A multi-dimensional definition of fragility is developed considering multiple variables such as floor acceleration and interstory drifts. The limit states which have uncertainties are defined as random variables in the calculation of fragility. A random description of the limit state has been adopted to calculate fragility and different cases have been considered. A case study of a Hospital loc...

The minimum-time pointwise motion of two manipu-lators grasping the same exible object is examined in this paper. We model the object as a spring with an associated damping factor. The coordinated motion is accomplished through the speciication of the trajectory for the mid-point between the two manipulators. The separate trajectories for each manipulator are not relevant per se, since they onl...

In quantum mechanics the kinetic energy term for a single particle is usually written in the form of the Laplace-Beltrami operator. This operator is a factor ordering of the classical kinetic energy. We investigate other relatively simple factor orderings and show that the only other solution for a conformally flat metric is the conformally invariant Laplace-Beltrami operator. For non-conformal...

The propagation of light in a disordered waveguide system composed of randomly different cores in size is treated as an initial value problem of the coupled mode equations and the average amplitude of light is theoretically derived using the scattering matrix. The damping factor obtained is compared with the numerical results. Both results are in good agreement with each other.

The influence of physical damping on the numerical stability of time integration analysis is an open question since decades ago. In this paper, it is shown that, under specific very general conditions, physical damping can be disregarded when studying the numerical stability. It is also shown that, provided the specific conditions are met, analysis of structural systems involved in extremely hi...

An understanding of natural regeneration processes, and the stand structural features that influence those processes, is vital to attaining goals associated with natural regeneration. This paper discusses natural regeneration concepts and the interactions that occur between shrubs and natural regeneration of ponderosa pine. The interactions observed recently in a series of related seedling recr...

The use of biofertilizers is part an environmentally friendly plant cultivation. In order to analyze the effect soaking seeds with several types on seedling growth and damping off disease in tomatoes, a greenhouse experiment has been carried out using fungicide Propineb as control treatment. used were mixed biofertilizer (BION-UP), Consortium isolates tomato rhizosphere bacteria (CITRB), consor...

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest-...

Seed production, seed dispersal and recruitment are critical processes in population dynamics, because they are almost never completely successful. We recorded the recruitment dynamics for the population of Dipteryx oleifera in a tropical rainforest in eastern Nicaragua (12 degrees 05' N., 83 degrees 55' W.) from March 2002 to August 2006. Seeds and seedlings had highly clumped distributions, w...