Free space optical communication provides a very important method for the satellites orbiting around the earth to communication with each other. In this paper , optical intersatellite link is modelled using optisystem software and then the effect of varying the transmitter power and aperture diameter of transmitter and receiver telescopes is analysed. The results shows that large transmitter po...

A three-dimensional ray tracing model with aiming algorithms for global positioning system (GPS) signal is proposed to make simulations conform to the realistic radio occultation (RO) signal propagation. The two aiming algorithms used in this study ensure the initial and end point ray trajectories are located in the prescribed region. In past studies, the ray tracing techniques applied to the R...

Communication via satellite begins when the satellite is positioned in the desired orbital position. Ground stations can communicate with LEO (Low Earth Orbiting) satellites only when the satellite is in their visibility region. The visibility region is in fact the horizon plane. Because of natural barriers or too high buildings in urban areas, practical horizon plane differs from the ideal one...

Hypertrophic scarring, a common proliferative disorder of dermal fibroblasts, results from an overproduction of fibroblasts and excessive deposition of collagen. Although treatment with surgical excision or steroid hormones can modify the symptoms, numerous treatment-related complications have been described. In view of this, we investigated the therapeutic effects of essential oil (EO) from rh...

Communication via satellite begins when the satellite is positioned in the desired orbital position. Ground stations can communicate with LEO (Low Earth Orbiting) satellites only when the satellite is in their visibility region. The duration of the visibility and so the communication duration varies for each satellite pass at the ground station, specifically for LEO satellites which do move too...

In this paper we present a model to study the end-to-end delay performance of a satellite-ATM network. We describe a satellite-ATM network architecture. The architecture presents a trade-off between the on-board switching/processing features and the complexity of the satellite communication systems. The end-to-end delay of a connection passing through a satellite constellation consists of the t...

| We propose a new framework for the link assignment (i.e., topological design) problem that arises from the use of inter-satellite links (ISL's) in Low-Earth Orbit (LEO) satellite networks. In the proposed framework, we model a LEO satellite network as a Finite State Automaton (FSA) where each state corresponds to an equal-length interval in the system period of the LEO satellite network. This...

Many (mathematical) problems, such as Cantor’s theorem, can be expressed very elegantly in higher-order logic, but lead to an exhaustive and un-intuitive formulation when coded in first-order logic. Thus, despite the difficulty of higher-order automated theorem proving, which has to deal with problems like the undecidability of higher-order unification (HOU) and the need for primitive substitut...

Whether a dwarf spheroidal galaxy is in equilibrium or being tidally disrupted by the Milky Way is an important question for the study of its dark matter content and distribution. This question is investigated using 328 recent observations from the dwarf spheroidal Leo I. For Leo I, tidal disruption is detected, at least for stars sufficiently far from the center, but the effect appears to be q...

four in vitro experiments (exp.) were conducted to evaluate lavender essential oil (leo) effects at 0 (control), 250 (low dose), 500 (medium dose), 750 and 1000 µl per l(high doses) of incubation medium on rumen gas production kinetics (exp.1), ruminal digestibility and fermentation (exp.2), methane production (exp.3) and rumen acidosis (exp.4). the asymptote of gas production (a) increased qua...