo PDF replicas as an unbiased linear basis, and of a genetic algorithm for the determination of the optimal basis. We validate the methodology by first showing that it faithfully reproduces a native Monte Carlo PDF set (NNPDF3.0), and then, that if applied to Hessian PDF set (MMHT14) which was transformed into a Monte Carlo set, it gives back the starting PDFs with minimal information loss. We then show that, when applied to a large Monte Carlo PDF set obtained as combination of several underlying sets, the methodology leads to a Hessian representation in terms of a rather smaller set of parameters (MC-H PDFs), thereby providing an alternative implementation of the recently suggested Meta-PDF idea and a Hessian version of the recently suggested PDF compression algorithm (CMC-PDFs). The mc2hessian conversion code is made publicly available together with (through LHAPDF6) a Hessian representations of the NNPDF3.0 set, and the MC-H PDF set. (orig.)

  17. Frequency domain optical tomography using a Monte Carlo perturbation method

    Science.gov (United States)

    Yamamoto, Toshihiro; Sakamoto, Hiroki

    2016-04-01

    A frequency domain Monte Carlo method is applied to near-infrared optical tomography, where an intensity-modulated light source with a given modulation frequency is used to reconstruct optical properties. The frequency domain reconstruction technique allows for better separation between the scattering and absorption properties of inclusions, even for ill-posed inverse problems, due to cross-talk between the scattering and absorption reconstructions. The frequency domain Monte Carlo calculation for light transport in an absorbing and scattering medium has thus far been analyzed mostly for the reconstruction of optical properties in simple layered tissues. This study applies a Monte Carlo calculation algorithm, which can handle complex-valued particle weights for solving a frequency domain transport equation, to optical tomography in two-dimensional heterogeneous tissues. The Jacobian matrix that is needed to reconstruct the optical properties is obtained by a first-order "differential operator" technique, which involves less variance than the conventional "correlated sampling" technique. The numerical examples in this paper indicate that the newly proposed Monte Carlo method provides reconstructed results for the scattering and absorption coefficients that compare favorably with the results obtained from conventional deterministic or Monte Carlo methods.

  18. Parallel MCNP Monte Carlo transport calculations with MPI

    International Nuclear Information System (INIS)

    The steady increase in computational performance has made Monte Carlo calculations for large/complex systems possible. However, in order to make these calculations practical, order of magnitude increases in performance are necessary. The Monte Carlo method is inherently parallel (particles are simulated independently) and thus has the potential for near-linear speedup with respect to the number of processors. Further, the ever-increasing accessibility of parallel computers, such as workstation clusters, facilitates the practical use of parallel Monte Carlo. Recognizing the nature of the Monte Carlo method and the trends in available computing, the code developers at Los Alamos National Laboratory implemented the message-passing general-purpose Monte Carlo radiation transport code MCNP (version 4A). The PVM package was chosen by the MCNP code developers because it supports a variety of communication networks, several UNIX platforms, and heterogeneous computer systems. This PVM version of MCNP has been shown to produce speedups that approach the number of processors and thus, is a very useful tool for transport analysis. Due to software incompatibilities on the local IBM SP2, PVM has not been available, and thus it is not possible to take advantage of this useful tool. Hence, it became necessary to implement an alternative message-passing library package into MCNP. Because the message-passing interface (MPI) is supported on the local system, takes advantage of the high-speed communication switches in the SP2, and is considered to be the emerging standard, it was selected

  19. 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)

  20. 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.

  1. 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.

  2. Development of ray tracing visualization program by Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, Kenji; Otani, Takayuki [Japan Atomic Energy Research Inst., Tokyo (Japan); Hasegawa, Yukihiro

    1997-09-01

    Ray tracing algorithm is a powerful method to synthesize three dimensional computer graphics. In conventional ray tracing algorithms, a view point is used as a starting point of ray tracing, from which the rays are tracked up to the light sources through center points of pixels on the view screen to calculate the intensities of the pixels. This manner, however, makes it difficult to define the configuration of light source as well as to strictly simulate the reflections of the rays. To resolve these problems, we have developed a new ray tracing means which traces rays from a light source, not from a view point, with use of Monte Carlo method which is widely applied in nuclear fields. Moreover, we adopt the variance reduction techniques to the program with use of the specialized machine (Monte-4) for particle transport Monte Carlo so that the computational time could be successfully reduced. (author)

  3. Optimum and efficient sampling for variational quantum Monte Carlo

    CERN Document Server

    Trail, John Robert; 10.1063/1.3488651

    2010-01-01

    Quantum mechanics for many-body systems may be reduced to the evaluation of integrals in 3N dimensions using Monte-Carlo, providing the Quantum Monte Carlo ab initio methods. Here we limit ourselves to expectation values for trial wavefunctions, that is to Variational quantum Monte Carlo. Almost all previous implementations employ samples distributed as the physical probability density of the trial wavefunction, and assume the Central Limit Theorem to be valid. In this paper we provide an analysis of random error in estimation and optimisation that leads naturally to new sampling strategies with improved computational and statistical properties. A rigorous lower limit to the random error is derived, and an efficient sampling strategy presented that significantly increases computational efficiency. In addition the infinite variance heavy tailed random errors of optimum parameters in conventional methods are replaced with a Normal random error, strengthening the theoretical basis of optimisation. The method is ...

  4. Efficiency of Monte Carlo sampling in chaotic systems.

    Science.gov (United States)

    Leitão, Jorge C; Lopes, J M Viana Parente; Altmann, Eduardo G

    2014-11-01

    In this paper we investigate how the complexity of chaotic phase spaces affect the efficiency of importance sampling Monte Carlo simulations. We focus on flat-histogram simulations of the distribution of finite-time Lyapunov exponent in a simple chaotic system and obtain analytically that the computational effort: (i) scales polynomially with the finite time, a tremendous improvement over the exponential scaling obtained in uniform sampling simulations; and (ii) the polynomial scaling is suboptimal, a phenomenon known as critical slowing down. We show that critical slowing down appears because of the limited possibilities to issue a local proposal in the Monte Carlo procedure when it is applied to chaotic systems. These results show how generic properties of chaotic systems limit the efficiency of Monte Carlo simulations.

  5. Application of biasing techniques to the contributon Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Dubi, A.; Gerstl, S.A.W.

    1980-01-01

    Recently, a new Monte Carlo Method called the Contribution Monte Carlo Method was developed. The method is based on the theory of contributions, and uses a new receipe for estimating target responses by a volume integral over the contribution current. The analog features of the new method were discussed in previous publications. The application of some biasing methods to the new contribution scheme is examined here. A theoretical model is developed that enables an analytic prediction of the benefit to be expected when these biasing schemes are applied to both the contribution method and regular Monte Carlo. This model is verified by a variety of numerical experiments and is shown to yield satisfying results, especially for deep-penetration problems. Other considerations regarding the efficient use of the new method are also discussed, and remarks are made as to the application of other biasing methods. 14 figures, 1 tables.

  6. Monte Carlo Simulation in Statistical Physics An Introduction

    CERN Document Server

    Binder, Kurt

    2010-01-01

    Monte Carlo Simulation in Statistical Physics deals with the computer simulation of many-body systems in condensed-matter physics and related fields of physics, chemistry and beyond, to traffic flows, stock market fluctuations, etc.). Using random numbers generated by a computer, probability distributions are calculated, allowing the estimation of the thermodynamic properties of various systems. This book describes the theoretical background to several variants of these Monte Carlo methods and gives a systematic presentation from which newcomers can learn to perform such simulations and to analyze their results. The fifth edition covers Classical as well as Quantum Monte Carlo methods. Furthermore a new chapter on the sampling of free-energy landscapes has been added. To help students in their work a special web server has been installed to host programs and discussion groups (http://wwwcp.tphys.uni-heidelberg.de). Prof. Binder was awarded the Berni J. Alder CECAM Award for Computational Physics 2001 as well ...

  7. Sequential Monte Carlo on large binary sampling spaces

    CERN Document Server

    Schäfer, Christian

    2011-01-01

    A Monte Carlo algorithm is said to be adaptive if it automatically calibrates its current proposal distribution using past simulations. The choice of the parametric family that defines the set of proposal distributions is critical for a good performance. In this paper, we present such a parametric family for adaptive sampling on high-dimensional binary spaces. A practical motivation for this problem is variable selection in a linear regression context. We want to sample from a Bayesian posterior distribution on the model space using an appropriate version of Sequential Monte Carlo. Raw versions of Sequential Monte Carlo are easily implemented using binary vectors with independent components. For high-dimensional problems, however, these simple proposals do not yield satisfactory results. The key to an efficient adaptive algorithm are binary parametric families which take correlations into account, analogously to the multivariate normal distribution on continuous spaces. We provide a review of models for binar...

