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  • 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

Effectiveness Of 5e Learning Cycle Model On High School Students

Aydemir, Nurdane 01 May 2012 (has links) (PDF)
The purpose of this study was to investigate the effect of instruction based on 5E learning cycle model (LCI) compared to Traditional Instruction (TI) and gender on 11th grade students&rsquo / understanding of solubility equilibrium concept, students&rsquo / perceived motivation, use of learning strategies, and attitudes towards chemistry. There were 53 students in the experimental group instructed by the LCI and 56 students in the control group instructed by the TI. Solution Concept Test and Science Process Skills Test were administered to students in both groups as a pre-test. Attitude Scale towards Chemistry and Motivated Strategies for Learning Questionnaire were given to students in both groups before and after the treatment. Moreover, Solubility Equilibrium Concept Test was administered to both groups as a post-test and retention test two months after treatment. Treatment implementation continued for seven weeks. After the instruction, semi-structured interviews were conducted with six students from experimental group and six students from control group. Data were analyzed by using MANCOVA. The results revealed that LCI was more effective than the TI on students&rsquo / understanding and retention of the solubility equilibrium concepts. In addition, LCI improved students&rsquo / attitudes towards chemistry, intrinsic goal orientation, task value, self-efficacy for learning and performance, rehearsal, elaboration, organization, critical thinking, metacognitive self-regulation, time and study environment, and peer learning. Moreover, females found as more positive towards chemistry and better organization and help seeking. Furthermore, interview results indicated that students in experimental group demonstrated better scientific understanding of solubility equilibrium concepts compared to those in control group.
2

Crises bancárias: aplicação dos aprendizados na prática para a teoria

Melges, Mariana de Andrade 09 August 2017 (has links)
Submitted by Mariana De Andrade Melges (melges90@hotmail.com) on 2017-09-06T20:01:31Z No. of bitstreams: 1 Dissertação Mariana Melges v29 - Final.pdf: 791929 bytes, checksum: d559997ba61743147b902d014b7c9c51 (MD5) / Rejected by Joana Martorini (joana.martorini@fgv.br), reason: Boa tarde, Mariana. Para que possamos aprovar o seu trabalho, é necessário que coloque os títulos em negrito (capa, contracapa e pág 4) e também a página de Lista de Figuras e Tabelas após o Abstract. Qualquer dúvida, mande e-mail no mestradoprofissional@fgv.br ou ligue 3799-7764 Att, Thais Oliveira. on 2017-09-11T18:06:10Z (GMT) / Submitted by Mariana De Andrade Melges (melges90@hotmail.com) on 2017-09-11T19:13:28Z No. of bitstreams: 1 Dissertação Mariana Melges v30 - Final.pdf: 791981 bytes, checksum: 3777c1b6006db9a3693b501a31d416f8 (MD5) / Rejected by Joana Martorini (joana.martorini@fgv.br), reason: Mariana, boa tarde. Tivemos que rejeitar novamente o seu trabalho, pois vimos que está faltando a "Introdução". Se puder, acrescente-a. Grata! on 2017-09-11T19:22:45Z (GMT) / Submitted by Mariana De Andrade Melges (melges90@hotmail.com) on 2017-09-11T19:41:07Z No. of bitstreams: 1 Dissertação Mariana Melges v30 - Final.pdf: 793658 bytes, checksum: 8b4eb16864eefcf982b15c25630d8a3a (MD5) / Approved for entry into archive by Joana Martorini (joana.martorini@fgv.br) on 2017-09-11T19:42:46Z (GMT) No. of bitstreams: 1 Dissertação Mariana Melges v30 - Final.pdf: 793658 bytes, checksum: 8b4eb16864eefcf982b15c25630d8a3a (MD5) / Made available in DSpace on 2017-09-12T15:27:57Z (GMT). No. of bitstreams: 1 Dissertação Mariana Melges v30 - Final.pdf: 793658 bytes, checksum: 8b4eb16864eefcf982b15c25630d8a3a (MD5) Previous issue date: 2017-08-09 / The present paper has the objective of adapt a model of financial intermediation, including in it key elements that drive this sector to a crisis like it was observed in the real world. Were evaluated the most relevant failure point in the relationship of the financial system in the moments that preceded the 2008s crisis, looking for information distortions that could take to a financial crisis. After that, it was presented a theoretical model which defines the equilibrium conditions of the financial system and then presented some applications of the deviations observed in reality to create an operation system that modifies this equilibrium taking it to grow the number of projects that are financed based on an increase of the moral hazard and also the risk of failure of these projects. In the end it was presented methodologies to mitigate the risks of crisis like the one experienced in the last few years. / O presente trabalho tem por objetivo adaptar um modelo de intermediação financeira, incluindo nele elementos chave que levam a uma crise no setor financeiro tal qual observado no mundo real. Foram avaliados os principais pontos de falha nas relações do sistema financeiro no período que precedeu a crise de 2008, buscando distorções de informações que possam levar a crises financeiras. Na sequência, foi apresentado um modelo teórico que define as condições de equilíbrio do sistema financeiro, a partir dele foram aplicadas as distorções levantadas da realidade de modo a criar um sistema de operação que modifica as condições de equilíbrio, aumentando a quantidade de projetos sendo financiados com base em um aumento do risco de falha desses projetos. Por fim foram apresentadas metodologias que mitigam os riscos de ocorrência de crises como as recém observadas.
3

