35,500 research outputs found

    Connectionism Reconsidered: Minds, Machines and Models

    Get PDF
    In this paper the issue of drawing inferences about biological cognitive systems on the basis of connectionist simulations is addressed. In particular, the justification of inferences based on connectionist models trained using the backpropagation learning algorithm is examined. First it is noted that a justification commonly found in the philosophical literature is inapplicable. Then some general issues are raised about the relationships between models and biological systems. A way of conceiving the role of hidden units in connectionist networks is then introduced. This, in combination with an assumption about the way evolution goes about solving problems, is then used to suggest a means of justifying inferences about biological systems based on connectionist research

    A case study of advancing remote sensing image analysis

    Get PDF
    Big data and cloud computing are two phenomena, which have gained significant reputation over the last few years. In computer science the approach shifted towards distributed architectures and high performance computing. In case of geographical information systems (GIS) and remote sensing image analysis, the new paradigms have already been successfully applied to several problems, and systems have been developed to support processing of geographical and remote sensing data in the cloud. However, due to different circumstances many previous workflows have to be reconsidered and redesigned. Our goal is to show a way how the existing approaches to remote sensing image analysis can be advanced to take advantages of these new paradigms. The task aiming in shifting the algorithms shall require a moderate effort and must avoid the complete redesign and reimplementation of the existing approaches. We present the whole journey as a case study using an existing industrial workflow for demonstration. Nevertheless, we define the rules of thumb, which can come in hand when shifting any existing GIS workflows. Our case study is the workflow of waterlogging and flood detection, which is an operative task at the Institute of Geodesy, Cartography and Remote Sensing (FÖMI). This task in currently operational using a semi-automatic single machine approach involving multiple software. The workflow is neither efficient nor scalable, thus it is not applicable in emergency situations where quick response is required. We present an approach utilizing distributed computing, which enables the automated execution of this task on large input data with much better response time. The approach is based on the well-known MapReduce paradigm, its open-source implementation, the Apache Hadoop framework and the AEGIS geospatial toolkit. This enables the replacement of multiple software to a single, generic framework. Results show that significant performance benefits can be achieved at the expense of minor accuracy loss

    Hex Player—a virtual musical controller

    Get PDF
    In this paper, we describe a playable musical interface for tablets and multi-touch tables. The interface is a generalized keyboard, inspired by the Thummer, and consists of an array of virtual buttons. On a generalized keyboard, any given interval always has the same shape (and therefore fingering); furthermore, the fingering is consistent over a broad range of tunings. Compared to a physical generalized keyboard, a virtual version has some advantages—notably, that the spatial location of the buttons can be transformed by shears and rotations, and their colouring can be changed to reflect their musical function in different scales. We exploit these flexibilities to facilitate the playing not just of conventional Western scales but also a wide variety of microtonal generalized diatonic scales known as moment of symmetry, or well-formed, scales. A user can choose such a scale, and the buttons are automatically arranged so their spatial height corresponds to their pitch, and buttons an octave apart are always vertically above each other. Furthermore, the most numerous scale steps run along rows, while buttons within the scale are light-coloured, and those outside are dark or removed. These features can aid beginners; for example, the chosen scale might be the diatonic, in which case the piano’s familiar white and black colouring of the seven diatonic and five chromatic notes is used, but only one scale fingering need ever be learned (unlike a piano where every key needs a different fingering). Alternatively, it can assist advanced composers and musicians seeking to explore the universe of unfamiliar microtonal scales

    Rules of Thumb in Life-Cycle Saving Decisions

    Get PDF
    We analyse life-cycle saving decisions when households use simple heuristics, or rules of thumb, rather than solve the underlying intertemporal optimization problem. We simulate life-cycle saving decisions using three simple rules and compute utility losses relative to the solution of the optimization problem. Our simulations suggest that utility losses induced by following simple decision rules are relatively low. Moreover, the two main saving motives re ected by the canonical life-cycle model { long-run consumption smoothing and short-run insurance against income shocks { can be addressed quite well by saving rules that do not require computationally demanding tasks such as backward induction

    Evolution of Prehension Ability in an Anthropomorphic Neurorobotic Arm

    Get PDF
    In this paper we show how a simulated anthropomorphic robotic arm controlled by an artificial neural network can develop effective reaching and grasping behaviour through a trial and error process in which the free parameters encode the control rules which regulate the fine-grained interaction between the robot and the environment and variations of the free parameters are retained or discarded on the basis of their effects at the level of the global behaviour exhibited by the robot situated in the environment. The obtained results demonstrate how the proposed methodology allows the robot to produce effective behaviours thanks to its ability to exploit the morphological properties of the robot’s body (i.e. its anthropomorphic shape, the elastic properties of its muscle-like actuators, and the compliance of its actuated joints) and the properties which arise from the physical interaction between the robot and the environment mediated by appropriate control rules

    Fiscal and Monetary Policy Interactions in a New Keynesian Model with Liquidity Constraints

    Get PDF
    This paper derives a New Keynesian dynamic general equilibrium model with liquidity constrained consumers and sticky prices. The model allows a role for both government spending and taxation in the DGE model. The model is then estimated using Euro area data. We demonstrate that there seems to be a significant role for rule-of-thumb consumer behaviour. Our model is then used to analyse the interaction between fiscal and monetary policies. We examine the extent to which fiscal policy (automatic stabilisers) assist or hinder monetary policy when the latter takes a standard forward-looking inflation targeting form. We also examine the extent to which inertia in fiscal policy and the presence of rule-of-thumb consumers affects output and inflation variability in the presence of such a monetary policy rule.

    Do tax distortions lead to more indeterminacy? A New Keynesian perspective

    Get PDF
    Following the recent developments of the literature on stabilization policies, this paper investigates the effect of tax distortions on equilibrium determinacy in a New Keynesian economy with rule-of-thumb consumers and capital accumulation. In particular, we focus on the inter-action between monetary policy and tax distortions in supporting the saddle-path equilibrium under the assumptions of balanced budget and monetary policy satisfying a Taylor rule.rule-of-thumb consumers, equilibrium determinacy, fiscal and monetary policy inter-actions, and tax distortions
    corecore