Simulations using IPCC-class climate models are subject to fail or crash for a variety of reasons. Statistical analysis of the failures can yield useful insights to better understand and improve the models. During the course of uncertainty quantification UQ ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation failures of the Parallel Ocean Program POP2. About 8.
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Simulations using IPCC-class climate models are subject to fail or crash for a variety of reasons. Statistical analysis of the failures can yield useful insights to better understand and improve the models.
During the course of uncertainty quantification UQ ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation failures of the Parallel Ocean Program POP2. About 8. We apply support vector machine SVM classification from the fields of pattern recognition and machine learning to quantify and predict the probability of failure as a function of the values of 18 POP2 parameters.
The SVM classifiers readily predict POP2 failures in an independent validation ensemble, and are subsequently used to determine the causes of the failures via a global sensitivity analysis. Four parameters related to ocean mixing and viscosity are identified as the major sources of POP2 failures.
Our method can be used to improve the robustness of complex scientific models to parameter perturbations and to better steer UQ ensembles. This work was performed under the auspices of the U. Multiple new procedures for treatment of complex anal fistula have been described in the past decades, but an ideal single technique has yet not been identified.
Factors that predict the outcome are required to identify the best procedure for each individual patient. The aim of this study was to find those predictors for advancement flap at midterm follow-up.
From to in a tertiary university clinic, all patients who underwent advancement flap for treatment of complex cryptoglandular fistula were prospectively enrolled. Pre- and postoperatively standardized anamnestic and clinical examinations were performed. Predictive factors for therapy failure were identified using univariate and multivariate analysis. There was no significant disturbance of continence among the entire study cohort as shown by the incontinence score preop 0.
Advancement flap for treatment of complex fistula is effective and has low risk of disturbed continence. BMI, suprasphincteric fistula and history of surgical abscess drainage are predictors for therapy failure. Failure probability under parameter uncertainty. In many problems of risk analysis, failure is equivalent to the event of a random risk factor exceeding a given threshold. Failure probabilities can be controlled if a decisionmaker is able to set the threshold at an appropriate level.
This abstract situation applies, for example, to environmental risks with infrastructure controls; to supply chain risks with inventory controls; and to insurance solvency risks with capital controls. However, uncertainty around the distribution of the risk factor implies that parameter error will be present and the measures taken to control failure probabilities may not be effective.
We show that parameter uncertainty increases the probability understood as expected frequency of failures. For a large class of loss distributions, arising from increasing transformations of location-scale families including the log-normal, Weibull, and Pareto distributions , the article shows that failure probabilities can be exactly calculated, as they are independent of the true but unknown parameters. Hence it is possible to obtain an explicit measure of the effect of parameter uncertainty on failure probability.
Failure probability can be controlled in two different ways: 1 by reducing the nominal required failure probability, depending on the size of the available data set, and 2 by modifying of the distribution itself that is used to calculate the risk control.
We furthermore show that the two approaches are consistent in achieving the required failure probability. Finally, we briefly discuss the effects of data pooling and its systemic risk implications. Directory of Open Access Journals Sweden. Full Text Available Cloud computing is a novel technology in the field of distributed computing. Usage of Cloud computing is increasing rapidly day by day. In order to serve the customers and businesses satisfactorily fault occurring in datacenters and servers must be detected and predicted efficiently in order to launch mechanisms to tolerate the failures occurred.
Failure in one of the hosted datacenters may propagate to other datacenters and make the situation worse. In order to prevent such situations one can predict a failure proliferating throughout the cloud computing system and launch mechanisms to deal with it proactively.
One of the ways to predict failures is to train a machine to predict failure on the basis of messages or logs passed between various components of the cloud.
In the training session the machine can identify certain message patterns relating to failure of data centers. Later on the machine can be used to check whether a certain group of message logs follow such patterns or not. Moreover each cloud server can be defined by a state which indicates whether the cloud is running properly or is facing some failure.
Parameters such as CPU usage memory usage etc. Using this parameters we can add a layer of detection where in we develop a decision tree based on these parameters which can classify whether the passed in parameters to the decision tree indicate failure state or proper state. This study sought to identify whether impaired global longitudinal strain GLS , diastolic dysfunction DD , or left atrial enlargement LAE should be added to stage B heart failure SBHF criteria in asymptomatic patients with type 2 diabetes mellitus.
SBHF is a precursor to clinical heart failure HF , and its recognition justifies initiation of cardioprotective therapy. A study has been conducted to evaluate how process parameters will exhibit the change in the event of the troubles related to reactor internal by using transient thermal-hydraulic analysis codes RETRAN3D-MOD, etc.
In the present study, the following six events are analytically investigated: 1 a leak from the upper plenum; 2 a leak from the middle part of a shroud; 3 a leak from the lower plenum; 4 a leak from the riser pipe for the jet-pump; 5 the blockage of the jet-pump nozzle; and 6 a leak from the jet-pump diffuser.
The results by analyses indicated that the leak from the upper plenum resulted in increasing in the inlet temperature of primary loop recirculation PLR and in the differential pressure at the core support plate, and decreasing in the neutron flux reactor power.
Similar analyses were made for the five other events to identify the pattern of relevant process parameter variation in each event. Detecting failure of climate predictions. The practical consequences of climate change challenge society to formulate responses that are more suited to achieving long-term objectives, even if those responses have to be made in the face of uncertainty1, 2.
