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Bayesian approach to the prediction problem in the exponential population
480
World Abstracts on Microelectronics and Reliabilitx
shown. In the last part of this paper the criterion with which one unit is chosen for repair when the two units fail simultaneously for the special case is given.
Reliability engineering in microelectronics. C, E. JOWETT. Microelectron. Reliab. 17.505 {1978}. Contracts often require that subsystem suppliers of electronic equipment have demonstrated capability in achieving comprehensive reliability programmes. Smaller companies-Mefined here as having fewer than 1000 employees--enjoy major advantages over larger companies. Owing to a high proportion of their staff being experienced reliability specialists, they can concentrate their efforts more quickly and are often in a position to quote more favourable prices while assigning a larger percentage of the price to reliability. Contributing factors are simplicity in organization and a close project team and management effort.
Evaluating system reliability. PAUL F. ALBRECHT. IEEE Spectrum, p. 43 (August 1978). How does one apply reliability-evaluation techniques to power systems'? The answer can be viewed as a five-step process. First, the modes in which the system may fail are defined, and the events that may lead to each such failure identified. The analytical procedure of modeling system failure in terms of these events follows. Then, in order to make practical application of the model, one must determine its parameters, such as the frequency and duration of equipment outages. Finally, the model can be applied to the real world, to evaluate the reliability of specific power system configurations, plans, and designs. Bayesian approach to the prediction problem in the exponential population. G. S. LINGAPPAIAH. IEEE Trans. Reliab. R-27, (3) 222 (August 1978). There are s samples available, each from an exponential population. Procedure for predicting any order statistic in the (s + l)-th sample is developed by obtaining the predictive distribution at stage s. Bounds for the sample size at stage s, in order to have the variance at stage s less than that at stage ,s - 1, are obtained. An illustrative example of actual prediction uses simulated samples. Results of earlier works on prediction are compared with the results here.
A delta-star mlnsformation approach for reliability evaluation. HARIOM GUPTA and JAYDEV SHARMA. IEEE Trans. Reliab. R-27, (3) 212 (August 1978). This paper presents new exact expressions for delta-star transformation to simplify complex reliability block diagrams consisting 2state or 3-state devices. The conditions are given under which the transformation applies. The expressions are interrelated and require less computation time for finding equivalent star configuration. Expressions can also be derived for star-delta transformation in the same way.
Quantitative H20 determination in components using a plasma chromatograph-mnss spectrometer. TtMOtH', \V ( ~ r r , ED'atN A. COrL. CHlt-Lbxx Lit: and C~.l~l (} ~IAJTENYI. Proc. IEEE Reliab. PIIr~ Syrup., San Diego {18-20 April 1978), p. 59. This report describes an experrment which forms the basic relationship allowing PC MS to be used for the quantitative determination of the H_,O content in a component, i.e.. plastic package or metal header. The method to establish the quantitative relationships, analysis conditions, species monitored, and standards carve is described.
Semiconductor component reliabilit) in an equipment operating in electromechanical telephone exchanges. F H. REYNOLDS and J. W. STEVENS. "Proc. IEEE Reliah. P/;y.~. Syrup., San Diego (18-20 April 1978k p. 7. The reliabiliI2~ of an electronic equivalent of an electromechanical impulse regenerator has been monitored on well over 6000 units for periods of up to nearly 3 years. The electronic regenerator incorporates a m o s integrated circuit as welt as transistors, diodes and passive components including a reed-relas. The exercise sought to ascertain the reliability benefits of electronic replacement and provide component failure-rate information such as might be expected to guide future equipment developments. The multiple-censored nature of the available data is suited to the maximum-likelihood method of estimating the statistical parameters of the lifetime distributions from which the hazard rate of the regenerator itself as well as those of the mos integrated circuit and the transistors is tbund to decline steadily with an approximately root-reciprocal time dependence. The results reveal that the reliability of the electronic regenerator is vastly superior to that of its electromechanical predecessor. At the same time, a failure mode in the mos integrated circuit is exposed, namely corrosion of the aluminium interconnection tracks, which would have seriously imperilled an equipment using integrated circuits extensively. Although this problem appears as a transient manufacturing deficiency, its occurrence emphasises the need for component procurement to adequate reliability specifications.
