364 research outputs found
Foregrounds:Opaque Stories about Learning
No full textForegrounds contributes to the development of theories of learning, in particular to theories of learning mathematics. It is relevant to students, student teachers, and researchers in the field of education as well as in mathematics education. Foregrounds contains six parts. Part I provides a summary of the notion of foreground as it has developed since the author introduced the idea in Towards a Philosophy of Critical Mathematics Education. In Part II, the reader meets some students who tell us about their neighbourhood, about drug dealing, violence, and about playing football. They tell us about their teachers, about mathematics, and about what they would like their teachers to do. They tell us about their hopes, expectations, and frustrations. Part III presents the notions of intentionality and life-world as developed by Brentano and Husserl. However, in Part IV the author provides a radical reinterpretation of these two notions. He describes real-life intentionalities and real-life worlds as profoundly structured by a range of social factors. Part V is composed as a meeting between, on the one hand, the students and their experiences as presented in Part II, and on the other hand these notions of real-life intentionalities and real-life worlds. Through this meeting the author develops further the notion of foreground. The concluding part (Part VI) brings more examples as illustrations. Ole Skovsmose has a special interest in critical mathematics education. He has investigated the landscape of investigation, students' experience of meaning, project work, mathematics education and democracy, mathematics in action, and mathematics and power. He has published more than 20 books in Danish, English and Portuguese as well as a huge number of articles. Sense has published the following books by Ole Skovsmose: Travelling through Education, In Doubt, An Invitation to Critical Mathematics Education, and Opening the Cage: Critique and Politics of Mathematics Education, which is edited together with Brian Greer.Aalborg UniversityState University of São Paul
Optimal solution error covariance in highly nonlinear problems of variational data assimilation
No full textThe problem of variational data assimilation for a nonlinear evolution model is formulated as an optimal control problem (see, e.g.[1]) to find the initial condition, boundary conditions or model parameters. The input data contain observation and background errors, hence there is an error in the optimal solution. For mildly nonlinear dynamics, the covariance matrix of the optimal solution error can be approximated by the inverse Hessian of the cost functional of an auxiliary data assimilation problem ([2], [3]). The relationship between the optimal solution error covariance matrix and the Hessian of the auxiliary control problem is discussed for different degrees of validity of the tangent linear hypothesis. For problems with strongly nonlinear dynamics a new statistical method based on computation of a sample of inverse Hessians is suggested. This method relies on the efficient computation of the inverse Hessian by means of iterative methods (Lanczos and quasi-Newton BFGS) with preconditioning. The method allows us to get a sensible approximation of the posterior covariance matrix with a small sample size. Numerical examples are presented for the model governed by Burgers equation with a nonlinear viscous term. The first author acknowledges the funding through the project 09-01-00284 of the Russian Foundation for Basic Research, and the FCP program "Kadry"
Footprints of information foragers: Behaviour semantics of visual exploration
No full textSocial navigation exploits the knowledge and experience of peer users of information resources. A wide variety of visual–spatial approaches become increasingly popular as a means to optimize information access as well as to foster and sustain a virtual community among geographically distributed users. An information landscape is among the most appealing design options of representing and communicating the essence of distributed information resources to users. A fundamental and challenging issue is how an information landscape can be designed such that it will not only preserve the essence of the underlying information structure, but also accommodate the diversity of individual users. The majority of research in social navigation has been focusing on how to extract useful information from what is in common between users' profiles, their interests and preferences. In this article, we explore the role of modelling sequential behaviour patterns of users in augmenting social navigation in thematic landscapes. In particular, we compare and analyse the trails of individual users in thematic spaces along with their cognitive ability measures. We are interested in whether such trails can provide useful guidance for social navigation if they are embedded in a visual–spatial environment. Furthermore, we are interested in whether such information can help users to learn from each other, for example, from