Comparative Reliability Prediction Using Physics of Failure Models

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000189-000195
Author(s):  
Milton Watts ◽  
K. Rob Harker

Quartzdyne Electronics has invested millions of device test hours in life testing of circuits in both powered and un-powered tests. In addition to time at temperature, these tests include thermal cycling and high impact drop testing. Recent projects have required the use of larger packages and components as we have expanded the variety of circuits that we build. It is desirable to predict the effects of these changes on long-term reliability before investing in tooling. In this study we will compare a new design which contains these larger components to the simpler, smaller designs for which we have extensive life-test data. Using a physics-of-failure approach, component mounting stresses will be analyzed using finite element modeling. These results will be compared to pre and post-aging shear strengths of actual components of varying sizes. Aging models will then be developed to predict the reliability of the new design based on the comparative stress margins of the individual components coupled with circuit complexity. Once validated, the aging models will enable reliability prediction and trade-off analysis for future designs.

2006 ◽  
Vol 326-328 ◽  
pp. 569-572 ◽  
Author(s):  
Seung Woo Lee ◽  
Seung Woo Han ◽  
Jun Yeob Song ◽  
Wan Doo Kim ◽  
Hwa Ki Lee

The reliability, that is long-term quality, requires a different approaching from short-term quality which is used before. As the electronic components are to be easily normalized on the reliability evaluation, many reliability prediction methodologies are used. In this study, integrated reference model of reliability prediction is serviced for existing PRISM and Bellcore which is related on reliability prediction about electronic components, and will service reliability data based on PoF (Physics of Failure) from domestic research center. The constructed frame of reliability evaluation system, which can predict and evaluate reliability of electronic components and MEMS, is designed by using online service of the reliability data accumulated on web. To evaluate proposed system, the reliability evaluation of PCB (Printed Circuits Boards), which is used in NC controller of machine tools, is introduced according to PRISM, the representative reference model of reliability prediction about electronic components based on MIL-HDBK-217F.


2009 ◽  
Vol 16 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Robin Alastair Amy ◽  
Guglielmo S. Aglietti ◽  
Guy Richardson

Increasingly modern electronic equipment is expected to provide more functionality whilst still being able to withstand shock and vibration loads. The process of reliability prediction has been hampered by the complicated response and failure characteristics of electronic equipment, with the currently available methods being a compromise between accuracy and cost. A process to quickly and confidently predict the reliability of proposed electronic equipment to dynamic loads would greatly benefit industry.This paper will illustrate the difficulties in predicting electronic equipment reliability, showing why progress has been slow, in addition to the difficulty in making a model that works across a broad range of equipment configurations. The four classes of reliability prediction methods (Handbook, Test data, Field data and Physics of Failure) will be contrasted before addressing the individual methods.It is pertinent to note that although the majority of failures in electronic equipment are due to thermal issues, this review focuses on shock and vibration induced failures.


Author(s):  
David M. Willumsen

The central argument of this book is that voting unity in European legislatures is not primarily the result of the ‘disciplining’ power of the leadership of parliamentary parties, but rather the result of a combination of ideological homogeneity through self-selection into political parties and the calculations of individual legislators about their own long-term benefits. Despite the central role of policy preferences in the subsequent behaviour of legislators, preferences at the level of the individual legislator have been almost entirely neglected in the study of parliaments and legislative behaviour. The book measures these using an until now under-utilized resource: parliamentary surveys. Building on these, the book develops measures of policy incentives of legislators to dissent from their parliamentary parties, and show that preference similarity amongst legislators explains a very substantial proportion of party unity, yet alone cannot explain all of it. Analysing the attitudes of legislators to the demands of party unity, and what drives these attitudes, the book argues that what explains the observed unity (beyond what preference similarity would explain) is the conscious acceptance by MPs that the long-term benefits of belonging to a united party (such as increased influence on legislation, lower transaction costs, and better chances of gaining office) outweigh the short-terms benefits of always voting for their ideal policy outcome. The book buttresses this argument through the analysis of both open-ended survey questions as well as survey questions on the costs and benefits of belonging to a political party in a legislature.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 714-715
Author(s):  
Marie Gualtieri

Abstract The recent reauthorization of the Older Americans Act adds language and definitions to current issues facing the aging population. Specifically, Title I includes definitions related to program adaptation and coordination, workforce and long-term care issues, nutrition and social isolation, as well as family caregivers. Different from the last authorization, these definitions span beyond the individual experience to include other entities impacted by an aging society, such as the workforce and families. Overall, the Title I reauthorization seeks to modernize policy to reflect the current influx of the older adult population and its consequences.