Are there alternatives to greenbelts? : evidence from a new land-use transport interaction model for Greater Beijing

Ma, Mingfei January 2017 (has links)
Urban greenbelts are considered a key instrument for shaping sustainable urban growth and protecting the environment in a large number of cities in the world. In most cities, there is a widely shared belief that urban greenbelts are beneficial to the natural environment. By contrast, there is little understanding of the underlying economic impacts of greenbelts and other green space configurations in fast growing cities. The unprecedented rate and scale of urbanisation in the emerging economies has brought the role of greenbelts into an even sharper focus. In cities within these fast growing economies, the urban population is expected to double in the coming decades, which means that greenbelts are under great pressures to adapt to the large forthcoming growth. Few existing urban models are capable of addressing the dynamic nature of the urban transformations and predicting the impacts of urban greenbelts in the developing world. This prompts us to develop a new modelling method that is capable of assessing the impacts of different configurations, scales and locations of green spaces. We then use it to examine alternative futures to the greenbelt through a case study of Greater Beijing. The method we developed is a new variant in the land use-transport interaction (LUTI) model family. This model is capable of addressing the non-equilibrium nature of urban land use and transport development and the equilibrium nature of the day-to-day adaptations made by businesses and citizens. This LUTI model aims to answer the following questions: what are the short-term and long-term economic impacts of a greenbelt on a fast growing city? Which alternative green space configuration performs better in terms of economic well-being and travel costs? Where and how much should the greenbelt land be progressively reshaped or released as the city grows? The new LUTI model is calibrated and validated using data collected for 1990, 2000 and 2010 for Greater Beijing, The model is first tested retrospectively through revisiting the past greenbelt policies in Beijing from 1990 to 2010. Then the impacts of different future green space configurations from 2010 to 2030 are predicted and assessed through quantifying economic costs/benefits and travel costs for socio-economic groups. The model results suggest that under rapid transformative urban change, the configuration, scale and location of a greenbelt have a significant impact on a city’s economic efficiency. Such impacts will transcend the greenbelt boundary, and even the boundary of Beijing Municipality, onto the entire city region. A narrow greenbelt launched in the early age of urban expansion could lead to spatial mismatch of residents and jobs. A wide and strictly controlled ring-shaped greenbelt is not the highest performing intervention either, in terms of economic well-being. The green-wedges configuration is a remedial policy that balances the economic efficiency and environmental benefits. Intensive development around metro/rail stations in the designated greenbelt could reduce spatial costs and promote sustainable travel modes. This implies that a careful siting of new development within existing designations of the greenbelt can be beneficial in terms of economic well-being and sustainable transport.
4