  8. Calibration and Monte Carlo modelling of neutron long counters

    CERN Document Server

    Tagziria, H

    2000-01-01

    The Monte Carlo technique has become a very powerful tool in radiation transport as full advantage is taken of enhanced cross-section data, more powerful computers and statistical techniques, together with better characterisation of neutron and photon source spectra. At the National Physical Laboratory, calculations using the Monte Carlo radiation transport code MCNP-4B have been combined with accurate measurements to characterise two long counters routinely used to standardise monoenergetic neutron fields. New and more accurate response function curves have been produced for both long counters. A novel approach using Monte Carlo methods has been developed, validated and used to model the response function of the counters and determine more accurately their effective centres, which have always been difficult to establish experimentally. Calculations and measurements agree well, especially for the De Pangher long counter for which details of the design and constructional material are well known. The sensitivit...

  9. VARIATIONAL MONTE-CARLO APPROACH FOR ARTICULATED OBJECT TRACKING

    Directory of Open Access Journals (Sweden)

    Kartik Dwivedi

    2013-12-01

    Full Text Available In this paper, we describe a novel variational Monte Carlo approach for modeling and tracking body parts of articulated objects. An articulated object (human target is represented as a dynamic Markov network of the different constituent parts. The proposed approach combines local information of individual body parts and other spatial constraints influenced by neighboring parts. The movement of the relative parts of the articulated body is modeled with local information of displacements from the Markov network and the global information from other neighboring parts. We explore the effect of certain model parameters (including the number of parts tracked; number of Monte-Carlo cycles, etc. on system accuracy and show that ourvariational Monte Carlo approach achieves better efficiency and effectiveness compared to other methods on a number of real-time video datasets containing single targets.

  10. Monte Carlo Methods for Tempo Tracking and Rhythm Quantization

    CERN Document Server

    Cemgil, A T; 10.1613/jair.1121

    2011-01-01

    We present a probabilistic generative model for timing deviations in expressive music performance. The structure of the proposed model is equivalent to a switching state space model. The switch variables correspond to discrete note locations as in a musical score. The continuous hidden variables denote the tempo. We formulate two well known music recognition problems, namely tempo tracking and automatic transcription (rhythm quantization) as filtering and maximum a posteriori (MAP) state estimation tasks. Exact computation of posterior features such as the MAP state is intractable in this model class, so we introduce Monte Carlo methods for integration and optimization. We compare Markov Chain Monte Carlo (MCMC) methods (such as Gibbs sampling, simulated annealing and iterative improvement) and sequential Monte Carlo methods (particle filters). Our simulation results suggest better results with sequential methods. The methods can be applied in both online and batch scenarios such as tempo tracking and transcr...

  11. Overview of the MCU Monte Carlo software package

    International Nuclear Information System (INIS)

    Highlights: • MCU is the Monte Carlo code for particle transport in 3D systems with depletion. • Criticality and fixed source problems are solved using pure point-wise approximation. • MCU is parallelized with MPI in three different modes. • MCU has coolant, fuel and xenon feedback for VVER calculations. • MCU is verified for reactors with thermal, intermediate and fast neutron spectrum. - Abstract: MCU (Monte Carlo Universal) is a project on development and practical use of a universal computer code for simulation of particle transport (neutrons, photons, electrons, positrons) in three-dimensional systems by means of the Monte Carlo method. This paper provides the information on the current state of the project. The developed libraries of constants are briefly described, and the potentialities of the MCU-5 package modules and the executable codes compiled from them are characterized. Examples of important problems of reactor physics solved with the code are presented

  12. Estimation of population variance in contributon Monte Carlo

    International Nuclear Information System (INIS)

    Based on the theory of contributons, a new Monte Carlo method known as the contributon Monte Carlo method has recently been developed. The method has found applications in several practical shielding problems. The authors analyze theoretically the variance and efficiency of the new method, by taking moments around the score. In order to compare the contributon game with a game of simple geometrical splitting and also to get the optimal placement of the contributon volume, the moments equations were solved numerically for a one-dimensional, one-group problem using a 10-mfp-thick homogeneous slab. It is found that the optimal placement of the contributon volume is adjacent to the detector; even at its most optimal the contributon Monte Carlo is less efficient than geometrical splitting

  13. Vectorizing and macrotasking Monte Carlo neutral particle algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Heifetz, D.B.

    1987-04-01

    Monte Carlo algorithms for computing neutral particle transport in plasmas have been vectorized and macrotasked. The techniques used are directly applicable to Monte Carlo calculations of neutron and photon transport, and Monte Carlo integration schemes in general. A highly vectorized code was achieved by calculating test flight trajectories in loops over arrays of flight data, isolating the conditional branches to as few a number of loops as possible. A number of solutions are discussed to the problem of gaps appearing in the arrays due to completed flights, which impede vectorization. A simple and effective implementation of macrotasking is achieved by dividing the calculation of the test flight profile among several processors. A tree of random numbers is used to ensure reproducible results. The additional memory required for each task may preclude using a larger number of tasks. In future machines, the limit of macrotasking may be possible, with each test flight, and split test flight, being a separate task.

  14. Monte Carlo tests of the ELIPGRID-PC algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.R.

    1995-04-01

    The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID computer code of Singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM{reg_sign} PC. However, no known independent validation of the ELIPGRID algorithm exists. This document describes a Monte Carlo simulation-based validation of a modified version of the ELIPGRID-PC code. The modified ELIPGRID-PC code is shown to match Monte Carlo-calculated hot-spot detection probabilities to within {plus_minus}0.5% for 319 out of 320 test cases. The one exception, a very thin elliptical hot spot located within a rectangular sampling grid, differed from the Monte Carlo-calculated probability by about 1%. These results provide confidence in the ability of the modified ELIPGRID-PC code to accurately predict hot-spot detection probabilities within an acceptable range of error.

  15. Strategies for improving the efficiency of quantum Monte Carlo calculations

    CERN Document Server

    Lee, R M; Nemec, N; Rios, P Lopez; Drummond, N D

    2010-01-01

    We describe a number of strategies for optimizing the efficiency of quantum Monte Carlo (QMC) calculations. We investigate the dependence of the efficiency of the variational Monte Carlo method on the sampling algorithm. Within a unified framework, we compare several commonly used variants of diffusion Monte Carlo (DMC). We then investigate the behavior of DMC calculations on parallel computers and the details of parallel implementations, before proposing a technique to optimize the efficiency of the extrapolation of DMC results to zero time step, finding that a relative time step ratio of 1:4 is optimal. Finally, we discuss the removal of serial correlation from data sets by reblocking, setting out criteria for the choice of block length and quantifying the effects of the uncertainty in the estimated correlation length and the presence of divergences in the local energy on estimated error bars on QMC energies.

  16. Construction of Monte Carlo operators in collisional transport theory

    International Nuclear Information System (INIS)

    A Monte Carlo approach for investigating the dynamics of quiescent collisional magnetoplasmas is presented, based on the discretization of the gyrokinetic equation. The theory applies to a strongly rotating multispecies plasma, in a toroidally axisymmetric configuration. Expressions of the Monte Carlo collision operators are obtained for general v-space nonorthogonal coordinates systems, in terms of approximate solutions of the discretized gyrokinetic equation. Basic features of the Monte Carlo operators are that they fullfill all the required conservation laws, i.e., linear momentum and kinetic energy conservation, and in addition that they take into account correctly also off-diagonal diffusion coefficients. The present operators are thus potentially useful for describing the dynamics of a multispecies toroidal magnetoplasma. In particular, strict ambipolarity of particle fluxes is ensured automatically in the limit of small departures of the unperturbed particle trajectories from some initial axisymmetric toroidal magnetic surfaces

  17. Meaningful timescales from Monte Carlo simulations of molecular systems

    CERN Document Server

    Costa, Liborio I

    2016-01-01

    A new Markov Chain Monte Carlo method for simulating the dynamics of molecular systems with atomistic detail is introduced. In contrast to traditional Kinetic Monte Carlo approaches, where the state of the system is associated with minima in the energy landscape, in the proposed method, the state of the system is associated with the set of paths traveled by the atoms and the transition probabilities for an atom to be displaced are proportional to the corresponding velocities. In this way, the number of possible state-to-state transitions is reduced to a discrete set, and a direct link between the Monte Carlo time step and true physical time is naturally established. The resulting rejection-free algorithm is validated against event-driven molecular dynamics: the equilibrium and non-equilibrium dynamics of hard disks converge to the exact results with decreasing displacement size.

