8,492 research outputs found
The Independent Sign Bias: Gaining Insight from Multiple Linear Regression
No full textAs electronic data becomes widely available, the need for tools that help people gain insight from data has arisen. A variety of techniques from statistics, machine learning, and neural networks have been applied to databases in the hopes of mining knowledge
from data. Multiple regression is one such method for modeling the relationship between a set of explanatory variables and a dependent variable by fitting a linear equation to observed data. Here, we investigate and discuss some factors that influence whether the resulting regression equation is a credible model of the
data.Pazzani, Michael J. and Bay, Stephen D. (1999). "The Indepdendent Sign Bias: Gaining Insight from Multiple Linear Regression" Proceedings of the Twenty First Annual Conference of the Cognitive Science Society.This research was funded in part by the National Science
Foundation grant IRI-9713990
D. Michael Quinn
No full textBlack and white photograph of author D. Michael Quinn, probably around 198
D. Michael Quinn
No full textBlack and white photograph of author D. Michael Quinn, probably around 198
Contrasting Global Patterns of Spatially Periodic Fairy Circles and Regular Insect Nests in Drylands
No full textNumerical analysis of spatial pattern is widely used in ecology to describe the characteristics of floral and faunal distributions. These methods allow attribution of pattern to causal mechanisms by uncovering the specific signatures of patterns and causal agents. For example, grassland-gap patterns called fairy circles (FCs) in Namibia and Australia are characterized by highly regular and homogenous distributions across landscapes that show spatially periodic ordering. These FCs have been suggested to be caused by both social insects and competitive plant interactions. We compared eight Namibian and Australian FC patterns and also modeled FCs to 16 patterns of social insect nests in Africa, Australia, and America that include the most regular termite mound patterns known. For pattern-process inference, we used spatial statistics based on both nearest-neighbor analysis and neighborhood-density functions. None of the analyzed insect-nest distributions attain the spatially periodic ordering that is typical of FCs. The inherently more variable patterns of termite and ant nests are commonly attributable to well documented aspects of the faunal life-history. Our quantitative evidence from drylands shows that the more variable insect-nest distributions in water-limited environments cannot explain the characteristic spatial signature of FCs. The analysis demonstrates the interpretation of scale-dependent neighborhood-density functions and that it is the identification of unique spatial signatures in regular patterns that need to be linked to process. While our results cannot verify a specific hypothesis, they support the hypothesis that FCs in these drylands are more likely an emergent vegetation pattern caused by strong plant competition for water
Dissertatio De Censu Augusti / Quam Sub Praesidio ... Dn. Ulrici Obrechti, In Alma Argentinensium Universitate Professoris Histor. ... Ad Examen Solenne Proponit Michael Förtsch/ Wertheimio-Francus Author. A. D. [...] Maii MDCLXXV.
No full textDISSERTATIO DE CENSU AUGUSTI / QUAM SUB PRAESIDIO ... DN. ULRICI OBRECHTI, IN ALMA ARGENTINENSIUM UNIVERSITATE PROFESSORIS HISTOR. ... AD EXAMEN SOLENNE PROPONIT MICHAEL FÖRTSCH/ WERTHEIMIO-FRANCUS AUTHOR. A. D. [...] MAII MDCLXXV.
Dissertatio De Censu Augusti / Quam Sub Praesidio ... Dn. Ulrici Obrechti, In Alma Argentinensium Universitate Professoris Histor. ... Ad Examen Solenne Proponit Michael Förtsch/ Wertheimio-Francus Author. A. D. [...] Maii MDCLXXV. (1)
Titelblatt (1)
Dissertatio De Censu Augusti (3
Interview with Michael Cronin
No full textMichael Cronin (Ph. D. Trinity College, Dublin). Author of the ground-breaking, Translating Ireland, (Routledge 1996) Michael Cronin is the foremost translation scholar working in Ireland today. Cronin established the cultural review Graph with Peter Sirr and Barra Ó Séaghdha in 1986 and was involved in the setting up of the Irish Translators Association and the creation of Ireland Literature Exchange, the body responsible for funding the translation of Iri..
LYRICOS : synthesis of singing voice using a sinusoidal model
No full textIssued as Final report, Project no. D-48-X46Final report has author: Michael Maco
N and P limitation of fynbos plants and the nutritional status of legume habitats in the Cape Floristic Region
No full textIn general, terrestrial ecosystems are limited by both N and P, but, as legumes fix atmospheric nitrogen, I hypothesized that fynbos legumes would be P limited and nonlegumes would be N limited, and that the degree to which these plants respond to N and P would depend on the levels of each of these two nutrients in the growth media. To test these hypotheses, three legumes and three non-legumes native to the fynbos were grown in a complete factorial arrangement of four levels of N and P in a glass house. Nitrogen was supplied at 20, 40, 80 and 150 mg kg-¹ soil and P at 0.8, 5, 15, and 31 mg kg-¹. Overall, the results showed that the responses of the legume and nonlegume species to N and P supply were species specific, but that the legume species seemed to be more limited by N supply than the non-legumes. There was no N x P interaction in this study, which implied that the plant response to N and P, did not depend on the levels of each other. Given the nitrogen fixing capabilities of legumes and high nutrient demanding lifestyle, I made the hypothesis that, on a given landscape, the soils on which the fynbos legumes occur were more nutrient rich than the bulk non-legume soils. Related to this hypothesis is the question of whether the more nutrient rich soils within the legume populations would be mirrored by leaves with both a higher specific leaf area and higher nutrient concentration, than the leaves of the non-legumes. To test these hypotheses, I determined the nutrient levels of both the soils and plants within both the legume- and non-legumes stands at eight different sites in the CFR. The data were subjected to multifactorial discriminant function analysis and Nested ANOVA analyses. The results of the analyses led to the conclusion that the soil on which legume stands occurred were rarely more fertile than the non-legumes on the landscape in the CFR, and, except for leaf N, there seemed to be no differences between leaf nutrient concentrations and the SLA of the legume and non-legume plants
The secretion of acid phosphatase by proteaceae as an adaptation to limited phosphate availability
No full textIncludes abstract.Includes bibliographical references (leaves 59-67).The Proteaceae are a distinctive component of South Africa’s Fynbos and Australia’s Kwongan vegetation and display a number of adaptations to the soils of these nutrientpoor regions, where availability of phosphate (P) is particularly limited. The Proteaceae are notable for the virtually family-wide ability to form cluster roots
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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