2020 ◽  
pp. 030802262097951
Author(s):  
Lizette Norin ◽  
Björn Slaug ◽  
Maria Haak ◽  
Susanne Iwarsson

Introduction Adults with spinal cord injuries are living longer than previously, and a majority are living in ordinary housing in the community. Housing accessibility is important for maintaining independent occupational performance for this population, but knowledge in this area is insufficient. We investigated housing adaptations and current accessibility problems among older adults with long-standing (>10 years) spinal cord injuries. Method Data from home visits among 122 older adults with spinal cord injuries in Sweden were used. Housing adaptations and environmental barriers were descriptively analysed. Findings Kitchens, entrances, and hygiene areas were common locations for housing adaptations and environmental barriers that generated accessibility problems. The most common adaptations were ramps, wheelchair-accessible stovetops, and ceiling-lifts. Wall-mounted cupboards and high shelves (kitchen), inaccessible storage areas (outside the dwelling), and a lack of grab bars (hygiene area) generated the most accessibility problems. Conclusion Despite housing adaptations, there are considerable accessibility problems in the dwellings of older adults with long-standing spinal cord injuries in Sweden, indicating that long-term follow-up of the housing situation of this population is necessary. Focusing on accessible housing as a prerequisite for occupational performance is at the core of occupational therapy, deserving attention on the individual as well as the societal level.


2021 ◽  
Vol 22 (12) ◽  
pp. 6274
Author(s):  
María Fernández ◽  
Alicia de de Coo ◽  
Inés Quintela ◽  
Eliane García ◽  
Márcio Diniz-Freitas ◽  
...  

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis (n = 50) and DS patients with healthy periodontium (n = 36). All samples were genotyped with the “Axiom Spanish Biobank” array, which contains 757,836 markers. An association analysis at the individual marker level using logistic regression, as well as at the gene level applying the sequence kernel association test (SKAT) was performed. The most significant genes were included in a pathway analysis using the free DAVID software. C12orf74 (rs4315121, p = 9.85 × 10−05, OR = 8.84), LOC101930064 (rs4814890, p = 9.61 × 10−05, OR = 0.13), KBTBD12 (rs1549874, p = 8.27 × 10−05, OR = 0.08), PIWIL1 (rs11060842, p = 7.82 × 10−05, OR = 9.05) and C16orf82 (rs62030877, p = 8.92 × 10−05, OR = 0.14) showed a higher probability in the individual analysis. The analysis at the gene level highlighted PIWIL, MIR9-2, LHCGR, TPR and BCR. At the signaling pathway level, PI3K-Akt, long-term depression and FoxO achieved nominal significance (p = 1.3 × 10−02, p = 5.1 × 10−03, p = 1.2 × 10−02, respectively). In summary, various metabolic pathways are involved in the pathogenesis of periodontitis in DS, including PI3K-Akt, which regulates cell proliferation and inflammatory response.


Economies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 18 ◽  
Author(s):  
Daniel Němec ◽  
Eva Kotlánová ◽  
Igor Kotlán ◽  
Zuzana Machová

While assessing the economic impacts of corruption, the corruption-related transmission channels which influence taxation as such have to be duly considered. Taking the example of the Czech Republic, this article aims to evaluate the impacts corruption has on the size of the shadow economy as well as on the individual sources of long-term economic growth, making use of a transmission channel through which corruption affects the tax burden components. Using the method of an extended DSGE model, it confirms the initial assumption that an increase in perceived corruption supports the shadow economy’s growth, but at the same time, it demonstrates that corruption and especially its perception has a significantly different effect on two key areas—the capital accumulation and the labour force size. It further identifies another sector of the economy representing taxes which are prone to tax evasion while asserting that corruption has a much more destructive effect on this sector of the economy, offering generalized implications for other post-communist EU member states in a similar situation.


1993 ◽  
Vol 6 (4) ◽  
pp. 329-343 ◽  
Author(s):  
Robert S. Root‐Bernstein ◽  
Maurine Bernstein ◽  
Helen Gamier
Keyword(s):  

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