  18. Properties of Reactive Oxygen Species by Quantum Monte Carlo

    CERN Document Server

    Zen, Andrea; Guidoni, Leonardo

    2014-01-01

    The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal ...

  19. The Monte Carlo method in quantum field theory

    CERN Document Server

    Morningstar, C

    2007-01-01

    This series of six lectures is an introduction to using the Monte Carlo method to carry out nonperturbative studies in quantum field theories. Path integrals in quantum field theory are reviewed, and their evaluation by the Monte Carlo method with Markov-chain based importance sampling is presented. Properties of Markov chains are discussed in detail and several proofs are presented, culminating in the fundamental limit theorem for irreducible Markov chains. The example of a real scalar field theory is used to illustrate the Metropolis-Hastings method and to demonstrate the effectiveness of an action-preserving (microcanonical) local updating algorithm in reducing autocorrelations. The goal of these lectures is to provide the beginner with the basic skills needed to start carrying out Monte Carlo studies in quantum field theories, as well as to present the underlying theoretical foundations of the method.

  20. A standard event class for Monte Carlo generators

    International Nuclear Information System (INIS)

    StdHepC++ is a CLHEP Monte Carlo event class library which provides a common interface to Monte Carlo event generators. This work is an extensive redesign of the StdHep Fortran interface to use the full power of object oriented design. A generated event maps naturally onto the Directed Acyclic Graph concept and we have used the HepMC classes to implement this. The full implementation allows the user to combine events to simulate beam pileup and access them transparently as though they were a single event

  1. Applications of quantum Monte Carlo methods in condensed systems

    CERN Document Server

    Kolorenc, Jindrich

    2010-01-01

    The quantum Monte Carlo methods represent a powerful and broadly applicable computational tool for finding very accurate solutions of the stationary Schroedinger equation for atoms, molecules, solids and a variety of model systems. The algorithms are intrinsically parallel and are able to take full advantage of the present-day high-performance computing systems. This review article concentrates on the fixed-node/fixed-phase diffusion Monte Carlo method with emphasis on its applications to electronic structure of solids and other extended many-particle systems.

  2. Research in the Mont Terri Rock laboratory: Quo vadis?

    Science.gov (United States)

    Bossart, Paul; Thury, Marc

    During the past 10 years, the 12 Mont Terri partner organisations ANDRA, BGR, CRIEPI, ENRESA, FOWG (now SWISSTOPO), GRS, HSK, IRSN, JAEA, NAGRA, OBAYASHI and SCK-CEN have jointly carried out and financed a research programme in the Mont Terri Rock Laboratory. An important strategic question for the Mont Terri project is what type of new experiments should be carried out in the future. This question has been discussed among partner delegates, authorities, scientists, principal investigators and experiment delegates. All experiments at Mont Terri - past, ongoing and future - can be assigned to the following three categories: (1) process and mechanism understanding in undisturbed argillaceous formations, (2) experiments related to excavation- and repository-induced perturbations and (3) experiments related to repository performance during the operational and post-closure phases. In each of these three areas, there are still open questions and hence potential experiments to be carried out in the future. A selection of key issues and questions which have not, or have only partly been addressed so far and in which the project partners, but also the safety authorities and other research organisations may be interested, are presented in the following. The Mont Terri Rock Laboratory is positioned as a generic rock laboratory, where research and development is key: mainly developing methods for site characterisation of argillaceous formations, process understanding and demonstration of safety. Due to geological constraints, there will never be a site specific rock laboratory at Mont Terri. The added value for the 12 partners in terms of future experiments is threefold: (1) the Mont Terri project provides an international scientific platform of high reputation for research on radioactive waste disposal (= state-of-the-art research in argillaceous materials); (2) errors are explicitly allowed (= rock laboratory as a “playground” where experience is often gained through

  3. Monte Carlo methods and models in finance and insurance

    CERN Document Server

    Korn, Ralf

    2010-01-01

    Offering a unique balance between applications and calculations, this book incorporates the application background of finance and insurance with the theory and applications of Monte Carlo methods. It presents recent methods and algorithms, including the multilevel Monte Carlo method, the statistical Romberg method, and the Heath-Platen estimator, as well as recent financial and actuarial models, such as the Cheyette and dynamic mortality models. The book enables readers to find the right algorithm for a desired application and illustrates complicated methods and algorithms with simple applicat

  4. Parton distribution functions in Monte Carlo factorisation scheme

    CERN Document Server

    Jadach, S; Sapeta, S; Siodmok, A; Skrzypek, M

    2016-01-01

    A next step in development of the KrkNLO method of including complete NLO QCD corrections to hard processes in a LO parton-shower Monte Carlo (PSMC) is presented. It consists of generalisation of the method, previously used for the Drell-Yan process, to Higgs-boson production. This extension is accompanied with the complete description of parton distribution functions (PDFs) in a dedicated, Monte Carlo (MC) factorisation scheme, applicable to any process of production of one or more colour-neutral particles in hadron-hadron collisions.

  5. Monte Carlo studies of domain growth in two dimensions

    International Nuclear Information System (INIS)

    Monte Carlo simulations have been carried out to study the effect of temperature on the kinetics of domain growth. The concept of ''spatial entropy'' is introduced. It is shown that ''spatial entropy'' of the domain can be used to give a measure of the roughening of the domain. Most of the roughening is achieved during the initial time (t< or approx. 10 Monte Carlo cycles), the rate of roughening being greater for higher temperatures. For later times the roughening of the domain for different temperatures proceeds at essentially the same rate. (author)

  6. Utilising Monte Carlo Simulation for the Valuation of Mining Concessions

    Directory of Open Access Journals (Sweden)

    Rosli Said

    2005-12-01

    Full Text Available Valuation involves the analyses of various input data to produce an estimated value. Since each input is itself often an estimate, there is an element of uncertainty in the input. This leads to uncertainty in the resultant output value. It is argued that a valuation must also convey information on the uncertainty, so as to be more meaningful and informative to the user. The Monte Carlo simulation technique can generate the information on uncertainty and is therefore potentially useful to valuation. This paper reports on the investigation that has been conducted to apply Monte Carlo simulation technique in mineral valuation, more specifically, in the valuation of a quarry concession.

  7. Monte Carlo simulations of phosphate polyhedron connectivity in glasses

    Energy Technology Data Exchange (ETDEWEB)

    ALAM,TODD M.

    2000-01-01

    Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.

  8. Further experience in Bayesian analysis using Monte Carlo Integration

    OpenAIRE

    Dijk, Herman; Kloek, Teun

    1980-01-01

    textabstractAn earlier paper [Kloek and Van Dijk (1978)] is extended in three ways. First, Monte Carlo integration is performed in a nine-dimensional parameter space of Klein's model I [Klein (1950)]. Second, Monte Carlo is used as a tool for the elicitation of a uniform prior on a finite region by making use of several types of prior information. Third, special attention is given to procedures for the construction of importance functions which make use of nonlinear optimization methods. *1 T...

  9. Monte Carlo Form-Finding Method for Tensegrity Structures

    Science.gov (United States)

    Li, Yue; Feng, Xi-Qiao; Cao, Yan-Ping

    2010-05-01

    In this paper, we propose a Monte Carlo-based approach to solve tensegrity form-finding problems. It uses a stochastic procedure to find the deterministic equilibrium configuration of a tensegrity structure. The suggested Monte Carlo form-finding (MCFF) method is highly efficient because it does not involve complicated matrix operations and symmetry analysis and it works for arbitrary initial configurations. Both regular and non-regular tensegrity problems of large scale can be solved. Some representative examples are presented to demonstrate the efficiency and accuracy of this versatile method.

