By using a magnetosphere-ionosphere (M-I) coupling model of polar cap arcs [Zhu et al., 1993], a systematic model study of the effects of ionospheric background conductivity on the formation of polar cap arcs has been conducted. The variations of the ionospheric background conductivity in the model study cover typical ionospheric onditions, including solar minimum, solar maximum, winter, and su...

In this paper, we generalize a result by Ball, Hill, Landjev and Ward on plane arcs to arcs with multiple points in spaces of arbitrary dimension. This result is further applied to the characterization of some non-Griesmer arcs in the 3-dimensional projective geometry over F4.

We show that doubling, linearly connected metric spaces are quasiarc connected. This gives a new and short proof of a theorem of Tukia.

In this paper, we generalize the so-called Korchmáros—Mazzocca arcs, that is, point sets of size q + t intersecting each line in 0, 2 or points a finite projective plane order q. For ≠ 2, means set is incident with exactly one meeting points. PG(2, pn), change definition above to any integer m and describe all examples when not divisible by p. We also study mod p variants these objects, give un...

We study the strong gravitational lensing properties of galaxy clusters obtained from N-body simulations with standard ΛCDM cosmology. We have used the 32 most massive clusters from a simulation at various redshifts and ray-traced through the clusters to investigate the giant arcs statistics. We have found that ∼ 40 − 50% of the clusters that produce giant arcs give multiple arcs, which agrees ...

This article presents the basic place/transition net structure definition for building various types of Petri nets. The basic net structure fields include places, transitions, and arcs (place-transition, transition-place) which may be supplemented with other fields (e.g., capacity, weight, marking, etc.) as needed. The theorems included in this article are divided into the following categories:...