Inhomogeneous higher-order summary statistics for point processes on linear networks

Statistics and Computing - As a workaround for the lack of transitive transformations on linear network structures, which are required to consider different notions of distributional invariance,...     

Home Environment and Its Relation with Quality of Life of Older People

In this cross-sectional study, we tested the relationship between sociophysical environment, quality of life (QOL), and perceived social support among elderly in Iran. The sample includes 128 participants recruited in the city of Shahrekord, Iran. We measured Evaluation of Older People Living Environment (EVOLVE); Control, Autonomy, Self-realization and Pleasure scale (CASP-19) and Multidimensional Scale of Perceived Social Support (MSPSS) tools respectively, through home-based observation and interview. A significant relationship was found between several domains of home environment, QOL, and perceived social support. The interaction effect of the home environment and gender in relation to QOL and perceived social support was statistically significant. Our results support that the home physical environment may not be considered a strong predictor of QOL among the Iranian elderly.     

On the Estimation of the Density of a Directional Data Stream

Many directional data such as wind directions can be collected extremely easily so that experiments typically yield a huge number of data points that are sequentially collected. To deal with such big data, the traditional nonparametric techniques rapidly require a lot of time to be computed and therefore become useless in practice if real time or online forecasts are expected. In this paper, we propose a recursive kernel density estimator for directional data which (i) can be updated extremely easily when a new set of observations is available and (ii) keeps asymptotically the nice features of the traditional kernel density estimator. Our methodology is based on Robbins–Monro stochastic approximations ideas. We show that our estimator outperforms the traditional techniques in terms of computational time while being extremely competitive in terms of efficiency with respect to its competitors in the sequential context considered here. We obtain expressions for its asymptotic bias and variance together with an almost sure convergence rate and an asymptotic normality result. Our technique is illustrated on a wind dataset collected in Spain. A Monte‐Carlo study confirms the nice properties of our recursive estimator with respect to its non‐recursive counterpart.     

Volunteering in Retirement and Its Impact on Seniors Subjective Quality of Life Through Personal Outlook: A Study of Older Australians

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This study examines the subjective quality of life of globally expanding senior citizens post-retirement, from a...     

The competing risks analysis for parallel and series systems using Type-II progressive censoring

Abstract

Recently, the study of the lifetime of systems in reliability and survival analysis in the presence of several causes of failure (competing risks) has attracted attention in the literature. In this paper, series and parallel systems with exponential lifetime for each item of the system are considered. Several causes of failure independently affect lifetime distributions and observations of failure times of the systems are considered under progressive Type-II censored scheme. For series systems, the maximum likelihood estimates of parameters are computed and confidence intervals for parameters of the model are obtained using Fisher information matrix. For parallel systems, the generalized EM algorithm which uses the Newton-Raphson algorithm inside the EM algorithm is used to compute the maximum likelihood estimates of parameters. Also, the standard errors of the maximum likelihood estimates are computed by using the supplemented EM algorithm. The simulation study confirms the good performance of the introduced approach.     

The Local Power of the CADF and CIPS Panel Unit Root Tests

Very little is known about the local power of second generation panel unit root tests that are robust to cross-section dependence. This article derives the local asymptotic power functions of the cross-section argumented Dickey–Fuller Cross-section Augmented Dickey-Fuller (CADF) and CIPS tests of Pesaran (2007), which are among the most popular tests around.     

Barriers to Remarriage Among Older People: Viewpoints of Widows and Widowers

We conducted this research based on a qualitative approach to describe the opinions of older widows and widowers on remarriage obstacles. Based on purposive sampling and inclusion criteria, we chose 48 participants on maximum diversity of sex, age, education, employment, and socioeconomic status. Two thirds of the participants were female, 40% had spent more than 10 years widowed, and 65% were living with their children. We collected data individually through semistructured, face-to-face interviews. Based on conventional content analyses, 2 independent researchers implemented data analysis manually. Barriers to remarriage were finally categorized into 4 main themes: personal, normative, interactive, and financial factors. Results of this study showed that older people are more concerned about public opinions and social norms surrounding remarriage. As long as these thoughts and norms are not changed, the concept of remarriage among widows and widowers remains a vital taboo and concern.     

Hard evidence and ambiguity aversion

This article shows that if an allocation rule can be implemented with unlimited information certification, then it can also be implemented with limited information certification if the designer can use ambiguous communication mechanisms, and if agents are averse to ambiguity in the sense of maxmin expected utility. The reverse implication is true if there is a single agent and a worst outcome.