Patent Failure Research Articles

Modeling latent and patent failures of electronic products

Burn-in and stress screening are becoming increasingly popular in the commercial electronics industry as customers become increasingly sensitive to failures occurring in the useful life of a product or system. For example, thermal stress screening (TSS) is an assembly-level electronics manufacturing process that evolved from the burn-in processes used in NASA and DoD programs. While burn-in subjects the product to expected field extremes to expose infant mortalities (patent failures), TSS briefy exposes a product to fast temperature rate-of-changes and out-of-specifications temperatures to expose failures that would occur during the useful life of the product. As a result, TSS ages the product in hopes of bringing out defects that would otherwise occur in the field (called latent defects). In support of this known failure behavior, the classical bathtub curve should be modified to aid in the economic modeling of various screen types. We have conducted extensive modeling efforts that have resulted in a systematic approach to explicitly model the latent failures in the bathtub curve. In this paper, we describe the efforts that have been dedicated to modeling latent failures known to exist in many products and systems. The resulting failure distribution is a truncated, mixed Weibull distribution. This model is proving to be an effective and relatively simple means to model the complex nature of failures of a system. With this increased flexibility, we can measure the impact of stress screens in varying conditions and ultimately design optimal screens.

The OZI rule and glueballs

The OZI rule works rather well but is peculiar in that an OZI-forbidden process can proceed via two successive OZI-allowed processes. This implies circumventing the OZI-forbidden diagram and also implies violation of crossing symmetry and unitarity. These peculiarities of the OZI rule are attributed to the facts of life of color confinement. The patent failure of the OZI rule in π−p→ϕϕn is demonstrated in detail. It is pointed out that, within the context of QCD, a logical explanation for this failure is the intervention of glueballs (multigluon resonances). A discussion of how to make and recognize glueballs and their importance to QCD is included.

COMMITTEE ON NUTRITION

Despite an imposing body of information derived from research, our ignorance concerning the etiology, pathogenesis, and treatment of obesity is remarkable. It is clear that when considering a given patient the terms "overweight" and "obese" are not necessarily synonymous. Evidence derived from various viewpoints suggests that obesity cannot be regarded as an etiologically unique metabolic disorder. It is likely that an excess of adipose tissue in man will ultimately prove to represent a clinical end-point common to a variety of hereditary and acquired disorders, as in the case of experimental animals, rather than a singular morbid condition with unique pathogenesis. The identification and evaluation of the inherited, acquired, metabolic, and psychogenic determinants of obesity still present an urgent challenge for future research. Mortality and morbidity rates for diabetes and cardiovascular disease are higher in obese adults than in those of average weight. These risks appear to be diminished by weight reduction. Because the majority of obese children do tend to remain obese as adults and because our society exerts considerable pressure towards relative leanness as a criterion for social acceptability, early treatment of obesity would seem to be a worthy objective. However, the fact is that no methods of treatment have as yet achieved more than minor success in significant sustained weight reduction. Since the natural history of childhood obesity remains ill-defined, the results of testimonials from inadequately controlled studies with short follow-up periods (less than 2 or 3 years) must be viewed with skepticism. Any attempts to achieve lasting weight reduction in obese children and adolescents should be tempered by a realization of the inherent difficulties of treatment and by sympathy for those children who, for reasons poorly understood by their physicians. lack the ability to regulate the delicate balance between physical activity and caloric intake. It appears that when treatment is directed at only a single element of the thermodynamic equilibrium, caloric intake, the chances of successful and lasting weight reduction are small. Prophylaxis may offer the most logical method for dealing with obesity. Prevention is necessary in high-risk families and should be undertaken by the family physician. The role of public health programs implemented by education may decrease the level of obesity in the remainder of the population. The efficacy of either approach remains to be determined. While there is knowledge of some of the metabolic derangements characteristic of the obese adult, little is known about these in childhood. In view of the apparent hazards of obesity in adult life, the patent failures characteristic of virtually all therapeutic approaches and the scientific void in knowledge of pathogenesis or pathophysiology make the study of obesity a compelling undertaking for the investigator.

"Liber et Alma Ceres" in Vergil "Georgics" 1. 7

T was manifestly appropriate for Vergil at start of his agricultural poem to name deities of wine and corn first in an invocation which proceeds to address other divine agents before it closes with Octavian. But why has he called Liber and Ceres most brilliant luminaries of firmament and celestial leaders of gliding year? According to Servius Danielis, lumina was an afterthought, whereby poet ensured that his original numina should not be repeated four lines later;' but this story may be suspected as an ingenuous fabrication and dismissed as a patent failure in its design to explain away novel astronomy. Obviously, substitution of numina for lumina does nothing to relieve Liber and Ceres of unwonted responsibility which Vergil so definitely assigned to them in heavens; for annum connotes zodiac, which is, in Thomas Campbell's phrase, the starry girdle of year,2 and labentem suggests gradual progression through it of sun in his annual course. Most editors have followed Apuleius in interpreting vss. 5 and 6 separately from vs. 7 and in understanding clarissima mundi lumina to be sun and moon.3 Consequently, they place a semicolon after vs. 6; but this punctuation, in denying Liber and Ceres their astral promotion, also deprives them of primacy which is rightfully theirs in exordium to Georgics.4 Worse still, uncouth asyndeton abruptly checks initial flow of one of most melodious passages in Vergil. On other hand, a few editions have maintained natural and euphonious apposition of lumina to Liber et alma Ceres by means of a comma after annum;6 but hitherto this interpretation has also involved traditional belief that clarissima mundi lumina are sun and moon. In order to find some justification for thus equating Liber and Ceres with two major luminaries of heaven, it is customary for modern to appeal to ancient commentators. Servius took refuge in Stoic pantheism, whereby, as he supposed, sun could be Liber as well as Apollo and moon Ceres as well as Diana, Juno, or Proserpina.6 Macrobius wrote a chapter full of far-fetched learning from Orphic and other sources to show that