scholarly journals On Joint Life Annuities

1886 ◽  
Vol 1 ◽  
pp. 29-60
Author(s):  
James John M'Lauchlan
Keyword(s):  
Exact Solution ◽  
A Priori ◽  
Adult Life ◽  
Life Tables ◽  
Uncertain Process ◽  
Probability Of Survival ◽  
Life Annuities ◽  
Methods Of Approximation

Recent investigations in the theory of life contingencies have thrown new light on the treatment of problems involving the probability of survival of several lives. For the exact solution of such problems by older methods, there are required complete tables of annuities (or other integral functions) on the number of lives to be dealt with. The time and labour necessary for the computation of tables of annuities on three or more joint lives, for every combination of ages, are so great as to have hitherto effectually prevented their construction; while tables of annuities on all combinations of quinquennial ages, like the joint-life tables given by Price and Milne, or the tables of annuities on three joint lives published by Filipowski in 1850, cannot generally be applied without a troublesome and uncertain process of interpolation. When, therefore, cases involving more than two lives have occurred, it has been usual in dealing with them to employ methods of approximation, leading to more or less error in the final result. Of late years, however, it has been found possible to express, with considerable exactness, the rate of mortality during the greater period of adult life, as a function of the age, by means of an hypothesis having at the same time important a priori considerations in its favour. Corresponding expressions have been deduced, representing the values of annuities on any number of joint lives, and relations have been established which enable us to determine the values of such annuities from tables of moderate extent, with considerable certainty and accuracy.

Efficient Reliability Assessment With the Conditional Probability Method

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Rami Mansour ◽  
Mårten Olsson
Keyword(s):  
Conditional Probability ◽  
Structural Reliability ◽  
A Priori ◽  
Reliability Assessment ◽  
Probability Of Failure ◽  
Assessment Method ◽  
Probability Method ◽  
Probability Of Survival ◽  
Design Variables ◽  
Reliability Method

Reliability assessment is an important procedure in engineering design in which the probability of failure or equivalently the probability of survival is computed based on appropriate design criteria and model behavior. In this paper, a new approximate and efficient reliability assessment method is proposed: the conditional probability method (CPM). Focus is set on computational efficiency and the proposed method is applied to classical load-strength structural reliability problems. The core of the approach is in the computation of the probability of failure starting from the conditional probability of failure given the load. The number of function evaluations to compute the probability of failure is a priori known to be 3n + 2 in CPM, where n is the number of stochastic design variables excluding the strength. The necessary number of function evaluations for the reliability assessment, which may correspond to expensive computations, is therefore substantially lower in CPM than in the existing structural reliability methods such as the widely used first-order reliability method (FORM).

scholarly journals An Iterative Regularization Method to Solve the Cauchy Problem for the Helmholtz Equation

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Hao Cheng ◽  
Ping Zhu ◽  
Jie Gao
Keyword(s):  
Cauchy Problem ◽  
Exact Solution ◽  
Helmholtz Equation ◽  
Error Estimates ◽  
Regularization Method ◽  
A Priori ◽  
A Posteriori ◽  
Iterative Regularization ◽  
Regularization Parameters ◽  
The Cauchy Problem

A regularization method for solving the Cauchy problem of the Helmholtz equation is proposed. Thea priorianda posteriorirules for choosing regularization parameters with corresponding error estimates between the exact solution and its approximation are also given. The numerical example shows the effectiveness of this method.

scholarly journals Persistence of an extracellular systemic infection across metamorphosis in a holometabolous insect

2018 ◽  
Vol 14 (2) ◽  
pp. 20170771 ◽  
Author(s):  
David F. Duneau ◽  
Brian P. Lazzaro
Keyword(s):  
Larval Stage ◽  
Adult Stage ◽  
A Priori ◽  
Adult Life ◽  
Bacterial Pathogen ◽  
Systemic Infection ◽  
Life Cycles ◽  
Life Stages ◽  
Holometabolous Insect ◽  
Complete Metamorphosis

Organisms with complex life cycles can differ markedly in their biology across developmental life stages. Consequently, distinct life stages can represent drastically different environments for parasites. This difference is especially striking with holometabolous insects, which have dramatically different larval and adult life stages, bridged by a complete metamorphosis. There is no a priori guarantee that a parasite infecting the larval stage would be able to persist into the adult stage. In fact, to our knowledge, transstadial transmission of extracellular pathogens has never been documented in a host that undergoes complete metamorphosis. We tested the hypothesis that a bacterial parasite originally sampled from an adult host could infect a larva, then survive through metamorphosis and persist into the adult stage. As a model, we infected the host Drosophila melanogaster with a horizontally transmitted, extracellular bacterial pathogen, Providencia rettgeri . We found that this natural pathogen survived systemic infection of larvae (L3) and successfully persisted into the adult host. We then discuss how it may be adaptive for bacteria to transverse life stages and even minimize virulence at the larval stage in order to benefit from adult dispersal.

scholarly journals Convergence Analysis of a Discontinuous Finite Volume Method for the Signorini Problem

2020 ◽  
Vol 12 (4) ◽  
pp. 49
Author(s):  
Yuping Zeng ◽  
Fen Liang
Keyword(s):  
Exact Solution ◽  
Error Estimate ◽  
Convergence Analysis ◽  
Finite Volume Method ◽  
Finite Volume ◽  
A Priori ◽  
Energy Norm ◽  
Signorini Problem ◽  
A Priori Error Estimate ◽  
Volume Method

We introduce and analyze a discontinuous finite volume method for the Signorini problem. Under suitable regularity assumptions on the exact solution, we derive an optimal a priori error estimate in the energy norm.

