10,717 research outputs found

    Using On-Line Quizzes to Help Students Learn Probability and Statistics

    Get PDF
    Online quizzes can be an effective and flexible means of helping learners develop key skills in probability and statistics. Quizzes give instant feedback, to help reinforce correct understanding and eliminate fundamental errors at an early stage in learning. We will describe our experience of designing and using quizzes with non-specialist and specialist students, on several different platforms including, most recently, Moodle. We describe Model Choice, a tool that helps students identify from a brief scenario the standard family of probability distributions they should work with to solve a problem. We will emphasize key design aspects of a successful quiz system, such as the importance of giving informative feedback to the learner. Using a standard platform, such as Moodle, is likely to require some compromise on design principles but building a stand-alone system to implement ideal design choices is very time-consuming

    STEM: Science, Technology, Engineering and Math

    Get PDF
    Science is on our minds at Linfield. Students and faculty spent the summer collaborating on research in the sciences, mathematics and technology, both here and abroad

    "The Conditions for Sustainable U.S. Recovery: The Role of Investment"

    Get PDF
    The anemic U.S. economic recovery and the threat of a double-dip recession stem from the weakness of investment, due to excess capacity created in the euphoric years of the "new economy" bubble. The current imbalances in the corporate sector (i.e., the all-time-high indebtedness in the face of falling asset prices) are preventing investment from picking up and are laying the foundations for a new, long-lasting expansion. Tax reductions may create a cyclical upturn in the short run, and may promote the anemic recovery, but such stimulus to demand is unsustainable in the long run. The root of the problem is the imbalance in the corporate sector, which will take time for correction.

    Intelligent Controls for a Semi-Active Hydraulic Prosthetic Knee

    Get PDF
    We discuss open loop control development and simulation results for a semi-active above-knee prosthesis. The control signal consists of two hydraulic valve settings. These valves control a rotary actuator that provides torque to the prosthetic knee. We develop open loop control using biogeography-based optimization (BBO), which is a recently developed evolutionary algorithm, and gradient descent. We use gradient descent to show that the control generated by BBO is locally optimal. This research contributes to the field of evolutionary algorithms by demonstrating that BBO is successful at finding optimal solutions to complex, real-world, nonlinear, time varying control problems. The research contributes to the field of prosthetics by showing that it is possible to find effective open loop control signals for a newly proposed semi-active hydraulic knee prosthesis. The control algorithm provides knee angle tracking with an RMS error of 7.9 degrees, and thigh angle tracking with an RMS error of 4.7 degrees. Robustness tests show that the BBO control solution is affected very little by disturbances added during the simulation. However, the open loop control is very sensitive to the initial conditions. So a closed loop control is needed to mitigate the effects of varying initial conditions. We implement a proportional, integral, derivative (PID) controller for the prosthesis and show that it is not a sufficient form of closed loop control. Instead, we implement artificial neural networks (ANNs) as the mechanism for closed loop control. We show that ANNs can greatly improve performance when noise and disturbance cause high tracking errors, thus reducing the risk of stumbles and falls. We also show that ANNs are able to improve average performance by as much as 8 over open loop control. We also discuss embedded system implementation with a microcontroller and associated hardware and softwar

    Using Sound to Enhance Users’ Experiences of Mobile Applications

    Get PDF
    The latest smartphones with GPS, electronic compass, directional audio, touch screens etc. hold potentials for location based services that are easier to use compared to traditional tools. Rather than interpreting maps, users may focus on their activities and the environment around them. Interfaces may be designed that let users search for information by simply pointing in a direction. Database queries can be created from GPS location and compass direction data. Users can get guidance to locations through pointing gestures, spatial sound and simple graphics. This article describes two studies testing prototypic applications with multimodal user interfaces built on spatial audio, graphics and text. Tests show that users appreciated the applications for their ease of use, for being fun and effective to use and for allowing users to interact directly with the environment rather than with abstractions of the same. The multimodal user interfaces contributed significantly to the overall user experience

    Broadcasting to the masses or building communities: Polish political parties’ online performance during 2011 elections in international perspective

