scholarly journals Empirical likelihood confidence band for the difference of survival functions under proportional hazards model

2015 ◽  
Vol 107 ◽  
pp. 228-235
Author(s):  
Mai Zhou ◽  
Shihong Zhu
Keyword(s):  
Empirical Likelihood ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Confidence Band ◽  
Survival Functions ◽  
Hazards Model ◽  
The Difference

scholarly journals An Inference-based Prognostic Framework for Health Management of Automotive Systems

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Chaitanya Sankavaram ◽  
Anuradha Kodali ◽  
Krishna Pattipati ◽  
Satnam Singh ◽  
Yilu Zhang ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Failure Time ◽  
Remaining Useful Life ◽  
Survival Functions ◽  
Time Data ◽  
Automotive Systems ◽  
Multiple Fault Diagnosis ◽  
Hazards Model ◽  
Useful Life

This paper presents a unified data-driven prognostic framework that combines failure time data, static parameter data and dynamic time-series data. The framework employs proportional hazards model and a soft dynamic multiple fault diagnosis algorithm for inferring the degraded state trajectories of components and to estimate their remaining useful life times. The framework takes into account the cross-subsystem fault propagation, a case prevalent in any networked and embedded system. The key idea is to use Cox proportional hazards model to estimate the survival functions of error codes and symptoms (probabilistic test outcomes/prognostic indicators) from failure time data and static parameter data, and use them to infer the survival functions of components via soft dynamic multiple fault diagnosis algorithm. The average remaining useful life and its higher-order central moments (e.g., variance, skewness, kurtosis) can be estimated from these component survival functions. The framework is demonstrated on datasets derived from two automotive systems, namely hybrid electric vehicle regenerative braking system, and an electronic throttle control subsystem simulator. Although the proposed framework is validated on automotive systems, it has the potential to be applicable to a wide variety of systems, ranging from aerospace systems to buildings to power grids.

A Note on Standard Errors for Survival Curves in Discrete-Time Survival Analysis

2005 ◽  
Vol 30 (1) ◽  
pp. 75-92 ◽  
Author(s):  
Rebecca Zwick ◽  
Jeffrey C. Sklar
Keyword(s):  
Logistic Regression ◽  
Discrete Time ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Standard Errors ◽  
Survival Functions ◽  
Hazards Model ◽  
Time Period ◽  
Flexible Form ◽  
Ordinary Logistic Regression

Cox (1972) proposed a discrete-time survival model that is somewhat analogous to the proportional hazards model for continuous time. Efron (1988) showed that this model can be estimated using ordinary logistic regression software, and Singer and Willett (1993) provided a detailed illustration of a particularly flexible form of the model that includes one parameter per time period. This work has been expanded to show how logistic regression output can also be used to estimate the standard errors of the survival functions. This is particularly simple under the model described by Singer and Willett, when there are no predictors other than time.

Longevity differences in the tenures of American and foreign Major League Soccer managers

2020 ◽  
Vol 16 (1) ◽  
pp. 17-26
Author(s):  
Zach Gilfix ◽  
James Meyerson ◽  
Vittorio Addona
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Performance Variables ◽  
Professional Soccer ◽  
Hazards Model ◽  
Major League Soccer ◽  
Major League ◽  
The Difference ◽  
Time Dependent Covariates ◽  
English Premier League

AbstractWe examine correlates of tenure length for professional soccer managers. Using 521 managers from Major League Soccer (MLS), Spain’s La Liga, and the English Premier League (EPL) whose tenures occurred between 2000 and 2015, we assess the association between both performance-related and non-performance variables, and manager duration. Performance variables include measures of a team’s ranking (or position) and relegation/promotion indicators. Non-performance variables include manager nationality and age, the timing of a manager’s hire, and the team’s wage bill. We employ survival analytic methods, including Cox’s proportional hazards model, to explore the effects of fixed and time-dependent covariates on coach tenure length. We find that La Liga managers have shorter survival, as do managers who were older when they were hired. Furthermore, finishing with a better ranking and, more importantly, improving on previous team performance yields longer survival. Most strikingly, however, we find a significant disparity in the comparison of domestic and foreign managers within a league. While the difference in longevity between domestic and foreign managers in La Liga and the EPL was minimal, American managers in MLS survived significantly longer than their foreign peers.

HRA Model for Hypercholesterolemia Based on a Longitudinal Health Database

1998 ◽  
Vol 37 (02) ◽  
pp. 130-133
Author(s):  
T. Kishimoto ◽  
Y. Iida ◽  
K. Yoshida ◽  
M. Miyakawa ◽  
H. Sugimori ◽  
...  
Keyword(s):  
Total Cholesterol ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Model Analysis ◽  
Serum Total Cholesterol ◽  
Hazards Model ◽  
The Mean ◽  
Health Database ◽  
Observation Period

AbstractTo evaluate the risk factors for hypercholesterolemia, we examined 4,371 subjects (3,207 males and 1,164 females) who received medical checkups more than twice at an AMHTS in Tokyo during the period from 1976 through 1991; and whose serum total cholesterol was under 250 mg/dl. The mean follow-up duration was 6.6 years. A self-registering questionnaire was administered at the time of the health checkup. The endpoint of this study was the onset of hypercholesterolemia when the level of serum total cholesterol was 250 mg/dl and over. We compared two prognosis groups (normal and hypercholesterol) in terms of age, examination findings and lifestyle. After assessing each variable, we employed Cox's proportional hazards model analysis to determine the factors related to the occurrence of hypercholesterolemia. According to proportional hazards model analysis, total cholesterol, triglyceride and smoking at the beginning, and hypertension during the observation period were selected in males; and total cholesterol at the beginning and age were selected in females to determine the factors related to the occurrence of hypercholesterolemia.

Correlates of Child Mortality in Pakistan: A Hazards Model Analysis

1999 ◽  
Vol 38 (1) ◽  
pp. 85-118 ◽  
Author(s):  
Jennifer Benneti
Keyword(s):  
Child Mortality ◽  
Proportional Hazards ◽  
Contraceptive Use ◽  
Proportional Hazards Model ◽  
Economic Status ◽  
Model Analysis ◽  
Health Seeking ◽  
Large Cities ◽  
Number Of Children ◽  
Hazards Model

This study investigated factors associated with child mortality in an area in Rawalpindi, one of the large cities of Pakistan. Using both demographic and anthropological methods, the research was conducted to specifically examine the processes and mechanisms whereby a link is established between child mortality and its covariates. Controlling for the socio-economic status as a determinant of child mortality, the study population was limited to a lower income stratum living in a homogeneous environment where all households had equal access to health-related and other facilities. Results of the proportional hazards model analysis on 130I index children suggest that non-economic factors like maternal health-seeking behaviour were related to high child mortality. The cultural norm of bearing a large number of children was the most significant correlate. In order of significance, this was followed by contraceptive use, current age of the mother, age at marriage and the hygienic conditions of the household. The study provides strong evidence of familial clustering of mortality by order of the household.

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