Results 31 to 40 of about 9,971 (251)

A Mathematical Model for the Growth Dynamics of Demand in the Fashion Industry within the Era of the COVID-19 Pandemic

International Journal of Mathematics and Mathematical Sciences, 2022
The outbreak of COVID-19 infection and its effects have not spared any economy on the globe. The fourth variant has just announced its appearance with its high death toll and impact on economic activities. The basic reproductive number R0, which measures
John Awuah Addor, Anthony Joe Turkson, Douglas Yenwon Kparib   +2 more
doaj   +1 more source

The concept of comonotonicity in actuarial science and finance: theory [PDF]

Insurance: Mathematics and Economics, 2002
In an insurance context, one is often interested in the distribution function of a sum of random variables. Such a sum appears when considering the aggregate claims of an insurance portfolio over a certain reference period. It also appears when considering discounted payments related to a single policy or a portfolio at different future points in time.
Dhaene, J.L.M., Denuit, M., Goovaerts, M.J., Kaas, R., Vynke, D.   +4 more
openaire   +5 more sources

A Mixture of Clayton, Gumbel, and Frank Copulas: A Complete Dependence Model

Journal of Probability and Statistics, 2022
Knowledge of the dependence between random variables is necessary in the area of risk assessment and evaluation. Some of the existing Archimedean copulas, namely the Clayton and the Gumbel copulas, allow for higher correlations on the extreme left and ...
M. A. Boateng, A. Y. Omari-Sasu, R. K. Avuglah, N. K. Frempong   +3 more
doaj   +1 more source

Conditional Survival for Pancreas Graft and Its Associated Factors After Pancreas Transplantation

Annals of Gastroenterological Surgery, EarlyView.
This study investigates conditional survival (CS) for pancreas grafts in recipients of pancreas transplantation (PTx) in Japan, using data from 526 cases. Findings reveal that CS increases over time post‐transplant, offering a more optimistic long‐term prognosis than traditional actuarial survival. While donor sex and PTx procedure type influence early
Yoshito Tomimaru, Toshinori Ito, Tetsuhisa Kitamura, Takashi Kenmochi, Yuichiro Doki, Hidetoshi Eguchi   +5 more
wiley   +1 more source

Associations of body mass index and waist circumference with incidence of overall and of 27 site‐specific cancers: a population‐based retrospective cohort study

Cancer Communications, EarlyView.
Abstract Background Overweight and obesity are known risk factors for cancer. The aim of this study was to investigate associations of body mass index (BMI) and waist circumference (WC) with incidence of 27 site‐specific cancers stratified by sex and menopausal status accounting for non‐linearity.
Seonghye Kim, Bongseong Kim, Kyu‐won Jung, Ga Eun Nam, Wonyoung Jung, Junhee Park, Kyung‐Do Han, Dong Wook Shin   +7 more
wiley   +1 more source

Noisy matrix completion for longitudinal data with subject‐ and time‐specific covariates

Canadian Journal of Statistics, EarlyView.
Abstract In this article, we consider the imputation of missing responses in a longitudinal dataset via matrix completion. We propose a fixed‐effect, longitudinal, low‐rank model that incorporates both subject‐specific and time‐specific covariates. To solve the optimization problem, a two‐step optimization algorithm is proposed, which provides good ...
Zhaohan Sun, Yeying Zhu, Joel A. Dubin
wiley   +1 more source

Bayesian Growth Curve Modelling of Student Academic Trajectories: The Impact of Individual-Level Characteristics and Implications for Education Policy

Applied Sciences
This study examined the factors influencing student academic performance in the Bachelor of Science (BSc) Actuarial Science programme, focusing on Grade 12 mathematics marks, admission point (AP) scores, socioeconomic background, and progression rates ...
Moeketsi Mosia, Felix O. Egara, Fadip Nannim, Moses Basitere   +3 more
doaj   +1 more source

Efficient and model‐agnostic parameter estimation under privacy‐preserving post‐randomization data

Canadian Journal of Statistics, EarlyView.
Abstract Balancing data privacy with public access is critical for sensitive datasets. However, even after de‐identification, the data are still vulnerable to, for example, inference attacks (by matching some keywords with external datasets). Statistical disclosure control (SDC) methods offer additional protection, and the post‐randomization method ...
Qinglong Tian, Jiwei Zhao
wiley   +1 more source

Predicting rare events using training data from stratified sampling designs, with application to human‐caused wildfire prediction

Canadian Journal of Statistics, EarlyView.
Abstract Response‐based sampling is often used in modelling rare events from large, imbalanced data for efficiency. When modelling the event with logistic regression, the sampling design may be adjusted for using sampling weights or an offset. We propose a stratified sampling design for modelling rare events with large data which improves on previous ...
Johanna de Haan‐Ward, Douglas G. Woolford, Simon J. Bonner   +2 more
wiley   +1 more source

Restricted Tweedie stochastic block models

Canadian Journal of Statistics, EarlyView.
Abstract The stochastic block model (SBM) is a widely used framework for community detection in networks, where the network structure is typically represented by an adjacency matrix. However, conventional SBMs are not directly applicable to an adjacency matrix that consists of nonnegative zero‐inflated continuous edge weights.
Jie Jian, Mu Zhu, Peijun Sang
wiley   +1 more source