Modeling and Simulation for Lifetime Predictions

NPS NRP Project PosterModeling and Simulation for Lifetime PredictionsNaval Surface Warfare Center (NSWC)This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Modeling and Simulation for Lifetime Predictions

NPS NRP Executive SummaryModeling and Simulation for Lifetime PredictionsNaval Surface Warfare Center (NSWC)This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

The Integration of Reliability, Availability, and Maintainability (RAM) into Model-Based Systems Engineering (MBSE)

NPS NRP Executive SummaryIn recent years, the expansion of new technology has resulted in a more challenging design process. This has inflated in complexity of the system as well as its operational sustainment including managing documentation, root causing failures, tracking changes, etc. With the increased challenge seen in designing modern system, Model-Based Systems Engineering (MBSE) has emerged as a paradigm shift to transition the system's design into the digital space. With this transition comes clear and authoritative advantages such as a single source of design truth, a more complete analysis of the system, an improved communication among members of the program, the reuse of models, and many more [Carol, 2016]. While these advantages have been observed in specific uses of MBSE, the ability to employ MBSE is currently limited by the availability of both the knowledge of its employment and the availability of models. Among other topic areas, this limitation includes reliability, availability, and maintainability (RAM). To expand the capability of MBSE, this research investigates the various elements of modeling RAM (i.e., the development of a RAM domain model). (Carol, 2016) E. Carroll and R. Malins, "Systematic literature review: How is model-based systems engineering justified," Sandia National Laboratories, 2016.Naval Surface Warfare Center (NSWC), Division CraneASN(RDA) - Research, Development, and AcquisitionThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

The Integration of Reliability, Availability, and Maintainability (RAM) into Model-Based Systems Engineering (MBSE)

NPS NRP Project PosterIn recent years, the expansion of new technology has resulted in a more challenging design process. This has inflated in complexity of the system as well as its operational sustainment including managing documentation, root causing failures, tracking changes, etc. With the increased challenge seen in designing modern system, Model-Based Systems Engineering (MBSE) has emerged as a paradigm shift to transition the system's design into the digital space. With this transition comes clear and authoritative advantages such as a single source of design truth, a more complete analysis of the system, an improved communication among members of the program, the reuse of models, and many more [Carol, 2016]. While these advantages have been observed in specific uses of MBSE, the ability to employ MBSE is currently limited by the availability of both the knowledge of its employment and the availability of models. Among other topic areas, this limitation includes reliability, availability, and maintainability (RAM). To expand the capability of MBSE, this research investigates the various elements of modeling RAM (i.e., the development of a RAM domain model). (Carol, 2016) E. Carroll and R. Malins, "Systematic literature review: How is model-based systems engineering justified," Sandia National Laboratories, 2016.Naval Surface Warfare Center (NSWC), Division CraneASN(RDA) - Research, Development, and AcquisitionThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Endothelial bound lipoprotein lipase (LpL) depletion in hypoalbuminemia results from decreased endothelial binding, not decreased secretion

Hypertriglyceridemia in nephrotic (NS) and Nagase analbuminemic rats (Analb) results from reduced triglyceride clearance. NS and Analb have reduced or absent albumin, reduced plasma oncotic pressure (π), but Analb lack proteinuria. The heparin releasable lipoprotein lipase (LpL) pool in both models is greatly reduced, suggesting reduced LpL is related to low albumin or π and not proteinuria. To determine the cause of endothelial LpL reduction, we studied effectors of endothelial LpL (eLpL) levels from gene expression, to delivery and endothelial binding. eLpL was measured as heparin releasable activity. eLpL and secretion rate was measured in isolated hearts perfused with heparin. mRNA levels were measured in rat hearts by kinetic RT-PCR. Finally, binding of 125I-LpL by competition assays rat endothelial cells measured serum-induced changes in affinity. eLpL in vivo was reduced in nephrotic and Analb rats. While the eLpL pool was reduced in isolated perfused hearts, neither LpL secretion by isolated hearts nor myocardial mRNA was reduced in NS or Analb. Binding of LpL to RAEC preincubated with serum from either NS or Analb was reduced compared to control. LpL mRNA levels and release rate was not altered in hearts from NS rats, while eLpL is depleted, suggesting that reduced eLpL in NS is not the result of reduced delivery. The finding that NS serum alters LpL binding to RAEC suggests LpL depletion results from decreased binding rather than defective delivery. This in turn is a consequence of reduced serum albumin or π but does not require proteinuria

