Load Models for Fatigue Reliability From Limited Data

1996 ◽  
Vol 118 (1) ◽  
pp. 64-68 ◽  
Author(s):  
S. R. Winterstein ◽  
C. H. Lange
Keyword(s):  
Probability Distributions ◽  
Weibull Model ◽  
Higher Moments ◽  
Fatigue Reliability ◽  
Limited Data ◽  
Probability Models ◽  
Load Models ◽  
Load Distributions ◽  
The Impact ◽  
Damage Estimates

Probability distributions of wind turbine loads are estimated from limited data. The impact of different models on fatigue damage is shown. Common one-parameter probability models, such as the Rayleigh and exponential, are found to give significantly different estimates of load distributions and damage. Greatest differences occur in materials with relatively high values of the S–N exponent b, such as composites. In such cases more accurate damage estimates are found by matching at least two moments of the load data (Weibull model), or still higher moments as well. For this purpose, a new, four-moment “generalized Weibull” model is introduced. For edgewise loads it appears a notable improvement over the basic Weibull model, while it supports the Weibull model in the flapwise case. Uncertainty in damage estimates is also quantified, along with the implied data needs.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

ANALISIS RISIKO OPERASIONAL MENGGUNAKAN PENDEKATAN DISTRIBUSI KERUGIAN DENGAN METODE AGREGAT

2011 ◽  
Vol 10 (2) ◽  
pp. 1
Author(s):  
Y. ARBI ◽  
R. BUDIARTI ◽  
I G. P. PURNABA
Keyword(s):  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Financial Institution ◽  
Expected Value ◽  
Insurance Companies ◽  
Limited Data ◽  
Loss Distribution Approach ◽  
Potential Loss ◽  
The Impact

Operational risk is defined as the risk of loss resulting from inadequate or failed internal processes or external problems. Insurance companies as financial institution that also faced at risk. Recording of operating losses in insurance companies, were not properly conducted so that the impact on the limited data for operational losses. In this work, the data of operational loss observed from the payment of the claim. In general, the number of insurance claims can be modelled using the Poisson distribution, where the expected value of the claims is similar with variance, while the negative binomial distribution, the expected value was bound to be less than the variance.Analysis tools are used in the measurement of the potential loss is the loss distribution approach with the aggregate method. In the aggregate method, loss data grouped in a frequency distribution and severity distribution. After doing 10.000 times simulation are resulted total loss of claim value, which is total from individual claim every simulation. Then from the result was set the value of potential loss (OpVar) at a certain level confidence.

scholarly journals COVID-19 Infection during Pregnancy: Risk of Vertical Transmission, Fetal, and Neonatal Outcomes

2021 ◽  
Vol 11 (6) ◽  
pp. 483
Author(s):  
Marwa Saadaoui ◽  
Manoj Kumar ◽  
Souhaila Al Khodor
Keyword(s):  
Pregnant Women ◽  
Vertical Transmission ◽  
Current Knowledge ◽  
Limited Data ◽  
Pregnancy Risk ◽  
Public Health Challenge ◽  
Short And Long Term ◽  
Critical Public Health ◽  
The Impact

The COVID-19 pandemic is a worldwide, critical public health challenge and is considered one of the most communicable diseases that the world had faced so far. Response and symptoms associated with COVID-19 vary between the different cases recorded, but it is amply described that symptoms become more aggressive in subjects with a weaker immune system. This includes older subjects, patients with chronic diseases, patients with immunosuppression treatment, and pregnant women. Pregnant women are receiving more attention not only because of their altered physiological and immunological function but also for the potential risk of viral vertical transmission to the fetus or infant. However, very limited data about the impact of maternal infection during pregnancy, such as the possibility of vertical transmission in utero, during birth, or via breastfeeding, is available. Moreover, the impact of infection on the newborn in the short and long term remains poorly understood. Therefore, it is vital to collect and analyze data from pregnant women infected with COVID-19 to understand the viral pathophysiology during pregnancy and its effects on the offspring. In this article, we review the current knowledge about pre-and post-natal COVID-19 infection, and we discuss whether vertical transmission takes place in pregnant women infected with the virus and what are the current recommendations that pregnant women should follow in order to be protected from the virus.

