Depression and fatigue have previously been suggested to share an underlying genetic contribution. The present study aims to investigate and characterize the familiality and genetic relationship between depression and fatigue. The familiality of depression and fatigue was assessed by calculating relative risks, measured by the prevalence ratio, within 643 monozygotic (MZ) and 577 dizygotic (DZ)...

The use of nonparametric approaches and semiparametric approaches for modeling fatigue and performance are analyzed. Nonparametric approaches in the form of stand-alone artificial neural networks and semiparametric (hybrid) approaches that combine neural networks with prior process knowledge are explored and compared with existing parametric approaches based on the two-process model of sleep re...

the object of this work is to present a study of the thermomechanical behavior of the automobile disc brake for the prediction of their resistance to fatigue. then, a study of purely mechanical dry contact between the disc and pads is developed with a good prediction becomes a major stake for the industrialists while modeling the loading and the boundary conditions around the disc.we used the s...

A crack moving dynamically through a sheet of Polymethylmethacrylate at high average velocity is found in reality to propagate in a non-steady, periodic, and perhaps discontinuous fashion. The spatial period of the fracture process in the direction of travel, or banding morphology, is of millimeter size and is consistent both in magnitude and discontinuous nature with a crazing mechanism propos...

Title of Document: IMPROVED PROBABILISTIC LIFE ESTIMATION IN ENGINEERING STRUCTURES: MODELING MULTI-SITE FATIGUE CRACKING Abdallah (Moh’d AR.) (Sh. M.) Al Tamimi, PhD, 2014 Directed By: Minta Martin Professor of Engineering, Mohammad Modarres, Reliability engineering The purpose of this paper is to investigate the effect of fatigue, in the presence of neighboring cracks, and to integrate that i...

Mine workers operate heavy equipment while experiencing varying psychological and physiological impacts caused by fatigue. These vary in scope severity across operators unique mine operations. Previous studies show the impact of fatigue on individuals, raising substantial concerns about safety operation. Unfortunately, data exist to illustrate risks, mechanisms complex pattern contributors are ...

This paper presents a stochastic model of fatigue-induced crack propagation in metallic materials. The crack growth rate predicted by the model is guaranteed to be non-negative. The model structure is built upon the underlying principle of Karhunen±Lo eve expansion and does not require solutions of stochastic di€erential equations in either Wiener integral or Itô integral setting. As such this ...

Step-loading fatigue tests have been conducted on two � -TiAl alloys with differing microstructures following quasi-static indentations intended to simulate assembly-related impact damage to lowpressure turbine blades. Fatigue tests were conducted at 600 �C using computer-controlled servohydrau­ lic loading at a frequency of 20 Hz. Reasonably good agreement was achieved between the fatigue data...

BACKGROUND Human factors involved with visual attention mechanism and fatigue are critical causes of modern aviation accidents. OBJECTIVE To investigate the connection between attention and flight fatigue, a mathematical model of pilot's visual attention allocation was established based on information processing channels. Multi-task condition and current psychophysical state were taken into a...

In this study, a phenomenological tissue damage model has been developed to describe the fatigue-induced stress softening and permanent set of biological tissues. Since damage evolution is an irreversible dissipative process, following thermodynamic principles, an equivalent strain proportional to the strain energy of the material is employed as the damage criterion. The maximum equivalent stra...