Education is rapidly moving away from the instructional models of the 19th century and educationalists are now asserting that not only do students need to be able to learn by rote but also to be able to think in a more profound and complex manner. Students are required to develop new processes to handle the rapidly changing world that they are expected to take part in as they complete their formal learning. This change is evident in all the developed nations and Australian students are finding that they are being asked to demonstrate a range of higher order thinking skills in all their school subjects. Science courses in Queensland require students to be assessed on both complex reasoning and scientific process skills. Studies have shown that students can develop these skills in a number of ways that include the exposure to appropriate open-ended hands-on tasks. As higher order thinking skills underlie the development of both complex reasoning and scientific process, it is important that science educators take appropriate steps to facilitate the development of this level of thinking. This study examined the use of some higher order thinking skills by students using Information Technology in their science classroom. It investigated the degree to which students used their higher order thinking skills when engaged in a computer simulation of a complex science task. The study involved two pairs of Year 9 students, one pair each from the upper and lower quartiles of the year level, in a private Years 4 to 12 boys' school in an inner Brisbane suburb. All students had been immersed in Information Technology in Years 4 to 8 as part of a technology-across-the-curriculum project for all year levels in the school and at the time of the study were at the end of their second semester in Year 9. Students had worked with a large number of computer applications in all their subjects, averaging about one lesson in the computer room per day across all their subjects for the past year of schooling. The school also had a policy for learning and teaching that revolved around the development in students of critical thinking and, specifically in Science, complex reasoning, and scientific process skills. During this study, students engaged in a computer simulation requiring the application of skills and knowledge already learnt in their science course. The modules of this simulation developed an understanding of the essentials for life and the quantities of a range of items from water to seeds to land areas that would be required for a number of people that would be needed to staff the Lunar Base. Prompts were given on the way, which assisted students in their decision making. Students progressed through the various areas and stages of the development of the Lunar Base until they were satisfied that each area supported the others and that there was no imbalance that needed to be corrected. Once all stages had been completed, students were free to change variables and experiment further as they saw fit in order that they might produce the most self-sufficient Lunar Base possible. There was some evidence that the simulation did encourage the students in the pairs observed to think in greater depth about the materials and to argue their convictions in an improved manner. As well as the students appearing to increase in competency in argument over the period of time, the four students in their final interviews, spoke of feeling satisfied with the results of the lessons. The students also appeared more engrossed in their task and the pedagogy provided in the task was appreciated as it gave meaning to why they were required to learn scientific materials as well also presenting them with ways to find the knowledge for themselves.

The aim of the study was to compare the effects of the use of interactive computer simulations for cognitive load change of grade 11 learners in the acquisition of knowledge and a science process skill in geometrical optics. Both the use of computer simulations and traditional teaching was teacher centred. The study was done in a rural area in South Africa, in the Limpopo Province in the district of Vhembe. The theoretical framework was based on the information processing model. Within the non-equivalent quasi experimental design a switching replications design study was used whereby 105 learners in four schools took part. This study found that in terms of the acquisition of knowledge, female learners gained more by the use of simulations than their male counterparts. No significant effect was found in the acquisition of the skill when computer simulations were used. Initial reduction of cognitive load was found when simulations were used and with time this increased. Experienced educators reduced the cognitive load through use of their knowledge and expertise and their role needs to be highlighted. Further studies are suggested to study the effect of a learner centred approach on decreasing the cognitive load and its effect on the acquisition of knowledge and skills. / Mathematics, Science and Technology Education / D. Phil. (Mathematics, Science and Technology Education with specialisation in Physics Education)

