Mortality Estimation: Biased Results from Unbiased Ages

Estimates of mortality rates from age distributions are biased by imprecision in age estimation, even if age estimates are unbiased. I have derived a method for predicting the magnitude of this bias from information on the precision of age determination. Monte Carlo simulations show that bias can be accurately predicted. The commonly used Chapman–Robson mortality estimator is shown to be robust to imprecision in age determination if all age-classes are included. Errors are likely, however, if one or more age-classes are excluded or if other mortality estimators are used. Biases can be corrected if the distribution of age-estimation errors is known.

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Improved estimation is a prerequisite for successful terminal guidance

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1243/095441005x9058 ◽

2005 ◽

Vol 219 (2) ◽

pp. 145-156 ◽

Cited By ~ 10

Author(s):

J Shinar ◽

V Turetsky

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Estimation Errors ◽

New Approach ◽

Target Acceleration ◽

The Future ◽

New Ideas ◽

Estimation System ◽

Terminal Guidance

Successful interception of manoeuvring anti-surface missiles that are expected in the future can be achieved only if the estimation errors against manoeuvring targets can be minimized. The paper raises new ideas for an improved estimation concept by separating the tasks of the estimation system and by explicit use of the time-to-go in the process. The outcome of the new approach is illustrated by results of Monte Carlo simulations in generic interception scenarios. The results indicate that if an eventual ‘jump’ in the commanded target acceleration is detected sufficiently rapidly, small estimation errors and consequently precise guidance can be obtained.

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Age determination in Cape Mountain Zebras Equus Zebra Zebra in the Mountain Zebra National Park

Koedoe ◽

10.4102/koedoe.v25i1.607 ◽

1982 ◽

Vol 25 (1) ◽

Author(s):

B. L Penzhorn

Keyword(s):

Age Estimation ◽

National Park ◽

Age Determination ◽

Tooth Wear ◽

Tooth Eruption ◽

Determination Method ◽

Age Classes

The sizes of foals up to two years old can be used for age estimation in the field. Tooth eruption and replacement, which is similar to Hartmann and plains zebras, can be used for age estimation up to four years. No age classes based on tooth wear could be defined, due to the paucity of material. Infundibula in the incisors are retained to a greater age than in Hartmann or plains zebras. Cementum layer counts offer a reliable age determination method, at least up to 15 years.

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The Effect of Parameter Uncertainties in an Age–Length Relationship upon Estimating the Age Composition of Catches

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-041 ◽

1983 ◽

Vol 40 (3) ◽

pp. 272-280 ◽

Cited By ~ 7

Author(s):

J. Majkowski ◽

J. Hampton

Keyword(s):

Sensitivity Analysis ◽

Monte Carlo ◽

Monte Carlo Simulations ◽

Probability Distributions ◽

Bluefin Tuna ◽

Parameter Uncertainties ◽

Age Classes ◽

Age Composition ◽

Length Relationship ◽

Southern Bluefin Tuna

A simple, but frequently applied, procedure for decomposing fish length frequencies into age-classes is considered. This decomposition consists of converting fish lengths into ages using an age–length relationship. A method for assessing the effect of parameter uncertainties in this relationship upon estimates of the age composition of catches is presented. It is assumed that the parameter uncertainties can be described by probability distributions. Our aim is to determine probability distributions of age composition estimates resulting from these uncertainties. This is done using a stochastic sensitivity analysis technique involving Monte Carlo simulations and/or a first-order theory if such a theory is valid in the case under consideration. The method is illustrated by its application to data from the southern bluefin tuna (Thunnus maccoyii) fishery. It is found that simulated (Monte Carlo) catch estimates for age-classes 3 (fish at age 2–3 yr) to 13 (fish at age 12–13 yr) are normally distributed. The coefficients of variation of these estimates are less than 12%. Simulated catch estimates for age-classes 1, 2, and 14–20 deviate considerably from normality and their ranges bounded by the 2.5 and 97.5 percentiles are extremely wide; they include values different by up to 810% from the best deterministic catch estimates.Key words: catch, age composition, uncertainties, sensitivity analysis, Monte Carlo simulations, southern bluefin tuna

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ASURANSI JIWA ENDOWMENT DENGAN PENGEMBALIAN PREMI MENGGUNAKAN SIMULASI MONTE CARLO

E-Jurnal Matematika ◽

10.24843/mtk.2019.v08.i02.p240 ◽

2019 ◽

Vol 8 (2) ◽

pp. 95

Author(s):

MADE EDI HENDRAWAN ◽

I NYOMAN WIDANA ◽

KETUT JAYANEGARA

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Interest Rates ◽

Life Insurance ◽

Mortality Rates ◽

Numerical Calculations ◽

Gompertz Distribution ◽

Constant Interest

Premium refunds are a sum of the money returned to the insured. The purpose of this study was to compare the premium of endowment life insurance with premium refund on constant interest rates numerical calculations and using Monte Carlo simulations. Gompertz distribution was used to obtain the mortality rates. The results showed that the premiums generated by Monte Carlo simulations for insurance participants issued under 45 years will be more expensive than the ones which were generated by numerical calculations. However, the premiums generated by Monte Carlo simulations for insurance participants issued above 45 years will be cheaper than the ones which were generated by numerical calculations.

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Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164854 ◽

1996 ◽

Vol 54 ◽

pp. 478-479

Author(s):

Matthew T. Johnson ◽

Ian M. Anderson ◽

Jim Bentley ◽

C. Barry Carter

Keyword(s):

Monte Carlo ◽

Quantitative Analysis ◽

Monte Carlo Simulations ◽

Cross Section ◽

Spatial Resolution ◽

Low Voltage ◽

Magnesium Ferrite ◽

X Ray ◽

Interaction Volume ◽

Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

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