  10. Diffusion Monte Carlo: Exponentially inefficent for large systems?

    CERN Document Server

    Nemec, Norbert

    2009-01-01

    The computational cost of a Monte Carlo algorithm can only be meaningfully discussed when taking into account the magnitude of the resulting statistical error. Aiming for a fixed error per particle, we study the scaling behavior of the diffusion Monte Carlo method for large quantum systems. We identify the correlation within the population of walkers as the dominant scaling factor for large systems. While this factor is negligible for small and medium sized systems that are typically studied, it ultimately shows exponential scaling beyond system sizes that can be estimated straightforwardly for each specific system.

  11. Novel Quantum Monte Carlo Approaches for Quantum Liquids

    Science.gov (United States)

    Rubenstein, Brenda M.

    Quantum Monte Carlo methods are a powerful suite of techniques for solving the quantum many-body problem. By using random numbers to stochastically sample quantum properties, QMC methods are capable of studying low-temperature quantum systems well beyond the reach of conventional deterministic techniques. QMC techniques have likewise been indispensible tools for augmenting our current knowledge of superfluidity and superconductivity. In this thesis, I present two new quantum Monte Carlo techniques, the Monte Carlo Power Method and Bose-Fermi Auxiliary-Field Quantum Monte Carlo, and apply previously developed Path Integral Monte Carlo methods to explore two new phases of quantum hard spheres and hydrogen. I lay the foundation for a subsequent description of my research by first reviewing the physics of quantum liquids in Chapter One and the mathematics behind Quantum Monte Carlo algorithms in Chapter Two. I then discuss the Monte Carlo Power Method, a stochastic way of computing the first several extremal eigenvalues of a matrix too memory-intensive to be stored and therefore diagonalized. As an illustration of the technique, I demonstrate how it can be used to determine the second eigenvalues of the transition matrices of several popular Monte Carlo algorithms. This information may be used to quantify how rapidly a Monte Carlo algorithm is converging to the equilibrium probability distribution it is sampling. I next present the Bose-Fermi Auxiliary-Field Quantum Monte Carlo algorithm. This algorithm generalizes the well-known Auxiliary-Field Quantum Monte Carlo algorithm for fermions to bosons and Bose-Fermi mixtures. Despite some shortcomings, the Bose-Fermi Auxiliary-Field Quantum Monte Carlo algorithm represents the first exact technique capable of studying Bose-Fermi mixtures of any size in any dimension. In Chapter Six, I describe a new Constant Stress Path Integral Monte Carlo algorithm for the study of quantum mechanical systems under high pressures. While

  12. A standard Event Class for Monte Carlo Generators

    Institute of Scientific and Technical Information of China (English)

    L.A.Gerren; M.Fischler

    2001-01-01

    StdHepC++[1]is a CLHEP[2] Monte Carlo event class library which provides a common interface to Monte Carlo Event Generators,This work is an extensive redesign of the StdHep Fortran interface to use the full power of object oriented design,A generated event maps naturally onto the Directed Acyclic Graph concept and we have used the HepMC classes to implement this.The full implementation allows the user to combine events to simulate beam pileup and access them transparently as though they were a single event.

  13. Parallelization of Monte Carlo codes MVP/GMVP

    Energy Technology Data Exchange (ETDEWEB)

    Nagaya, Yasunobu; Mori, Takamasa; Nakagawa, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sasaki, Makoto

    1998-03-01

    General-purpose Monte Carlo codes MVP/GMVP are well-vectorized and thus enable us to perform high-speed Monte Carlo calculations. In order to achieve more speedups, we parallelized the codes on the different types of the parallel processing platforms. The platforms reported are a distributed-memory vector-parallel computer Fujitsu VPP500, a distributed-memory massively parallel computer Intel Paragon and a distributed-memory scalar-parallel computer Hitachi SR2201. As mentioned generally, ideal speedup could be obtained for large-scale problems but parallelization efficiency got worse as the batch size per a processing element (PE) was smaller. (author)

  14. Enhancements for Multi-Player Monte-Carlo Tree Search

    Science.gov (United States)

    Nijssen, J. (Pim) A. M.; Winands, Mark H. M.

    Monte-Carlo Tree Search (MCTS) is becoming increasingly popular for playing multi-player games. In this paper we propose two enhancements for MCTS in multi-player games: (1) Progressive History and (2) Multi-Player Monte-Carlo Tree Search Solver (MP-MCTS-Solver). We analyze the performance of these enhancements in two different multi-player games: Focus and Chinese Checkers. Based on the experimental results we conclude that Progressive History is a considerable improvement in both games and MP-MCTS-Solver, using the standard update rule, is a genuine improvement in Focus.

  15. Monte Carlo simulation of electrons in dense gases

    Science.gov (United States)

    Tattersall, Wade; Boyle, Greg; Cocks, Daniel; Buckman, Stephen; White, Ron

    2014-10-01

    We implement a Monte-Carlo simulation modelling the transport of electrons and positrons in dense gases and liquids, by using a dynamic structure factor that allows us to construct structure-modified effective cross sections. These account for the coherent effects caused by interactions with the relatively dense medium. The dynamic structure factor also allows us to model thermal gases in the same manner, without needing to directly sample the velocities of the neutral particles. We present the results of a series of Monte Carlo simulations that verify and apply this new technique, and make comparisons with macroscopic predictions and Boltzmann equation solutions. Financial support of the Australian Research Council.

  16. Modelling cerebral blood oxygenation using Monte Carlo XYZ-PA

    Science.gov (United States)

    Zam, Azhar; Jacques, Steven L.; Alexandrov, Sergey; Li, Youzhi; Leahy, Martin J.

    2013-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for the management of many lifethreatening conditions. Non-invasive monitoring of cerebral blood oxygenation with a photoacoustic technique offers advantages over current invasive and non-invasive methods. We introduce a Monte Carlo XYZ-PA to model the energy deposition in 3D and the time-resolved pressures and velocity potential based on the energy absorbed by the biological tissue. This paper outlines the benefits of using Monte Carlo XYZ-PA for optimization of photoacoustic measurement and imaging. To the best of our knowledge this is the first fully integrated tool for photoacoustic modelling.

  17. Cosmological Markov Chain Monte Carlo simulation with Cmbeasy

    CERN Document Server

    Müller, C M

    2004-01-01

    We introduce a Markov Chain Monte Carlo simulation and data analysis package for the cosmological computation package Cmbeasy. We have taken special care in implementing an adaptive step algorithm for the Markov Chain Monte Carlo in order to improve convergence. Data analysis routines are provided which allow to test models of the Universe against up-to-date measurements of the Cosmic Microwave Background, Supernovae Ia and Large Scale Structure. The observational data is provided with the software for convenient usage. The package is publicly available as part of the Cmbeasy software at www.cmbeasy.org.

  18. La imagen del pase.

    Directory of Open Access Journals (Sweden)

    Hernando Bernal.

    1999-11-01

    Full Text Available A partir de un texto del poeta Octavio Paz llamado «La imagen», se busca proseguir la equivalencia entre las imágenes de la poesía y la función que ellas tienen para el poeta, y el fantasma fundamental y su función para el analizante que está en el momento del pase. Se parte de la idea de que la poesía busca entrar en el ser así como el psicoanálisis tiene como finalidad apuntar al corazón del ser del sujeto. Se hace entonces una distinción del concepto de «ser» para el psicoanálisis, haciendo alusión también al discurso de la filosofía. Esclarecido el sentido de lo que es el «ser» para el psicoanálisis, se aborda de lleno – entre otras cosas, relacionadas con la experiencia del pase específicamente- la equivalencia entre la definición que hace Octavio Paz de «La Imagen» y el momento del pase en el análisis de un sujeto, imagen que, al igual que el mito para la filosofía, las leyes para la ciencia y el matema para el psicoanálisis, se constituyen en los instrumentos con los que cada una de estas disciplinas horadan en lo real.