MEASURING EARLY LIFE DISPARITY IN INDIA

2015 ◽  
Vol 48 (4) ◽  
pp. 457-471
Author(s):  
Akansha Singh ◽  
Laishram Ladusingh
Keyword(s):  
Early Life ◽  
Adult Life ◽  
Decomposition Analysis ◽  
Life Tables ◽  
Child Life ◽  
Valuable Insight ◽  
Registration System ◽  
Premature Deaths ◽  
Life Years ◽  
The Difference

SummaryEarly life disparity – defined as the average life years lost due to death by the age of 60 years – can be used to assess more systematically the effect of savings from death at a young age. In addition, it can give valuable insight into the consequences of death in the early stages of life. Early life disparity can further be categorized into child life disparity (0–14 years) and adult life disparity (15–60 years). This study estimated early life disparity using complete life tables for the period 1970–1975 to 2006–2010, which were constructed from abridged life tables and death rates provided by the Sample Registration System (SRS) in India. The contribution of premature deaths to the difference in life disparity was estimated using a replacement algorithm. The findings clearly indicated an overall declining trend in early life disparity in India, with a notable reduction in child life disparity, and a deceleration of adult life disparity during the period 1970–1975 to 2006–2010. Interstate variations in early life disparity were seen to converge with time. Decomposition analysis suggested that these variations could be minimized further by averting death during childhood.

A priori prediction of the probability of survival in vehicle crashes using anthropomorphic test devices and human body models

2019 ◽  
Vol 20 (5) ◽  
pp. 544-549 ◽  
Author(s):  
Sebastian Büchner ◽  
Mirko Junge ◽  
Giacomo Marini ◽  
Franz Fürst ◽  
Sylvia Schick ◽  
...  
Keyword(s):  
Human Body ◽  
A Priori ◽  
Vehicle Crashes ◽  
Probability Of Survival ◽  
Human Body Models

First estimates of the probability of survival in a small-bodied, high-elevation frog (Boreal Chorus Frog, Pseudacris maculata), or how historical data can be useful

2016 ◽  
Vol 94 (9) ◽  
pp. 599-606 ◽  
Author(s):  
E. Muths ◽  
R.D. Scherer ◽  
S.M. Amburgey ◽  
T. Matthews ◽  
A.W. Spencer ◽  
...  
Keyword(s):  
Historical Data ◽  
A Priori ◽  
Common Species ◽  
High Elevation ◽  
Color Morph ◽  
Historical Information ◽  
Probability Of Survival ◽  
Pseudacris Maculata ◽  
Recent Climate ◽  
Chorus Frog

In an era of shrinking budgets yet increasing demands for conservation, the value of existing (i.e., historical) data are elevated. Lengthy time series on common, or previously common, species are particularly valuable and may be available only through the use of historical information. We provide first estimates of the probability of survival and longevity (0.67–0.79 and 5–7 years, respectively) for a subalpine population of a small-bodied, ostensibly common amphibian, the Boreal Chorus Frog (Pseudacris maculata (Agassiz, 1850)), using historical data and contemporary, hypothesis-driven information–theoretic analyses. We also test a priori hypotheses about the effects of color morph (as suggested by early reports) and of drought (as suggested by recent climate predictions) on survival. Using robust mark–recapture models, we find some support for early hypotheses regarding the effect of color on survival, but we find no effect of drought. The congruence between early findings and our analyses highlights the usefulness of historical information in providing raw data for contemporary analyses and context for conservation and management decisions.

scholarly journals Regularization of a Cauchy problem for the heat equation

2018 ◽  
Vol 1 (T5) ◽  
pp. 184-192
Author(s):  
Au Van Vo ◽  
Tuan Hoang Nguyen
Keyword(s):  
Cauchy Problem ◽  
Exact Solution ◽  
Heat Equation ◽  
Error Estimates ◽  
A Priori ◽  
Cauchy Data ◽  
Linear Source ◽  
Truncation Method ◽  
Ill Posed ◽  
Regularized Solution

In this paper, we study a Cauchy problem for the heat equation with linear source in the form ut(x,t)= uxx(x,t)+f(x,t), u(L,t)=  φ(t), u(L,t)= Ψ (t), (x,t) ∈ (0,L) ×(0, 2π). This problem is ill-posed in the sense of Hadamard. To regularize the problem, the truncation method is proposed to solve the problem in the presence of noisy Cauchy data φε and Ψε satisfying ‖ φε - φ ‖+‖ Ψε - Ψ ‖ ≤ ε and that fε satisfying ‖ fε(x,. ) - f(x,.) ‖ ≤ ε .  We give some error estimates between the regularized solution and the exact solution under some different a-priori conditions of exact solution.

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