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ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

REDUCING THE EFFECTS OF COlliNEARITY IN REGRESSION OF HEAT TRANSFER DATA

Get access (open in a dialog) DOI: 10.1615/IHTC11.2830
pages 3-8

Abstract

Collinearity among dimensionless groups of the-independent variables may often prevent obtaining statistically valid, reliable correlations. In this paper commonly used collinearity indicators (such as condition number of the normal matrix, variance inflation factor and confidence intervals) and a new indicator, "truncation error to noise ratio" (TNR) are used to investigate the level of collinearity and its harmful effects. It is shown that the dominance of one particular variable in several dimensionless groups is a common source of collinearity. Proper experimental design, which considers the range and precision of the independent variables and use of several different fluids can minimize the harmful effects of collinearity. From among the collinearity indicators tested, the TNR has proven to be superior in predicting the cases where collinearity prevents obtaining statistically significant results.