Accelerated Test Procedure for Estimating Proportion of Early Failures of Metal Film Resistors

1989 ◽  
pp. 859-870
Author(s):  
I. Likar ◽  
S. Kolenko
Keyword(s):  
Metal Film ◽  
Test Procedure ◽  
Accelerated Test ◽  
Early Failures

Accelerated Ozone Test for Predicting Outdoor Effectiveness of Ozone Protective Waxes in SBR

1964 ◽  
Vol 37 (4) ◽  
pp. 990-1005
Author(s):  
W. J. Mueller ◽  
S. Palinchak ◽  
P. B. Stickney
Keyword(s):  
Test Procedure ◽  
Test Method ◽  
Optimum Conditions ◽  
Accelerated Test ◽  
Critical Variable ◽  
Several Variables ◽  
Exposure Temperature ◽  
Aging Studies ◽  
Static Conditions ◽  
Protective Effectiveness

Abstract Accelerated laboratory and outdoor aging studies were made to establish base lines leading to the development of an accelerated test method which could be used to predict the efficiency of ozone-protective waxes under static conditions. The effect of several variables on the rate of ozone cracking in an ozone chamber was determined, and it was found that exposure temperature was the most critical variable. The type of recipe and time between curing and stretching the samples were also found to be important in arriving at a suitable test procedure. The ozone concentration, although important, was found to be less critical than some of the other variables. An accelerated test method is proposed for determining the effectiveness of ozone-protective waxes. Two outdoor aging studies were made to determine the reliability of the accelerated test in predicting the protective effectiveness of waxes. For a limited number of waxes, it was found that a good correlation exists between the results of the two methods, provided that correct temperatures are used. The best correlation was obtained between dumbbell and bent loop specimens exposed outdoors and the accelerated test if the accelerated test was run at 60° and 120° F. The optimum conditions for correlating between the accelerated test and cable exposed outdoors involved carrying out the accelerated test at 60° and 105° or 110° F.

Development of the Accelerated Test Procedure for the SPT Discharge Chamber Wall Wearing During Long Thruster Operation

2003 ◽  
Author(s):  
Vladimir Kim ◽  
Vartan Abgaryan ◽  
Vyacheslav Kozlov ◽  
Alexander Skrylnikov ◽  
L. Jolivet ◽  
...  
Keyword(s):  
Discharge Chamber ◽  
Test Procedure ◽  
Chamber Wall ◽  
Accelerated Test

The method of replication affects metal film granularity and resolution

1989 ◽  
Vol 47 ◽  
pp. 708-709
Author(s):  
George C. Ruben
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Film Thickness ◽  
Single Molecule ◽  
Metal Film ◽  
Vertical Surface ◽  
High Resolution Imaging ◽  
Controllable Factors ◽  
Resolution Imaging

Single molecule resolution in electron beam sensitive, uncoated, noncrystalline materials has been impossible except in thin Pt-C replicas ≤ 150Å) which are resistant to the electron beam destruction. Previously the granularity of metal film replicas limited their resolution to ≥ 20Å. This paper demonstrates that Pt-C film granularity and resolution are a function of the method of replication and other controllable factors. Low angle 20° rotary , 45° unidirectional and vertical 9.7±1 Å Pt-C films deposited on mica under the same conditions were compared in Fig. 1. Vertical replication had a 5A granularity (Fig. 1c), the highest resolution (table), and coated the whole surface. 45° replication had a 9Å granulartiy (Fig. 1b), a slightly poorer resolution (table) and did not coat the whole surface. 20° rotary replication was unsuitable for high resolution imaging with 20-25Å granularity (Fig. 1a) and resolution 2-3 times poorer (table). Resolution is defined here as the greatest distance for which the metal coat on two opposing faces just grow together, that is, two times the apparent film thickness on a single vertical surface.

Benefits from Computerized Adaptive Testing as Seen in Simulation Studies

1999 ◽  
Vol 15 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Lutz F. Hornke
Keyword(s):  
Measurement Error ◽  
Computerized Adaptive Testing ◽  
Test Procedure ◽  
Adaptive Testing ◽  
Parameter Estimates ◽  
Simulation Studies ◽  
Computerized Adaptive Test ◽  
Item Banks ◽  
Item Parameters ◽  
General Reliability

Summary: Item parameters for several hundreds of items were estimated based on empirical data from several thousands of subjects. The logistic one-parameter (1PL) and two-parameter (2PL) model estimates were evaluated. However, model fit showed that only a subset of items complied sufficiently, so that the remaining ones were assembled in well-fitting item banks. In several simulation studies 5000 simulated responses were generated in accordance with a computerized adaptive test procedure along with person parameters. A general reliability of .80 or a standard error of measurement of .44 was used as a stopping rule to end CAT testing. We also recorded how often each item was used by all simulees. Person-parameter estimates based on CAT correlated higher than .90 with true values simulated. For all 1PL fitting item banks most simulees used more than 20 items but less than 30 items to reach the pre-set level of measurement error. However, testing based on item banks that complied to the 2PL revealed that, on average, only 10 items were sufficient to end testing at the same measurement error level. Both clearly demonstrate the precision and economy of computerized adaptive testing. Empirical evaluations from everyday uses will show whether these trends will hold up in practice. If so, CAT will become possible and reasonable with some 150 well-calibrated 2PL items.

Evaluating the Validity of a Bayesian Program for Predicting Stage in Hodgkin’s Disease

1981 ◽  
Vol 20 (03) ◽  
pp. 174-178 ◽  
Author(s):  
A. I. Barnett ◽  
J. Cynthia ◽  
F. Jane ◽  
Nancy Gutensohn ◽  
B. Davies
Keyword(s):  
New England ◽  
Hodgkin's Disease ◽  
Bayesian Model ◽  
Medical Center ◽  
Hodgkin’S Disease ◽  
Test Procedure ◽  
Disease Patient ◽  
Probabilistic Information ◽  
Probabilistic Forecasts ◽  
England Medical

A Bayesian model that provides probabilistic information about the spread of malignancy in a Hodgkin’s disease patient has been developed at the Tufts New England Medical Center. In assessing the model’s reliability, it seemed important to use it to make predictions about patients other than those relevant to its construction. The accuracy of these predictions could then be tested statistically. This paper describes such a test, based on 243 Hodgkin’s disease patients of known pathologic stage. The results obtained were supportive of the model, and the test procedure might interest those wishing to determine whether the imperfections that attend any attempt to make probabilistic forecasts have gravely damaged their accuracy.

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