20,039 research outputs found

    Measurement of NO plus plus e minus dissociative recombination in expanding air flows

    Get PDF
    Measurement of nitric oxide ion-electron dissociative recombination in expanding air flow

    Sources of electron energy in weakly ionized expansions of nitrogen

    Get PDF
    Sources of electron energy in weakly ionized expansions of nitroge

    EVALUATING ALTERNATIVE FARMING SYSTEMS: A FUZZY MADM APPROACH

    Get PDF
    This paper develops a decision support method that integrates measures of achievement in the economic, environmental, and social aspects of farming. The decision support method combines multiple attribute decision making (MADM) with fuzzy logic. The fuzzy MADM model fully ranks decision alternatives relative to the preferences of decision makers and overcomes several problems inherent in other MADM approaches. It is concluded that fuzzy MADM can improve decision making on the farm.fuzzy logic, fuzzy sets, multiple attribute decision making, MADM, Institutional and Behavioral Economics, Research Methods/ Statistical Methods,

    An Intergenerational Model of Wages, Hours and Earnings

    Get PDF
    In this paper we develop and estimate a factor model of the earnings, labor supply, and wages of young men and young women, their parents and their siblings. We estimate the model using data on matched sibling and parent-child pairs from the National Longitudinal Survey of Labor Market Experience. We measure the extent to which a set of unobserved parental and family factors that drive wage rates and work hours independently of wage rates lead to similarities among family members in labor market outcomes. We find strong family similarities in work hours that run along gender lines. These similarities are primarily due to preferences rather than to labor supply responses to family similarities in wages. The wage factors of the father and mother influence the wages of both sons and daughters. A `sibling' wage factor also plays an important role in wage determination. We find that intergenerational correlations in wages substantially overestimate the direct influence of fathers, and especially mothers, on wages. This is because the father's and mother's wage factors are positively correlated. The relative importance for the variance in earnings of the direct effect of wages, the labor supply response induced by wages, and effect of hours preferences varies by gender, and by age in the case of women. For all groups most of the effect of wages on earnings is direct rather than through a labor supply response.

    A critical examination of compound stability predictions from machine-learned formation energies

    Get PDF
    Machine learning has emerged as a novel tool for the efficient prediction of material properties, and claims have been made that machine-learned models for the formation energy of compounds can approach the accuracy of Density Functional Theory (DFT). The models tested in this work include five recently published compositional models, a baseline model using stoichiometry alone, and a structural model. By testing seven machine learning models for formation energy on stability predictions using the Materials Project database of DFT calculations for 85,014 unique chemical compositions, we show that while formation energies can indeed be predicted well, all compositional models perform poorly on predicting the stability of compounds, making them considerably less useful than DFT for the discovery and design of new solids. Most critically, in sparse chemical spaces where few stoichiometries have stable compounds, only the structural model is capable of efficiently detecting which materials are stable. The nonincremental improvement of structural models compared with compositional models is noteworthy and encourages the use of structural models for materials discovery, with the constraint that for any new composition, the ground-state structure is not known a priori. This work demonstrates that accurate predictions of formation energy do not imply accurate predictions of stability, emphasizing the importance of assessing model performance on stability predictions, for which we provide a set of publicly available tests

    Action anticipation through attribution of false belief by 2 year olds

    Get PDF
    Two-year-olds engage in many behaviors that ostensibly require the attribution of mental states to other individuals. Yet the overwhelming consensus has been that children of this age are unable to attribute false beliefs. In the current study, we used an eyetracker to record infants' looking behavior while they watched actions on a computer monitor. Our data demonstrate that 25-month-old infants correctly anticipate an actor's actions when these actions can be predicted only by attributing a false belief to the actor

    Letter from G. A. Dunn to B. R. Colson

    Get PDF
    Letter from G. A. Dunn to B. R. Colson. The one-page handwritten note is dated 16 August 1907. There is a transcript of the correspondence is included in the item PDF

    Letter from G. A. Dunn to Perry M. Colson

    Get PDF
    Letter from G. A. Dunn to Perry M. Colson. The one-page handwritten note is dated 29 May 1907. There is a transcript of the correspondence in the item PDF

    Experimentally estimated dead space for GaAs and InP based planar Gunn diodes

    Get PDF
    The authors would like to thank the staff of the James Watt Nanofabrication Centre at the University of Glasgow for help in fabricating the devices which is reported in this paper. ‘Part of this work was supported by ESPRC through EP/H011862/ 1, and EP/H012966/1.Peer reviewedPublisher PD

    Sonic levitation apparatus

    Get PDF
    A sonic levitation apparatus is disclosed which includes a sonic transducer which generates acoustical energy responsive to the level of an electrical amplifier. A duct communicates with an acoustical chamber to deliver an oscillatory motion of air to a plenum section which contains a collimated hole structure having a plurality of parallel orifices. The collimated hole structure converts the motion of the air to a pulsed. Unidirectional stream providing enough force to levitate a material specimen. Particular application to the production of microballoons in low gravity environment is discussed
    • 

    corecore