Application of the bootstrap method to quantify uncertainty in seismic hazard estimates

1992 ◽  
Vol 82 (1) ◽  
pp. 104-119
Author(s):  
Michéle Lamarre ◽  
Brent Townshend ◽  
Haresh C. Shah
Keyword(s):  
Confidence Interval ◽  
Seismic Hazard ◽  
Statistical Method ◽  
Bootstrap Method ◽  
Earthquake Magnitude ◽  
Earthquake Catalog ◽  
Uncertainty Measure ◽  
Attenuation Models ◽  
The Bootstrap Method

Abstract This paper describes a methodology to assess the uncertainty in seismic hazard estimates at particular sites. A variant of the bootstrap statistical method is used to combine the uncertainty due to earthquake catalog incompleteness, earthquake magnitude, and recurrence and attenuation models used. The uncertainty measure is provided in the form of a confidence interval. Comparisons of this method applied to various sites in California with previous studies are used to confirm the validity of the method.

scholarly journals The Cost of Capital for Investment in the Warsaw Stock Exchange Indexes – Versus Djia

2021 ◽  
Vol 21 (1) ◽  
pp. 122-143
Author(s):  
Stanisław Urbański
Keyword(s):  
Confidence Interval ◽  
Cost Of Capital ◽  
Stock Exchange ◽  
Bootstrap Method ◽  
Market Returns ◽  
Investment Projects ◽  
Warsaw Stock Exchange ◽  
The Cost ◽  
Stock Indexes ◽  
The Bootstrap Method

Abstract Research background and purpose: The CAPM, Fama-French and modified Fama-French models were used to estimate the cost of the capital of the DJIA and selected Polish stock indexes were used. The estimated cost of capital was the cost of the portfolio of corporate investment projects estimated by market returns. Research methodology: The model tests were run on 276 monthly returns of stocks listed on the markets in the years 1995–2019. The bootstrap method to estimate the confidence interval of the cost of capital was used. Results: The highest and positive cost of capital median was found for the DJIA index, about 0.85% monthly, and for the WIG20 and WIGDIV indexes, about 0.25% monthly. The cost of capital median for the mWIG80, WIGBANK and WIGCHEMIA indexes were found to be negative. This was due to large errors in the estimated cost of capital. Novelty: Minor errors in the estimation of the cost of capital of index DJIA may result from a more rational policy for the implementation of investment projects by companies included in the index.

scholarly journals A homogeneous earthquake catalogue for Turkey

2021 ◽  
Vol 21 (7) ◽  
pp. 2059-2073
Author(s):  
Onur Tan
Keyword(s):  
Seismic Hazard ◽  
Bootstrap Method ◽  
Regression Method ◽  
Earthquake Catalogue ◽  
The Other ◽  
Magnitude Of Completeness ◽  
Earthquake Parameters ◽  
Orthogonal Regression ◽  
International Seismological Centre ◽  
The Bootstrap Method

Abstract. A new homogenized earthquake catalogue for Turkey is compiled for the period 1900–2018. The earthquake parameters are obtained from the Bulletin of International Seismological Centre that was fully updated in 2020. New conversion equations between moment magnitude and the other scales (md, ML, mb, Ms, and M) are determined using the general orthogonal regression method to build up a homogeneous catalogue, which is the essential database for seismic hazard studies. The 95 % confidence intervals are estimated using the bootstrap method with 1000 samples. The equivalent moment magnitudes (Mw*) for the entire catalogue are calculated using the magnitude relations to homogenize the catalogue. The magnitude of completeness is 2.7 Mw*. The final catalogue is not declustered or truncated using a threshold magnitude in order to be a widely usable catalogue. It contains not only Mw* but also the average and median of the observed magnitudes for each event. Contrary to the limited earthquake parameters in the previous catalogues for Turkey, the 45 parameters of ∼378 000 events are presented in this study.

scholarly journals Insights in Hypothesis Testing and Making Decisions in Biomedical Research

2016 ◽  
Vol 10 (1) ◽  
pp. 196-200 ◽  
Author(s):  
Varin Sacha ◽  
Demosthenes B. Panagiotakos
Keyword(s):  
Confidence Interval ◽  
Hypothesis Testing ◽  
Confidence Intervals ◽  
Biomedical Research ◽  
Bootstrap Method ◽  
Resampling Methods ◽  
Effect Measure ◽  
Social Fields ◽  
The Bootstrap Method

It is a fact that p values are commonly used for inference in biomedical and other social fields of research. Unfortunately, the role of p value is very often misused and misinterpreted; that is why it has been recommended the use of resampling methods, like the bootstrap method, to calculate the confidence interval, which provides more robust results for inference than does p value. In this review a discussion is made about the use of p values through hypothesis testing and its alternatives using resampling methods to develop confidence intervals of the tested statistic or effect measure.

scholarly journals Estimate of the rate of unreported COVID-19 cases during the first outbreak in Rio de Janeiro

