89 research outputs found

    The use of special exceptions in zoning practice

    Get PDF
    Thesis (M.C.P.) Massachusetts Institute of Technology. Dept. of Architecture, 1951.Bibliography: leaf 54.by Owen W. Burnham and Morris E. Johnson.M.C.P

    Design of Experiments for Screening

    Full text link
    The aim of this paper is to review methods of designing screening experiments, ranging from designs originally developed for physical experiments to those especially tailored to experiments on numerical models. The strengths and weaknesses of the various designs for screening variables in numerical models are discussed. First, classes of factorial designs for experiments to estimate main effects and interactions through a linear statistical model are described, specifically regular and nonregular fractional factorial designs, supersaturated designs and systematic fractional replicate designs. Generic issues of aliasing, bias and cancellation of factorial effects are discussed. Second, group screening experiments are considered including factorial group screening and sequential bifurcation. Third, random sampling plans are discussed including Latin hypercube sampling and sampling plans to estimate elementary effects. Fourth, a variety of modelling methods commonly employed with screening designs are briefly described. Finally, a novel study demonstrates six screening methods on two frequently-used exemplars, and their performances are compared

    Translocations as Experiments in the Ecological Resilience of an Asocial Mega-Herbivore

    Get PDF
    Species translocations are remarkable experiments in evolutionary ecology, and increasingly critical to biodiversity conservation. Elaborate socio-ecological hypotheses for translocation success, based on theoretical fitness relationships, are untested and lead to complex uncertainty rather than parsimonious solutions. We used an extraordinary 89 reintroduction and 102 restocking events releasing 682 black rhinoceros (Diceros bicornis) to 81 reserves in southern Africa (1981–2005) to test the influence of interacting socio-ecological and individual characters on post-release survival. We predicted that the socio-ecological context should feature more prominently after restocking than reintroduction because released rhinoceros interact with resident conspecifics. Instead, an interaction between release cohort size and habitat quality explained reintroduction success but only individuals' ages explained restocking outcomes. Achieving translocation success for many species may not be as complicated as theory suggests. Black rhino, and similarly asocial generalist herbivores without substantial predators, are likely to be resilient to ecological challenges and robust candidates for crisis management in a changing world

    Looking for the women in Baron and Taylor's (1969) Educational administration and the social sciences

    Get PDF
    A search for women in Baron and Taylor's (1969) Educational administration and the social sciences [London: The Athlone Press] using feminist poststructural discourse analysis (FPDA) has revealed a changing discourse about gendered educational administration over the course of 50 years. Whilst few women are featured in the text itself, citations of women's writing surface the historical contributions of women as headmistresses and public servants. Women who have cited the text since its publication have challenged gendered theory and academic writing conventions. FPDA is used to explore the gendered educational administration discourse through the intertextuality of academic writing. Fluctuations between powerfulness and powerlessness are revealed depending on the socio-political context and women's circumstances

    Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

    Get PDF

    Lawson criterion for ignition exceeded in an inertial fusion experiment

    Get PDF
    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    Owen Wallace Burnham, Saving the legacy: an oral history of Utah's World War II veterans, ACCN 2070, American West Center, University of Utah

    No full text
    Transcript (48 pages) of an interview by Winston P. Erickson with Owen W. Burnham on August 28, 2000. This is from tape numbers 92 and 93 in the "Saving the Legacy Oral History ProjectBurnham (b. 1923) recalls his childhood in Blanding, Utah, and describes his basic training as part of the 17th Airborne Division shortly after Pearl Harbor. His unit landed in Naples, Italy, in March of 1944, and later fought in France and Germany. He was mustered out of the service in 1946. 48 pages
    • 

    corecore