2,718 research outputs found

    Progressor: Personalized visual access to programming problems

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    This paper presents Progressor, a visualization of open student models intended to increase the student's motivation to progress on educational content. The system visualizes not only the user's own model, but also the peers' models. It allows sorting the peers' models using a number of criteria, including the overall progress and the progress on a specific topic. Also, in this paper we present results of a classroom study confirming our hypothesis that by showing a student the peers' models and ranking them by progress it is possible to increase the student's motivation to compete and progress in e-learning systems. © 2011 IEEE

    On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid

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    Golumbic, Lipshteyn and Stern \cite{Golumbic-epg} proved that every graph can be represented as the edge intersection graph of paths on a grid (EPG graph), i.e., one can associate with each vertex of the graph a nontrivial path on a rectangular grid such that two vertices are adjacent if and only if the corresponding paths share at least one edge of the grid. For a nonnegative integer kk, BkB_k-EPG graphs are defined as EPG graphs admitting a model in which each path has at most kk bends. Circular-arc graphs are intersection graphs of open arcs of a circle. It is easy to see that every circular-arc graph is a B4B_4-EPG graph, by embedding the circle into a rectangle of the grid. In this paper, we prove that every circular-arc graph is B3B_3-EPG, and that there exist circular-arc graphs which are not B2B_2-EPG. If we restrict ourselves to rectangular representations (i.e., the union of the paths used in the model is contained in a rectangle of the grid), we obtain EPR (edge intersection of path in a rectangle) representations. We may define BkB_k-EPR graphs, k0k\geq 0, the same way as BkB_k-EPG graphs. Circular-arc graphs are clearly B4B_4-EPR graphs and we will show that there exist circular-arc graphs that are not B3B_3-EPR graphs. We also show that normal circular-arc graphs are B2B_2-EPR graphs and that there exist normal circular-arc graphs that are not B1B_1-EPR graphs. Finally, we characterize B1B_1-EPR graphs by a family of minimal forbidden induced subgraphs, and show that they form a subclass of normal Helly circular-arc graphs

    The Pulsed Neutron Beam EDM Experiment

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    We report on the Beam EDM experiment, which aims to employ a pulsed cold neutron beam to search for an electric dipole moment instead of the established use of storable ultracold neutrons. We present a brief overview of the basic measurement concept and the current status of our proof-of-principle Ramsey apparatus

    Fermionization of two distinguishable fermions

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    In this work we study a system of two distinguishable fermions in a 1D harmonic potential. This system has the exceptional property that there is an analytic solution for arbitrary values of the interparticle interaction. We tune the interaction strength via a magnetic offset field and compare the measured properties of the system to the theoretical prediction. At the point where the interaction strength diverges, the energy and square of the wave function for two distinguishable particles are the same as for a system of two identical fermions. This is referred to as fermionization. We have observed this phenomenon by directly comparing two distinguishable fermions with diverging interaction strength with two identical fermions in the same potential. We observe good agreement between experiment and theory. By adding one or more particles our system can be used as a quantum simulator for more complex few-body systems where no theoretical solution is available

    Open social student modeling: Visualizing student models with parallel introspectiveviews

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    This paper explores a social extension of open student modeling that we call open social student modeling. We present a specific implementation of this approach that uses parallel IntrospectiveViews to visualize models representing student progress with QuizJET parameterized self-assessment questions for Java programming. The interface allows visualizing not only the student's own model, but also displaying parallel views on the models of their peers and the cumulative model of the entire class or group. The system was evaluated in a semester-long classroom study. While the use of the system was non-mandatory, the parallel IntrospectiveViews interface caused an increase in all of the usage parameters in comparison to a regular portal-based access, which allowed the student to achieve a higher success rate in answering the questions. The collected data offer some evidence that a combination of traditional personalized guidance with social guidance was more effective than personalized guidance alone. © 2011 Springer-Verlag

    Women and sport in films in twenty-first century (2000-2009)

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    Este documento profundiza en el rol y cualidades asociadas a la mujer en el cine deportivo de la primera década del siglo XXI, objeto de estudio poco habitual en el campo de la investigación cinematográfica. Para ello, se determinó una muestra compuesta por 74 películas, seleccionadas a través de un muestreo no probabilístico por cuotas y mediante un diseño de investigación de tipo descriptivo, siendo el análisis de contenido el instrumento elegido para llevarlo a cabo. Los resultados mostraron que se reflejaba con fidelidad el modelo deportivo imperante en la actualidad, así como el canon moderno que se atribuye al sexo femenino, lo cual debería cuestionar el modelo que se muestra y perpetúa en este tipo de produccionesThis paper explores the roles and qualities of women in sport films from the first decade of the twenty-first century, which is an unusual subject of study in the field of film research. For this purpose we analysed a sample of 74 films that were selected through a non-probability quota sampling and using a descriptive investigation model. The sample was determined by way of content analysis. The results showed that the films reflected the current sports model, as well as the modern female stereotypes. This should help to question the current model shown in these types of film

    Multipurpose Prevention Technologies: Biomedical Tools to Prevent HIV-1, HSV-2, and Unintended Pregnancies

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    Statistics clearly show an unmet need for highly effective contraception, especially in less developed countries. Many of these countries are at the core of the HIV/AIDS epidemic and show very high prevalence rates for other sexually transmitted infections (STIs) such as that caused by HSV-2. A woman at risk of unintended pregnancy due to unprotected intercourse is also at risk for HIV/STI. Owing to their causative interrelationship, combining protection against these conditions will result in enhanced prevention and health benefits. Existing multipurpose prevention modalities such as condoms and physical barriers, albeit efficacious, face cultural hurdles that have so far hindered their widespread use. Success has recently been demonstrated in large clinical trials, demonstrating proof of concept of microbicides in reducing the incidence of HIV-1 and HSV-2 among at-risk populations. The challenge heretofore is to refine these products to make them more potent, convenient, accessible, and acceptable. Potent antiviral drugs released topically in the female reproductive tract by innovative delivered systems and formulations will provide safe, effective, and acceptable multipurpose prevention tools. This paper provides an overview of existing and novel approaches to multipurpose prevention strategies
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