  19. de desarrollo del milenio

    Directory of Open Access Journals (Sweden)

    Diana Alarcón

    2006-01-01

    Full Text Available En septiembre de 2000 la Asamblea general de la Organización de las Naciones Unidas (ONU decidió por consenso adoptar la Declaración del Milenio de donde se derivan los Objetivos de Desarrollo del Milenio que proponen metas sociales específicas dentro del marco del desarrollo humano que deben ser alcanzadas en el 2015. México, como país de ingreso medio, ya ha logrado algunas de las metas y ha mostrado un buen ritmo hacia el cumplimiento de otras. Buena parte de estos logros están asociados al rápido progreso social registrado durante los noventa. En otros renglones, sin embargo, la situación es distinta. La revisión hecha en este trabajo muestra que hay áreas en las que el progreso de los noventa fue lento, rubros en los que los logros sociales no son suficientes y situaciones en las que aún cuando el progreso y el desarrollo son buenos en promedio, la desigualdad que caracteriza el desarrollo del país significa que sectores importantes de la población no tienen acceso a servicios básicos. En particular resalta la débil asociación que existe entre el crecimiento económico, la distribución de ingresos y la incidencia de la pobreza. Nuestra revisión del progreso social en los últimos años nos lleva a concluir que el cumplimiento de los objetivos a los que México se comprometió requiere de una redefinición de las prioridades de desarrollo que permita fortalecer el impacto del crecimiento económico sobre el desarrollo social para cerrar las grandes brechas que existen entre distintos grupos de población y regiones

  20. Scelta dell'habitat del tasso (Meles meles in un'area dell'Oltrepò pavese

    Directory of Open Access Journals (Sweden)

    Valentina Rigo

    2003-10-01

    .f.=1; p<0.001 e siti che presentino, nelle vicinanze, la presenza di castagne: risorsa trofica importante per l'animale (Χ²=6.220; d.f.=1; p=0.013. A differenza di quanto emerso in altre ricerche, il substrato geo-litologico e la distanza dai corsi d'acqua non risultano parametri statisticamente significativi, mentre un basso sviluppo delle strade, che rappresentano un disturbo ed un reale pericolo per i tassi, caratterizza i luoghi scelti per le tane. L'animale sembra prediligere, per le proprie tane, secondo quanto emerge anche dall'analisi multivariata, luoghi con un minore disturbo antropico. In conclusione, il tipo di ambiente, la copertura arborea e arbustiva, l'esposizione dei versanti, la presenza di adeguate risorse trofiche nelle vicinanze, la lontananza da strade e lo sviluppo dei centri abitati sono componenti che influenzano significativamente la presenza del tasso. Fattori geologici, litologici, e idrogeologici sono invece di scarsa importanza nell'area considerata.

  1. An analysis on the costs of Belo Monte hydroelectric power plant; Uma analise sobre os custos da hidreletrica Belo Monte

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcos Vinicius Miranda da [Universidade de Sao Paulo (PIPGE/USP), SP (Brazil). Programa Interunidades de Pos-Graduacao em Energia], e-mail: energiapara@yahoo.com.br

    2008-07-01

    The Belo Monte hydropower plant's low generation cost is among the arguments used by Centrais Eletricas do Norte do Brazil (ELETRONORTE), a Brazilian state electric utility, to make possible its construction. This paper shows that the generation cost presented by ELETROBRAS is very low in relation to the world pattern of cost and probably unrealistic. It also shows that the generation cost cannot be used separately to determine the Belo Monte dam's economic feasibility. There is the need to include other costs, such as: socio environmental degradation and control, financial compensation for using the hydraulic resources, transmission and thermal backup stations, beyond, evidently, generation cost for assuring the credibility of the Belo Monte hydropower plant's economic analysis. (author)

  2. del Estado Carabobo

    Directory of Open Access Journals (Sweden)

    Jennifer Fuenmayor

    2006-01-01

    Full Text Available Al iniciarse el proceso de descentralización político-territorial a finales de los ochenta, las gobernaciones de Venezuela deben redefinir sus directrices debido al traspaso de funciones y competencias que les son otorgadas desde el gobierno central, e insertarse en una dinámica orientada hacia una economía de mercado impulsada por la globalización, y enmarcada en el discurso del desarrollo sustentable. El propósito de este artículo es explorar las acciones desplegadas por la Gobernación de Carabobo en el período 1990-2004, en pro del desarrollo sustentable y sostenible en los ámbitos: económico, ambiental y social. Para ello se considera la definición que nos da Dourojeanni (1999 sobre el desarrollo sustentable y sostenible. Se parte del supuesto de que debido a la orientación neoliberal del Gobierno de Carabobo, este ha concentrado sus esfuerzos en la promoción del crecimiento, la eficiencia, la productividad y la competitividad, privilegiando con ello sólo un ámbito del desarrollo: el económico. La metodología consistió en el estudio de documentos teóricos y empí-Al iniciarse el proceso de descentralización político-territorial a finales de los ochenta, las gobernaciones de Venezuela deben redefinir sus directrices debido al traspaso de funciones y competencias que les son otorgadas desde el gobierno central, e insertarse en una dinámica orientada hacia una economía de mercado impulsada por la globalización, y enmarcada en el discurso del desarrollo sustentable. El propósito de este artículo es explorar las acciones desplegadas por la Gobernación de Carabobo en el período 1990-2004, en pro del desarrollo sustentable y sostenible en los ámbitos: económico, ambiental y social. Para ello se considera la definición que nos da Dourojeanni (1999 sobre el desarrollo sustentable y sostenible. Se parte del supuesto de que debido a la orientación neoliberal del Gobierno de Carabobo, este ha concentrado sus esfuerzos en

  3. PRESENTE Y FUTURO DEL DERECHO DEL TRABAJO: BREVE HISTORIA JURÍDICA DEL DERECHO DEL TRABAJO EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Iván Daniel Jaramillo Jassir

    2010-11-01

    Full Text Available El acontecimiento jurídico del siglo XX, sin duda, lo constituye el nacimiento y consolidación de una disciplina jurídica que tiene por objeto regular la relación capital-trabajo en forma autónoma. El presente escrito tiene como finalidad describir las vicisitudes del nacimiento del derecho del trabajo y los procesos que han enmarcado la evolución de esta rama del derecho así como una descripción de las tendencias que experimenta esta disciplina en el inicio del siglo XXI.

  4. del Estado Aragua

    Directory of Open Access Journals (Sweden)

    Joselys Cintia Zerpa

    2008-01-01

    Full Text Available Diagnostica la situación actual de los bienes que conforman al patrimonio histórico-cultural del Municipio Zamora, Estado Aragua, Venezuela. La Investigación es descriptiva y de campo, comprendió la elaboración de un inventario de los bienes inmuebles, festividades religiosas y manifestaciones artesanales del municipio. Se estudiaron la condición física y uso actual de estos bienes y los planes y proyectos existentes. Analizó el marco normativo que los rige. Se obtuvo la opinión de los representantes de organismos públicos relacionados con la actividad turística del Municipio, de los visitantes, cronistas e historiadores. Aportes: La mayoría de los bienes se encuentran en buen estado de conservación, Las manifestaciones culturales, festividades y la artesanía se desarrollan periódicamente pero no son aprovechadas turísticamente, Se determinó que existe un marco normativo para tales bienes y No existen propuestas actuales referentes a estos bienes. Se reflejó el interés de los sectores institucional y privado para la incorporación de estos bienes a la oferta turística del Municipio y del Estado

  5. Historia del vuelo aviano

    Directory of Open Access Journals (Sweden)

    Sanz, José Luis

    1998-12-01

    Full Text Available Not available.El análisis del registro fósil proporciona información sobre la historia evolutiva del aparato volador aviano y el origen y desarrollo del vuelo moderno. Existen dos hipótesis alternativas para explicar las complejas presiones de selección que configuraron la aparición del vuelo. La propuesta del corredor («desde el suelo hacia arriba» es la que mejor se ajusta a la evidencia disponible. El ave primitiva Archaeopteryx produciría, probablemente, algún tipo de vuelo batido, aunque su capacidad de maniobra, despegue y aterrizaje sería limitada. El vuelo activo moderno comenzó, durante el Cretácico inferior, con las aves ornitotoraces basales, como Iberomesornis. No obstante, esta ave primitiva, cuya capacidad de vuelo estaba claramente incrementada con respecto a la condición ancestral presente en Archaeopteryx, tampoco parece tener las perfectas habilidades voladoras de las aves modernas.

  6. Apostillas acerca del postrabajo

    Directory of Open Access Journals (Sweden)

    Arturo Torrecilla

    2000-04-01

    Full Text Available El más reciente debate en torno al postrabajo transforma la herencia de los dos ciclos que le precedieron desde los años setenta. El primero se correspondía con la crítica de la división social y técnica de labores informada por una filosofía de la alienación o bien por una rectificación de la arquitectónica marxista pero salvaguardando la promesa laborista del buen trabajo. El segundo ciclo hacía eco del rechazo a las cadenas de montaje fordistas y se abría al horizonte de la abolición del trabajo salarial, manteniendo sin embargo el abolengo del sujeto unitario de la historia. La presente escena asume una densidad mayor, producto del encuentro entre las nuevas tecnologías informacionales, las discusiones en el ámbito de la sociología y la antropología, de la tecnología y la ciencia, junto al dueto que inaugura el posmodernismo.