the ones who have been successful in retrieving documents. In this article, we first describe how users' trails in sessions of an experimental study of visual information retrieval can be characterized by Hidden Markov Models. Trails of users with the most successful retrieval performance are used to estimate parameters of such models. Optimal virtual trails generated from the models are visualized and animated as if they were actual trails of individual users in order to highlight behavioural patterns that may foster social navigation. The findings of the research will provide direct input to the design of social navigation systems as well as to enrich theories of social navigation in a wider context. These findings will lead to the further development and consolidation of a tightly coupled paradigm of spatial, semantic and social navigation
Význam lidských vzorů a řízení středních škol pro zapojení žen ve STEM oborech: Analýza z prostředí České republiky
No full textTitle: Role Models, High School Management and Female Engagement in STEM: Evidence from the Czech Republic Author: Jiří Grosman, BSc Institute: CERGE-EI Supervisor: PhDr. Jan Zapal, Ph.D., CERGE-EI Abstract: The fact that the gender wage gap remains at least in part driven by women's self-selection out of profitable career choices has been an established fact in the labour economics literature. What has been given comparatively less attention by economists, however, are the motivating factors of such self-selection. In this thesis, I design an empirical strategy aimed to assess the strength of a particular driver of differential gendered choices: high school management, and the associated policy intervention. Specifically, I examine the STEM preferences of high school students using population data on Czech university applicants between the years of 2007-2021. By employing both matching and a difference- in-differences estimation framework to facilitate causal interpretation, I argue that school mentoring programmes, and the way the school is being run, can significantly affect the choices made by a non-negligible number of female students - an inference corroborated by the data and my subsequent analysis. Keywords: gender gap; STEM; high school; education 1Název práce: Význam lidských vzorů a řízení středních škol pro zapojení žen ve STEM oborech: analýza z prostředí České republiky Autor: Jiří Grosman, BSc Pracoviště: CERGE-EI Vedoucí práce: PhDr. Jan Zápal, Ph.D., CERGE-EI Abstrakt: Skutečnost, že gender wage gap je alespoň do určité míry motivován selekcí méně výdělečných profesí ze strany žen je v současném oboru ekonomie pracovního trhu v zásadě obecně přijímaným faktem. Čemu však byla doposud věnována srovnatelně menší pozornost odobrníků jsou faktory, jež tuto selekci způsobují. V rámci této diplomové práce si za pomoci vlastní výzkumné strate- gie kladu za cíl změřit důležitost jednoho specifického motivátoru rozdílných, gendrově podmíněných rozhodnutí: způsob vedení středních škol, a s ním spo- jených opatření. Konkrétně, skrze analýzu celorepublikových dat zachycujících údaje o přihláškách uchazečů o studium na vysokých školách z let 2007-2011 v této práci mapuji inklinaci studentů SŠ ucházet se o vědní (STEM) obory v dalším studiu. Za užití kauzálních matching a difference-in-deifferences modelů argumentuji, že školní mentoringové programy společně se způsobem, jakým je škola vedena, mohou statisticky významným způsobem ovlivnit studijně-profesní rozhodnutí nemalého množství studentek - tvrzení, v jehož prospěch hovoří jak mnou zmapovaná data, tak...CERGEFakulta sociálních vědFaculty of Social Science
Compressive failure predictions for carbon fiber-reinforced composites: A comparative study between imaging modalities
No full textWe compare compressive strength predictions for carbon fiber-reinforced composites based on different imaging modalities. We use X-ray computed tomography and optical microscopy for acquiring 3D and 2D images, respectively. Based on the acquired images, the fiber orientation distribution is estimated and used as input for 2D and 3D finite element models of both imaging modalities. Subsequently, the four model predictions are compared with experimental data to quantify their capabilities in terms of stiffness and strength. All models predict compressive failure associated with kink band formation near areas with a high degree of fiber misalignment. The 3D models predict a stiffness within one standard deviation of the experimental results but with significantly higher strength. We argue that the strength prediction shows a potential, as the measured strength is limited by load introduction failure. The 2D models predict a stiffness 4-7% higher than the 3D models. The strength predictions are similar to the measured strengths but 32-48% lower than the prediction based on 3D X-ray μCT. The discrepancy between strength predictions shows that a simple 2D approach is too limited for the investigated composite and that 3D models based on more advanced imaging modalities are required to accurately predict compressive failure
The works of Thomas Nelson Page.