A new physical mechanism for soft errors in dynamic memories. TIMOTHY C. MAY and MURRAY H. WOODS. Proc. IEEE Reliab. Phys. Syrup., San Diego (18-20 April 1978L p. 33. A new physical soft error mechanism in dynamic RAMs and CCDs is the upset of stored data by the passage of heavily-ionizing radiation through the memory array area. Alpha particles are emitted in the radioactive decay of uranium and thorium present in parts-per-million levels in packaging materials. When an alpha particle penetrates the die surface, it can create enough electron- hole pairs near a storage node to cause a random, single-bit error. Results of experiments and measurements of alpha activity of materials are reported and a physical model for the soft error is developed. Implications for the future of dynamic memories are also discussed
4. M I C R O E L E C T R O N I C S - -
Microcomputers invade the linear world. ROBERT L. MORRISON. IEEE Spectrum p. 38 Ouly 1978). Analog interfacing techniques are in demand as microcomputers are exploited in inexpensive equipment for linear applications.
Some package reliability implications of current trends in large scale silicon integrated circuits. L. K. ANDERSON.Proc. IEEE Reliab. Phys. Symp., San Diego (18-20 April 1978), p. 121. Increasing scale of integration has tended to change the focus of integrated circuit packaging from low cost to
GENERAL
high electrical and thermal performance and improved reliability. Today's high-speed densely-packed LSI chips pose some new packaging reliability challenges. These are explored briefly.
Solid-state devices and the age of indolence. D. H. ROBERTS. Electron. Power p. 661 (September 1978), Solid-state device technology is extending man's capabilities and the subsequent change in manufacturing technology offers a major threat to large segments of existing manufacturing
World Abstracts on Microelectronics and Reliabilitx
shown. In the last part of this paper the criterion with which one unit is chosen for repair when the two units fail simultaneously for the special case is given.
Reliability engineering in microelectronics. C, E. JOWETT. Microelectron. Reliab. 17.505 {1978}. Contracts often require that subsystem suppliers of electronic equipment have demonstrated capability in achieving comprehensive reliability programmes. Smaller companies-Mefined here as having fewer than 1000 employees--enjoy major advantages over larger companies. Owing to a high proportion of their staff being experienced reliability specialists, they can concentrate their efforts more quickly and are often in a position to quote more favourable prices while assigning a larger percentage of the price to reliability. Contributing factors are simplicity in organization and a close project team and management effort.
Evaluating system reliability. PAUL F. ALBRECHT. IEEE Spectrum, p. 43 (August 1978). How does one apply reliability-evaluation techniques to power systems'? The answer can be viewed as a five-step process. First, the modes in which the system may fail are defined, and the events that may lead to each such failure identified. The analytical procedure of modeling system failure in terms of these events follows. Then, in order to make practical application of the model, one must determine its parameters, such as the frequency and duration of equipment outages. Finally, the model can be applied to the real world, to evaluate the reliability of specific power system configurations, plans, and designs. Bayesian approach to the prediction problem in the exponential population. G. S. LINGAPPAIAH. IEEE Trans. Reliab. R-27, (3) 222 (August 1978). There are s samples available, each from an exponential population. Procedure for predicting any order statistic in the (s + l)-th sample is developed by obtaining the predictive distribution at stage s. Bounds for the sample size at stage s, in order to have the variance at stage s less than that at stage ,s - 1, are obtained. An illustrative example of actual prediction uses simulated samples. Results of earlier works on prediction are compared with the results here.