  7. Las carreras del futuro

    Directory of Open Access Journals (Sweden)

    Luis Piscoya Hermoza

    2011-07-01

    Full Text Available La primera década del siglo XXI ha estado signada por un énfasis en los estudiosde prospectiva, los mismos que, a partir de procesos de complejizacióny articulación de la sociedad planetaria como son la digitalización, el progresivodeterioro del medio ambiente, la necesidad del cambio de la matriz energéticay la globalización del mercado, han ensayado hipótesis para identificar lastendencias que se fortalecerán y profundizarán durante las próximas décadas.Desde el punto de vista metodológico, existen muchas maneras de clasificarlaspara conceptualizarlas y entenderlas mejor. Sin embargo, considerando lanaturaleza de esta edición nos proponemos enfocar directamente aquellas queestán estrechamente ligadas a la formación universitaria.Naturalmente, no pensamos que estamos ante tendencias inevitables en lamedida que epistemológicamente la creencia en leyes históricas deterministases insostenible y la práctica social nos muestra que la construcción del futuroes nuestra responsabilidad y siempre rebasa las mejores previsiones.

  8. La espiral del mestizaje

    Directory of Open Access Journals (Sweden)

    Guillermo Cervantes

    2009-01-01

    Full Text Available El presente ensayo explora el papel jugado por el mestizaje como instrumento para forjar una identidad nacional en México; donde lo indígena convive y se fusiona con lo europeo, en la persecución y construcción de algo entendido propiamente como mexicano. Partiendo desde la época colonial en la Nueva España, abordaremos el papel concedido al indígena mexicano y su lenta inclusión en la sociedad mediante la adopción de prácticas consideradas como occidentales y civilizadas en detrimento de sus prácticas indígenas tradicionales, consideradas primitivas y atrasadas, como medio de asimilación. Fenómeno que más tarde habría de proponer al mestizo como estereotipo de la identidad nacional mexicana durante el siglo XIX; y que culminaría en su consolidación a principios del siglo XX. Así mismo se aborda la percepción del mestizaje como medio de civilización en la idiosincrasia del mexicano y del méxico-americano para culminar con una evolución de la constante búsqueda de lo occidental, esta vez mediante la asimilación al modo de vida estadounidense, como continuación del proceso civilizatorio entendido como mestizaje

  9. El Cuerpo del Saber

    Directory of Open Access Journals (Sweden)

    Lourdes Consuelo Pacheco Ladrón de Guevara

    2015-01-01

    Full Text Available En el presente artículo se aborda la exclusión del cuerpo realizado por la cien - cia moderna puesto que en la tradición del conocimiento científico el cuerpo se convirtió en un obstáculo epistemológico. Las mujeres fueron consideradas estructuradas por el cuerpo, sus deseos y pulsiones en tanto los varones fueron autovalorados como signados por la razón, la objetividad y la neutralidad. La incorporación de las mujeres a la ciencia llevó a discutir los postulados de la ciencia, el silenciamiento del cuerpo y el reconocimiento de la subjetividad como parte del quehacer científico. Los saberes desde el cuerpo de las muje - res enuncian otra forma de conocer, transgreden la legitimidad de la ciencia masculina de la dominación porque su proceso de construcción no ocurre en el distanciamiento del mundo, sino en la proximidad con él.

  10. del empleo independiente

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Díaz

    2005-01-01

    Full Text Available Se describen los cambios que la gerencia pública del trabajo debe asumir por el aumento del empleo independiente, partiendo de la hipótesis que las decisiones planteadas dependen de que el Estado pueda superar severos condicionantes que limitan su accionar, cada vez más reducido. Siguiendo un enfoque metodológico cualitativo descriptivo y requiriéndose de la contextualización por el lado de la administración previsional; se constata que pese al número de iniciativas disponibles, la gerencia del trabajo, adoptó una reforma uniforme sin logros satisfactorios. Sin embargo, países que no lo hicieron, obtuvieron resultados similares, por rígidos condicionantes en curso, tales como la incursión a la economía mundial; la crisis de lo colectivo; la no inclusión de la seguridad social en la agenda partidista; y la falta de una gerencia propia y especializada. Se concluye que la seguridad social no es un programa neutral y que las mejoras gerenciales sólo serán posibles al superarse tales restricciones. Por su parte, el Ministerio del Trabajo, como ente principal, a causa de la contracción del mercado, pierde significado e importancia, pues las políticas públicas se desplazan prioritariamente a otros programas de tipo asistencial.

  11. Pseudopotentials for quantum-Monte-Carlo-calculations; Pseudopotentiale fuer Quanten-Monte-Carlo-Rechnungen

    Energy Technology Data Exchange (ETDEWEB)

    Burkatzki, Mark Thomas

    2008-07-01

    The author presents scalar-relativistic energy-consistent Hartree-Fock pseudopotentials for the main-group and 3d-transition-metal elements. The pseudopotentials do not exhibit a singularity at the nucleus and are therefore suitable for quantum Monte Carlo (QMC) calculations. The author demonstrates their transferability through extensive benchmark calculations of atomic excitation spectra as well as molecular properties. In particular, the author computes the vibrational frequencies and binding energies of 26 first- and second-row diatomic molecules using post Hartree-Fock methods, finding excellent agreement with the corresponding all-electron values. The author shows that the presented pseudopotentials give superior accuracy than other existing pseudopotentials constructed specifically for QMC. The localization error and the efficiency in QMC are discussed. The author also presents QMC calculations for selected atomic and diatomic 3d-transitionmetal systems. Finally, valence basis sets of different sizes (VnZ with n=D,T,Q,5 for 1st and 2nd row; with n=D,T for 3rd to 5th row; with n=D,T,Q for the 3d transition metals) optimized for the pseudopotentials are presented. (orig.)

  12. Stochastic simulation and Monte-Carlo methods; Simulation stochastique et methodes de Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Graham, C. [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France); Ecole Polytechnique, 91 - Palaiseau (France); Talay, D. [Institut National de Recherche en Informatique et en Automatique (INRIA), 78 - Le Chesnay (France); Ecole Polytechnique, 91 - Palaiseau (France)

    2011-07-01

    This book presents some numerical probabilistic methods of simulation with their convergence speed. It combines mathematical precision and numerical developments, each proposed method belonging to a precise theoretical context developed in a rigorous and self-sufficient manner. After some recalls about the big numbers law and the basics of probabilistic simulation, the authors introduce the martingales and their main properties. Then, they develop a chapter on non-asymptotic estimations of Monte-Carlo method errors. This chapter gives a recall of the central limit theorem and precises its convergence speed. It introduces the Log-Sobolev and concentration inequalities, about which the study has greatly developed during the last years. This chapter ends with some variance reduction techniques. In order to demonstrate in a rigorous way the simulation results of stochastic processes, the authors introduce the basic notions of probabilities and of stochastic calculus, in particular the essential basics of Ito calculus, adapted to each numerical method proposed. They successively study the construction and important properties of the Poisson process, of the jump and deterministic Markov processes (linked to transport equations), and of the solutions of stochastic differential equations. Numerical methods are then developed and the convergence speed results of algorithms are rigorously demonstrated. In passing, the authors describe the probabilistic interpretation basics of the parabolic partial derivative equations. Non-trivial applications to real applied problems are also developed. (J.S.)

  13. Distribution of trace elements in altered pyroclastites from Monte Vulture volcano (southern Italy

    Directory of Open Access Journals (Sweden)

    Piccarreta, G.

