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Monte Carlo comparisons of parameter estimators of the 2-parameter Weibull distribution
484
World Abstracts on Microelectronics and Reliability
integration in terms of manufacturing parameters and yield learning curves. The calculated functions for system failure rates are similar to those for the prices per bit. An important result of the model is the realization that failure rate is a designing parameter, which is determined not only by the conditions of applications but which is highly determined by the manufacturing process itself i.e. by test specifications, yield, time needed to acquire manufacturing experience and choice of integration scales. Summarizing, the quality of an LSl-circuit is expressed by a quality number which includes the price per bit, the failure rate and the access time.
Screening results of JAN transitors and diodes used in military and aerospace programmes. PAUL E. SCHEFFEL. 15lh A. Proc. Reliab. Phys. IEEE, Nevada. p. 163 11977). Recently compiled results of High Reliability Parts Testing show that JAN (Joint Army Navy) components procured to the requirements of MIL-S-19500 and MIL-STD-750 are much less reliable than needed by most Military and Aerospace users today. In fact, many users are finding such a reliability problem with their JAN Transistor and Diode procurements that they have initiated programs which dictate substantially more data review and inspection prior t o use.
3. C I R C U I T
AND
SYSTEMS
RELIABILITY,
Complete ranking of reliability-related distributions. THOMAS A. BISHOP and EDWARD J. DUDEWICZ. IEEE Trans. Reliab. R-26, (5) 362 (December 1977). In reliability and life testing problems, an experimenter often wishes to rank several populations of items (e.g., devices which serve the same function) in order of 'goodness'. In many cases it is trivial to decide how to rank the populations, but difficult to decide how many devices of each type to test, and also difficult to evaluate the probability that the ranking is correct. This paper considers these difficult aspects when the 'goodness' of a population is simply related to its scale parameter (as is the case for many distributions used in reliability and life testing studies). The techniques provide a guaranteed probability of correct ranking (over usual scale parameter spaces), and in many cases this probability can be evaluated by a Monte Carlo sampling experiment. This furnishes a rational way to choose sample size in reliability and life testing when comparison of competing devices is the basic experimental goal. Reliability of power supplies. Prof. R. BILLINTON. Electr,m. Power p. 307 (April 1978). The utilisation of electrical energy in an advanced technological society is closely related to the quality of life. The general acceptance and utilisation of reliability-engineering concepts in all phases of utility management, design and operation is vital if the electric power industry is to continue to satisfy the systemload requirement as economically as possible and with a reasonable assurance of continuity and quality. A 4-unit redundant system with common-cause failures. BALBIR S. DHILLON. IEEE Trans. Reliab. R-26, (5) 373 (December 1977). This theoretical note presents a mathematical model of a 4-unit (i.i.d.) redundant system subject to common-cause failures Is-dependent failures). Laplace transforms of the state probability equations are developed. Monte Carlo comparisons of parameter estimators of the 2-parameter Weilmll distribution. ALAN J. GROSS and DAN LURIE. IEEE Trans. Reliab. R-26, (5) 356 (December 1977). A Monte Carlo Simulation was carried out in order to compare three different estimators of the 2-parameter Wet-
Investigation of metalization failures of glass sealed ceramic dual in line integrated circuits. DAVID B. WmLMOTT. 15th A. Proc. Reliab. Phys. IEEE, Nevada. p. 158 (1977t. A cause of field failures in C E R D I P integrated circuits is shown to be due to exceesive moisture, excessive ionic contamination and high negative protentials on the die surface which resulted in electrolytic corrosion of aluminum. The feasibility of using a one week low temperature bias aging to detect this failure mode in suspect Lots is discussed. Additionally, a model is presented to account for a source of the ionic contamination on particular devices.
dc voltage effects on saw device interdigitai electrodes. F. S. H1CKERNELt. 15th A. Proc. Reliab. Phys. IEEE, Nevada. p. 144 (1977L The transducer electrodes of high frequency surface acoustic wave (SAW) devices can be damaged by dc voltage transients as low as 150volts. Controlled dc pulsed voltage levels applied to SAW device aluminum interdigital electrodes on piezoelectric qt, artz and lithium niobate have served to define arc discharge and surface fracture conditions affecting device performance. It is recommended that high frequency SAW devices be handled as voltage sensitive parts.
