1NIST/ITL StRD 2Dataset Name: Nelson (Nelson.dat) 3 4File Format: ASCII 5 Starting Values (lines 41 to 43) 6 Certified Values (lines 41 to 48) 7 Data (lines 61 to 188) 8 9Procedure: Nonlinear Least Squares Regression 10 11Description: These data are the result of a study involving 12 the analysis of performance degradation data from 13 accelerated tests, published in IEEE Transactions 14 on Reliability. The response variable is dialectric 15 breakdown strength in kilo-volts, and the predictor 16 variables are time in weeks and temperature in degrees 17 Celcius. 18 19 20Reference: Nelson, W. (1981). 21 Analysis of Performance-Degradation Data. 22 IEEE Transactions on Reliability. 23 Vol. 2, R-30, No. 2, pp. 149-155. 24 25Data: 1 Response ( y = dialectric breakdown strength) 26 2 Predictors (x1 = time; x2 = temperature) 27 128 Observations 28 Average Level of Difficulty 29 Observed Data 30 31Model: Exponential Class 32 3 Parameters (b1 to b3) 33 34 log[y] = b1 - b2*x1 * exp[-b3*x2] + e 35 36 37 38 Starting values Certified Values 39 40 Start 1 Start 2 Parameter Standard Deviation 41 b1 = 2 2.5 2.5906836021E+00 1.9149996413E-02 42 b2 = 0.0001 0.000000005 5.6177717026E-09 6.1124096540E-09 43 b3 = -0.01 -0.05 -5.7701013174E-02 3.9572366543E-03 44 45Residual Sum of Squares: 3.7976833176E+00 46Residual Standard Deviation: 1.7430280130E-01 47Degrees of Freedom: 125 48Number of Observations: 128 49 50 51 52 53 54 55 56 57 58 59 60Data: y x1 x2 61 15.00E0 1E0 180E0 62 17.00E0 1E0 180E0 63 15.50E0 1E0 180E0 64 16.50E0 1E0 180E0 65 15.50E0 1E0 225E0 66 15.00E0 1E0 225E0 67 16.00E0 1E0 225E0 68 14.50E0 1E0 225E0 69 15.00E0 1E0 250E0 70 14.50E0 1E0 250E0 71 12.50E0 1E0 250E0 72 11.00E0 1E0 250E0 73 14.00E0 1E0 275E0 74 13.00E0 1E0 275E0 75 14.00E0 1E0 275E0 76 11.50E0 1E0 275E0 77 14.00E0 2E0 180E0 78 16.00E0 2E0 180E0 79 13.00E0 2E0 180E0 80 13.50E0 2E0 180E0 81 13.00E0 2E0 225E0 82 13.50E0 2E0 225E0 83 12.50E0 2E0 225E0 84 12.50E0 2E0 225E0 85 12.50E0 2E0 250E0 86 12.00E0 2E0 250E0 87 11.50E0 2E0 250E0 88 12.00E0 2E0 250E0 89 13.00E0 2E0 275E0 90 11.50E0 2E0 275E0 91 13.00E0 2E0 275E0 92 12.50E0 2E0 275E0 93 13.50E0 4E0 180E0 94 17.50E0 4E0 180E0 95 17.50E0 4E0 180E0 96 13.50E0 4E0 180E0 97 12.50E0 4E0 225E0 98 12.50E0 4E0 225E0 99 15.00E0 4E0 225E0 100 13.00E0 4E0 225E0 101 12.00E0 4E0 250E0 102 13.00E0 4E0 250E0 103 12.00E0 4E0 250E0 104 13.50E0 4E0 250E0 105 10.00E0 4E0 275E0 106 11.50E0 4E0 275E0 107 11.00E0 4E0 275E0 108 9.50E0 4E0 275E0 109 15.00E0 8E0 180E0 110 15.00E0 8E0 180E0 111 15.50E0 8E0 180E0 112 16.00E0 8E0 180E0 113 13.00E0 8E0 225E0 114 10.50E0 8E0 225E0 115 13.50E0 8E0 225E0 116 14.00E0 8E0 225E0 117 12.50E0 8E0 250E0 118 12.00E0 8E0 250E0 119 11.50E0 8E0 250E0 120 11.50E0 8E0 250E0 121 6.50E0 8E0 275E0 122 5.50E0 8E0 275E0 123 6.00E0 8E0 275E0 124 6.00E0 8E0 275E0 125 18.50E0 16E0 180E0 126 17.00E0 16E0 180E0 127 15.30E0 16E0 180E0 128 16.00E0 16E0 180E0 129 13.00E0 16E0 225E0 130 14.00E0 16E0 225E0 131 12.50E0 16E0 225E0 132 11.00E0 16E0 225E0 133 12.00E0 16E0 250E0 134 12.00E0 16E0 250E0 135 11.50E0 16E0 250E0 136 12.00E0 16E0 250E0 137 6.00E0 16E0 275E0 138 6.00E0 16E0 275E0 139 5.00E0 16E0 275E0 140 5.50E0 16E0 275E0 141 12.50E0 32E0 180E0 142 13.00E0 32E0 180E0 143 16.00E0 32E0 180E0 144 12.00E0 32E0 180E0 145 11.00E0 32E0 225E0 146 9.50E0 32E0 225E0 147 11.00E0 32E0 225E0 148 11.00E0 32E0 225E0 149 11.00E0 32E0 250E0 150 10.00E0 32E0 250E0 151 10.50E0 32E0 250E0 152 10.50E0 32E0 250E0 153 2.70E0 32E0 275E0 154 2.70E0 32E0 275E0 155 2.50E0 32E0 275E0 156 2.40E0 32E0 275E0 157 13.00E0 48E0 180E0 158 13.50E0 48E0 180E0 159 16.50E0 48E0 180E0 160 13.60E0 48E0 180E0 161 11.50E0 48E0 225E0 162 10.50E0 48E0 225E0 163 13.50E0 48E0 225E0 164 12.00E0 48E0 225E0 165 7.00E0 48E0 250E0 166 6.90E0 48E0 250E0 167 8.80E0 48E0 250E0 168 7.90E0 48E0 250E0 169 1.20E0 48E0 275E0 170 1.50E0 48E0 275E0 171 1.00E0 48E0 275E0 172 1.50E0 48E0 275E0 173 13.00E0 64E0 180E0 174 12.50E0 64E0 180E0 175 16.50E0 64E0 180E0 176 16.00E0 64E0 180E0 177 11.00E0 64E0 225E0 178 11.50E0 64E0 225E0 179 10.50E0 64E0 225E0 180 10.00E0 64E0 225E0 181 7.27E0 64E0 250E0 182 7.50E0 64E0 250E0 183 6.70E0 64E0 250E0 184 7.60E0 64E0 250E0 185 1.50E0 64E0 275E0 186 1.00E0 64E0 275E0 187 1.20E0 64E0 275E0 188 1.20E0 64E0 275E0 189