scholarly journals Estimation of the population size by using the one-inflated positive Poisson model

2016 ◽  
Vol 66 (2) ◽  
pp. 425-448 ◽  
Author(s):  
Ryan T. Godwin ◽  
Dankmar Böhning
Keyword(s):  
Population Size ◽  
Poisson Model ◽  
The One

A semi-hybrid model for malaria with limited superinfection

1998 ◽  
Vol 30 (04) ◽  
pp. 1027-1057 ◽  
Author(s):  
Philippe Picard
Keyword(s):  
Stochastic Model ◽  
Population Size ◽  
Hybrid Model ◽  
Human Population ◽  
Threshold Level ◽  
The Other ◽  
The Difference ◽  
The One

Modelling malaria with consistency necessitates the introduction of at least two families of interconnected processes. Even in a Markovian context the simplest fully stochastic model is intractable and is usually transformed into a hybrid model, by supposing that these two families are stochastically independent and linked only through two deterministic connections. A model closer to the fully stochastic model is presented here, where one of the two families is subordinated to the other and just a unique deterministic connection is required. For this model a threshold theorem can be proved but the threshold level is not the one obtained in a hybrid model. The difference disappears only when the human population size approaches infinity.

scholarly journals Costs and benefits of using rhythmic rate codes

2021 ◽  
Author(s):  
Erik J. Peterson ◽  
Bradley Voytek
Keyword(s):  
Nervous System ◽  
Population Size ◽  
Synaptic Connection ◽  
Poisson Model ◽  
Neural Oscillations ◽  
Costs And Benefits ◽  
Rate Code ◽  
Firing Rates ◽  
Alternative Approach ◽  
Connection Type

AbstractNeural oscillations are one of the most well-known macroscopic phenomena observed in the nervous system, and the benefits of oscillatory coding have been the topic of frequent analysis. Many of these studies focused on communication between populations which were already oscillating, and sought to understand how synchrony and communication interact. In this paper, take an alternative approach. We focus on measuring the costs, and benefits, of moving to an from an aperiodic code to a rhythmic one. We utilize a Linear-Nonlinear Poisson model, and assume a rate code. We report that no one factor seems to predict the costs, or benefits, of translating into a rhythmic code. Instead the synaptic connection type, strength, population size, and stimulus and oscillation firing rates interact in nonlinear ways. We suggest a number of experiments that might be used to confirm these predictions.Author summaryIt’s good to oscillate, sometimes.

scholarly journals Bayesian over-dispersed Poisson model and the Bornhuetter & Ferguson claims reserving method

2012 ◽  
Vol 6 (2) ◽  
pp. 258-283 ◽  
Author(s):  
Peter D. England ◽  
Richard J. Verrall ◽  
Mario V. Wüthrich
Keyword(s):  
Poisson Model ◽  
The Other ◽  
Prior Distributions ◽  
Prediction Uncertainty ◽  
General Insurance ◽  
Other Hand ◽  
Different Types ◽  
Chain Ladder ◽  
The One ◽  
Classical Chain

AbstractWe consider the Bayesian over-dispersed Poisson (ODP) model for claims reserving in general insurance. We choose two different types of prior distributions for the parameters and then study the different Bayesian predictors. This study leads, on the one hand, to the classical chain ladder predictor and, on the other hand, to Bornhuetter & Ferguson predictors. We highlight (either analytically or numerically) how these predictors are obtained and how their prediction uncertainty can be determined.

scholarly journals INSURANCE RISK WITH VARIABLE NUMBER OF POLICIES

2008 ◽  
Vol 22 (2) ◽  
pp. 213-219
Author(s):  
Ivo Adan ◽  
Vidyadhar Kulkarni
Keyword(s):  
Life Insurance ◽  
Poisson Model ◽  
Variable Number ◽  
Insurance Fund ◽  
Insurance Company ◽  
Insurance Risk ◽  
Constant Rate ◽  
Remarkable Result ◽  
New Policies ◽  
The One

In this article we consider an insurance company selling life insurance policies. New policies are sold at random points in time, and each policy stays active for an exponential amount of time with rate μ, during which the policyholder pays premiums continuously at rate r. When the policy expires, the insurance company pays a claim of random size. The aim is to compute the probability of eventual ruin starting with a given number of policies and a given level of insurance fund. We establish the remarkable result that the ruin probability is identical to the one in the standard compound Poisson model where the insurance fund increases at constant rate r and claims occur according to a Poisson process with rate μ.