MAINTENANCE
AND
REDUNDANCY
bull distribution. The estimators were lhe ML tmaximum likekihoodl estimators and two other estimator pairs suggested by B a i n & Antic. The Bain-Antlc estimators are better than the ML estimator for small samples (in that their bias, standard deviation, and rms error are smaller), whereas the ME estimator is superior in large samples.
Estimation of reliability after corrective action. RAM C. DAHIVA. IEEE Trans. Reliab. R-26, (5) 348 (December 1977). Asymptotic distributions of several estimators, proposed in the literature for estimating reliability after corrective action, are derived here. Furthermore, the maximum likelihood estimators for the special case of equal failure probabilities are obtained, Some of the estimators appearing in the literature are shown to be not s-consistent. Majority and similarity voting in analogue redundant systems. K. B. KLAASSENand J. C. L. VAN PEPPEN. MieraelecIronic. Reliab. 16, 47 (1977). In this paper some decision strategies for the combination of the outputs of a number of redundant analogue subsystems arc studied. The intention is thereby to combine the redundant outputs in such a way that the resulting output is insensitive to the drift and noise failures that occur in the subsystems. Majority voting is a stochastic concept. It is based upon an estimator for the absolute maximum of the density function of the errors in the subsystem outputs. Similarity voting is a deterministic concept, whereby the subsystem output differences are compared to a tolerance reference. The outputs exceeding the Iolerance limits with respect to the remaining outputs are considered to be dissimilar and the other outputs to be similar. A similarity voter establishes a weighted mean of the similar outputs only. The effectiveness of the various strategies against noise and drift failures is determined with the help of Monte Carlo simulations. Reliability of several standby-priority-redundant systems. J. R. ARORA. IEEE Trans. Reliab. R-26, (4) 290 (October 19771. This paper develops 3 models for standby redundant systems consisting of dissimilar units. In an effort to m-
World Abstracts on Microelectronics and Reliability
integration in terms of manufacturing parameters and yield learning curves. The calculated functions for system failure rates are similar to those for the prices per bit. An important result of the model is the realization that failure rate is a designing parameter, which is determined not only by the conditions of applications but which is highly determined by the manufacturing process itself i.e. by test specifications, yield, time needed to acquire manufacturing experience and choice of integration scales. Summarizing, the quality of an LSl-circuit is expressed by a quality number which includes the price per bit, the failure rate and the access time.
Screening results of JAN transitors and diodes used in military and aerospace programmes. PAUL E. SCHEFFEL. 15lh A. Proc. Reliab. Phys. IEEE, Nevada. p. 163 11977). Recently compiled results of High Reliability Parts Testing show that JAN (Joint Army Navy) components procured to the requirements of MIL-S-19500 and MIL-STD-750 are much less reliable than needed by most Military and Aerospace users today. In fact, many users are finding such a reliability problem with their JAN Transistor and Diode procurements that they have initiated programs which dictate substantially more data review and inspection prior t o use.