A delta-star mlnsformation approach for reliability evaluation. HARIOM GUPTA and JAYDEV SHARMA. IEEE Trans. Reliab. R-27, (3) 212 (August 1978). This paper presents new exact expressions for delta-star transformation to simplify complex reliability block diagrams consisting 2state or 3-state devices. The conditions are given under which the transformation applies. The expressions are interrelated and require less computation time for finding equivalent star configuration. Expressions can also be derived for star-delta transformation in the same way.
Quantitative H20 determination in components using a plasma chromatograph-mnss spectrometer. TtMOtH', \V ( ~ r r , ED'atN A. COrL. CHlt-Lbxx Lit: and C~.l~l (} ~IAJTENYI. Proc. IEEE Reliab. PIIr~ Syrup., San Diego {18-20 April 1978), p. 59. This report describes an experrment which forms the basic relationship allowing PC MS to be used for the quantitative determination of the H_,O content in a component, i.e.. plastic package or metal header. The method to establish the quantitative relationships, analysis conditions, species monitored, and standards carve is described.
Semiconductor component reliabilit) in an equipment operating in electromechanical telephone exchanges. F H. REYNOLDS and J. W. STEVENS. "Proc. IEEE Reliah. P/;y.~. Syrup., San Diego (18-20 April 1978k p. 7. The reliabiliI2~ of an electronic equivalent of an electromechanical impulse regenerator has been monitored on well over 6000 units for periods of up to nearly 3 years. The electronic regenerator incorporates a m o s integrated circuit as welt as transistors, diodes and passive components including a reed-relas. The exercise sought to ascertain the reliability benefits of electronic replacement and provide component failure-rate information such as might be expected to guide future equipment developments. The multiple-censored nature of the available data is suited to the maximum-likelihood method of estimating the statistical parameters of the lifetime distributions from which the hazard rate of the regenerator itself as well as those of the mos integrated circuit and the transistors is tbund to decline steadily with an approximately root-reciprocal time dependence. The results reveal that the reliability of the electronic regenerator is vastly superior to that of its electromechanical predecessor. At the same time, a failure mode in the mos integrated circuit is exposed, namely corrosion of the aluminium interconnection tracks, which would have seriously imperilled an equipment using integrated circuits extensively. Although this problem appears as a transient manufacturing deficiency, its occurrence emphasises the need for component procurement to adequate reliability specifications.
A new physical mechanism for soft errors in dynamic memories. TIMOTHY C. MAY and MURRAY H. WOODS. Proc. IEEE Reliab. Phys. Syrup., San Diego (18-20 April 1978L p. 33. A new physical soft error mechanism in dynamic RAMs and CCDs is the upset of stored data by the passage of heavily-ionizing radiation through the memory array area. Alpha particles are emitted in the radioactive decay of uranium and thorium present in parts-per-million levels in packaging materials. When an alpha particle penetrates the die surface, it can create enough electron- hole pairs near a storage node to cause a random, single-bit error. Results of experiments and measurements of alpha activity of materials are reported and a physical model for the soft error is developed. Implications for the future of dynamic memories are also discussed
4. M I C R O E L E C T R O N I C S - -
Microcomputers invade the linear world. ROBERT L. MORRISON. IEEE Spectrum p. 38 Ouly 1978). Analog interfacing techniques are in demand as microcomputers are exploited in inexpensive equipment for linear applications.
Some package reliability implications of current trends in large scale silicon integrated circuits. L. K. ANDERSON.Proc. IEEE Reliab. Phys. Symp., San Diego (18-20 April 1978), p. 121. Increasing scale of integration has tended to change the focus of integrated circuit packaging from low cost to
GENERAL
high electrical and thermal performance and improved reliability. Today's high-speed densely-packed LSI chips pose some new packaging reliability challenges. These are explored briefly.
Solid-state devices and the age of indolence. D. H. ROBERTS. Electron. Power p. 661 (September 1978), Solid-state device technology is extending man's capabilities and the subsequent change in manufacturing technology offers a major threat to large segments of existing manufacturing