• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 3
  • 1
  • 1
  • Tagged with
  • 13
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Impacto de la incertidumbre del modelo geologíco en un proyecto minero

Letelier Maturana, Isabel Beatriz January 2012 (has links)
Ingeniero Civil de Minas / La definición de los recursos de un yacimiento constituye el primer eslabón de la cadena del negocio minero. Si éstos son definidos con una alta probabilidad de error, todos los procesos posteriores, entre ellos el diseño de la mina, la planificación y evaluación del proyecto, podrían no tener un buen desempeño. Si bien resulta inimaginable generar modelos de reservas exentos de error, es fundamental que los parámetros definidos para la evaluación de recursos aseguren una desviación razonable, que no impacte de manera desmedida los procesos posteriores. Este trabajo consiste en seleccionar una densidad de malla de sondajes adecuada para determinar las reservas para el Proyecto Hipógeno de la Mina Spence. A partir de los sondajes originales, cuyo espaciamiento es de aproximadamente 100 x 100 metros, se construye un modelo de bloques de referencia, en base a lo cual se consideran distintas mallas de sondajes y por simulación se construyen nuevos modelos de bloques. Luego, para un plan minero único, se evalúan las desviaciones de cobre fino en los modelos de bloques, en el plan minero y finalmente en el valor del proyecto. Los resultados obtenidos para periodos anuales se resumen en la siguiente tabla: Densidad de malla [m] Error Modelo [%] Error Planificación [%] Error VAN [%] 35 4.36 3.25 12.9 50 5.72 4.56 20.4 70 7.64 7.17 28.8 100 10.34 9.5 40.8 150 22.66 18.25 94.8 200 30.04 25.75 148.8 Como es de esperar, a menor densidad de malla se obtiene una mayor probabilidad de error. El comportamiento del error de modelo, planificación y beneficio económico es aproximadamente lineal, con un cambio de pendiente a partir de la malla 100 x 100 metros. Como resultado de este trabajo, se concluye que la densidad de perforación que cumple con la definición de recursos medidos para el proyecto hipógeno de Spence corresponde a la malla de 100 x 100 metros, y para recursos indicados, una malla de entre 100 x 100 y 150 x 150 metros. Es posible que parte del aumento del error sobre la malla de 100 x 100 esté relacionado con el uso de una malla similar para la construcción del modelo de referencia, ya que para una malla menos densa, los cuerpos pequeños se pierden. Para determinar si este efecto existe, se podría repetir el ejercicio para casos con modelos de referencia construidos a partir de otras densidades de malla.
2

Sequence Stratigraphy and Paleoecology of the Middle Cambrian Spence Shale Member of the Langston Formation of Northeastern Utah and Southeastern Idaho

Wright, Scott H. 01 May 1999 (has links)
The Middle Cambrian Spence Shale Member contains meter-scale, shallowing-up cycles (parasequences) and record approximately 360 ky of deposition. These meter-scale cycles are nested within transgressive systems tracts (TST) and highstand systems tracts (HST) which reflect different stages of a lower-order, higher-magnitude sea-level excursion. Fossil assemblages are located in stratigraphic positions within the Spence Shale Member that can be predicted on the basis of sequence architecture. The cycle architecture, taphonomy, and geochemistry of the Spence parasequences confirm synthetic sections and theoretical models of meter-scale cycles developed in other studies. Delineation of meterscale cycles, based on taphonomic and sedimentologic criteria, allows high-resolution (100-500 ky) correlation. This study also documented the Cambrian existence of the Tooele and Arco Arches and aided in further understanding paleoenvironmental conditions within the Spence Shale Member.
3

Effects of Amount of Postshift Training on Resistance to Extinction

Wheeler, Royce Lee 05 1900 (has links)
The investigation sought to examine resistance to extinction (Rn) as a function of previous experience with downward shifts in reward magnitude. It was suggested that previous research conducted within the framework of the Spence-Amsel frustration hypothesis and the sequential hypothesis failed to administer sufficient postshift trials to adequately establish the relationships that may exist. Under one condition, four groups of rats received twenty extinction trials following forty postshift trials. Under another condition, four groups were extinguished following eighty postshift trials. An inverse magnitude of reward effect occurred in the preshift phases, however, which prevented an adequate analysis of either the shift or the Rn data, This unexpected effect was discussed within the framework of Black's incentive-motivation interpretation of reinforcement.
4

