Frailty models based on Lévy processes

Generalizing the standard frailty models of survival analysis, we propose to model frailty as a weighted Lévy process. Hence, the frailty of an individual is not a fixed quantity, but develops over time. Formulae for the population hazard and survival functions are derived. The power variance function Lévy process is a prominent example. In many cases, notably for compound Poisson processes, quasi-stationary distributions of survivors may arise. Quasi-stationarity implies limiting population hazard rates that are constant, in spite of the continual increase of the individual hazards. A brief discussion is given of the biological relevance of this finding.

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Frailty models power variance function with cure fraction and latent risk factors negative binomial

Communication in Statistics- Theory and Methods ◽

10.1080/03610926.2016.1218029 ◽

2016 ◽

Vol 46 (19) ◽

pp. 9763-9776 ◽

Cited By ~ 4

Author(s):

Vinicius Fernando Calsavara ◽

Agatha Sacramento Rodrigues ◽

Vera Lúcia Damasceno Tomazella ◽

Mário de Castro

Keyword(s):

Risk Factors ◽

Negative Binomial ◽

Variance Function ◽

Frailty Models ◽

Power Variance Function ◽

Cure Fraction ◽

Power Variance

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On the Individual

European Psychologist ◽

10.1027//1016-9040.4.4.205 ◽

1999 ◽

Vol 4 (4) ◽

pp. 205-218 ◽

Cited By ~ 34

Author(s):

David Magnusson

Keyword(s):

School Psychologist ◽

Real Life ◽

Psychological Research ◽

Developmental Research ◽

Future Directions ◽

The 1950S ◽

The Individual ◽

Over Time

A description of two cases from my time as a school psychologist in the middle of the 1950s forms the background to the following question: Has anything important happened since then in psychological research to help us to a better understanding of how and why individuals think, feel, act, and react as they do in real life and how they develop over time? The studies serve as a background for some general propositions about the nature of the phenomena that concerns us in developmental research, for a summary description of the developments in psychological research over the last 40 years as I see them, and for some suggestions about future directions.

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Geographical aspects of the diffusion of passive houses

International Review of Applied Sciences and Engineering ◽

10.1556/irase.4.2013.2.9 ◽

2013 ◽

Vol 4 (2) ◽

pp. 151-156 ◽

Cited By ~ 3

Author(s):

G. Kozma ◽

E. Molnár ◽

K. Czimre ◽

J. Pénzes

Keyword(s):

Energy Consumption ◽

Energy Resources ◽

Substantial Part ◽

Renewable Energy Resources ◽

Passive House ◽

The Earth ◽

Passive Houses ◽

The Individual ◽

Geographical Locations ◽

Over Time

Abstract In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air. The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.

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Personality change and environmental concerns

10.31234/osf.io/jk94r ◽

2020 ◽

Author(s):

Christopher James Hopwood ◽

Ted Schwaba ◽

Wiebke Bleidorn

Keyword(s):

Personality Traits ◽

Personality Change ◽

Environmental Concerns ◽

Big Five Personality ◽

German Population ◽

Individual Level ◽

Sustainable Behavior ◽

Nationally Representative ◽

The Individual ◽

Over Time

Personal concerns about climate change and the environment are a powerful motivator of sustainable behavior. People’s level of concern varies as a function of a variety of social and individual factors. Using data from 58,748 participants from a nationally representative German sample, we tested preregistered hypotheses about factors that impact concerns about the environment over time. We found that environmental concerns increased modestly from 2009-2017 in the German population. However, individuals in middle adulthood tended to be more concerned and showed more consistent increases in concern over time than younger or older people. Consistent with previous research, Big Five personality traits were correlated with environmental concerns. We present novel evidence that increases in concern were related to increases in the personality traits neuroticism and openness to experience. Indeed, changes in openness explained roughly 50% of the variance in changes in environmental concerns. These findings highlight the importance of understanding the individual level factors associated with changes in environmental concerns over time, towards the promotion of more sustainable behavior at the individual level.

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A Modeling of Banks Systemic Risk in a Levy Process Framework

SSRN Electronic Journal ◽

10.2139/ssrn.1773589 ◽

2011 ◽

Author(s):

F. Gideon

Keyword(s):

Systemic Risk ◽

Lévy Process ◽

Levy Process ◽

Process Framework

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A comparative study with bootstrap resampling technique to uncover behavior of unconditional hazards and survival functions for gamma and inverse Gaussian frailty models

Mathematical Sciences ◽

10.1007/s40096-020-00366-1 ◽

2021 ◽

Author(s):

Nihal Ata Tutkun ◽

Pius Marthin

Keyword(s):

Comparative Study ◽

Frailty Models ◽

Bootstrap Resampling ◽

Inverse Gaussian ◽

Survival Functions

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ExpanDrogram: Dynamic Visualization of Big Data Segmentation over Time

Journal of Data and Information Quality ◽

10.1145/3434778 ◽

2021 ◽

Vol 13 (2) ◽

pp. 1-27

Author(s):

A. Khalemsky ◽

R. Gelbard

Keyword(s):

Big Data ◽

Visual Presentation ◽

Trend Detection ◽

Dynamic Visualization ◽

Segmentation Process ◽

Key Points ◽

Wide Range ◽

History Of ◽

The Individual ◽

Over Time

In dynamic and big data environments the visualization of a segmentation process over time often does not enable the user to simultaneously track entire pieces. The key points are sometimes incomparable, and the user is limited to a static visual presentation of a certain point. The proposed visualization concept, called ExpanDrogram, is designed to support dynamic classifiers that run in a big data environment subject to changes in data characteristics. It offers a wide range of features that seek to maximize the customization of a segmentation problem. The main goal of the ExpanDrogram visualization is to improve comprehensiveness by combining both the individual and segment levels, illustrating the dynamics of the segmentation process over time, providing “version control” that enables the user to observe the history of changes, and more. The method is illustrated using different datasets, with which we demonstrate multiple segmentation parameters, as well as multiple display layers, to highlight points such as new trend detection, outlier detection, tracking changes in original segments, and zoom in/out for more/less detail. The datasets vary in size from a small one to one of more than 12 million records.

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