Discrete Predictive Analysis in Probabilistic Safety Assessment

This paper presents methods for predicting future numbers of component failures for probabilistic safety assessments (PSAs). The research is motivated and illustrated by discrete failure data from the nuclear industry, including failure counts for emergency diesel generators, pumps, and motor operated valves. Failure counts are modeled with Poisson and binomial distributions. Multiple-failure environments create extra problems for predictive inference, and are a primary focus of this paper. Common cause failures (CCFs), in particular, refer to the simultaneous failure of system components due to an external event. CCF prediction is investigated, and approximate inference methods are derived for various CCF models

Common Cause Failure Prediction Using Data Mapping

To estimate power plant reliability, a probabilistic safety assessment might combine failure data from various sites. Because dependent failures are a critical concern in the nuclear industry, combining failure data from component groups of different sizes is a challenging problem. One procedure, called data mapping, translates failure data across component group sizes. This includes common cause failures, which are simultaneous failure events of two or more components in a group. In this paper, we present methods for predicting future plant reliability using mapped common cause failure data. The prediction technique is motivated by discrete failure data from emergency diesel generators at U.S. plants. The underlying failure distributions are based on homogeneous Poisson processes. Both Bayesian and frequentist prediction methods are presented, and if non-informative prior distributions are applied, the upper prediction bounds for the generators are the same

Nonparametric Estimation of a Distribution Subject to a Stochastic Precedence Constraint

For any two random variables X and Y with distributions F and G defined on [0,∞), X is said to stochastically precede Y if P(X≤Y) ≥ 1/2. For independent X and Y, stochastic precedence (denoted by X≤spY) is equivalent to E[G(X–)] ≤ 1/2. The applicability of stochastic precedence in various statistical contexts, including reliability modeling, tests for distributional equality versus various alternatives, and the relative performance of comparable tolerance bounds, is discussed. The problem of estimating the underlying distribution(s) of experimental data under the assumption that they obey a stochastic precedence (sp) constraint is treated in detail. Two estimation approaches, one based on data shrinkage and the other involving data translation, are used to construct estimators that conform to the sp constraint, and each is shown to lead to a root n-consistent estimator of the underlying distribution. The asymptotic behavior of each of the estimators is fully characterized. Conditions are given under which each estimator is asymptotically equivalent to the corresponding empirical distribution function or, in the case of right censoring, the Kaplan–Meier estimator. In the complementary cases, evidence is presented, both analytically and via simulation, demonstrating that the new estimators tend to outperform the empirical distribution function when sample sizes are sufficiently large

Markov versus quantum dynamic models of belief change during evidence monitoring

This work is licensed under a Creative Commons Attribution 4.0 International License.Two different dynamic models for belief change during evidence monitoring were evaluated: Markov and quantum. They were empirically tested with an experiment in which participants monitored evidence for an initial period of time, made a probability rating, then monitored more evidence, before making a second rating. The models were qualitatively tested by manipulating the time intervals in a manner that provided a test for interference effects of the first rating on the second. The Markov model predicted no interference, whereas the quantum model predicted interference. More importantly, a quantitative comparison of the two models was also carried out using a generalization criterion method: the parameters were fit to data from one set of time intervals, and then these same parameters were used to predict data from another set of time intervals. The results indicated that some features of both Markov and quantum models are needed to accurately account for the results

Patterns of Sexual Arousal in Young, Heterosexual Men Who Experience Condom-Associated Erection Problems (CAEP)

Introduction Condom-associated erection problems (CAEP) are reported by a substantial number of young men and are associated with inconsistent and/or incomplete condom use. The underlying mechanisms of CAEP are not well understood and research examining the possibility that men who report CAEP differ from other men in their sexual responsivity is lacking. Aim This study used psychophysiological methods to examine whether men who report CAEP have a higher threshold for sexual arousal, a stronger need for tactile stimulation, and/or more easily lose their sexual arousal due to neutral distractors or performance-related demands. Methods A total of 142 young, heterosexual men (53% reporting CAEP) were presented with four 3-minute erotic film clips. Three film clips were combined with one of the following manipulations: 1) distraction, 2) performance demand, or 3) vibrotactile stimulation. One erotic film clip was presented with no further instructions or manipulations. Main Outcome Measures Average penile circumference changes during the first, second, and third minute (Time) of the erotic film stimuli (Condition) were submitted to a mixed-model ANOVA with Condition and Time as within-subjects factors and Group (CAEP/No-CAEP) as between-subjects factor. Results Significant main effects of Condition and Time and a significant interaction of Group×Time were found. No significant interactions involving Condition were found. Men who reported CAEP had smaller erectile responses during the first minute, regardless of film condition, than men who reported no CAEP (F(1,141)=8.64, p<.005). Conclusion The findings suggest that men with and without CAEP differ in the ease with which they become sexually aroused. Men reporting CAEP needed more time and/or more intense stimulation to become aroused. To our knowledge, this study is the first to use psychophysiological methods to assess sexual responsivity in men who report CAEP