Jo Spence e Hannah Wilke: narrativas da dor / Jo Spence and Hannah Wilke: narratives of pain

Arcanjo, Kárita Gonzaga de Oliveira 10 July 2014 (has links)
Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-02-05T17:46:11Z No. of bitstreams: 2 Dissertação - Kárita Gonzaga de Oliveira Arcanjo - 2014.pdf: 6146846 bytes, checksum: 955bf89826e7ed17b1c516a0341460d3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-02-19T10:52:15Z (GMT) No. of bitstreams: 2 Dissertação - Kárita Gonzaga de Oliveira Arcanjo - 2014.pdf: 6146846 bytes, checksum: 955bf89826e7ed17b1c516a0341460d3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-19T10:52:15Z (GMT). No. of bitstreams: 2 Dissertação - Kárita Gonzaga de Oliveira Arcanjo - 2014.pdf: 6146846 bytes, checksum: 955bf89826e7ed17b1c516a0341460d3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This research aims to investigate the sick body and the pain representation by means of photography, considering its documentary and narrative elements. To that end we elected the photographic series The Picture of Health? (1982-1986) and Narratives of Disease (1990) by Jo Spence (1934-92) and Intra-Venus (1992-1993) by Hannah Wilke (1940-93), which focus on the cancer photographic documentation, taking into account their meanings as photographic narratives. In these series we have as interests the pathological pain of the sick and treated body and the image built from its appropriation by these artists. Basing on the study of self-portrait we discuss the relationship between pose and identity in the photographic image constitution as well as the concepts of photography-document proposed by André Rouillé and photographic narrative adopted by Susan e. Bell. Thus, we understand Jo Spence‘s and Hannah Wilke‘s narratives as potent instruments to face the pain, the silence and the stigma which the cancer patient is submitted, and still, a way for questioning the female image socially and culturally constructed. / Essa pesquisa tem como objetivo investigar a representação do corpo doente e da dor por meio da fotografia, levando em conta seus elementos documentais e narrativos. Para tal elegemos como recorte as séries fotográficas The Picture of Health? (1982-1986) e Narratives of Disease (1990) de Jo Spence (1934-92) e Intra-Vênus (1992-1993) de Hannah Wilke (1940-93), produzidas com foco na documentação fotográfica do câncer, considerando suas significações enquanto narrativas fotográficas. Nessas obras nos interessa a dor patológica do corpo doente, medicalizado e a imagem que se constrói a partir de sua apropriação por essas artistas. Partindo do estudo do autorretrato, abordamos a relação que se estabelece entre pose e identidade na constituição da imagem fotográfica, bem como os conceitos de fotografia-documento proposto por André Rouillé e de narrativa fotográfica adotado por Susan E. Bell. Desse modo, entendemos as narrativas de Jo Spence e Hannah Wilke como potentes instrumentos de enfrentamento da dor, do silêncio e do estigma aos quais o portador de câncer está submetido, e de questionamento de uma visualidade da imagem feminina construída social e culturalmente.
5

Instruments to assess anxiety symptoms in brazilian population and the case of the Spence Children's Anxiety Scale (SCAS) : cross-cultural adaptation and psychometric properties