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / This study aimed to investigate how innovative problem-solving learning activities (AD), based on computer simulations, contribute to the development of conceptual, procedural and attitudinal contents. Yet these AD, aimed to develop associated with numerical computing environment (ACN) skills. For this reason, we work with the development, implementation and evaluation of structured from the problem-solving strategy AD. This motion has occurred along class of freshmen undergraduate course in Meteorology, Federal University of Santa Maria (UFSM). Data collection involved the following data collection instruments: initial and final questionnaires, records obtained from the person meetings and even from the responses obtained in the solutions delivered by students of AD. The analysis of these data was done at the time of evaluation, and allowed us to conclude that these activities provide the development of conceptual, procedural and attitudinal contents concomitantly, and the development of skills associated with a mathematical software for general use. Finally, the assessment performed by the students indicated that these activities are more instructive and interesting than the strategy of problem resolutions pencil and paper. / O presente trabalho procurou investigar como atividades didáticas (AD) inovadoras de resolução de problemas, baseadas em simulações computacionais, contribuem para o desenvolvimento de conteúdos conceituais, procedimentais e atitudinais. Ainda estas AD objetivaram o desenvolvimento de competências associadas a um ambiente de computação numérica (ACN). Para isso, trabalhamos com a elaboração, implementação e avaliação das AD estruturadas a partir da estratégia de resolução de problemas. Este processo de implementação ocorreu junto à turma de ingressantes de um curso de graduação em Meteorologias da Universidade Federal de Santa Maria (UFSM). A obtenção dos dados envolveu os seguintes instrumentos de coleta: questionários inicial e final, registros obtidos a partir dos encontros presenciais realizados e ainda a partir das respostas obtidas nas soluções das AD entregues pelos estudantes. A análise destes dados deu-se no momento de avaliação, e possibilitou-nos concluir que estas atividades proporcionam o desenvolvimento dos conteúdos conceituais, procedimentais e atitudinais concomitantemente, e ainda o desenvolvimento de competências associadas a um software matemático de uso geral. Por fim, a avaliação realizada pelos estudantes indicou que estas atividades são mais instrutivas e interessantes do que a estratégia de resoluções de problema de lápis e papel.

Made available in DSpace on 2016-08-17T14:53:01Z (GMT). No. of bitstreams: 1 Fernando Henrique Costa Pinheiro.pdf: 2854886 bytes, checksum: a56fe59d5aabb7763901adeb614ad703 (MD5) Previous issue date: 2008-10-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work depicts transmission line modeling for lightning strike time domain simulation. It is studied and presented the main mechanisms associated to lightning formation and striking high-voltage transmission lines and wave propagation theory concerned to the hit point. Following, it is presented and analyzed transmission lines, shield wires and tower models available in the used ATPDraw computer program. Finally, a complete model is constructed taking into account a real utility transmission branch (ELETRONORTE-Ma), including transmission lines, respective towers and shield wires, through computational models available in the ATPDraw computer program. Computer simulations are carried out and the final model is tested for different scenarios: a standard lightning striking a transmission tower; a standard lightning striking a transmission tower with lower tower foot resistance; lightning striking transmission tower for different soil conditions (dry and humid); insulation strength analysis taking into account different hit points (middle of a shield wire and at the top of a transmission tower). The results show that the model behaved as expected. / Este trabalho aborda a modelagem de linhas de transmissão para análises e simulações no domínio do tempo de transitórios eletromagnéticos resultantes de descargas atmosféricas incidentes. É estudado e apresentado os principais mecanismos associados à formação das descargas atmosféricas, os aspectos relevantes à incidência de descargas em linhas de transmissão e os seus mecanismos de propagação em relação ao ponto de incidência. Em seguida é apresentado e analisado modelos de linhas de transmissão, cabos pára-raios e de torres disponíveis para uso no programa computacional ATPDraw. Por fim, é elaborado um modelo de um trecho real da ELETRONORTE MA incluindo linha de transmissão, suas torres e seus cabos pára-raios, através de modelos disponíveis na versão usada do programa ATPDraw. São realizadas simulações computacionais, onde o modelo é testado para vários cenários: surto atmosférico na forma de onda padrão incidindo sobre uma torre; surto atmosférico na forma de onda padrão incidindo sobre uma torre com resistência de dispersão reduzida; surtos atmosféricos incidentes sobre torres nos cenários de solos secos e úmidos; e impactos nos isolamentos no meio do vão e em uma torre de um surto atmosférico incidente nos cabos pára-raios. Para todos os testes realizados, a resposta do modelo esteve de acordo com o comportamento esperado.