Stochastic and temperature-related aspects of the Preisach model of hysteresis

Schubert, Sven 22 June 2011 (has links)
Ziel der vorliegenden Arbeit ist es, das Preisach-Modell bezüglich stochastischer äußerer Felder und temperaturbezogener Aspekte zu untersuchen. Das phänomenologische Preisach-Modell wird oft erfolgreich angewendet, um Systeme mit Hysterese zu beschreiben. Im ersten Teil der Arbeit wird die Antwort des Preisach-Modells auf stochastische äußere Felder untersucht. Hier liegt das Augenmerk hauptsächlich auf der Autokorrelation; sie dient dazu den Einfluss des hysteretischen Gedächtnisses zu quantifizieren. Mit analytischen Methoden wird gezeigt, dass sich ein Langzeitgedächtnis, sichtbar in der Autokorrelation der Systemantwort, entwickeln kann, selbst wenn das treibende Feld unkorreliert ist. Im Anschluss werden diese Resultate, m.H. von Simulationen, auf äußere Felder ausgeweitet, die selbst Korrelationen aufweisen können. Der zweite Teil der Arbeit befasst sich mit dem Einfluss einer endlichen Temperatur auf das Preisach-Modell. Es werden unterschiedliche Methoden besprochen, wie das Nichtgleichgewichtsmodell in seiner mikromagnetischen Interpretation mit Temperatur als Gleichgewichtseigenschaft verknüpft werden kann. Eine Formulierung wird genutzt, um die Magnetisierung von Nickelnanopartikeln in einer Fullerenmatrix zu simulieren und mit Experimenten zu vergleichen. Des Weiteren wird die Relaxationsdynamik des Gedächtnisses des Preisach-Modells bei endlichen Temperaturen untersucht. / The aim of this thesis is to investigate the Preisach model in regard to stochastically driving and temperature-related aspects. The Preisach model is a phenomenological model for systems with hysteresis which is often successfully applied. Hysteresis is a widespread phenomenon which is observed in nature and the key feature of certain technological applications. Further, it contributes to phenomena of interest in social science and economics as well. Prominent examples are the magnetization of ferromagnetic materials in an external magnetic field or the adsorption-desorption hysteresis observed in porous media. Hysteresis involves the development of a hysteresis memory, and multistability in the interrelations between external driving fields and system response. In the first part, we mainly investigate the response of Preisach hysteresis models driven by stochastic input processes with regard to autocorrelation functions to quantify the influence of the system’s memory. Using rigorous methods, it is shown that the development of a hysteresis memory is reflected in the possibility of long-time tails in the autocorrelation functions, even for uncorrelated driving fields. In the case of uncorrelated driving, these long-time tails in the autocorrelations of the system’s response are determined only by the tails of the involved densities. They will be observed if there are broad Preisach densities assigning a high weight to elementary loops of large width and narrow input densities such that rare extreme events of the input time series contribute significantly to the output for a long period of time. Afterwards, these results are extended by simulations to driving fields which themselves show correlations. It is shown that the autocorrelation of the output does not decay faster than the autocorrelation of the input process. Further, there is a possibility that long-term memory in the hysteretic response is more pronounced in the case of uncorrelated driving than in the case of correlated driving. The behavior of the output probability distribution at the saturation values is quite universal. It is not affected by the presence of correlations and allows conclusions whether the input density is much more narrow than the Preisach density or not. Moreover, the existence of effective Preisach densities is shown which define equivalence classes of systems of input and Preisach densities which lead to realizations of the same output variable. The asymptotic behavior of an effective Preisach density determines the asymptotic correlation decay of the system’s response in the case of uncorrelated driving. In the second part, temperature-related effects are considered. It is reviewed how the non-equilibrium Preisach model in its micromagnetic picture can be related to temperature within the framework of extended irreversible thermodynamics. The irreversible response of a ferromagnetic material, namely, Nickel nanoparticles in a fullerene matrix, is simulated. The model includes superparamagnetism where ferromagnetism breaks down at temperatures lower than the Curie temperature and the results are compared to experimental data. Furthermore, we adapt known results for the thermal relaxation of the system’s memory in the form of a front propagation in the Preisach plane derived basically from solving a master equation and by the use of a contradictory assumption. A closer look is taken at short time scales which dissolves the contradiction and shows that the known results apply, taking into account the fact that the dividing line propagation starts with an additional delay time depending on the front coordinates in the Preisach plane. Additionally, it is outlined how thermal relaxation behavior in the Preisach model of hysteresis can be studied using a Fokker-Planck equation. The latter is solved analytically in the non-hysteretic limit using eigenfunction methods. The results indicate a change in the relaxation behavior, especially on short time scales.

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