No full textThis edition is limited to 230 sets with the portrait signed by the author. No. .I. In ole Virginia.--II. The burial of the guns.--III. On Newfound River.--IV-V. Red Rock; a chronicle of reconstruction.--VI-VII. Gordon Keith.--VIII. The old gentleman of the black stock. Santa Claus's partner.--IX. Bred in the bone.--X. Pastime stories. Poems.--XI. Two little Confederates. Among the camps. Two prisoners.--XII. The old South; essays social and political.--XIII. The Old Dominion, her making and her manners.--XIV. Under the crust. Tommy Trot's visit to Santa Claus.--XV-XVI. John Marvel, assistant.--XVII-XVIII. Robert E. Lee, man and soldier.Mode of access: Internet
Macroeconomic and policy implications of population aging in Brazil
No full textThis paper analyzes the macroeconomic implications of population aging in Brazil. Three alternative yet complementary methodologies are adopted, and depending on policy responses to the fiscal implications of aging, there are two main findings: First, saving rates could increase and not necessarily fall as a consequence of aging in Brazil -- thus contradicting conventional views. Second, lifetime wealth across generations could increase -- as capital deepening generates a second demographic dividend. Two policy responses to aging are emphasized: First, a structural policy response of linking mandatory retirement (or entitlement) ages to increasing life expectancy would boost labor supply and reduce the fiscal costs of aging. Second, in terms of preferable parametric policy responses, the second demographic dividend will be promoted to the highest extent by keeping taxes and debt unchanged while allowing public pensions to adjust downward. Such a policy response would keep pensions from further crowding out private saving -- thus balancing capital accumulation with intergenerational income distribution. In conclusion, Brazil will not necessarily experience a fall in saving and growth, but if government policies are appropriately, adequately, and timely formulated, population aging is likely to lead to substantial capital deepening and increases in lifetime income, wealth, and welfare.Emerging Markets,Access to Finance,Population Policies,Economic Theory&Research,Debt Markets
Tuotannonohjaus tilausohjautuvassa tuotannossa
No full textTämän opinnäytetyön toimeksiantaja oli Nordic Tank Oy. Työssä perehdytään Logica V-10 -toiminnanohjausjärjestelmän käyttöön Nordic Tank Oy:n tuotannonohjauksessa.
Opinnäytetyön teoriaosuudessa perehdytään toiminnanohjauksen teoriaan sekä peruskäsitteisiin. Teoriaosuuden jälkeen kuvataan kohdeyrityksen tuotannonohjauksessa käytettävä ohjelmisto sekä keskeiset yrityksen tuotantoon ja tuotannonohjaukseen liittyvät käsitteet.
Kokeellisessa osiossa havainnollistetaan kohdeyrityksen tuotannonohjausta esimerkin avulla ja kuvataan, miten toiminnanohjausjärjestelmää voi hyödyntää tuotannonohjauksessa. Esimerkkinä oleva Case hakeperävaunu on täysin kuvitteellinen perävaunuprojekti, joka on luotu vain tätä työtä varten eikä sillä ole odotettavissa minkäänlaista teollista tulevaisuutta. Case toteutettiin ohjelman testiversiossa.
Työn lopussa on pohdintoja sekä näkemyksiä mahdollisista ongelmakohdista sekä jokunen kehitysehdotus.This thesis was made for Nordic Tank Oy. In the thesis we focus on the Locica V-10-operation management system and how it is used in Nordic Tank Oy.
In the theory section of the thesis we focus on the theory of the operation man-agement and some basic concepts. After the theory section we learn about the theory of the target company production control system.
The experimental section of the study illustrated the production management system of the wood chip trailer of the target company. The wood ship trailer is the imaginary trailer project which was created only for this study. The case of the wood chip trailer project was carried out in the test version of the program.
At the end of the thesis some thoughts of the author are presented. There are also some views of the author and a couple of proposals for improvement for the future
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