922 resultados para Applied Geophysics
Resumo:
In the present paper we concentrate on solving sequences of nonsymmetric linear systems with block structure arising from compressible flow problems. We attempt to improve the solution process by sharing part of the computational effort throughout the sequence. This is achieved by application of a cheap updating technique for preconditioners which we adapted in order to be used for our applications. Tested on three benchmark compressible flow problems, the strategy speeds up the entire computation with an acceleration being particularly pronounced in phases of instationary behavior.
Resumo:
The paper will consist of three parts. In part I we shall present some background considerations which are necessary as a basis for what follows. We shall try to clarify some basic concepts and notions, and we shall collect the most important arguments (and related goals) in favour of problem solving, modelling and applications to other subjects in mathematics instruction. In the main part II we shall review the present state, recent trends, and prospective lines of development, both in empirical or theoretical research and in the practice of mathematics instruction and mathematics education, concerning (applied) problem solving, modelling, applications and relations to other subjects. In particular, we shall identify and discuss four major trends: a widened spectrum of arguments, an increased globality, an increased unification, and an extended use of computers. In the final part III we shall comment upon some important issues and problems related to our topic.
Resumo:
This thesis presents the ideas underlying a computer program that takes as input a schematic of a mechanical or hydraulic power transmission system, plus specifications and a utility function, and returns catalog numbers from predefined catalogs for the optimal selection of components implementing the design. Unlike programs for designing single components or systems, the program provides the designer with a high level "language" in which to compose new designs. It then performs some of the detailed design process. The process of "compilation" is based on a formalization of quantitative inferences about hierarchically organized sets of artifacts and operating conditions. This allows the design compilation without the exhaustive enumeration of alternatives.
Resumo:
As stated in Aitchison (1986), a proper study of relative variation in a compositional data set should be based on logratios, and dealing with logratios excludes dealing with zeros. Nevertheless, it is clear that zero observations might be present in real data sets, either because the corresponding part is completely absent –essential zeros– or because it is below detection limit –rounded zeros. Because the second kind of zeros is usually understood as “a trace too small to measure”, it seems reasonable to replace them by a suitable small value, and this has been the traditional approach. As stated, e.g. by Tauber (1999) and by Martín-Fernández, Barceló-Vidal, and Pawlowsky-Glahn (2000), the principal problem in compositional data analysis is related to rounded zeros. One should be careful to use a replacement strategy that does not seriously distort the general structure of the data. In particular, the covariance structure of the involved parts –and thus the metric properties– should be preserved, as otherwise further analysis on subpopulations could be misleading. Following this point of view, a non-parametric imputation method is introduced in Martín-Fernández, Barceló-Vidal, and Pawlowsky-Glahn (2000). This method is analyzed in depth by Martín-Fernández, Barceló-Vidal, and Pawlowsky-Glahn (2003) where it is shown that the theoretical drawbacks of the additive zero replacement method proposed in Aitchison (1986) can be overcome using a new multiplicative approach on the non-zero parts of a composition. The new approach has reasonable properties from a compositional point of view. In particular, it is “natural” in the sense that it recovers the “true” composition if replacement values are identical to the missing values, and it is coherent with the basic operations on the simplex. This coherence implies that the covariance structure of subcompositions with no zeros is preserved. As a generalization of the multiplicative replacement, in the same paper a substitution method for missing values on compositional data sets is introduced
Resumo:
This paper presents the use of a mobile robot platform as an innovative educational tool in order to promote and integrate different curriculum knowledge. Hence, it is presented the acquired experience within a summer course named ldquoapplied mobile roboticsrdquo. The main aim of the course is to integrate different subjects as electronics, programming, architecture, perception systems, communications, control and trajectory planning by using the educational open mobile robot platform PRIM. The summer course is addressed to a wide range of student profiles. However, it is of special interests to the students of electrical and computer engineering around their final academic year. The summer course consists of the theoretical and laboratory sessions, related to the following topics: design & programming of electronic devices, modelling and control systems, trajectory planning and control, and computer vision systems. Therefore, the clues for achieving a renewed path of progress in robotics are the integration of several knowledgeable fields, such as computing, communications, and control sciences, in order to perform a higher level reasoning and use decision tools with strong theoretical base
Resumo:
Exercises and solutions for a second year applied maths course.