scholarly journals Statistical Analysis and Machine Learning Prediction of Fog-Caused Low-Visibility Events at A-8 Motor-Road in Spain

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 679
Author(s):  
Sara Cornejo-Bueno ◽  
David Casillas-Pérez ◽  
Laura Cornejo-Bueno ◽  
Mihaela I. Chidean ◽  
Antonio J. Caamaño ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Probability Distributions ◽  
Pearson Correlation ◽  
Likelihood Method ◽  
Neural Network Approach ◽  
Event Duration ◽  
Full Characterization ◽  
Low Visibility ◽  
Learning Machine ◽  
The Impact

This work presents a full statistical analysis and accurate prediction of low-visibility events due to fog, at the A-8 motor-road in Mondoñedo (Galicia, Spain). The present analysis covers two years of study, considering visibility time series and exogenous variables collected in the zone affected the most by extreme low-visibility events. This paper has then a two-fold objective: first, we carry out a statistical analysis for estimating the fittest probability distributions to the fog event duration, using the Maximum Likelihood method and an alternative method known as the L-moments method. This statistical study allows association of the low-visibility depth with the event duration, showing a clear relationship, which can be modeled with distributions for extremes such as Generalized Extreme Value and Generalized Pareto distributions. Second, we apply a neural network approach, trained by means of the ELM (Extreme Learning Machine) algorithm, to predict the occurrence of low-visibility events due to fog, from atmospheric predictive variables. This study provides a full characterization of fog events at this motor-road, in which orographic fog is predominant, causing important traffic problems during all year. We also show how the ELM approach is able to obtain highly accurate low-visibility events predictions, with a Pearson correlation coefficient of 0.8, within a half-hour time horizon, enough to initialize some protocols aiming at reducing the impact of these extreme events in the traffic of the A-8 motor road.

Sexting among singles in the USA: prevalence of sending, receiving, and sharing sexual messages and images

Sexual Health ◽  
2016 ◽  
Vol 13 (5) ◽  
pp. 428 ◽  
Author(s):  
Justin R. Garcia ◽  
Amanda N. Gesselman ◽  
Shadia A. Siliman ◽  
Brea L. Perry ◽  
Kathryn Coe ◽  
...  
Keyword(s):  
Text Messages ◽  
Future Research ◽  
Limited Data ◽  
Single Adults ◽  
Social Lives ◽  
Psychosocial Wellbeing ◽  
Sexually Explicit ◽  
The Usa ◽  
Sexual Messages ◽  
The Impact

Background: The transmission of sexual images and messages via mobile phone or other electronic media (sexting) has been associated with a variety of mostly negative social and behavioural consequences. Research on sexting has focussed on youth, with limited data across demographics and with little known about the sharing of private sexual images and messages with third parties. Methods: The present study examines sexting attitudes and behaviours, including sending, receiving, and sharing of sexual messages and images, across gender, age, and sexual orientation. A total of 5805 single adults were included in the study (2830 women; 2975 men), ranging in age from 21 to 75+ years. Results: Overall, 21% of participants reported sending and 28% reported receiving sexually explicit text messages; both sending and receiving ‘sexts’ was most common among younger respondents. Although 73.2% of participants reported discomfort with unauthorised sharing of sexts beyond the intended recipient, of those who had received sext images, 22.9% reported sharing them with others (on average with 3.17 friends). Participants also reported concern about the potential consequences of sexting on their social lives, careers, and psychosocial wellbeing. Conclusion: Views on the impact of sexting on reputation suggest a contemporary struggle to reconcile digital eroticism with real-world consequences. These findings suggest a need for future research into negotiations of sexting motivations, risks, and rewards.

scholarly journals A Novel Framework to Determine the Impact of Time Varying Load Models on Wind DG Planning

