With increasing global reliance on the Internet as a medium to transmit information comes an increased risk of cyber-attack. Social networking sites are the most popular tools in internet for social interaction between the people. Online social networks (OSNs) have rapidly become a prominent and widely used service, offering a wealth of personal and sensitive information with significant securi...

Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of precipitation formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, w...

It is generally believed that the magnetic free energy accumulated in the corona serves as a main energy source for solar explosions such as coronal mass ejections (CMEs). In the framework of the flux rope catastrophe model for CMEs, the energy may be abruptly released either by an ideal magnetohydrodynamic (MHD) catastrophe, which belongs to a global magnetic topological instability of the sys...

We consider the production of a ``fast flux'' hypothetical millicharged particles (mCPs) in interstellar medium. two possible sources induced by cosmic rays: (a) $pp\ensuremath{\rightarrow}(\mathrm{meson})\ensuremath{\rightarrow}\phantom{\rule{0ex}{0ex}}(\mathrm{mCP})$, which adds to atmospheric mCPs, and (b) cosmic-ray upscattering on component dark matter. notice that galactic magnetic fields...

We model how the mid-IR colors of young stellar objects (YSOs) vary with stellar temperature. The spectral energy distribution (SED) of each object has contributions from the thermal emission of circumstellar dust, from direct stellar photospheric emission, and from scattered stellar emission. We first isolate the effects of stellar contributions (direct + scattered) to the SED using homologous...

We present the broad band, radio to X-ray, properties of a large sample of mostly previously optically unidentified radio-loud X-ray sources from the correlation of a ROSAT All-Sky Survey source list with the 5 GHz Green Bank Survey of the northern sky (RGB sample) which is one of the largest well-defined flux-limited surveys of AGN ever obtained. Further, the RGB pushes 1-2 orders of magnitude...

-The size distribution of pelagic producers and the size and trophic position of consumers determine the composition and magnitude of sinking fluxes from the surface communities in a simple model of oceanic food webs. Picoplankton, the dominant producers in the model, contribute little to the sinking material, due primarily to the large number of trophic steps between picoplankton and the consu...

The nutrient cycles of coastal upwelling zones are studied with simple mass balance models of Ekman transport, longshore transport, surface productivity, and dissolved phosphorous. The models are constrained with data from the Peru, northwest Africa, and Oregon upwelling systems. The onshore-offshore mass balance model agrees with published Ekman transport, surface productivity, and nutrient da...

The development of a preferred crystallographic orientation in the plane of growth, an in-plane texture, is addressed in a model that incorporates anisotropic growth rates of a material and self-shadowing. Most crystalline materials exhibit fast growth along certain crystallographic directions and slow growth along others. This crystallographic growth anisotropy, which may be due to differences...

The composite method of the flux observer and reduced order speed observer and its design procedure for a nonlinear dynamic system is presented. The traditional approach with flux and speed observer and derive six order nonlinear model that describes motor model in field oriented coordinates. The model takes into the error in flux estimation. For flux regulation traditional PI controllers are u...