    Get PDF
    This paper analyses within the context of election contests the extent to which parties use the range of Web 2.0 tools, in particular social networking sites, weblogs and microblogs, in order to build communities online; we contrast this with the more traditional political use of the online environment for broadcasting. Using the 2011 Polish general election as a case study, we analyse the use of the online environment by all political parties, categorising features as offering a range of functions to serve visitors, from informing to allowing interaction. We also assess how different groups of visitors are targeted through different features or platforms. The data from the content analysis thus provides a rich picture of the online strategy of each party and the extent to which the Internet was used in the campaign. These data are supplemented by web cartography analysis which identifies the interlinkages between the websites of political parties, official information sources and the media. The cartography allows us to analyse the direction of traffic flow within the electoral websphere, the extent to which parties create open platforms with high levels of linkage to one another or if they maintain enclosed communities linking only to supportive sites. Overall our paper will provide an understanding of party election strategies during elections allowing discussion regarding the impact this might have on parties, media actors and voters. In particular we demonstrate how parties can use the range of web features to build communities of specific groups of visitors, in particular those with issue specific interests, those leaning towards supporting a party, and existing partisan campaigners. The use of these tools, we argue, can increase loyalty and lead to the conversion of supporters to activists. The paper leads into a discussion of how social networking tools have the potential to enhance the link between parties, members and supporters but that this depends on how the party utilises the online environment. Finally we aim to fit the Polish case study within a larger picture of political parties’ online performance during elections. Here we will compare our data on Poland with similar data which analysed the performance of parties in German 2009 general elections, parliamentary elections in Great Britain 2010 and French parliamentary election in 2012

    Innovation Activities Abroad and the Effects of Liability of Foreignness: Where it Hurts

    Get PDF
    The innovation activities of foreign subsidiaries have been identified as an important source of competitive advantage for multinational corporations. The success of these engagements depends heavily on tapping host country pools of localized expertise. To achieve this foreign subsidiaries have to overcome cultural and social barriers (liability of foreignness). We derive potential stumbling blocks in the innovation process theoretically and argue that these materialize as neglected projects, cancellations or budget overruns. We test these hypotheses empirically for more than 1,000 firms with innovation activities in Germany from various sectors. We find that foreign-controlled firms are not challenged by liability of foreignness at the project mobilization stage. The lack of local embeddedness becomes more binding as projects have to be prioritized and managed which we identify as more frequent mistakes and delays. We argue that this is the result of shared practices within the multinational firm that do not readily fit into the local context. Finally, we derive management recommendations how foreign innovation engagements can achieve similar levels of effectiveness and efficiency as host country competitors. --Liability of foreignness,offshoring R&D,internationalization,innovation management

    The "Artificial Mathematician" Objection: Exploring the (Im)possibility of Automating Mathematical Understanding

    Get PDF
    Reuben Hersh confided to us that, about forty years ago, the late Paul Cohen predicted to him that at some unspecified point in the future, mathematicians would be replaced by computers. Rather than focus on computers replacing mathematicians, however, our aim is to consider the (im)possibility of human mathematicians being joined by “artificial mathematicians” in the proving practice—not just as a method of inquiry but as a fellow inquirer

    The Paradox of Observing, Autopoiesis, and the Future of Social Sciences

    Get PDF
    The current debates in social sciences show that the paradox of observing—the embeddedness of observer in the process of observing—is at the heart of the controversy about their cognitive status and future. Although the problem of observing has been addressed in numerous theoretical perspectives—some of which (Habermas, Leydesdorff, Maturana, and Luhmann) are examined in this article—the prospects for resolving this paradox remain problematic. Locating a point that allows reflection on the process of autopoiesis in general, not just the operation of a particular autopoietic system, may be one condition for resolving this paradox. Such point will offer reflection on all autopoietic systems, including the observer. The dynamic balance between equilibrium and disequilibrium is the mechanism which regulates the process of autopoiesis. Since the function of regulation is essentially a reflective function, this equilibrium between equilibrium and disequilibrium, which can be identified with the concept of homeorhesis introduced by Conrad Waddington, may offer a possibility to reflect on the process of observing
    corecore