This study develops the structure and closure of an econometric regime-switching model within a partial equilibrium framework that has the ability to generate reliable estimates and projections of endogenous variables under market-switching regimes. Models used in policy evaluation usually either ignore the possibility of regime switching, using just a single method of price determination based on average effects, or incorporate highly stylised components that may not reflect the complexities of a particular market. This study proposes an approach that allows the incorporation of features of regime switching in a multisector commodity level model which capture salient features of the South African market and are therefore able to produce more reliable projections of the evolution of the sector under alternative shocks. The following hypothesis is tested in the study: With the correct model structure and closure, a combination of modelling techniques can be applied to develop a simulation model that has the ability to generate reliable estimates and projections of endogenous variables under market-switching regimes. The technique that is used to “close” a simultaneous or recursive simulation model determines the manner in which market equilibrium is achieved in the model. The choice of closure technique will depend on the equilibrium pricing condition in a specific market, specifically which market regime prevails in the market. It is important to note that trade flow and equilibrium pricing conditions under various trade regimes in the SA grain markets do not occur strictly according to these definitions. In the SA white and yellow maize markets some level of trade does occur with neighbouring countries at price levels that suggest that the market is trading under a type of regional autarky isolated from world markets. Industry experts argue that trade in the Southern African region is largely driven by regional issues like staple food, adverse weather conditions, location and quality concerns of genetically modified imported maize from non-African destinations, and to a lesser extent by arbitrage opportunities. This study, therefore, refers to “near-autarky”. Given the fact that markets can fluctuate between different trade regimes (therefore equilibrium pricing conditions), some type of regime-switching model needs to be utilised to determine model closure. A switching mechanism is introduced that allows the white maize model to switch between model closer under import parity, near-autarky, and export parity, the yellow maize model to switch between model closure under import parity and near-autarky, and the wheat model to close under import parity. Various approaches are used to test whether the regime-switching model complies with the hypothesis of this study. The first approach involves the simulation of baseline projections under a combination of different trade regimes in the grain markets. The second approach illustrates the usefulness of the automated switch between the various model closure techniques by comparing ex-post simulation results of the regime-switching model to the results of a previous version of the sector model that does not have the ability to switch between various market regimes. The last approach presents a more hands-on application of the regime-switching model to real-life examples by analysing the impact of a combination of market- and policy-related shocks in the form of scenario analysis. This study proves that the regime-switching model is able to capture a richer variety of market behaviour than standard models as a result of the regime-switching innovation outlined, therefore more accurately capturing the likely effects of shocks on the domestic market. It is therefore consistent with the hypothesis of this study. The regime-switching model is, by design, more rigorous than the previous model in that it emphasises price formation and correct model closure under alternative regimes. Although the model is particularly appropriate for the South African grain market as specified here, it provides a template for which models for other countries and commodities may be developed. / Thesis (PhD (Agricultural Economics))--University of Pretoria, 2006. / Agricultural Economics, Extension and Rural Development / unrestricted

Simulações por computador permitem reduzir custo e, muitas vezes, realizar experimentos que na vida real seriam impraticáveis, ou por questões ambientais (explosões nucleares), ou por fatores que estão fora do controle do ser humano (colisões entre estrelas). Entretanto, e muito difícil manipular e analisar as centenas de gigabytes, ou mesmo terabytes, que tais simulações produzem como resultado. Os trabalhos que lidam com tais conjuntos de dados, tipicamente, empregam tanto técnicas de visualização científica como técnicas de visualização da informação, em geral refletindo o comportamento dos dados em um único instante de tempo. Entretanto, a análise da evolução temporal e a disponibilização de representações visuais integradas ainda é um grande desafio. Esse trabalho introduz diversas estratégias buscando tratar estes problemas, as quais tem em comum a utilização de projeções multidimensionais para apoiar a análise exploratória dos de dados, tanto em um instante de tempo específico, como ao longo da evolução temporal. O objetivo é favorecer a localização de grupos de elementos com comportamento similar e acompanhar sua evolução ao longo da simulação. Uma das estratégias introduzidas resume o comportamento temporal dos dados multidimensionais em uma única visualização, o que permite rastrear as entidades com comportamento similar e analisá-las ao longo da simulação / Computer simulations of physical phenomena allow reducing costs and studying behavior that would be unfeasible to observe in real life situations, either due to environmental limitations, e.g., a nuclear explosion, or due to factors that are beyond human control (e.g., collisions between stars). Millions of primitives (voxels, vertices or particle) may be required to accurately capture system behavior, thus generating very large data sets that are typically time-varying and multidimensional, as multiple simulation variables describe each primitive. Therefore, analyzing the hundreds of gigabytes or even terabytes resulting from these simulations remains a challenge. Current solutions that handle this type of data usually rely on Scientific or Information Visualization techniques, but typically revealing data behavior at a particular time instant. It remains a major challenge to provide visualizations capable of assisting analysts trying to inspect and understand behavior along the temporal domain. This work is an attempt in this direction, introducing several strategies to handle these problems. They have in common the use of multidimensional projection techniques to support exploratory analysis of simulation data, both at specic time instants and along the simulation as a whole. The goal is to favor the perception of groups of elements showing similar behavior and track their temporal evolution. One of the strategies introduced summarizes, in a single visual representation, the temporal behavior of the multidimensional data space, thus allowing analysts to identify and analyze the entities with similar behavior along the simulation