DeSousa, Diogo Araújo January 2013 (has links)
Esta dissertação é composta por quatro estudos acerca de instrumentos para a avaliação de sintomas de ansiedade. O objetivo do Estudo 1 foi realizar uma revisão sistemática dos instrumentos disponíveis para avaliar sintomas de ansiedade e transtornos de ansiedade (TA) em população brasileira. O objetivo do Estudo 2 foi realizar o processo de adaptação transcultural da Spence Children’s Anxiety Scale (SCAS) para o Brasil. O objetivo do Estudo 3 foi examinar a sensibilidade e especificidade da Screen for Child Anxiety Related Emotional Disorders (SCARED) para o diagnóstico de TA em uma amostra comunitária de crianças e adolescentes brasileiros. O objetivo do Estudo 4 foi investigar as propriedades psicométricas da SCAS em amostras comunitária e clínica de crianças e adolescentes brasileiros. Os resultados do Estudo 1 fornecem um panorama das características e evidências de adequação dos instrumentos disponíveis para avaliar sintomas de ansiedade e TA em população brasileira. Os resultados dos Estudos 2, 3 e 4, em conjunto, apresentam a versão brasileira da SCAS como um instrumento adequado para avaliar sintomas de ansiedade infantil em contextos comunitário e clínico no Brasil. Implicações para a avaliação e o tratamento psicológico e psiquiátrico de TA são discutidas. / This Master Thesis encompasses four studies about instruments to the assessment of anxiety symptoms. The aim of the Study 1 was to conduct a systematic review of the instruments available to assess anxiety symptoms and anxiety disorders (AD) in Brazilian population. The aim of the Study 2 was to perform the cross-cultural adaptation process of the Spence Children’s Anxiety Scale (SCAS) to Brazil. The aim of the Study 3 was to examine the sensitivity and specificity of the Screen for Child Anxiety Related Emotional Disorders (SCARED) to the diagnosis of AD in a community sample of Brazilian children and adolescents. The aim of the Study 4 was to investigate the psychometric properties of the SCAS in a community and a clinical sample of Brazilian children and adolescents. Results from Study 1 provide an overview of the characteristics and the adequacy evidences of the instruments available to assess anxiety symptoms and AD in Brazilian population. Results from Studies 2, 3, and 4, altogether, present the Brazilian version of the SCAS as an instrument suitable to assess pediatric anxiety symptoms in Brazilian community and clinical settings. Implications for the psychological and psychiatric assessment and treatment of AD are discussed.
6

Geoquímica de las Aguas Subterráneas del Yacimiento Mantos Blancos, II Región de Antofagasta, Chile: Comparación con Aguas Subterráneas del Pórfido Spence y con Inclusiones Fluidas Atrapadas en Atacamitas de Ambos Depósitos

Robles Bello, Marcela Paz January 2008 (has links)
En este estudio se caracterizó la composición geoquímica de las aguas subterráneas del yacimiento de Mantos Blancos, comparándola con datos previamente publicados de las aguas subterráneas del yacimiento Spence. Se compararon los totales de sólidos disueltos y se observaron las relaciones geoquímicas entre los iones mayoritarios de ambas aguas. Se realizó una comparación de los valores de salinidad de las inclusiones fluidas de Mantos Blancos con los obtenidos de las inclusiones fluidas de Spence, además de la confrontación de estos valores con los adquiridos en la geoquímica de las aguas de los yacimientos mencionados anteriormente. Se determinó que las aguas subterráneas de Mantos Blancos presentan una variación importante en salinidad, además de la existencia de 2 miembros extremos, Miembro Terminal Salino y Miembro Terminal Diluido. Estas aguas subterráneas resultaron ser bastante similares a las aguas de Spence. Además se puede apreciar la existencia de una correlación entre las salinidades de las aguas subterráneas y las de las inclusiones fluidas de ambos yacimientos, denotando una génesis común. Gracias a la correlación de las aguas subterráneas de Mantos Blancos con las aguas de Spence se puede sugerir una procedencia profunda para las aguas que dieron origen a las atacamitas (ej. “deep formation waters”), consistente con la hipótesis de Cameron y otros del “tectoning pumping”.
7

Instruments to assess anxiety symptoms in brazilian population and the case of the Spence Children's Anxiety Scale (SCAS) : cross-cultural adaptation and psychometric properties

DeSousa, Diogo Araújo January 2013 (has links)
Esta dissertação é composta por quatro estudos acerca de instrumentos para a avaliação de sintomas de ansiedade. O objetivo do Estudo 1 foi realizar uma revisão sistemática dos instrumentos disponíveis para avaliar sintomas de ansiedade e transtornos de ansiedade (TA) em população brasileira. O objetivo do Estudo 2 foi realizar o processo de adaptação transcultural da Spence Children’s Anxiety Scale (SCAS) para o Brasil. O objetivo do Estudo 3 foi examinar a sensibilidade e especificidade da Screen for Child Anxiety Related Emotional Disorders (SCARED) para o diagnóstico de TA em uma amostra comunitária de crianças e adolescentes brasileiros. O objetivo do Estudo 4 foi investigar as propriedades psicométricas da SCAS em amostras comunitária e clínica de crianças e adolescentes brasileiros. Os resultados do Estudo 1 fornecem um panorama das características e evidências de adequação dos instrumentos disponíveis para avaliar sintomas de ansiedade e TA em população brasileira. Os resultados dos Estudos 2, 3 e 4, em conjunto, apresentam a versão brasileira da SCAS como um instrumento adequado para avaliar sintomas de ansiedade infantil em contextos comunitário e clínico no Brasil. Implicações para a avaliação e o tratamento psicológico e psiquiátrico de TA são discutidas. / This Master Thesis encompasses four studies about instruments to the assessment of anxiety symptoms. The aim of the Study 1 was to conduct a systematic review of the instruments available to assess anxiety symptoms and anxiety disorders (AD) in Brazilian population. The aim of the Study 2 was to perform the cross-cultural adaptation process of the Spence Children’s Anxiety Scale (SCAS) to Brazil. The aim of the Study 3 was to examine the sensitivity and specificity of the Screen for Child Anxiety Related Emotional Disorders (SCARED) to the diagnosis of AD in a community sample of Brazilian children and adolescents. The aim of the Study 4 was to investigate the psychometric properties of the SCAS in a community and a clinical sample of Brazilian children and adolescents. Results from Study 1 provide an overview of the characteristics and the adequacy evidences of the instruments available to assess anxiety symptoms and AD in Brazilian population. Results from Studies 2, 3, and 4, altogether, present the Brazilian version of the SCAS as an instrument suitable to assess pediatric anxiety symptoms in Brazilian community and clinical settings. Implications for the psychological and psychiatric assessment and treatment of AD are discussed.
8

