NIST/ITL StRD
Dataset Name: Nelson (Nelson.dat)
File Format: ASCII
Starting Values (lines 41 to 43)
Certified Values (lines 41 to 48)
Data (lines 61 to 188)
Procedure: Nonlinear Least Squares Regression
Description: These data are the result of a study involving
the analysis of performance degradation data from
accelerated tests, published in IEEE Transactions
on Reliability. The response variable is dialectric
breakdown strength in kilo-volts, and the predictor
variables are time in weeks and temperature in degrees
Celcius.
Reference: Nelson, W. (1981).
Analysis of Performance-Degradation Data.
IEEE Transactions on Reliability.
Vol. 2, R-30, No. 2, pp. 149-155.
Data: 1 Response ( y = dialectric breakdown strength)
2 Predictors (x1 = time; x2 = temperature)
128 Observations
Average Level of Difficulty
Observed Data
Model: Exponential Class
3 Parameters (b1 to b3)
log[y] = b1 - b2*x1 * exp[-b3*x2] + e
Starting values Certified Values
Start 1 Start 2 Parameter Standard Deviation
b1 = 2 2.5 2.5906836021E+00 1.9149996413E-02
b2 = 0.0001 0.000000005 5.6177717026E-09 6.1124096540E-09
b3 = -0.01 -0.05 -5.7701013174E-02 3.9572366543E-03
Residual Sum of Squares: 3.7976833176E+00
Residual Standard Deviation: 1.7430280130E-01
Degrees of Freedom: 125
Number of Observations: 128
Data: y x1 x2
15.00E0 1E0 180E0
17.00E0 1E0 180E0
15.50E0 1E0 180E0
16.50E0 1E0 180E0
15.50E0 1E0 225E0
15.00E0 1E0 225E0
16.00E0 1E0 225E0
14.50E0 1E0 225E0
15.00E0 1E0 250E0
14.50E0 1E0 250E0
12.50E0 1E0 250E0
11.00E0 1E0 250E0
14.00E0 1E0 275E0
13.00E0 1E0 275E0
14.00E0 1E0 275E0
11.50E0 1E0 275E0
14.00E0 2E0 180E0
16.00E0 2E0 180E0
13.00E0 2E0 180E0
13.50E0 2E0 180E0
13.00E0 2E0 225E0
13.50E0 2E0 225E0
12.50E0 2E0 225E0
12.50E0 2E0 225E0
12.50E0 2E0 250E0
12.00E0 2E0 250E0
11.50E0 2E0 250E0
12.00E0 2E0 250E0
13.00E0 2E0 275E0
11.50E0 2E0 275E0
13.00E0 2E0 275E0
12.50E0 2E0 275E0
13.50E0 4E0 180E0
17.50E0 4E0 180E0
17.50E0 4E0 180E0
13.50E0 4E0 180E0
12.50E0 4E0 225E0
12.50E0 4E0 225E0
15.00E0 4E0 225E0
13.00E0 4E0 225E0
12.00E0 4E0 250E0
13.00E0 4E0 250E0
12.00E0 4E0 250E0
13.50E0 4E0 250E0
10.00E0 4E0 275E0
11.50E0 4E0 275E0
11.00E0 4E0 275E0
9.50E0 4E0 275E0
15.00E0 8E0 180E0
15.00E0 8E0 180E0
15.50E0 8E0 180E0
16.00E0 8E0 180E0
13.00E0 8E0 225E0
10.50E0 8E0 225E0
13.50E0 8E0 225E0
14.00E0 8E0 225E0
12.50E0 8E0 250E0
12.00E0 8E0 250E0
11.50E0 8E0 250E0
11.50E0 8E0 250E0
6.50E0 8E0 275E0
5.50E0 8E0 275E0
6.00E0 8E0 275E0
6.00E0 8E0 275E0
18.50E0 16E0 180E0
17.00E0 16E0 180E0
15.30E0 16E0 180E0
16.00E0 16E0 180E0
13.00E0 16E0 225E0
14.00E0 16E0 225E0
12.50E0 16E0 225E0
11.00E0 16E0 225E0
12.00E0 16E0 250E0
12.00E0 16E0 250E0
11.50E0 16E0 250E0
12.00E0 16E0 250E0
6.00E0 16E0 275E0
6.00E0 16E0 275E0
5.00E0 16E0 275E0
5.50E0 16E0 275E0
12.50E0 32E0 180E0
13.00E0 32E0 180E0
16.00E0 32E0 180E0
12.00E0 32E0 180E0
11.00E0 32E0 225E0
9.50E0 32E0 225E0
11.00E0 32E0 225E0
11.00E0 32E0 225E0
11.00E0 32E0 250E0
10.00E0 32E0 250E0
10.50E0 32E0 250E0
10.50E0 32E0 250E0
2.70E0 32E0 275E0
2.70E0 32E0 275E0
2.50E0 32E0 275E0
2.40E0 32E0 275E0
13.00E0 48E0 180E0
13.50E0 48E0 180E0
16.50E0 48E0 180E0
13.60E0 48E0 180E0
11.50E0 48E0 225E0
10.50E0 48E0 225E0
13.50E0 48E0 225E0
12.00E0 48E0 225E0
7.00E0 48E0 250E0
6.90E0 48E0 250E0
8.80E0 48E0 250E0
7.90E0 48E0 250E0
1.20E0 48E0 275E0
1.50E0 48E0 275E0
1.00E0 48E0 275E0
1.50E0 48E0 275E0
13.00E0 64E0 180E0
12.50E0 64E0 180E0
16.50E0 64E0 180E0
16.00E0 64E0 180E0
11.00E0 64E0 225E0
11.50E0 64E0 225E0
10.50E0 64E0 225E0
10.00E0 64E0 225E0
7.27E0 64E0 250E0
7.50E0 64E0 250E0
6.70E0 64E0 250E0
7.60E0 64E0 250E0
1.50E0 64E0 275E0
1.00E0 64E0 275E0
1.20E0 64E0 275E0
1.20E0 64E0 275E0