1,330 research outputs found

    Detection of plant stress through multispectral photography

    Get PDF
    There are no author-identified significant results in this report

    From: William G. Downs, Jr. (6/17/62)

    Get PDF

    From: William G. Downs, Jr.

    Get PDF

    A procedure used for a ground truth study of a land use map of North Alabama generated from LANDSAT data

    Get PDF
    A land use map of a five county area in North Alabama was generated from LANDSAT data using a supervised classification algorithm. There was good overall agreement between the land use designated and known conditions, but there were also obvious discrepancies. In ground checking the map, two types of errors were encountered - shift and misclassification - and a method was developed to eliminate or greatly reduce the errors. Randomly selected study areas containing 2,525 pixels were analyzed. Overall, 76.3 percent of the pixels were correctly classified. A contingency coefficient of correlation was calculated to be 0.7 which is significant at the alpha = 0.01 level. The land use maps generated by computers from LANDSAT data are useful for overall land use by regional agencies. However, care must be used when making detailed analysis of small areas. The procedure used for conducting the ground truth study together with data from representative study areas is presented

    Glass shell manufacturing in space

    Get PDF
    Highly-uniform, hollow glass spheres (shells), which are used for inertial confinement fusion targets, were formed from metal-organic gel powder feedstock in a vertical furnace. As a result of the rapid pyrolysis caused by the furnace, the gel is transformed to a shell in five distinct stages: (a) surface closure of the porous gel; (b) generation of a closed-cell foam structure in the gel; (c) spheridization of the gel and further expansion of the foam; (d) coalescence of the closed-cell foam to a single-void shell; and (e) fining of the glass shell. The heat transfer from the furnace to the falling gel particle was modeled to determine the effective heating rate of the gel. The model predicts the temperature history for a particle as a function of mass, dimensions, specific heat, and absorptance as well as furnace temperature profile and thermal conductivity of the furnace gas. A model was developed that predicts the gravity-induced degradation of shell concentricity in falling molten shells as a function of shell characteristics and time

    Earth resources-regional transfer activity contracts review

    Get PDF
    A regional transfer activity contracts review held by the Earth Resources Office was summarized. Contracts in the earth resources field primarily directed toward applications of satellite data and technology in solution of state and regional problems were reviewed. A summary of the progress of each contract was given in order to share experiences of researchers across a seven state region. The region included Missouri, Kentucky, Tennessee, Mississippi, Alabama, Georgia, and North Carolina. Research in several earth science disciplines included forestry, limnology, water resources, land use, geology, and mathematical modeling. The use of computers for establishment of information retrieval systems was also emphasized

    Cost-effectiveness analysis of the management of distal ureteral stones in children

    Get PDF
    Objective To determine the most cost-effective approach to the management of distal ureteral stones in children given the potential for recurrent renal colic during a trial of passage versus potential stent discomfort and complications of ureteroscopy. Methods We developed a decision tree to project costs and clinical outcomes associated with observation, medical explusive therapy (MET), and ureteroscopy for the management of an index patient with a 4mm distal ureteral stone. We determined which strategy would be least costly and offer the most pain-free days within 30 days of diagnosis. We performed a one-way sensitivity analysis on the probability of successful stone passage with MET. We obtained probabilities from the literature and costs from the 2016 Pediatric Health Information System Database. Results Ureteroscopywas the costliest strategy but maximized the number of pain-free days within 30 days of diagnosis (5,282/29painfreedays).METwaslesscostlythanureteroscopybutalsolesseffective(5,282/29 pain-free days). MET was less costly than ureteroscopybut also less effective (615/21.8 pain-free days). Observation cost more than MET and was also less effective ($2,139/15.5 pain-free days). The one-way sensitivity analysis on the probability of successful stone passage with MET demonstrated that ureteroscopyalways has the highest net monetary benefits value and is therefore the recommended strategy given a fixed WTP. Discussion Using a rigorous decision-science approach, we found that ureteroscopy is the recommended strategy in children with small distal ureteral stones. Although it cost more than MET, it resulted in more pain-free days in the first 30 days following diagnosis given the faster resolution of the stone episode

    Glass shell manufacturing in space

    Get PDF
    A heat transfer model was developed that mathematically describes the heating and calculates the thermal history of a gel particle in free-fall through the furnace. The model parameters that greatly affect the calculations were found to be gel particle mass, geometry, specific heat, and furnace gas. Empirical testing of the model has commenced. The code calculations and the initial empirical testing results both indicate that the gel-to-shell transformation occurs early and rapidly in the thermal history of the gel particle, and that for current work the heat transfer rate is not a limitation in shell production

    Perceptions of Electoral Fairness and Voter Turnout

    Get PDF
    Previous research has established a link between turnout and the extent to which voters are faced with a “meaningful” partisan choice in elections; this study extends the logic of this argument to perceptions of the “meaningfulness” of electoral conduct. It hypothesizes that perceptions of electoral integrity are positively related to turnout. The empirical analysis to test this hypothesis is based on aggregate-level data from 31 countries, combined with survey results from Module 1 of the Comparative Study of Electoral Systems survey project, which includes new and established democracies. Multilevel modeling is employed to control for a variety of individual- and election-level variables that have been found in previous research to influence turnout. The results of the analysis show that perceptions of electoral integrity are indeed positively associated with propensity to vote. </jats:p

    Toward a Theory of Innovation

    Full text link
    The purpose of this article is to eliminate further conceptual obstacles to the develop ment of a workable theory of innovation and to move toward a better theoretic statement. The approach to overcoming the conceptual problems centers primarily around four ideas: (1) building a theory around the "innovation decision" as the unit of analysis, rather than either innovations or adopters: (2) lifting the level of general ity of independent variables so that a great deal of statistical interaction is avoided; (3) splitting the act of innovation into two stages, diffusion and adoption, to eliminate the confounding effects of time of awareness in studies of innovation; (4) introducing the idea of a "fair-trial point" into the conceptualization of innovation, solving sev eral additional problems at once.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68286/2/10.1177_009539977901000401.pd
    corecore