22 resultados para 17398


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系统论述了滑坡监测资料的整理方法:滤波和等时化。讨论了滑坡运动响应的主要组成成分。重点阐述了滑坡发生时间预报的理论基础,此基础不同于一般物理方程建立的思路, 而是直接来源于观察和经验总结,并抽象为一定的数学模型。单次滑坡发生的整个过程包括孕育、加速、减速、停止等4个阶段,滑坡发生时间则指加速向减速转换的特征时间点,此点是滑坡爆发的峰值点,也是需要预报的特征时间。能够反映滑坡如此运动过程的典型数学函数是Pearl曲线,本质上此S型曲线与系统有阻尼的自由振动微分方程是一致的,也与生物群体演化的虫口方程一致,它们都共同反映了物质运动的一般规律,因此可以用来预测滑坡运动过程。直接运用一般力学微分方程描述滑坡运动过程的困难在于缺乏对滑体系统力学参数的精确把握,直接运用Logisistic虫口微分方程则存在模型参数识别的困难,作者还发现某些误用灰色系统理论对Verhulst非线性方程参数进行辨识。文末,为展示方法而不强调结果,以拥有10a监测资料的某滑坡为例,分析预报了滑坡活动过程,并进行了预测结果的数学检验。

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This paper studies operating profitability drivers in the Four Main Tobacco Manufacturers for the period 2004-2014. The operating profitability is analyzed as return on assets (ROA) based on the DuPont Extended Model breakdown in degree of operational risk, gross sales margin and assets turnover. The sources of ROA are market share and price strategies appraised through the drivers: firm-size, global value and strategic choices. Using consolidated data, results suggest that firm-size and global value holds a positive relationship with ROA. Also innovation through less harmful tobacco products can lead to better ROA despite no correlation between R&D and ROA.

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Provient de Falconet, n° 17398.

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Conocer las estructuras mentales que están en formación durante la etapa de Preescolar, las estructuras básicas de Matemáticas y relacionarlas entre sí. Elaborar un programa de Matemáticas para Preescolar adecuado a las características madurativas del párvulo y contrastarlo empíricamente. 202 alumnos de las escuelas públicas de prácticas de la Escuela de Formación del Profesorado de EGB de la Universidad de Barcelona. Muestra piloto compuesta por 81 alumnos de los mismos centros. Se inscribe en el marco teórico de la Psicología evolutiva de Piaget. Hipótesis: la programación de Matemáticas propuesta facilita la maduración; el paso de actividades perceptivas a actividades operatorias permite la adquisición de los objetivos de Matemáticas de los programas oficiales. Variable independiente: programa de Matemáticas; variable dependiente: dominio de las Matemáticas al final de curso; variable interna: edad y nivel de maduración. Para contrastar la hipótesis, plantea un diseño experimental pretest posttest de grupos paralelos: el grupo experimental sigue las clases con la programación propuesta y el grupo control sigue el método tradicional. Construye dos instrumentos de medida validados empíricamente para medir el dominio de las Matemáticas al inicio y final de curso y contrastar así la validez de la programación propuesta. Batería de pruebas operatorias ad hoc, prueba de conceptos básicos de Boehm y prueba de contenido de Matemáticas ad hoc, aplicada al final del curso. Prueba de Kolmogorov, fiabilidad según método de Hoyt, índices de validez y análisis de ítems. Ecuación de regresión múltiple para relacionar las variables, significación estadística mediante F de Fisher y bondad de ajuste mediante el cálculo del coeficiente Durwin Watson. Existe relación entre la programación y la maduración: el grupo experimental obtiene un mayor aumento de porcentajes de preguntas correctas conservadas al final del curso respecto al grupo control. Existe relación entre la programación y la adquisición de objetivos matemáticos: el grupo experimental presenta menor amplitud y valores más elevados de media y mediana respecto al grupo control en la prueba de contenido.

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Mixture model techniques are applied to a daily index of monsoon convection from ERA‐40 reanalysis to show regime behavior. The result is the existence of two significant regimes showing preferred locations of convection within the Asia/Western‐North Pacific domain, with some resemblance to active‐break events over India. Simple trend analysis over 1958–2001 shows that the first regime has become less frequent while the second becomes much more dominant. Both undergo a change in structure contributing to the total OLR trend over the ERA‐40 period. Stratifying the data according to a large‐scale dynamical index of monsoon interannual variability, we show the regime occurrence to be strongly perturbed by the seasonal condition, in agreement with conceptual ideas. This technique could be used to further examine predictability issues relating the seasonal mean and intraseasonal monsoon variability or to explore changes in monsoon behavior in centennial‐scale model integrations.

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Sociologisk Forsknings digitala arkiv

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Music can be found in peculiar historical and social context with distinct functions, such as religious rituals, ethic-esthetic education of subjects, therapeutic elements, critic and maintenance of established patterns, among others. Considered as language, music acts on dialogue dimensions of the body, the senses, the affectionate-cognitive and of social interactions. Their uses reveal the social forces that cross the culture and constitution of subjectivities. The attribution of senses by the subjects to musical production reveals the cultural voices in dialogue, that circumscribe determined social places to them. Our aim in this work is to investigate the child musical appreciation, with children about 7 to 9 years old, and, by attributing uses and senses to music, unveil the voices that settle the places intended and assumed by infancy in contemporaneity The child constructs its musical appreciation through cultural access and mediation, possible by circulation in several socializing groups like family, school, church, infant groups, community groups and, more recently, publicity and media These last two spheres, enabled by the development of the technological means of communication, contributed to the dissemination of the set of consume ideas and for the emergence of the cultural industry, characteristic of the capitalistic production way in its present configuration. They develop new possibilities of perception of the world, in which the limits between childhood and adulthood are not anymore the same that have been established in previous centuries. So, the child musical appreciation is constituted by homogeneity regarding the senses built and disseminated by cultural industry and by the logical merchandizing, and singularities, associated to the construction of senses in interaction with global, local, and multiple contexts, through which the subject circulates and constitutes himself polyphonically

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delta subunit-containing gamma-aminobutyric acid, type A (GABA(A))receptors are expressed extrasynaptically and mediate tonic inhibition. In cerebellar granule cells, they often form receptors together with alpha(1) and/or alpha(6) subunits. We were interested in determining the architecture of receptors containing both subunits. We predefined the subunit arrangement of several different GABA(A) receptor pentamers by concatenation. These receptors composed of alpha(1), alpha(6), beta(3), and delta subunits were expressed in Xenopus oocytes. Currents elicited in response to GABA were determined in the presence and absence of 3alpha,21-dihydroxy-5alpha-pregnan-20-one (THDOC) or ethanol, or currents were elicited by 4,5,6,7-tetrahydroisoxazolo[5,4-c]-pyridin-3-ol (THIP). Several subunit configurations formed active channels. We therefore conclude that delta can assume multiple positions in a receptor pentamer made up of alpha(1), alpha(6), beta(3), and delta subunits. The different receptors differ in their functional properties. Functional expression of one receptor type was only evident in the combined presence of the neurosteroid THDOC with the channel agonist GABA. Most, but not all, receptors active with GABA/THDOC responded to THIP. None of the receptors was modulated by ethanol concentrations up to 30 mm. Several observations point to a preferred position of delta subunits between two alpha subunits in alpha(1)alpha(6)beta(3)delta receptors. This property is shared by alpha(1)beta(3)delta and alpha(6)beta(3)delta receptors, but there are differences in the additionally expressed isoforms.

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anonym