917 resultados para Experimental test


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Este artículo pertenece a una sección de la revista dedicada a psicología y creatividad

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Diseño de un programa específico de intervención sobre las habilidades y estrategias en el desarrollo de las relaciones espaciales. Hipótesis: los sujetos con necesidades educativas especiales que presentan deficiencias en el uso y manejo de las relaciones espaciales obtendrán unas mejoras significativas en su organización y estructuración mental, después de seguir un programa especial de intervención, con respecto a sujetos que no siguen dicho programa. Compuesta por 15 alumnos de segundo de EGB de un centro rural, seleccionada según los criterios: nivel escolar, criterio de los profesores, medio sociocultural, CI, edad, sexo y resultados del Raven. A partir de dos grupos: experimental (5 niños y 2 niñas) y control (5 niños y 3 niñas), se le aplicó al grupo experimental el programa de diseño de unidades didácticas de orientación del espacio. Test de organización de puntos para evaluar la organización y estructuración perceptiva. Matrices progresivas de Raven para evaluar el potencial de aprendizaje. Columbia, Terman Merrill y Wisc para evaluar la capacidad intelectual. Diseño de unidades didácticas de orientación espacial como intervención en el grupo experimental.. Test-retest al principio y final de la implantación del programa. Hay cambio significativo en el grupo que ha seguido el tratamiento. Se aprecian ciertas mejoras en el razonamiento de los sujetos tratados con el programa específico de intervención, especialmente las mejoras se observan en los problemas que precisan de las habilidades en la orientación espacial. Los sujetos del grupo experimental consiguieron cierto nivel de representación mental de las relaciones espaciales; generalización de esas relaciones e interiorización y descentración de las mismas. También se redujo la conducta impulsiva y autorregulación de las respuestas.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

El objetivo general de la presente investigación es determinar si existe relación entre las estrategias de enseñanza que utiliza la educadora de párvulos y el desarrollo de las competencias cognitivas en los párvulos que asisten al último nivel del sistema preescolar. La muestra es probabilística, estratificada y se encuentra formada por un total de 153 niños procedentes de las escuelas municipales de ciudad de Curicó. Las variables que intervienen en este estudio son las estrategias metodológicas y las competencias cognitivas, que se encuentran definidas tanto desde el punto de vista conceptual y operacional. Además intervienen una serie de variables concomitantes entre las cuales se entran el sexo, la edad, la escolaridad de los padres, etc. Los instrumentos utilizados para llevar a cabo el presente estudio consisten en una batería de escalas con orientación constructivista para evaluar competencias cognitivas en párvulos. Se concluye que, en general, la calidad de las estrategias de las educadoras no es muy efectiva en el desarrollo de competencias cognitivas y que no hay impacto significativo de la educación parvularia, en el desarrollo cognitivo de niños y niñas del sector urbano, como los son los párvulos de este estudio. Además, se realiza una comparación entre los resultados obtenidos y el estudio realizado por el Centro de educación para el trabajo y el desarrollo humano (CEDEP). Finalmente destaca que, su principal aportación es que al difundir cuáles son las estrategias pedagógicas que correlacionan con el desarrollo de las competencias cognitivas en los párvulos, se propicia que se reproduzcan con mayor calidad y frecuencia en el que hacer de las educadoras de párvulos, aquellas que generan mejores resultados.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Estudiar la Enseñanza programada, sus características, su historia, y tipos de programas. 50 alumnos de edades comprendidas entre 11 y 14 años, uno como grupo control, y otro grupo experimental. Test Otis (en su forma A) y test inicial. Las conclusiones son relativas. No se puede afirmar superioridad de un método sobre otro porque no hemos encontrado diferencias significativas. Se considera que el sistema de fichas para la Enseñanza Programada resulta anti-económico. Se considera una gran diferencia entre el interés que despertó en los niños el método de Enseñanza Programada y la poca atención que prestaban los de grupo de control. Puede argumentarse que este mayor interés por la Enseñanza Programada que por el método tradicional era debido a la novedad del primero. Hemos de hacer una enseñanza activa e interesante.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