3. C I R C U I T
AND
SYSTEMS
RELIABILITY,
Complete ranking of reliability-related distributions. THOMAS A. BISHOP and EDWARD J. DUDEWICZ. IEEE Trans. Reliab. R-26, (5) 362 (December 1977). In reliability and life testing problems, an experimenter often wishes to rank several populations of items (e.g., devices which serve the same function) in order of 'goodness'. In many cases it is trivial to decide how to rank the populations, but difficult to decide how many devices of each type to test, and also difficult to evaluate the probability that the ranking is correct. This paper considers these difficult aspects when the 'goodness' of a population is simply related to its scale parameter (as is the case for many distributions used in reliability and life testing studies). The techniques provide a guaranteed probability of correct ranking (over usual scale parameter spaces), and in many cases this probability can be evaluated by a Monte Carlo sampling experiment. This furnishes a rational way to choose sample size in reliability and life testing when comparison of competing devices is the basic experimental goal. Reliability of power supplies. Prof. R. BILLINTON. Electr,m. Power p. 307 (April 1978). The utilisation of electrical energy in an advanced technological society is closely related to the quality of life. The general acceptance and utilisation of reliability-engineering concepts in all phases of utility management, design and operation is vital if the electric power industry is to continue to satisfy the systemload requirement as economically as possible and with a reasonable assurance of continuity and quality. A 4-unit redundant system with common-cause failures. BALBIR S. DHILLON. IEEE Trans. Reliab. R-26, (5) 373 (December 1977). This theoretical note presents a mathematical model of a 4-unit (i.i.d.) redundant system subject to common-cause failures Is-dependent failures). Laplace transforms of the state probability equations are developed. Monte Carlo comparisons of parameter estimators of the 2-parameter Weilmll distribution. ALAN J. GROSS and DAN LURIE. IEEE Trans. Reliab. R-26, (5) 356 (December 1977). A Monte Carlo Simulation was carried out in order to compare three different estimators of the 2-parameter Wet-
Investigation of metalization failures of glass sealed ceramic dual in line integrated circuits. DAVID B. WmLMOTT. 15th A. Proc. Reliab. Phys. IEEE, Nevada. p. 158 (1977t. A cause of field failures in C E R D I P integrated circuits is shown to be due to exceesive moisture, excessive ionic contamination and high negative protentials on the die surface which resulted in electrolytic corrosion of aluminum. The feasibility of using a one week low temperature bias aging to detect this failure mode in suspect Lots is discussed. Additionally, a model is presented to account for a source of the ionic contamination on particular devices.
dc voltage effects on saw device interdigitai electrodes. F. S. H1CKERNELt. 15th A. Proc. Reliab. Phys. IEEE, Nevada. p. 144 (1977L The transducer electrodes of high frequency surface acoustic wave (SAW) devices can be damaged by dc voltage transients as low as 150volts. Controlled dc pulsed voltage levels applied to SAW device aluminum interdigital electrodes on piezoelectric qt, artz and lithium niobate have served to define arc discharge and surface fracture conditions affecting device performance. It is recommended that high frequency SAW devices be handled as voltage sensitive parts.
MAINTENANCE
AND
REDUNDANCY
bull distribution. The estimators were lhe ML tmaximum likekihoodl estimators and two other estimator pairs suggested by B a i n & Antic. The Bain-Antlc estimators are better than the ML estimator for small samples (in that their bias, standard deviation, and rms error are smaller), whereas the ME estimator is superior in large samples.
Estimation of reliability after corrective action. RAM C. DAHIVA. IEEE Trans. Reliab. R-26, (5) 348 (December 1977). Asymptotic distributions of several estimators, proposed in the literature for estimating reliability after corrective action, are derived here. Furthermore, the maximum likelihood estimators for the special case of equal failure probabilities are obtained, Some of the estimators appearing in the literature are shown to be not s-consistent. Majority and similarity voting in analogue redundant systems. K. B. KLAASSENand J. C. L. VAN PEPPEN. MieraelecIronic. Reliab. 16, 47 (1977). In this paper some decision strategies for the combination of the outputs of a number of redundant analogue subsystems arc studied. The intention is thereby to combine the redundant outputs in such a way that the resulting output is insensitive to the drift and noise failures that occur in the subsystems. Majority voting is a stochastic concept. It is based upon an estimator for the absolute maximum of the density function of the errors in the subsystem outputs. Similarity voting is a deterministic concept, whereby the subsystem output differences are compared to a tolerance reference. The outputs exceeding the Iolerance limits with respect to the remaining outputs are considered to be dissimilar and the other outputs to be similar. A similarity voter establishes a weighted mean of the similar outputs only. The effectiveness of the various strategies against noise and drift failures is determined with the help of Monte Carlo simulations. Reliability of several standby-priority-redundant systems. J. R. ARORA. IEEE Trans. Reliab. R-26, (4) 290 (October 19771. This paper develops 3 models for standby redundant systems consisting of dissimilar units. In an effort to m-