The MATHUSLA Test Stand

The rate of muons from LHC $pp$ collisions reaching the surface above the ATLAS interaction point is measured and compared with expected rates from decays of $W$ and $Z$ bosons and $b$- and $c$-quark jets. In addition, data collected during periods without beams circulating in the LHC provide a measurement of the background from cosmic ray inelastic backscattering that is compared to simulation predictions. Data were recorded during 2018 in a 2.5 $\times$ 2.5 $\times$ 6.5~$\rm{m}^3$ active volume MATHUSLA test stand detector unit consisting of two scintillator planes, one at the top and one at the bottom, which defined the trigger, and six layers of RPCs between them, grouped into three $(x,y)$-measuring layers separated by 1.74 m from each other. Triggers selecting both upward-going tracks and downward-going tracks were used.Comment: 18 pages, 11 figures, 1 tabl

Elg i nordtrønderske kommuner 2013; en vurdering av elgbestandene i fylket

En faggruppe bestående av representanter fra Nord-Trøndelag fylkeskommune, Fjellstyrene i Steinkjer, Høgskolen i Nord- Trøndelag (HiNT), Miljø- og landbruksforvaltningen i Midtre Namdal og Norsk institutt for naturforskning (NINA) har basert på sett elg-data, fellingsstatistikk og slaktevekter vurdert utviklingen i elgbestandene i Nord-Trøndelag, og gitt anbefalinger om den videre forvaltningen av elgbestandene. I tillegg har gruppen vurdert datakvaliteten og forvaltningsmålene i de forskjellige kommunene. Prosjektet er å betrakte som et pilotprosjekt som forhåpentligvis kan danne grunnlaget for tilsvarende vurderinger i årene som kommer. Elgbestanden i Nord-Trøndelag har stort sett økt i antall siden starten av 1970-tallet, inntil en (foreløpig) topp ble nådd i perioden 2002-2004. Bestanden har siden holdt seg relativt stabil i antall, men med store variasjoner innenfor fylket. Med unntak for Hjorteviltregion 4 ser vi en nedgang i rekrutteringen av kalv i alle hjorteviltregionene, særlig i løpet av de siste 5-10 årene. En tilsvarende negativ trend finner vi i utviklingen av de aldersspesifikke slaktevektene, med unntak for Hjorteviltregion 5. Based on dressed weights and «Sett elg» (Moose seen)-data from Hjorteviltregisteret and hunting statistics from SSB (Statistics Norway) a research group has evaluated the development of moose populations in Nord- Trøndelag in order to give advice to municipal game boards, which are responsible for moose management in Nord- Trøndelag. The moose situation tend to be variable, due to railway lines and main roads in the landscape. Moose population have been increasing in recent years, and the open clear-cuts, which used to produce enough food for an increasing moose population now tend to be to densely forested for the moose to find enough food. The conclusion is that we will have to consider dressed weights and and the food situation in the years to come.Nord- Trøndelag Fylkeskommun

Infection-Associated Nuclear Degeneration in the Rice Blast Fungus Magnaporthe oryzae Requires Non-Selective Macro-Autophagy

addresses: School of Biosciences, University of Exeter, Exeter, Devon, United Kingdom.notes: PMCID: PMC3308974Freely-available open access article.The rice blast fungus Magnaporthe oryzae elaborates a specialized infection structure called an appressorium to breach the rice leaf surface and gain access to plant tissue. Appressorium development is controlled by cell cycle progression, and a single round of nuclear division occurs prior to appressorium formation. Mitosis is always followed by programmed cell death of the spore from which the appressorium develops. Nuclear degeneration in the spore is known to be essential for plant infection, but the precise mechanism by which it occurs is not known

Microautophagy of the Nucleus Coincides with a Vacuolar Diffusion Barrier at Nuclear–Vacuolar Junctions

Nuclear-vacuolar (NV) junctions are organelle contact sites in yeast. They exclude nuclear pores from the organelle interface. On the vacuolar side, a lipid-dependent process excludes specific membrane proteins, such as V-ATPase, from the contact site. This suggests that NV junctions establish selective diffusion barriers