Such a decision-analytic focus uses the products of climate science as probabilistic predictions about the effects of management policies3.
Here we present methods to detect when climate predictions are failing to capture the system dynamics. For a single model, we measure goodness of fit based on the empirical distribution function, and define failure when the distribution of observed values significantly diverges from the modelled distribution.
For a set of models, the same statistic can be used to provide relative weights for the individual models, and we define failure when there is no linear weighting of the ensemble models that produces a satisfactory match to the observations. Early detection of failure of a set of predictions is important for improving model predictions and the decisions based on them.
We show that these methods would have detected a range shift in northern pintail 20 years before it was actually discovered, and are increasingly giving more weight to those climate models that forecast a September ice-free Arctic by Echocardiographic assessment of right ventricular function in routine practice: Which parameters are useful to predict one-year outcome in advanced heart failure patients with dilated cardiomyopathy? Right ventricular RV function has recently gained attention as a prognostic predictor of outcome even in patients who have left-sided heart failure.
Since several conventional echocardiographic parameters of RV systolic function have been proposed, our aim was to determine if any of these parameters tricuspid annular plane systolic excursion: TAPSE, tissue Doppler derived systolic tricuspid annular motion velocity: S', fractional area change: FAC are associated with outcome in advanced heart failure patients with dilated cardiomyopathy DCM.
Receiver-operating characteristic curve analysis showed that the optimal FAC cut-off value to identify patients with an event was rights reserved. Parameters governing the failure of steel components. The most important feature of any component is the ability to carry safely the load it is designed for. The strength of the component is influenced mainly by three groups of parameters : 1.
The loading of the structure; Here the possible loading cases are: normal operation, testing, emergency and faulted conditions; the kinds of loading can be divided into: internal pressure, external forces and moments, temperature loading.
The defects in the structure: cavities and inclusions, pores, flaws or cracks. The material properties: Young's modulus, Yield - and ultimate strength, absorbed charpy energy, fracture toughness, etc. For different failure modes one has to take into account different material properties, the loading and the defects are assumed to be within certain deterministic bounds, from which deterministic safety factors can be determined with respect to any failure mode and failure criterion.
However, since all parameters have a certain scatter about a mean value, there is a probability to exceed the given bounds. From the extrapolation of the distribution a value for the failure probability can be estimated.
Toward full-chip prediction of yield-limiting contact patterning failure : correlation of simulated image parameters to advanced contact metrology metrics. This paper will focus on nm node contact patterning, and will correlate SEM Profile Grade output to the extensive suite of model-based image tags from the Calibre TM opc-verification engine.
With an understanding of which image parameters are most highly correlated to the occurrence of incomplete contact formation for a given process, the process model can be used to automatically direct inspection metrology to those layout instances that pose the highest risk of patterning failure through the lithographic process window.
Such an approach maximizes the value content of in-line metrology. Failure Prediction for Autonomous Driving. The primary focus of autonomous driving research is to improve driving accuracy. While great progress has been made, state-of-the-art algorithms still fail at times.
Such failures may have catastrophic consequences. It therefore is important that automated cars foresee problems ahead as early as possible. This is also of paramount importance if the driver will be asked to take over.
We conjecture that failures do not occur randomly. For instance, driving models may fail more likely at places Predicting survival in heart failure. AimsUsing a large international database from multiple cohort studies, the aim is to create a generalizable easily used risk score for mortality in patients with heart failure HF. The function and failure of sensory predictions. Humans and other primates are equipped with neural mechanisms that allow them to automatically make predictions about future events, facilitating processing of expected sensations and actions.
Prediction -driven control and monitoring of perceptual and motor acts are vital to normal cognitive functioning. This review provides an overview of corollary discharge mechanisms involved in predictions across sensory modalities and discusses consequences of predictive coding for cognition and behavior.
Converging evidence now links impairments in corollary discharge mechanisms to neuropsychiatric symptoms such as hallucinations and delusions. We review studies supporting a prediction-failure hypothesis of perceptual and cognitive disturbances. We also outline neural correlates underlying prediction function and failure , highlighting similarities across the visual, auditory, and somatosensory systems.
In linking basic psychophysical and psychophysiological evidence of visual, auditory, and somatosensory prediction failures to neuropsychiatric symptoms, our review furthers our understanding of disease mechanisms. Strain limit criteria to predict failure. In recent years extensive effort has been expended to qualify existing structures for conditions that are beyond the original design basis. Determination of the component failure load is useful for this type of evaluation.
This paper presents criteria based upon strain limits to predict the load at failure. The failure modes addressed are excessive plastic deformations, localized plastic strains, and structural instability. The effects of analytical method sophistication, as built configurations, material properties degradation, and stress state are addressed by the criteria.
The results from real data show that our predictive manufacturing analytics approach, using genetic algorithms and Voronoi tessellations, is capable of predicting product failure with reasonable accuracy.
The potential application of this method contributes Uncertainties in container failure time predictions.
TC Kimlik No: Pratisyen Hekim. Uzman Doktor. Temel Anestezi. The optimum doses of and injection locations for periprostatic nerve blockade for transrectal ultrasound guided biopsy of the prostate: a prospective, randomized, placebo controlled study. J Urol.