Members of the elderly population is disproportionately prone to experiencing mobility impairment due to their aging bodies and as a result have frail bodies that are at a higher risk of grave injury due to falling. In order to combat this assistive mobility devices such as exoskeletons have been developed to help patients enhance their range of motion. With additive manufacturing techniques, such as fused deposition modeling (FDM), becoming a more mainstream form of design, the inclusion of lightweight polymers such as nylon 12 as primary construction materials for these devices has increased. In this thesis computer aided design (CAD) software was used to design a prototype lower body exoskeleton and simulation software was used to give the device the characteristics of Stratasys' nylon 12 carbon fiber FDM material to verify it if could be used as the primary construction material for this device when extruded from a FDM printer on either the XZ or ZX printing plane. From the simulations it was found that the material printed along the XZ plane could create a device that could withstand the weight of an average elderly male patient (200 lbs.) as well as the 35 lbs. of force applied to the device by a linear actuation motor that would be used to extend and contract the exoskeleton leg.

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The aim of this study was firstly to evaluate the impact of two interactive-engagement models of instruction, namely Whole Class Discussions (WCD) and Computer Simulations (CS) on first year physics student-teachers’ conceptual understanding of Newtonian mechanics, and on their epistemological beliefs about physics. The force concept inventory was used to evaluate the impact on conceptual understanding while the Epistemological Beliefs About Physical Science questionnaire was used to evaluate the impact on their epistemological beliefs. The findings suggest that interactive engagement models had a positive impact on students’ conceptual understanding of Newtonian mechanics, and on their epistemological beliefs about physics. The study also contributed WCD and CS activities that can be used or adapted with an aim of enhancing conceptual understanding in physics. The study did not show any direct relationship between students’ conceptual understanding of Newtonian mechanics and their epistemological beliefs about physics. Key words: Interactive-engagement, Whole Class Discussion, Computer Simulations, epistemological beliefs about physics. / Physics / M.Sc. (Physics Education)

<p>Accurate calculations of free energies for molecular association and solvation are important for the understanding of biochemical processes, and are useful in many pharmaceutical applications. In this thesis, molecular dynamics (MD) simulations are used to calculate thermodynamic properties for solvation and ligand binding.</p><p>The thermodynamic integration technique is used to calculate p<i>K</i>_a values for three aspartic acid residues in two different proteins. MD simulations are carried out in explicit and Generalized-Born continuum solvent. The calculated p<i>K</i>_a values are in qualitative agreement with experiment in both cases. A combination of MD simulations and a continuum electrostatics method is applied to examine p<i>K</i>_a shifts in wild-type and mutant epoxide hydrolase. The calculated p<i>K</i>_a values support a model that can explain some of the pH dependent properties of this enzyme.</p><p> Development of the linear interaction energy (LIE) method for calculating solvation and binding free energies is presented. A new model for estimating the electrostatic term in the LIE method is derived and is shown to reproduce experimental free energies of hydration. An LIE method based on a continuum solvent representation is also developed and it is shown to reproduce binding free energies for inhibitors of a malaria enzyme. The possibility of using a combination of docking, MD and the LIE method to predict binding affinities for large datasets of ligands is also investigated. Good agreement with experiment is found for a set of non-nucleoside inhibitors of HIV-1 reverse transcriptase.</p><p>Approaches for decomposing solvation and binding free energies into enthalpic and entropic components are also examined. Methods for calculating the translational and rotational binding entropies for a ligand are presented. The possibility to calculate ion hydration free energies and entropies for alkali metal ions by using rigorous free energy techniques is also investigated and the results agree well with experimental data.</p>