Instruments to assess anxiety symptoms in brazilian population and the case of the Spence Children's Anxiety Scale (SCAS) : cross-cultural adaptation and psychometric properties

DeSousa, Diogo Araújo January 2013 (has links)
Esta dissertação é composta por quatro estudos acerca de instrumentos para a avaliação de sintomas de ansiedade. O objetivo do Estudo 1 foi realizar uma revisão sistemática dos instrumentos disponíveis para avaliar sintomas de ansiedade e transtornos de ansiedade (TA) em população brasileira. O objetivo do Estudo 2 foi realizar o processo de adaptação transcultural da Spence Children’s Anxiety Scale (SCAS) para o Brasil. O objetivo do Estudo 3 foi examinar a sensibilidade e especificidade da Screen for Child Anxiety Related Emotional Disorders (SCARED) para o diagnóstico de TA em uma amostra comunitária de crianças e adolescentes brasileiros. O objetivo do Estudo 4 foi investigar as propriedades psicométricas da SCAS em amostras comunitária e clínica de crianças e adolescentes brasileiros. Os resultados do Estudo 1 fornecem um panorama das características e evidências de adequação dos instrumentos disponíveis para avaliar sintomas de ansiedade e TA em população brasileira. Os resultados dos Estudos 2, 3 e 4, em conjunto, apresentam a versão brasileira da SCAS como um instrumento adequado para avaliar sintomas de ansiedade infantil em contextos comunitário e clínico no Brasil. Implicações para a avaliação e o tratamento psicológico e psiquiátrico de TA são discutidas. / This Master Thesis encompasses four studies about instruments to the assessment of anxiety symptoms. The aim of the Study 1 was to conduct a systematic review of the instruments available to assess anxiety symptoms and anxiety disorders (AD) in Brazilian population. The aim of the Study 2 was to perform the cross-cultural adaptation process of the Spence Children’s Anxiety Scale (SCAS) to Brazil. The aim of the Study 3 was to examine the sensitivity and specificity of the Screen for Child Anxiety Related Emotional Disorders (SCARED) to the diagnosis of AD in a community sample of Brazilian children and adolescents. The aim of the Study 4 was to investigate the psychometric properties of the SCAS in a community and a clinical sample of Brazilian children and adolescents. Results from Study 1 provide an overview of the characteristics and the adequacy evidences of the instruments available to assess anxiety symptoms and AD in Brazilian population. Results from Studies 2, 3, and 4, altogether, present the Brazilian version of the SCAS as an instrument suitable to assess pediatric anxiety symptoms in Brazilian community and clinical settings. Implications for the psychological and psychiatric assessment and treatment of AD are discussed.
9

"Modelo de gestión y administración de proyectos operacionales"