    1995-08-01

    Full Text Available Three pyroclastic deposits from Monte Yulture volcanic area (Potenza, southern Italy looking like paleosols in the field were investigated in a previous study for mineralogy and major elements to estimate the stage of the weathering. Here is dealt with the behaviour of sorne trace elements (Ce, La, Ba, Ni, Cr, Y, Rb, Sr, Y, Zr and Nb in the same deposits to give a comprehensive geochemical picture. The distribution of the chemical elements within the whole rock and after its attack with Na-pyrosulfate (residue + solute has been considered. Ba and Sr, as well as their distribution, appear to be controlled by the residual crystals in each of the deposits; La, Ce, Y and Nb are more concentrated in the solute that once was represented by vitric component, allophane, and Fe-Si-Al gels, biotite, carbonates and analcite; Y, Cr, and Ni show similar trends in whole rock and in solute. In particular La, Ce, Y, Y, Cr and Ni in the lowermost unit increase with the depth, as well as the contents of gels and allophane. Probably this behaviour was superimposed by the fluctuation of the water tables, as documented by the occurrence of a carbonate level upon the unit lies. It is concluded that the earliest stage of weathering did not affect the trace element distribution and that interpretations about chemical changes in deeply altered pyroclastic rocks should be always the outcome of careful accurate analyses.En un trabajo previo se estudiaron tres depósitos piroclásticos, considerados como paleosuelos, del área volcánica del Monte Yulture (Potenza, Italia para deducir su grado de meteorización. En el presente trabajo se estudia el comportamiento de algunos elementos traza (Ce, La, Ba, Ni, Cr, Y, Rb, Sr, Y, Zr, Nb en esos depósitos para intentar obtener una imagen geoquímica más completa. Se ha estudiado la distribución de elementos traza en la roca total y después de un ataque con pirosulfato-Na (residuo + solución. Ba y Sr parecen estar controlados

  14. Improved Monte Carlo model for multiple scattering calculations

    Institute of Scientific and Technical Information of China (English)

    Weiwei Cai; Lin Ma

    2012-01-01

    The coupling between the Monte Carlo (MC) method and geometrical optics to improve accuracy is investigated.The results obtained show improved agreement with previous experimental data,demonstrating that the MC method,when coupled with simple geometrical optics,can simulate multiple scattering with enhanced fidelity.

  15. Monte Carlo simulation of the seed germination process

    International Nuclear Information System (INIS)

    Paper presented a mathematical model of seed germination process based on the Monte Carlo method and theoretical premises resulted from the physiology of seed germination suggesting three consecutive stages: physical, biochemical and physiological. The model was experimentally verified by determination of germination characteristics for seeds of ground tomatoes, Promyk cultivar, within broad range of temperatures (from 15 to 30 deg C)

  16. Variational Monte Carlo Calculations of Energy per Particle Nuclear Matter

    OpenAIRE

    Manisa, K.

    2004-01-01

    In this paper, symmetrical nuclear matter has been investigated. Total, kinetic and potential energies per particle were obtained for nuclear matter by Variational Monte Carlo method. We have observed that the results are in good agreement with those obtained by various authors who used different potentials and techniques.

  17. Monte Carlo Simulation Optimizing Design of Grid Ionization Chamber

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Yu-lai; WANG; Qiang; YANG; Lu

    2013-01-01

    The grid ionization chamber detector is often used for measuring charged particles.Based on Monte Carlo simulation method,the energy loss distribution and electron ion pairs of alpha particle with different energy have been calculated to determine suitable filling gas in the ionization chamber filled with

  18. Monte Carlo simulation of magnetic nanostructured thin films

    Institute of Scientific and Technical Information of China (English)

    Guan Zhi-Qiang; Yutaka Abe; Jiang Dong-Hua; Lin Hai; Yoshitake Yamazakia; Wu Chen-Xu

    2004-01-01

    @@ Using Monte Carlo simulation, we have compared the magnetic properties between nanostructured thin films and two-dimensional crystalline solids. The dependence of nanostructured properties on the interaction between particles that constitute the nanostructured thin films is also studied. The result shows that the parameters in the interaction potential have an important effect on the properties of nanostructured thin films at the transition temperatures.

  19. Quantum Monte Carlo simulation of topological phase transitions

    CERN Document Server

    Yamamoto, Arata

    2016-01-01

    We study the electron-electron interaction effects on topological phase transitions by the ab-initio quantum Monte Carlo simulation. We analyze two-dimensional class A topological insulators and three-dimensional Weyl semimetals with the long-range Coulomb interaction. The direct computation of the Chern number shows the electron-electron interaction modifies or extinguishes topological phase transitions.

  20. Simulating Strongly Correlated Electron Systems with Hybrid Monte Carlo

    Institute of Scientific and Technical Information of China (English)

    LIU Chuan

    2000-01-01

    Using the path integral representation, the Hubbard and the periodic Anderson model on D-dimensional cubic lattice are transformed into field theories of fermions in D + 1 dimensions. These theories at half-filling possess a positive definite real symmetry fermion matrix and can be simulated using the hybrid Monte Carlo method.

  1. Observations on variational and projector Monte Carlo methods

    Energy Technology Data Exchange (ETDEWEB)

    Umrigar, C. J., E-mail: CyrusUmrigar@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853 (United States)

    2015-10-28

    Variational Monte Carlo and various projector Monte Carlo (PMC) methods are presented in a unified manner. Similarities and differences between the methods and choices made in designing the methods are discussed. Both methods where the Monte Carlo walk is performed in a discrete space and methods where it is performed in a continuous space are considered. It is pointed out that the usual prescription for importance sampling may not be advantageous depending on the particular quantum Monte Carlo method used and the observables of interest, so alternate prescriptions are presented. The nature of the sign problem is discussed for various versions of PMC methods. A prescription for an exact PMC method in real space, i.e., a method that does not make a fixed-node or similar approximation and does not have a finite basis error, is presented. This method is likely to be practical for systems with a small number of electrons. Approximate PMC methods that are applicable to larger systems and go beyond the fixed-node approximation are also discussed.

  2. JCOGIN. A parallel programming infrastructure for Monte Carlo particle transport

    International Nuclear Information System (INIS)

    The advantages of the Monte Carlo method for reactor analysis are well known, but the full-core reactor analysis challenges the computational time and computer memory. Meanwhile, the exponential growth of computer power in the last 10 years is now creating a great opportunity for large scale parallel computing on the Monte Carlo full-core reactor analysis. In this paper, a parallel programming infrastructure is introduced for Monte Carlo particle transport, named JCOGIN, which aims at accelerating the development of Monte Carlo codes for the large scale parallelism simulations of the full-core reactor. Now, JCOGIN implements the hybrid parallelism of the spatial decomposition and the traditional particle parallelism on MPI and OpenMP. Finally, JMCT code is developed on JCOGIN, which reaches the parallel efficiency of 70% on 20480 cores for fixed source problem. By the hybrid parallelism, the full-core pin-by-pin simulation of the Dayawan reactor was implemented, with the number of the cells up to 10 million and the tallies of the fluxes utilizing over 40GB of memory. (author)

  3. Criticality benchmarks validation of the Monte Carlo code TRIPOLI-2

    Energy Technology Data Exchange (ETDEWEB)

    Maubert, L. (Commissariat a l' Energie Atomique, Inst. de Protection et de Surete Nucleaire, Service d' Etudes de Criticite, 92 - Fontenay-aux-Roses (France)); Nouri, A. (Commissariat a l' Energie Atomique, Inst. de Protection et de Surete Nucleaire, Service d' Etudes de Criticite, 92 - Fontenay-aux-Roses (France)); Vergnaud, T. (Commissariat a l' Energie Atomique, Direction des Reacteurs Nucleaires, Service d' Etudes des Reacteurs et de Mathematique Appliquees, 91 - Gif-sur-Yvette (France))

    1993-04-01

    The three-dimensional energy pointwise Monte-Carlo code TRIPOLI-2 includes metallic spheres of uranium and plutonium, nitrate plutonium solutions, square and triangular pitch assemblies of uranium oxide. Results show good agreements between experiments and calculations, and avoid a part of the code and its ENDF-B4 library validation. (orig./DG)

  4. Testing Dependent Correlations with Nonoverlapping Variables: A Monte Carlo Simulation

    Science.gov (United States)

    Silver, N. Clayton; Hittner, James B.; May, Kim

    2004-01-01

    The authors conducted a Monte Carlo simulation of 4 test statistics or comparing dependent correlations with no variables in common. Empirical Type 1 error rates and power estimates were determined for K. Pearson and L. N. G. Filon's (1898) z, O. J. Dunn and V. A. Clark's (1969) z, J. H. Steiger's (1980) original modification of Dunn and Clark's…

  5. Monte Carlo Simulations of Impact Ionization Feedback in MOSFET Structures

    OpenAIRE

    Bude, Jeff D.