2021 ◽  
Author(s):  
Maria Soledad ARONNA ◽  
Roberto Guglielmi ◽  
Lucas Machado Moschen
Keyword(s):  
Confidence Interval ◽  
Health System ◽  
Rio De Janeiro ◽  
Least Squares Method ◽  
Weighted Least Squares ◽  
Bootstrap Method ◽  
Parameters Estimation ◽  
B Splines ◽  
Weighted Least Squares Method ◽  
The Bootstrap Method

In this work we fit an epidemiological model SEIAQR (Susceptible - Exposed - Infectious - Asymptomatic - Quarantined - Removed) to the data of the first COVID-19 outbreak in Rio de Janeiro, Brazil. Particular emphasis is given to the unreported rate, that is, the proportion of infected individuals that is not detected by the health system. The evaluation of the parameters of the model is based on a combination of error-weighted least squares method and appropriate B-splines. The structural and practical identifiability is analyzed to support the feasibility and robustness of the parameters' estimation. We use the bootstrap method to quantify the uncertainty of the estimates. For the outbreak of March-July 2020 in Rio de Janeiro, we estimate about 90% of unreported cases, with a 95% confidence interval (85%, 93%).

The bootstrap method as a test for non-centrosymmetricity – Application to tazheranite (Zr,Ca,Ti)O2

1999 ◽  
Vol 214 (7) ◽  
Author(s):  
M. Prencipe ◽  
G. Ferraris ◽  
S. V. Soboleva
Keyword(s):  
Single Crystal ◽  
Statistical Method ◽  
Diffraction Data ◽  
Bootstrap Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Bootstrap Method

AbstractThe bootstrap statistical method is applied to the analysis of single-crystal X-ray diffraction data of tazheranite [(Zr,Ca,Ti)O

The 2018 national seismic hazard assessment of Australia: Quantifying hazard changes and model uncertainties

2020 ◽  
Vol 36 (1_suppl) ◽  
pp. 5-43 ◽  
Author(s):  
Trevor I Allen ◽  
Jonathan D Griffin ◽  
Mark Leonard ◽  
Dan J Clark ◽  
Hadi Ghasemi
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Earthquake Catalog ◽  
Motion Models ◽  
Ground Motion Attenuation ◽  
Attenuation Models ◽  
Instrumental Period ◽  
Ground Motion Models

Seismic hazard assessments in stable continental regions such as Australia face considerable challenges compared with active tectonic regions. Long earthquake recurrence intervals relative to historical records make forecasting the magnitude, rates, and locations of future earthquakes difficult. Similarly, there are few recordings of strong ground motions from moderate-to-large earthquakes to inform development and selection of appropriate ground-motion models (GMMs). Through thorough treatment of these epistemic uncertainties, combined with major improvements to the earthquake catalog, a 2018 National Seismic Hazard Assessment (NSHA18) of Australia has been undertaken. The resulting hazard levels at the 10% in 50-year probability of exceedance level are in general significantly lower than previous assessments, including hazard factors used in the Australian earthquake loading standard ( AS 1170.4–2007 (R2018)), demonstrating our evolving understanding of seismic hazard in Australia. The key reasons for the decrease in seismic hazard factors are adjustments to catalog magnitudes for earthquakes in the early instrumental period, and the use of modern ground-motion attenuation models. This article summarizes the development of the NSHA18 explores uncertainties associated with the hazard model, and identifies the dominant factors driving the resulting changes in hazard compared with previous assessments.

scholarly journals Uncertainty and the ranking of economics journals

2020 ◽  
Vol 125 (3) ◽  
pp. 2545-2560
Author(s):  
Johan Lyhagen ◽  
Per Ahlgren
Keyword(s):  
Invariant Measure ◽  
Confidence Intervals ◽  
Bootstrap Method ◽  
Point Of View ◽  
Uncertainty Measure ◽  
Invariant Method ◽  
Bootstrap Approach ◽  
Economics Journals ◽  
High Degree ◽  
The Bootstrap Method

AbstractJournal rankings often show significant changes compared to previous rankings. This gives rise to the question of how well estimated the rank of a journal is. In this contribution, we consider uncertainty in a ranking of economics journals. We use the invariant method of Pinski and Narin to rank the journals. We propose an uncertainty measure, which is based on a bootstrap approach. The measure is the average absolute change in rank, which we see as a reasonable uncertainty measure regarding rankings. We further calculate, based on the bootstrap method, 95% confidence interval for the observed values of the invariant method. We show that ranks of the highest, as well as the lowest, ranked journals are well estimated, while there is a high degree of uncertainty regarding the rank of many mid-ranked journals. The distribution of the underlying measure is useful for identifying groups of journals that are more or less of the same quality (from the point of view of the invariant measure). The journal with the highest observed value of the invariant measure, Journal of Political Economy, has the best performance and constitutes a singleton, whereas Quarterly Journal of Economics and Econometrica form the next group (there is a slight overlap between the two with respect to confidence intervals). The journals ranked between about 190–230 form another group in which there are no major quality differences between the journals, as the confidence intervals are overlapping.

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