The existence of software faults in safety-critical systems is not tolerable. The goals of software reliability assessment are estimating the failure probability of the program, θ, and gaining statistical confidence that θ is realistic. The paper presents practical problems and challenges encountered in an ongoing effort to assess and quantify software reliability of NASA’s Day-of-Launch I-Load...

Task allocation and load balancing are critical in faulttolerant robotic team design. This paper deals with the problems of allocating and reallocating tasks to multiple robots in a fault-tolerant manner. Using a tree structure to store global information about active robots and unfinished sub-tasks, each robot can reallocate itself to tasks independently when robot failure occurs in the team. ...

Load-sharing systems have several practical applications. In load-sharing systems, the event of a component failure will result in a higher load, therefore inducing a higher failure rate, in each of the surviving components. This introduces failure dependency among the load-sharing components, which in turn increases the complexity in analyzing these systems. In this paper, we provide a closed-...

Hypertrophy is a critical event in the onset of failure in chronically overloaded hearts. Focal adhesion kinase (FAK) has attracted particular attention as a mediator of hypertrophy induced by increased load. Here, we demonstrate increased expression and phosphorylation of FAK in the hypertrophic left ventricles (LVs) of aortic-banded mice. We used an RNA interference strategy to examine whethe...

During the design stage, realistic life time predictions for components help to reduce test cycles and allow for an optimization with respect to both production and repair costs (see e.g. Schuëller et al. 1996). Accurate predictions of the mean life time and its standard deviation can be obtained from a fracture mechanics approach that takes the uncertainties in the material parameters into acc...

PURPOSE The purpose of this study was to evaluate the influence of different coping thicknesses and veneer ceramic cooling rates on the failure load of zirconia-ceramic crowns. MATERIALS AND METHODS Zirconia copings of two different thicknesses (0.5 mm or 1.5 mm; n=20 each) were fabricated from scanning 40 identical abutment models using a dental computer-aided design and computer-aided manuf...

We give an overview of a complex systems approach to large blackouts of electric power transmission systems caused by cascading failure. Instead of looking at the details of particular blackouts, we study the statistics and dynamics of series of blackouts with approximate global models. Blackout data from several countries suggest that the frequency of large blackouts is governed by a power law...

BACKGROUND AND AIMS Previous studies on grass leaf tensile properties (behaviour during mechanical stress) have focused on agricultural applications such as resistance to trampling and palatability; no investigations have directly addressed mechanical properties during water stress, and hence these are the subject of this study. METHODS Critical (lethal) relative water contents were determine...