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Ali Ahmed ◽  
Muhammad Faisal Nadeem ◽  
Irfan Khan ◽  
Hani Alquhayz ◽  
Muhammad Adnan Khan ◽  
...  
Keyword(s):  
Time Varying ◽  
Load Models ◽  
The Impact

CHANGING PRESCRIBING CULTURE – A FOCUS ON CODEINE POSTPARTUM

2016 ◽  
Vol 101 (9) ◽  
pp. e2.12-e2 ◽  
Author(s):  
Noor Al-Adhami ◽  
Karen Whitfield ◽  
Angela North
Keyword(s):  
Breast Feeding ◽  
Medical Staff ◽  
Successful Outcome ◽  
Postpartum Women ◽  
Limited Data ◽  
Training And Education ◽  
Key Stakeholders ◽  
Postpartum Analgesia ◽  
The Impact ◽  
Breast Fed

AimTo eliminate the prescribing of codeine and codeine combination products postpartum to improve safety in breast fed infants.Concerns have been raised over the use of codeine and codeine combination products during breast feeding after the death of a neonate whose mother had been prescribed codeine postpartum. High concentrations of morphine were found in the infant's blood and this was attributed to the mother being a CYP2D6 ultrafast metaboliser.1 MethodsThe evidence surrounding the safety of codeine and codeine combination products in children, during the postpartum period and specifically for breast fed infants was collated. The evidence was presented to key stakeholders including obstetricians, midwives, safety and quality representatives, nurse unit managers and acute pain team representatives. Postpartum analgesia was discussed and an agreed protocol developed. Training and education sessions were undertaken to obstetric medical and nursing staff.ResultsThe evidence that was presented to key stakeholders included:▸ Reports over the safety concerns surrounding the use of codeine and codeine combination products during breast feeding▸ Guidelines and contraindications about the use of codeine in children that had been issued by international regulatory bodies (US Food and Drug Administration and European Medicines Agency).▸ Recommendations from the Australian Medicines Handbook to avoid in breast feeding2 ▸ Recommendations from Hale's Medications and Mothers Milk that reported limited data and had made a recent re-classification from L3 (limited data–probably compatible) to L4 (limited data–possibly hazardous).3 Before presenting the evidence to key stakeholders and undertaking training to nursing and medical staff, more than 90% of postpartum women were prescribed a codeine containing product as part of their ‘as required’ analgesic regimen.Since the intervention, codeine combination products have now been almost completely eliminated on medication charts for postpartum women (less than 5%). Those that are prescribed are ceased once highlighted to medical staff. The obstetric pharmacist now presents a session on postpartum analgesia at every new resident medical officer orientation outlining suitable medications to prescribe. In addition all new pharmacists to the women's and new born's team receive training about postpartum analgesia.ConclusionThis study highlights the impact that can be achieved when health care professionals work together to change the culture and prescribing habits in a hospital setting, to enhance patient safety. Evaluating the evidence and presenting to stakeholders as well as providing ongoing training and education to medical, nursing and pharmacy staff are all essential to a successful outcome.

Simplifications of Uniform Expressions Specified by Systems

2021 ◽  
pp. 1-28
Author(s):  
Florent Koechlin ◽  
Cyril Nicaud ◽  
Pablo Rotondo
Keyword(s):  
Generating Functions ◽  
Higher Moments ◽  
The Impact ◽  
Simple Reduction

In this article, we study the impact of applying simple reduction rules to random syntactic formulas encoded as trees. We assume that there is an operator that has an absorbing pattern and prove that if we use this property to simplify a uniform random expression with [Formula: see text] nodes, then the expected size of the result is bounded by a constant. The same holds for higher moments, establishing the lack of expressivity of uniform random expressions. Our framework is quite general as we consider expressions defined by systems of combinatorial equations. For our proofs, we rely on Drmota’s multidimensional theorem for systems of generating functions.