scholarly journals Overdispersed-Poisson Model in Claims Reserving: Closed Tool for One-Year Volatility in GLM Framework

Risks ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 139
Author(s):  
Stefano Strascia ◽  
Agostino Tripodi
Keyword(s):  
Generalized Linear Models ◽  
Linear Models ◽  
Poisson Model ◽  
Point Of View ◽  
Approximation Techniques ◽  
The Monte Carlo Method ◽  
Calculation Point ◽  
One Year ◽  
The One ◽  
Bootstrap Methodology

The aim of this paper is to carry out a closed tool to estimate the one-year volatility of the claims reserve, calculated through the generalized linear models (GLM), notably the overdispersed- Poisson model. Up to now, this one-year volatility has been estimated through the well-known bootstrap methodology that demands the use of the Monte Carlo method with a re-reserving technique. Nonetheless, this method is time consuming under the calculation point of view; therefore, approximation techniques are often used in practice, such as an emergence pattern based on the link between the one-year volatility—resulting from the Merz–Wüthrich method—and the ultimate volatility—resulting from the Mack method.

A semi-hybrid model for malaria with limited superinfection

1998 ◽  
Vol 30 (4) ◽  
pp. 1027-1057 ◽  
Author(s):  
Philippe Picard
Keyword(s):  
Stochastic Model ◽  
Population Size ◽  
Hybrid Model ◽  
Human Population ◽  
Threshold Level ◽  
The Other ◽  
The Difference ◽  
The One

Modelling malaria with consistency necessitates the introduction of at least two families of interconnected processes. Even in a Markovian context the simplest fully stochastic model is intractable and is usually transformed into a hybrid model, by supposing that these two families are stochastically independent and linked only through two deterministic connections. A model closer to the fully stochastic model is presented here, where one of the two families is subordinated to the other and just a unique deterministic connection is required. For this model a threshold theorem can be proved but the threshold level is not the one obtained in a hybrid model. The difference disappears only when the human population size approaches infinity.

scholarly journals Linguistic system and sociolinguistic environment as competing factors in linguistic variation: A typological approach

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Kaius Sinnemäki
Keyword(s):  
Second Language ◽  
Population Size ◽  
Word Order ◽  
Relative Effect ◽  
Complex Case ◽  
Linguistic Variation ◽  
Speech Community ◽  
Second Language Speakers ◽  
Generalized Linear Mixed Effects ◽  
The One

AbstractThis paper brings together typological and sociolinguistic approaches to language variation. Its main aim is to evaluate the relative effect of language internal and external factors on the number of cases in the world’s languages. I model word order as a language internal predictor; it is well-known that, for instance, languages with verb-final word order (that is, languages in which both nominal arguments precede the main lexical verb) tend to develop complex case systems more often than languages with SVO word order do. I model population size and the proportion of second language speakers in the speech community as sociolinguistic predictors; these factors have been suggested recently to influence the distribution of the number of cases in the world’s languages. Modelling the data with generalized linear mixed effects modelling suggests an interaction between the number of cases, word order, and the proportion of second language speakers on the one hand, and between the number of cases, word order, and population size, on the other. This kind of complex interactions have not been previously reported in typological research wherefore they call for more complex explanations than previously suggested for cross-linguistic variation.

scholarly journals The “One-fifth Rule” with Rollbacks for Self-Adjustment of the Population Size in the (1 + (λ,λ)) Genetic Algorithm

2020 ◽  
Vol 27 (4) ◽  
pp. 488-508
Author(s):  
Anton Olegovich Bassin ◽  
Maxim Viktorovich Buzdalov ◽  
Anatoly Abramovich Shalyto
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Population Size ◽  
Negative Impact ◽  
The Self ◽  
Adjustment Procedure ◽  
Random Weights ◽  
The One ◽  
Adjustment Of Parameters ◽  
Original Rule

Self-adjustment of parameters can significantly improve the performance of evolutionary algorithms. A notable example is the (1 + (λ,λ)) genetic algorithm, where adaptation of the population size helps to achieve the linear running time on the OneMax problem. However, on problems which interfere with the assumptions behind the self-adjustment procedure, its usage can lead to the performance degradation. In particular, this is the case with the “one-fifth rule” on problems with weak fitness-distance correlation.We propose a modification of the “one-fifth rule” in order to have less negative impact on the performance in the cases where the original rule is destructive. Our modification, while still yielding a provable linear runtime on OneMax, shows better results on linear function with random weights, as well as on random satisfiable MAX-3SAT problems.