Моніторинг розвитку навичок мовлення та аудіювання

Мета цього дослідження є спостереження та аналіз змін якості навичок володіння мовленням і якості володіння навичками аудіювання в процесі навчання. Завдання дослідження полягає у наступному : а) вивчити яким чином сучасні методи моніторингу впливають на поліпшення якості володіння мовленням, б) простежити якісні зміни знань студентів на трьох етапах: стартовому, поточному та підсумковому. Методами моніторингу є анкетування. самостійна робота, тестування

Statistical models for quantifying diagnostic accuracy with multiple lesions per patient

We propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive lesions was assumed to be distributed as a binomial mixture. We considered univariate and bivariate, both parametric and nonparametric mixture models. We applied our tools to simulated data and data of a study assessing diagnostic accuracy of virtual colonography with computed tomography in 200 patients suspected of having one or more polyps

Prognostic systems representation in a function-based Bayesian model during engineering design

Prognostics and Health Management (PHM) systems are usually only considered and set up in the late stage of design or even during the system’s lifetime, after the major design decision have been made. However, considering the PHM system’s impact on the system failure probabilities can benefit the system design early on and subsequently reduce costs. The identification of failure paths in the early phases of engineering design can guide the designer toward a safer, more reliable and cost-efficient design. Several functional failure modeling methods have been developed recently. One of their advantages is to allow for risk assessment in the early stages of the design. Risk and reliability functional failure analysis methods currently developed do not explicitly model the PHM equipment used to identify and prevent potential system failures. This paper proposes a framework to optimize prognostic systems selection and positioning during the early stages of a complex system design. A Bayesian network, incorporating the PHM systems, is used to analyze the functional model and failure propagation. The algorithm developed within the proposed framework returns the optimized placement of PHM hardware in the complex system, allowing the designer to evaluate the need for system improvement. A design tool was developed to automatically apply the proposed method. A generic pressurized water nuclear reactor primary coolant loop system is used to present a case study illustrating the proposed framework. The results obtained for this particular case study demonstrate the promise of the method introduced in this paper. The case study notably exhibits how the proposed framework can be used to support engineering design teams in making better informed decisions early in the design phase

Postnatal Acute Famine and Risk of Overweight: The Dutch Hungerwinter Study

Objective. To examine the association between undernutrition during postnatal periods of development and the risk of overweight in adulthood. Methods. We studied 8,091 women from Prospect-EPIC, exposed to the Dutch famine at ages between 0 and 21 years, recruited at ages between 49 and 70 years. We used linear and logistic regression models to explore the effect of famine on BMI, waist circumference, and the risk of overweight. Results. Overall, postnatal famine exposure was associated with increased BMI and waist circumference in a dose-dependent manner (P  for trend < 0.01). Furthermore, risk of overweight was increased following famine exposure (P  for trend = 0.01), with those severely exposed at ages 0–9 years having 25% (95% CI 1.05 to 1.50) higher risk compared to unexposed women. Conclusions. This study is the first to directly show a positive association between short and transient undernutrition during postnatal development and BMI, waist circumference, and overweight in adulthood

Developing an advanced module for back-contact solar cells

This paper proposes a novel concept for integrating ultrathin solar cells into modules. It is conceived as a method for fabricating solar panels starting from back-contact crystalline silicon solar cells. However, compared to the current state of the art in module manufacturing for back-contact solar cells, this novel concept aims at improvements in performance, reliability, and cost through the use of an alternative encapsulant, namely silicones as opposed to ethylene vinyl acetate, an alternative deposition technology, being wet coating as opposed to dry lamination; and alternative module-level metallization techniques, as opposed to cell-level tabbing-stringing or conductive foil interconnects. The process flow is proposed, and the materials and fabrication technologies are discussed. As the durability of the module, translated into the module's lifetime, is very important in the targeted application, namely solar cell modules, modeling and reliability testing results and considerations are presented to illustrate how the experimental development process may be guided by experience and theoretical derivations. Finally, feasibility is demonstrated in some first proofs of the concept, and an outlook is given pointing out the direction for further research