In this paper, we describe, analyze and compare techniques for extracting spatial knowledge from a terrain model. Specifically, we investigate techniques for extracting a morphological representation from a terrain model based on an approximation of a Morse-Smale complex. A Morse-Smale complex defines a decomposition of a topographic surface into regions with vertices at the critical points and...

Stellar photometry of nearby irregular galaxies of the Local Group is used to identify and study the young and old stellar populations of these galaxies. An analysis of the spatial distributions of stars of different ages in face-on galaxies shows that the young stellar populations in irregular galaxies are concentrated toward the center, and form local inhomogeneities in star-forming regions, ...

We suggest that the irregular structure in Saturn’s B ring arises from the formation of shear-free ring-particle assemblies of up to ∼ 100 km in radial extent. The characteristic scale of the irregular structure is set by the competition between tidal forces and the yield stress of these assemblies; the required tensile strength of ∼ 10 dyn cm is consistent with the sticking forces observed in ...

The regular and irregular past tense has become a focus for recent debates about the structure of the language processing system, asking whether language functions are subserved by different neural and functional mechanisms or whether all processes can be accommodated within a single unified system. A critical claim of leading single mechanism accounts is that the relationship between an irregu...

in this research, the charged system search (css) and enhanced charged system search (ecss) algorithm are used to obtain the optimum design of irregular grillage systems with different spacing and various boundary conditions. the cross-sectional properties of the beams are selected as the design variables and the weight of structure is used as the objective function. the displacement limitation...

Developments in the field of Structure and Earthquake Engineering and also consequences of earthquakes have been led to develop some continually changes and improvement of seismic regulations around the world. In regards to seismicity of Iran, it is necessary and also possible to review and edit the Seismic Regulations of Iran and compare it with the other countries; so it seems that a comparat...