scholarly journals Trend and equity of general practitioners’ allocation in China Based on the Data from 2012-2017

2020 ◽  
Author(s):  
Qianqian Yu ◽  
Wenqiang Yin ◽  
Dongmei Huang ◽  
Kui Sun ◽  
Zhongming Chen ◽  
...  
Keyword(s):  
Population Size ◽  
General Practitioners ◽  
Gini Coefficient ◽  
Geographical Area ◽  
Zhejiang Province ◽  
Western Region ◽  
Eastern Region ◽  
Special Administrative Region ◽  
Middle Region ◽  
The One

Abstract Background: The aim of this study is to evaluate the trend and equity of general practitioners allocation at the national level in mainland China including 22 provinces, 5 autonomous regions and 4 municipalities based on the data from 2012-2017, and provide reference for regional health planning and rational allocation of general practitioners. Methods: We treat the data of general practitioners from 22 provinces, 5 autonomous regions and 4 municipalities (except Taiwan, Hong Kong Special Administrative Region and Macao Special Administrative Region) as the research materials. The population and geographical area of each region are obtained from China Statistical Yearbook (2013-2018). The general practitioners' data are from China Health and Family Planning Yearbook (2013-2018). We use the Lorenz curve, Gini coefficient and agglomeration degree to analyze the equity of general practitioners in population and geographical area allocation in China. Results: In 2017, the total number of general practitioners in China was 252,727, and the number of general practitioners per 10,000 residents was 1.82. The number of general practitioners accounted for 7.45% of the total number of practicing (assistant) doctors. From 2012 to 2017, the Gini coefficient for general practitioners based on population fell from 0.31 to 0.24, while the Gini coefficient based on geographical area remained unchanged at 0.73. The agglomeration degree based on population increased from 0.72 to 0.73 in the west region, among of which Tibet, Shaanxi, etc. was about 0.5. And the one in Eastern region dropped from 1.477 to 1.329, while in Zhejiang province, Beijing and Shanghai then were much higher than 1. The one in Middle region rose from 0.646 to 0.802, but in Heilongjiang and Hunan provinces they were lower. The agglomeration degree based on geographical area in western region increased from 0.270 to 0.277, among which Tibet, Qinghai and Xinjiang were lower than 0.1. In eastern region it fell from 1.447 to 1.329, and the ones in Shanghai, Beijing, Tianjin and Zhejiang province are much higher than 10. The degree in middle region increased from 1.149 to 1.423, among which Heilongjiang was lower. Conclusions: The number of general practitioners in China has increased significantly, but the total allocation is still insufficient. China has a fairly fair allocation of general practitioners' resources based on population size, which is improving constantly. However, the equity distribution based on geographical area is poor and does not change much in recent years. The distribution of general practitioners in different regions is uneven and with large regional differences. In western region, there is a shortage of general practitioners in terms of population size and geographical area, while in eastern region, there is an excessive concentration of resources. We propose that concerning departments should establish and improve the incentive mechanism and performance appraisal mechanism of general practitioners to improve the occupational attractiveness. They can use the Internet+ to empower general practitioners’ service capacity and efficiency. The government should increase their input for western region and take some measures to encourage eastern region to support western area. We should strive to develop medical education in western regions to cultivate more better general practitioners and achieve balanced development in different regions.

Number of ghost crab burrows does not correspond to population size

2013 ◽  
Vol 8 (9) ◽  
pp. 843-847 ◽  
Author(s):  
Willian Silva ◽  
Tereza Calado
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Anthropogenic Impacts ◽  
Sandy Beaches ◽  
Ghost Crab ◽  
Ocypode Quadrata ◽  
Ghost Crabs ◽  
The One ◽  
Number Of Individuals

AbstractGhost crabs are distributed worldwide on sandy beaches, and several studies have associated the number of ghost crab burrows with the levels of anthropogenic impacts on the beaches under study. However, our results show that the use of ghost crab Ocypode quadrata burrows to assess levels of anthropogenic impacts on sand beaches may not be accurate, as previously thought, because the number of burrows does not represent an estimate of the population size. In addition, we propose three hypotheses to explain the extremely low number of individuals/number of burrows ratio: the “secret chamber”, the “multiple openings”, and the “one crab, several burrows” hypotheses. We also observed an unusual sex ratio.

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