Hidalgo Ramírez, Pedro Daniel January 2013 (has links)
Magíster en Gestión y Dirección de Empresas / El éxito en la gestión de proyectos mineros se ha vuelto un desafío cada día más difícil de cumplir debido a las actuales condiciones del mercado, las cuales han impuesto restricciones para acceder a una mano de obra calificada e insumos críticos a precios competitivos. Bajo este escenario, es primordial ejercer una correcta administración y gestión de los recursos de capital disponibles para la ejecución de una cartera de proyectos, a fin de garantizar el cumplimiento de las metas planteadas en materia de seguridad, plazos de implementación y presupuesto; lo cual asegura la rentabilidad comprometida a los inversionistas. Si bien la gestión de proyectos mayores es estándar en las distintas compañías mineras, al hacer foco en los proyectos denominados operacionales que cada minera administra, no existe una metodología del todo estandarizada. Los proyectos operacionales se caracterizan por niveles de inversión de tamaño medio (bajo los 250 MUSD y superiores a 10 MUSD) y cuyos retornos de igual forma son acotados, pero cuyos alcances presentan una alta interferencia con los procesos productivos existentes. En este sentido, se presenta el desafío de elaborar un marco metodológico para la ejecución estandarizada de este tipo de proyectos, utilizando una estructura organizacional óptima. Es importante destacar que la gestión de proyectos es una disciplina que se aprende en la práctica sin mayores herramientas, y por tanto cualquier intento por documentar los aprendizajes y mejores prácticas será un aporte para mejorar las posibilidades de éxito del grupo de ejecución. Los aprendizajes plasmados en este documento corresponden a la ejecución de proyectos que se realiza en el Asset Pampa Norte, en especial para su operación Minera Spence, en el marco de los proyectos de crecimiento que actualmente se encuentra ejecutando la faena. El desarrollo del marco procedimental formará parte de un trabajo más amplio que paralelamente busca estandarizar los procesos de gestión de Proyectos en el Asset, siendo este documento un inicio para la estandarización de los proyectos en la etapa de ejecución. De esta forma, este documento buscara facilitar la definición de metas individuales de cada área así como también las del equipo de ejecución y establecer regímenes de medida que permitan capturar el real desempeño de las empresas de construcción y montaje.
10

Effek van projektiewe narratiewe op kinders in kinderhuise se tekeninge van vrees

Olivier, Andries J. 12 1900 (has links)
Thesis (MEdPsych (Educational Psychology)--Stellenbosch University, 2008. / The study investigated the effect of using projective narratives and drawings that depict diminished fear, on the anxiety levels of a group of children living in children’s homes, by means of a mixed methodology. The sample consisted of 30 middle childhood children (mean age = 9.60 years, SD = 1.13) from three children’s homes in the Western Cape. Drawings were used to elicit content of fear or anxiety (anxiety evoking drawing/bangmaaktekening) and proposed coping (anxiety lessening drawing/bangwegvattekening). After completing the anxiety provoking drawing, participants in the experimental group were asked to tell a story to other children with a similar fear to lessen/take that fear away (projective narrative). The Spence Childhood Anxiety Scale (SCAS) was completed after each drawing, and drawings evaluated through the use of anxiety scales, to measure changes in anxiety levels according to the concept of triangulation. The categories ghosts, snakes, and people were found to be the most prevalent content of fear from anxiety provoking drawings, and undifferentiated fears were also common within this population. Control of anxiety from anxiety lessening drawings indicated a definite prevalence of emotion focused (secondary) coping strategies, specifically religious solace. The content of projective narratives echoed this finding, although proposed solutions were more differentiated. Ownership of projections also occurred. The experimental effect was not significant, although mean anxiety levels were considerably lower in the drawings in comparison with that of the SCAS. Drawings are thus seen as an effective, nonthreatening technique to study anxiety phenomena. A comparison of the mean item scores of the SCAS subscales indicated that symptoms of separation anxiety, generalised anxiety disorder, and obsessivecompulsive anxiety disorder were prevalent among this group of children in children’s homes. A clear distinction was found between markers of state- and trait-anxiety through the qualitative analysis of the drawings, with anxiety lessening drawings showing definite diminished state-anxiety, although more established markers of trait-anxiety did not necessarily change. There are also indications that transference of activated negative emotional stimuli occurred on an unconscious level between the two drawings. Introducing the combination of projective narratives in the intervention stage of the study appeared to facilitate learning or the experience of observed positive affect in anxiety lessened drawings. Future research would benefit from including a normative group to establish more clear markers of state- and trait-anxiety in drawings, and by the use of a bigger sample to investigate factor loadings of the SCAS among children in children’s homes. The high prevalence of anxiety symptoms in this population emphasises their status as a vulnerable population, and the need for possible group intervention – specifically the psycho-education of effective coping strategies for anxiety.

Page generated in 0.015 seconds