La aplicación de materiales compuestos de matriz polimérica reforzados mediante fibras largas (FRP, Fiber Reinforced Plastic), está en gradual crecimiento debido a las buenas propiedades específicas y a la flexibilidad en el diseño. Uno de los mayores consumidores es la industria aeroespacial, dado que la aplicación de estos materiales tiene claros beneficios económicos y medioambientales. Cuando los materiales compuestos se aplican en componentes estructurales, se inicia un programa de diseño donde se combinan ensayos reales y técnicas de análisis. El desarrollo de herramientas de análisis fiables que permiten comprender el comportamiento mecánico de la estructura, así como reemplazar muchos, pero no todos, los ensayos reales, es de claro interés. Susceptibilidad al daño debido a cargas de impacto fuera del plano es uno de los aspectos de más importancia que se tienen en cuenta durante el proceso de diseño de estructuras de material compuesto. La falta de conocimiento de los efectos del impacto en estas estructuras es un factor que limita el uso de estos materiales. Por lo tanto, el desarrollo de modelos de ensayo virtual mecánico para analizar la resistencia a impacto de una estructura es de gran interés, pero aún más, la predicción de la resistencia residual después del impacto. En este sentido, el presente trabajo abarca un amplio rango de análisis de eventos de impacto a baja velocidad en placas laminadas de material compuesto, monolíticas, planas, rectangulares, y con secuencias de apilamiento convencionales. Teniendo en cuenta que el principal objetivo del presente trabajo es la predicción de la resistencia residual a compresión, diferentes tareas se llevan a cabo para favorecer el adecuado análisis del problema. Los temas que se desarrollan son: la descripción analítica del impacto, el diseño y la realización de un plan de ensayos experimentales, la formulación e implementación de modelos constitutivos para la descripción del comportamiento del material, y el desarrollo de ensayos virtuales basados en modelos de elementos finitos en los que se usan los modelos constitutivos implementados.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The interface between humans and technology is a rapidly changing field. In particular as technological methods have improved dramatically so interaction has become possible that could only be speculated about even a decade earlier. This interaction can though take on a wide range of forms. Indeed standard buttons and dials with televisual feedback are perhaps a common example. But now virtual reality systems, wearable computers and most of all, implant technology are throwing up a completely new concept, namely a symbiosis of human and machine. No longer is it sensible simply to consider how a human interacts with a machine, but rather how the human-machine symbiotic combination interacts with the outside world. In this paper we take a look at some of the recent approaches, putting implant technology in context. We also consider some specific practical examples which may well alter the way we look at this symbiosis in the future. The main area of interest as far as symbiotic studies are concerned is clearly the use of implant technology, particularly where a connection is made between technology and the human brain and/or nervous system. Often pilot tests and experimentation has been carried out apriori to investigate the eventual possibilities before human subjects are themselves involved. Some of the more pertinent animal studies are discussed briefly here. The paper however concentrates on human experimentation, in particular that carried out by the authors themselves, firstly to indicate what possibilities exist as of now with available technology, but perhaps more importantly to also show what might be possible with such technology in the future and how this may well have extensive social effects. The driving force behind the integration of technology with humans on a neural level has historically been to restore lost functionality in individuals who have suffered neurological trauma such as spinal cord damage, or who suffer from a debilitating disease such as lateral amyotrophic sclerosis. Very few would argue against the development of implants to enable such people to control their environment, or some aspect of their own body functions. Indeed this technology in the short term has applications for amelioration of symptoms for the physically impaired, such as alternative senses being bestowed on a blind or deaf individual. However the issue becomes distinctly more complex when it is proposed that such technology be used on those with no medical need, but instead who wish to enhance and augment their own bodies, particularly in terms of their mental attributes. These issues are discussed here in the light of practical experimental test results and their ethical consequences.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Observations by the EISCAT experiments “POLAR” and Common Programme CP-3 reveal non-Maxwellian ion velocity distributions in the auroral F-region ionosphere. Analysis of data from three periods is presented. During the first period, convection velocities are large (≈2 km s-1) and constant over part of a CP-3 latitude scan; the second period is one of POLAR data containing a short-lived (<1 min.) burst of rapid (>1.5 km s-1) flow. We concentrate on these two periods as they allow the study of a great many features of the ion-neutral interactions which drive the plasma non-thermal and provide the best available experimental test for models of the 3-dimensional ion velocity distribution function. The third period is included to illustrate the fact that non-thermal plasma frequently exists in the auroral ionosphere: the data, also from the POLAR experiment, cover a three-hour period of typical auroral zone flow and analysis reveals that the ion distribution varies from Maxwellian to the threshold of a toroidal form.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Este trabalho consiste nem teste experimental de algumas proposições teóricas no campo da obtenção de conceitos, particularmente as de Bruner, Goodnow e Austin (1956) e de Glanzer, Huttenlocker e Clark (1963). Investigou-se a influência de suas variáveis no processo de obtenção de conceitos: a) o tipo de conteúdo do material de estímulo; b)o número de dimensões do conceito predeterminado pelo experimentador. Foram testadas as seguintes hipóteses: a) maior dificuldade em obter conceito quando o material é temático; b)maior dificuldade em obter conceitos de duas dimensões. Tais predições não se confirmaram. Foi utilizado como paradigma experimental o modelo das estratégias de seleção de Bruner et al (1956). Os objetivos principais foram testar os procedimentos experimentais e escolher uma variável dependente adequada para medida de eficácia na obtenção de conceitos. Foram feitas sugestões para pesquisas futuras.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Composites based on PEEK + PTFE + CARBON FIBER + Graphite (G_CFRP) has increased application in the top industries, as Aerospace, Aeronautical, Petroleum, Biomedical, Mechanical and Electronics Engineering challenges. A commercially available G_CFRP was warmed up to three different levels of thermal energy to identify the main damage mechanisms and some evidences for their intrinsic transitions. An experimental test rig for systematize a heat flux was developed in this dissertation, based on the Joule Effect. It was built using an isothermal container, an internal heat source and a real-time measurement system for test a sample by time. A standard conical-cylindrical tip was inserted into a soldering iron, commercially available and identified by three different levels of nominal electrical power, 40W (manufacturer A), 40W (manufacturer B), 100W and 150W, selected after screening tests: these power levels for the heat source, after one hour of heating and one hour of cooling in situ, carried out three different zones of degradation in the composite surface. The bench was instrumented with twelve thermocouples, a wattmeter and a video camera. The twelve specimens tested suffered different degradation mechanisms, analyzed by DSC (Differential Scanning Calorimetry) and TG (Thermogravimetry) techniques, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-Rays (EDX) Analysis. Before and after each testing, it was measured the hardness of the sample by HRM (Hardness Rockwell M). Excellent correlations (R2=1) were obtained in the plots of the evaporated area after one hour of heating and one hour of cooling in situ versus (1) the respective power of heat source and (2) the central temperature of the sample. However, as resulting of the differential degradation of G_CFRP and their anisotropy, confirmed by their variable thermal properties, viscoelastic and plastic properties, there were both linear and non-linear behaviour between the temperature field and Rockwell M hardness measured in the radial and circumferential directions of the samples. Some morphological features of the damaged zones are presented and discussed, as, for example, the crazing and skeletonization mechanism of G_CFRP

