58,232 research outputs found

    Choosing friends carefully: allies for critical computing

    Get PDF
    In this paper, we argue firstly that researchers in critical computing should address the specific information and communication technology (ICT) needs and activities of those agencies concerned with emancipatory issues. Secondly, we argue that a critical perspective, explicitly foregrounding empowerment and emancipatory concerns, forms a basis for emphasising the practice of individuals, groups and organsations , rather than purely focusing on organisational form in social action. We discuss this context of social action, identifying some relevant ICT-related challenges. We identify three themes that highlight factors that differentiate ICT support for social action groups from the setting of conventional business and service organisations: Free / Libre Open- Source Software, techniques and technologies for engagement through storytelling, and learning and evaluation in social action.</p

    Improving supplementary feeding in species conservation

    Get PDF
    Supplementary feeding is often a knee-jerk reaction to population declines, and its application is not critically evaluated, leading to polarized views among managers on its usefulness. Here, we advocate a more strategic approach to supplementary feeding so that the choice to use it is clearly justified over, or in combination with, other management actions and the predicted consequences are then critically assessed following implementation. We propose combining methods from a set of specialist disciplines that will allow critical evaluation of the need, benefit, and risks of food supplementation. Through the use of nutritional ecology, population ecology, and structured decision making, conservation managers can make better choices about what and how to feed by estimating consequences on population recovery across a range of possible actions. This structured approach also informs targeted monitoring and more clearly allows supplementary feeding to be integrated in recovery plans and reduces the risk of inefficient decisions. In New Zealand, managers of the endangered Hihi (Notiomystis cincta) often rely on supplementary feeding to support reintroduced populations. On Kapiti island the reintroduced Hihi population has responded well to food supplementation, but the logistics of providing an increasing demand recently outstretched management capacity. To decide whether and how the feeding regime should be revised, managers used a structured decision making approach informed by population responses to alternative feeding regimes. The decision was made to reduce the spatial distribution of feeders and invest saved time in increasing volume of food delivered into a smaller core area. The approach used allowed a transparent and defendable management decision in regard to supplementary feeding, reflecting the multiple objectives of managers and their priorities

    Control of common scab without the use of water

    Get PDF
    The most effective way to control common scab is by irrigating a potato crop at tuber initiation. With the introduction of legislation such as the Water Framework Directive this will become increasingly difficult. In this field experiment, we assessed the potential of a number of non-water measures for controlling this disease. Common scab on daughter tubers at harvest was reduced by applying rapeseed meal at 1 t ha-1 to the beds and then incorporating it into the soil, and adding a mixture of Trichoderma viride isolates into the furrow at planting. None of these treatments was as effective as using water

    A Completely Invariant SUSY Transform of Supersymmetric QED

    Full text link
    We study the SUSY breaking of the covariant gauge-fixing term in SUSY QED and observe that this corresponds to a breaking of the Lorentz gauge condition by SUSY. Reasoning by analogy with SUSY's violation of the Wess-Zumino gauge, we argue that the SUSY transformation, already modified to preserve Wess-Zumino gauge, should be further modified by another gauge transformation which restores the Lorentz gauge condition. We derive this modification and use the resulting transformation to derive a Ward identitiy relating the photon and photino propagators without using ghost fields. Our transformation also fulfills the SUSY algebra, modulo terms that vanish in Lorentz gauge

    Low-Threshold Electrically Pumps Vertical-Cavity Surface-Emitting Microlasers

    Get PDF
    Vertical-cavity electrically driven lasers with three GaInAs quantum wells and diameters of several ÎŒm exhibit room-temperature pulsed current thresholds as low as 1.3mA with 958 nm output wavelength

    Task oriented nonlinear control laws for telerobotic assembly operations

    Get PDF
    The goal of this research is to achieve very intelligent telerobotic controllers which are capable of receiving high-level commands from the human operator and implementing them in an adaptive manner in the object/task/manipulator workspace. Initiatives by the authors at Integrated Systems, Inc. to identify and develop the key technologies necessary to create such a flexible, highly programmable, telerobotic controller are presented. The focus of the discussion is on the modeling of insertion tasks in three dimensions and nonlinear implicit force feedback control laws which incorporate tool/workspace constraints. Preliminary experiments with dual arm beam assembly in 2-D are presented
    • 

    corecore