Resumo:
This resource is for Health Scientist
Resumo:
Objective: to assess, in a randomized sample of measurements made with the NBAS scale, in preterm and / or low birth weight babies, some psychometric characteristics of the same as her construct validity and internal consistency. Materials and methods: we designed a study of assessment of Psychometric properties. From a study of cross-sectional measurements, there were made assessment of the statistic behavior of the items, individually and in their internal consistency, then, there were carried out, type exploratory and confirmatory factor analysis. Results: we find that, in the analysis of preterm or low birth weight babies, the scale remains largely, the overall structure of factors proposed since 1982, in relation to the dimensions of habituation, social interactive and complementary. The items that make up the dimensions of SNA and motor systems are integrated. Also, we found Cronbach alpha values for internal consistency, which reflects higher to medium correlation levels in the behavioral and reflex items. Conclusion: the NBAS scale reflects characteristics of construct validity and internal consistency, which credits it as a useful tool in clinical assessment of neurodevelopmental effects of preterm or low birth weight babies. It is necessary to analyze the structure of the scale when used for purposes of scientific research.
Resumo:
Introduction: During the past years, alveolar recruitment maneuvers (RM) have produced growing interest due to their beneficial potential in pulmonary protection, and have been introduced in clinical practice. Objective: To describe and analyze the knowledge of MR and its application at seven intensive care units in the city of Cali, Colombia. Methods and materials: Descriptive Cross-Sectional Study with an intentional sample of 64 professionals working in seven intensive care units and who apply MR. The self-completed survey was made up of thirteen questions, and the application period was two months. Results: Out of 64 professionals surveyed, 77.8% of them follow a protocol guide; 54.7% employes during RM the ideal Positive end-expiratory pressure (PEEP), which maintains a saturation > 90% and a PaO2 > 60 mmHg; 42.1% tolerates airway pressures between 35 and 50 cmH2O; 48.4% perform RM with a progressive increase of the PEEP and a low tidal volume. Conclusions: Regarding the knowledge related to RM, heterogeneity was found in the answers. There is currently no consensus about which is the most effective and secure way to implement an MR. This study can be the starting point to create awareness towards the revision of knowledge, capacities and abilities that are required to perform RM.
Resumo:
Está escrito para los estudiantes que preparan el General Certificate Secondary Education (GCSE) en ciencias. Contiene, además, actividades escritas para ayudar a los alumnos a desarrollar las habilidades obligatorias para este curso y recuadros con palabras clave y datos clave que son definidos en el texto. Se acompaña de un recurso dirigido al profesor.
Resumo:
Este recurso para el profesor se apoya en el libro del alumno que sirve para preparar el General Certificate Secondary Education (GCSE) en ciencias. Proporciona al docente: tareas para cumplir con los criterios de evaluación, actividades prácticas, fichas para el desarrollo de destrezas y plantillas. Se completa con un doble CD-ROM.
Resumo:
Esta escrito para apoyar las nueva especificación Edexcel AS en las tecnologías de la información y la comunicación (ICT). Su contenido se estructura en tres unidades: la edad de la información; la economía digital; y el trabajador del conocimiento.
Resumo:
Esta escrito para ayudar a los profesores y estudiantes en la preparación del curso sobre las tecnologías de la información y de la comunicación (ICT) para las especificaciones AQA AS. Su contenido se estructura en cuatro secciones, la primera trata de las ICT y la sociedad; la segunda sobre las ICT y las organizaciones; la tercera sobre utilización de datos; y la última sobre portfolios.
Resumo:
Este recurso ha sido escrito para ayudar a los alumnos a formar su cartera de pruebas para el nivel 2 del curso Edexcel BTEC en ciencia aplicada y también a cómo obtener una calificación de aprobado, notable o distinción. El programa de estudios BTEC ofrece una cualificación profesional o laboral. El contenido se divide en tres grandes unidades: química y nuestra Tierra; energía y nuestro universo; biología y nuestro entorno.
Resumo:
Libro para estudiantes de tecnologías de la información y la comunicación, de enseñanza secundaria - bachillerato, orientado a la consecución del certificado de Edexcel nivel A2. Contiene las unidades 7 a 12 y cubre las siguientes materias: uso de bases de datos, gestión de proyectos TIC, uso de programas multimedia, uso de hojas de cálculo, y personalización de aplicaciones. Incluye proyectos de ejemplo y casos de estudio que permiten al alumno entender cómo planificar, producir, revisar y presentar sus propios porfolios digitales. Cd-rom con material de apoyo.