"David Heiser" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On > Behalf Of Abram Fridman > Sent: Thursday, May 16, 2002 1:49 PM > To: [EMAIL PROTECTED] > Subject: Dependency and multicollinearity > > > Hello, > > > > I've a problem and desperately need help. > > Once I already posted a question here, but now I need to repeat > > what I am doing. > > > > I have 74 fractured specimens with fracture area of 3 to 5 mm^2 each. > > There are 7 fracture modes (1 to 5 per specimen). I measured area of > > each fracture mode on each specimen, and now I need to test my > > hypotheses that force, needed to break specimen, could be described > > as > > F = C + K1*S1 + K2*S2 + . + K7*S7 > > > > Where S1-S7 - areas of different fracture types (predictors). > > ----------------------------------------------------------------- > Your model is in error. It does not describe microfracture physics. A > fracture of one type develops uneven stress on adjacent areas, leading to > premature failure. Get a metallurgist who knows about microstructure and > fracture dynamics involved in your problem.
I am a metallurgist (but specimens are not metallic). The model is right (as a first approximation) because force correlates with energy necessary for fracture, and each type of fracture has its own specific energy. The purpose of study is to determine "bad" and "good" types of fracture. . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