    1998-01-01

    Although impact ionization feedback is recognized as an important current multiplication mechanism, its importance as a carrier heating mechanism has been largely overlooked. This work emphasizes the inclusion of impact ionization feedback in Monte Carlo device simulations, and its implications for carrier heating in sub-micron CMOS and EEPROM technologies.

  6. Exact Dynamics via Poisson Process: a unifying Monte Carlo paradigm

    Science.gov (United States)

    Gubernatis, James

    2014-03-01

    A common computational task is solving a set of ordinary differential equations (o.d.e.'s). A little known theorem says that the solution of any set of o.d.e.'s is exactly solved by the expectation value over a set of arbitary Poisson processes of a particular function of the elements of the matrix that defines the o.d.e.'s. The theorem thus provides a new starting point to develop real and imaginary-time continous-time solvers for quantum Monte Carlo algorithms, and several simple observations enable various quantum Monte Carlo techniques and variance reduction methods to transfer to a new context. I will state the theorem, note a transformation to a very simple computational scheme, and illustrate the use of some techniques from the directed-loop algorithm in context of the wavefunction Monte Carlo method that is used to solve the Lindblad master equation for the dynamics of open quantum systems. I will end by noting that as the theorem does not depend on the source of the o.d.e.'s coming from quantum mechanics, it also enables the transfer of continuous-time methods from quantum Monte Carlo to the simulation of various classical equations of motion heretofore only solved deterministically.

  7. Microbial contamination in poultry chillers estimated by Monte Carlo simulations

    Science.gov (United States)

    The risk of microbial contamination during poultry processing may be reduced by the operating characteristics of the chiller. The performance of air chillers and immersion chillers were compared in terms of pre-chill and post-chill contamination using Monte Carlo simulations. Three parameters were u...

  8. Research of Monte Carlo Simulation in Commercial Bank Risk Management

    Institute of Scientific and Technical Information of China (English)

    BeimingXiao

    2004-01-01

    Simulation method is an important-tool in financial risk management. It can simulate financial variable or economic wriable and deal with non-linear or non-nominal issue. This paper analyzes the usage of "Monte Carlo" approach in commercial bank risk management.

  9. Revisiting Residential Segregation by Income: A Monte Carlo Test

    OpenAIRE

    Junfu Zhang

    2003-01-01

    A long-standing hypothesis states that racial housing segregation in the U.S. results from the income inequalities between blacks and whites. This paper reexamines this hypothesis with a new methodology. We present a Monte Carlo study to show that segregation by income explains only a small proportion of the high level of segregation.

  10. Monte Carlo Greeks for financial products via approximative transition densities

    OpenAIRE

    Joerg Kampen; Anastasia Kolodko; John Schoenmakers

    2008-01-01

    In this paper we introduce efficient Monte Carlo estimators for the valuation of high-dimensional derivatives and their sensitivities (''Greeks''). These estimators are based on an analytical, usually approximative representation of the underlying density. We study approximative densities obtained by the WKB method. The results are applied in the context of a Libor market model.

  11. On the inner workings of Monte Carlo codes

    NARCIS (Netherlands)

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

    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

  12. Monte Carlo: in the beginning and some great expectations

    International Nuclear Information System (INIS)

    The central theme will be on the historical setting and origins of the Monte Carlo Method. The scene was post-war Los Alamos Scientific Laboratory. There was an inevitability about the Monte Carlo Event: the ENIAC had recently enjoyed its meteoric rise (on a classified Los Alamos problem); Stan Ulam had returned to Los Alamos; John von Neumann was a frequent visitor. Techniques, algorithms, and applications developed rapidly at Los Alamos. Soon, the fascination of the Method reached wider horizons. The first paper was submitted for publication in the spring of 1949. In the summer of 1949, the first open conference was held at the University of California at Los Angeles. Of some interst perhaps is an account of Fermi's earlier, independent application in neutron moderation studies while at the University of Rome. The quantum leap expected with the advent of massively parallel processors will provide stimuli for very ambitious applications of the Monte Carlo Method in disciplines ranging from field theories to cosmology, including more realistic models in the neurosciences. A structure of multi-instruction sets for parallel processing is ideally suited for the Monte Carlo approach. One may even hope for a modest hardening of the soft sciences

  13. Recent improvements on Monte Carlo modelling at ATLAS

    CERN Document Server

    Soualah, Rachik; The ATLAS collaboration

    2015-01-01

    The most recent findings on the Monte Carlo simulation of proton-proton collisions at ATLAS are presented. In this, the most recent combined MPI and shower tunes performed using 7 TeV ATLAS data are reported, as well as improved modeling of electroweak processes, and processes containing top using recent MC generators and PDF sets.

  14. Monte-Carlo tree search for Poly-Y

    NARCIS (Netherlands)

    Wevers, Lesley; Brinke, te Steven

    2014-01-01

    Monte-Carlo tree search (MCTS) is a heuristic search algorithm that has recently been very successful in the games of Go and Hex. In this paper, we describe an MCTS player for the game of Poly-Y, which is a connection game similar to Hex. Our player won the CodeCup 2014 AI programming competition. O

  15. Radio emission from cosmic ray air showers : Monte Carlo simulations

    NARCIS (Netherlands)

    Huege, T.; Falcke, H.D.E.

    2005-01-01

    We present time-domain Monte Carlo simulations of radio emission from cosmic ray air showers in the scheme of coherent geosynchrotron radiation. Our model takes into account the important air shower characteristics such as the lateral and longitudinal particle distributions, the particle track lengt

  16. A Variational Monte Carlo Approach to Atomic Structure

    Science.gov (United States)

    Davis, Stephen L.

    2007-01-01

    The practicality and usefulness of variational Monte Carlo calculations to atomic structure are demonstrated. It is found to succeed in quantitatively illustrating electron shielding, effective nuclear charge, l-dependence of the orbital energies, and singlet-tripetenergy splitting and ionization energy trends in atomic structure theory.

  17. Auxiliary-field quantum Monte Carlo methods in nuclei

    CERN Document Server

    Alhassid, Y

    2016-01-01

    Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal and ground state properties of correlated quantum many-body systems in model spaces that are many orders of magnitude larger than those that can be treated by conventional diagonalization methods. We review recent developments and applications of these methods in nuclei using the framework of the configuration-interaction shell model.

  18. Monte Carlo Simulation on Glueball Search at BESⅢ

    Institute of Scientific and Technical Information of China (English)

    QIN Hu; SHEN Xiao-Yan

    2007-01-01

    The J/ψ radiative decays are suggested as promising modes for glueball search. A full Monte Carlo simulation of J/ψ→γηη and γηη', based on the design of BESⅢ detector, is performed to study the sensitivity of searching for a possible tensor glueball at BESⅢ.

  19. Harnessing graphical structure in Markov chain Monte Carlo learning

    Energy Technology Data Exchange (ETDEWEB)

    Stolorz, P.E. [California Inst. of Technology, Pasadena, CA (United States); Chew P.C. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1996-12-31

    The Monte Carlo method is recognized as a useful tool in learning and probabilistic inference methods common to many datamining problems. Generalized Hidden Markov Models and Bayes nets are especially popular applications. However, the presence of multiple modes in many relevant integrands and summands often renders the method slow and cumbersome. Recent mean field alternatives designed to speed things up have been inspired by experience gleaned from physics. The current work adopts an approach very similar to this in spirit, but focusses instead upon dynamic programming notions as a basis for producing systematic Monte Carlo improvements. The idea is to approximate a given model by a dynamic programming-style decomposition, which then forms a scaffold upon which to build successively more accurate Monte Carlo approximations. Dynamic programming ideas alone fail to account for non-local structure, while standard Monte Carlo methods essentially ignore all structure. However, suitably-crafted hybrids can successfully exploit the strengths of each method, resulting in algorithms that combine speed with accuracy. The approach relies on the presence of significant {open_quotes}local{close_quotes} information in the problem at hand. This turns out to be a plausible assumption for many important applications. Example calculations are presented, and the overall strengths and weaknesses of the approach are discussed.

  20. Quantum Monte Carlo diagonalization method as a variational calculation

    Energy Technology Data Exchange (ETDEWEB)

    Mizusaki, Takahiro; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Honma, Michio

    1997-05-01

    A stochastic method for performing large-scale shell model calculations is presented, which utilizes the auxiliary field Monte Carlo technique and diagonalization method. This method overcomes the limitation of the conventional shell model diagonalization and can extremely widen the feasibility of shell model calculations with realistic interactions for spectroscopic study of nuclear structure. (author)