scholarly journals A framework for global river flood risk assessments

2013 ◽  
Vol 17 (5) ◽  
pp. 1871-1892 ◽  
Author(s):  
H. C. Winsemius ◽  
L. P. H. Van Beek ◽  
B. Jongman ◽  
P. J. Ward ◽  
A. Bouwman
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
Hydrological Model ◽  
Flood Hazard ◽  
Probability Distributions ◽  
Flood Routing ◽  
Risk Assessments ◽  
First Case ◽  
Impact Models ◽  
Damage Estimates

Abstract. There is an increasing need for strategic global assessments of flood risks in current and future conditions. In this paper, we propose a framework for global flood risk assessment for river floods, which can be applied in current conditions, as well as in future conditions due to climate and socio-economic changes. The framework's goal is to establish flood hazard and impact estimates at a high enough resolution to allow for their combination into a risk estimate, which can be used for strategic global flood risk assessments. The framework estimates hazard at a resolution of ~ 1 km2 using global forcing datasets of the current (or in scenario mode, future) climate, a global hydrological model, a global flood-routing model, and more importantly, an inundation downscaling routine. The second component of the framework combines hazard with flood impact models at the same resolution (e.g. damage, affected GDP, and affected population) to establish indicators for flood risk (e.g. annual expected damage, affected GDP, and affected population). The framework has been applied using the global hydrological model PCR-GLOBWB, which includes an optional global flood routing model DynRout, combined with scenarios from the Integrated Model to Assess the Global Environment (IMAGE). We performed downscaling of the hazard probability distributions to 1 km2 resolution with a new downscaling algorithm, applied on Bangladesh as a first case study application area. We demonstrate the risk assessment approach in Bangladesh based on GDP per capita data, population, and land use maps for 2010 and 2050. Validation of the hazard estimates has been performed using the Dartmouth Flood Observatory database. This was done by comparing a high return period flood with the maximum observed extent, as well as by comparing a time series of a single event with Dartmouth imagery of the event. Validation of modelled damage estimates was performed using observed damage estimates from the EM-DAT database and World Bank sources. We discuss and show sensitivities of the estimated risks with regard to the use of different climate input sets, decisions made in the downscaling algorithm, and different approaches to establish impact models.

scholarly journals Are In Vitro Susceptibilities to Azole Antifungals Predictive of Clinical Outcome in the Treatment of Candidemia?

2018 ◽  
Vol 56 (12) ◽  
Author(s):  
Twisha S. Patel ◽  
Peggy L. Carver ◽  
Gregory A. Eschenauer
Keyword(s):  
Invasive Candidiasis ◽  
Randomized Trials ◽  
Published Data ◽  
Murine Models ◽  
Limited Data ◽  
Content Type ◽  
Clinical Breakpoints ◽  
The Impact ◽  
The Relationship

ABSTRACT The purpose of this review is to critically analyze published data evaluating the impact of azole pharmacokinetic and pharmacodynamic parameters, MICs, and Candida species on clinical outcomes in patients with candidemia. Clinical breakpoints (CBPs) for fluconazole and voriconazole, which are used to determine susceptibility, have been defined by the Clinical and Laboratory Standards Institute (CLSI) for Candida species. Studies evaluating the relationship between treatment efficacy and in vitro susceptibility, as well as the pharmacodynamic targets, have been conducted in patients treated with fluconazole for candidemia; however, for species other than Candida albicans and Candida glabrata, and for other forms of invasive candidiasis, data remain limited and randomized trials are not available. Limited data evaluating these relationships with voriconazole are available. While pharmacodynamic targets for posaconazole and isavuconazole have been proposed based upon studies conducted in murine models, CBPs have not been established by CLSI. Fluconazole remains an important antifungal agent for the treatment of candidemia, and data supporting its use based on in vitro susceptibility are growing, particularly for C. albicans and C. glabrata. Further investigation is needed to establish the roles of voriconazole, posaconazole, and isavuconazole in the treatment of candidemia and for all agents in the treatment of other forms of invasive candidiasis.

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