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The Glutatione-S-transferases (GSTs) comprise a family of enzymes closely associated with the cell detoxification of xenobiotics. GSTs exist as homo- or heterodimers and have been grouped into at least seven distinct classes. The main function of GSTs is to catalyze the conjugation of reduced glutathione (GSH) to an electrophilic site of a broad range of potentially toxic and carcinogenic compounds, thereby making such compounds less dangerous and enabling their ready-excretion. Placental GST, known as GST-P 7-7, is the main isoform found in normal placental tissue and comprises 67% of the total GST concentration in this tissue. During development, GST-P 7-7 decreases in concentration and is absent in adult tissues. Interestingly, GST-P 7-7 expression has been detected in adult tissues after exposure to carcinogenic agents in several experimental test systems, being considered a reliable biomarker of exposure and susceptibility in early phases of carcinogenesis. In this article, we review a series of studies involving GST-P 7-7 expression as a suitable tool for understanding cancer pathogenesis, especially cancer risk.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The fuel consumption is an important factor in the vehicle development due the fact that it has a direct effect on its trade aims. Besides that, it is known that the petrol is a scarce fuel. In this paper it is presented a procedure of fuel consumption calculation for a vehicle traveling in driving schedule. In such calculation it has been taken into account the operational conditions (load, pavement, climbing road, among others) and the building characteristics (map engine, transmission, frontal area, tire, among others) of road vehicles. There has also been an application of the theoretical model developed in a sample Mercedes-Benz do Brasil vehicle which has been compared with the values of experimental tests. Copyright © 1997 Society of Automotive Engineers, Inc.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The capacitor placement problem for radial distribution networks aims to determine capacitor types, sizes, locations and control scheme. This is a combinatorial problem that can be formulated as a mixed integer nonlinear program. The paper presents an algorithm inspired in artificial immune systems and developed for this specific problem. A good performance was obtained through experimental tests applied to known systems. © 2006 IEEE.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

In the last decades there was a great development in the study of control systems to attenuate the harmful effect of natural events in great structures, as buildings and bridges. Magnetorheological fluid (MR), that is an intelligent material, has been considered in many proposals of project for these controllers. This work presents the controller design using feedback of states through LMI (Linear Matrix Inequalities) approach. The experimental test were carried out in a structure with two degrees of freedom with a connected shock absorber MR. Experimental tests were realized in order to specify the features of this semi-active controller. In this case, there exist states that are not measurable, so the feedback of the states involves the project of an estimator. The coupling of the MR damper causes a variation in dynamics properties, so an identification methods, based on experimental input/output signal was used to compare with the numerical application. The identification method of Prediction Error Methods - (PEM) was used to find the physical characteristics of the system through realization in modal space of states. This proposal allows the project of a semi-active control, where the main characteristic is the possibility of the variation of the damping coefficient.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The aim of this work is to present a modified Space Vector Modulation (SVM) suitable for Tri-state Three-phase inverters. A standard SVM algorithm and the Tri-state PWM (Pulse Width Modulation) are presented and their concept are mixed into the novel SVM. The proposed SVM is applied to a three-phase tri-state integrated Boost inverter, intended to Photovoltaic Energy Applications. The main features for this novel SVM are validated through simulations and also by experimental tests. The obtained results prove the feasibility of the proposal. © 2011 IEEE.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)