arXiv subjects

Sina Dortaj

Publications and source records attributed to Sina Dortaj.

2 recordsLinked to original sources

arXiv2024

Connectivity Aware and Energy Efficient Self-Organizing Distributed IoT Topology Control

Internet of Things has pervaded every area of modern life. From a research and industry standpoint, there has been an increasing demand and desire in recent years to develop Internet of Things networks with distributed structure. Wireless communication under emergency circumstances is one of the important applications that distributed Internet of Things can have. In order for a network to be functional in this scenario, it must be developed without the aid of a pre-established or centralized structure and operated in a self-organized manner to accommodate the communication requirements of the time. Although the design and development of such networks can be highly advantageous, they frequently confront difficulties, the most significant of which is attaining and maintaining effective connectivity to have reliable communications despite the requirement to optimize energy usage. In this study, we present a model for self-organizing topology control for ad hoc-based Internet of Things networks that can address the aforementioned challenges. The model that will be presented employs the notion of the Hamiltonian function in classical mechanics and has two key objectives: regulating the network's topology and dynamics to enhance connectivity to a desirable level while requiring the least amount of energy possible. The results of the simulation indicate that the proposed model satisfactorily fulfills the goals of the problem.

cs.NI↗

arXiv2020

Numerical Simulation and the Universality Class of the KPZ Equation for Curved Substrates

The Kardar-Parisi-Zhang (KPZ) equation for surface growth has been analyzed for over three decades. Some experiments indicated the power law for the interface width, $w(t)\sim t^β$, remains the same as in growth on planar surfaces. Escudero (Phys. Rev. Lett. {\bf 100}, 116101, 2008) argued, however, that for the radial KPZ equations in (1+1)-dimension $w(t)$ should increase as $w(t)\sim [\ln(t)]^{1/2}$ in the long-time limit. Krug (Phys. Rev. Lett. {\bf 102}, 139601, 2009) argued, however, that the dynamics of the interface must remain unchanged with a change in the geometry. Other studies indicated that for radial growth the exponent $β$ should remain the same as that of the planar case, regardless of whether the growth is linear or nonlinear, but that the saturation regime will not be reached anymore. We present the results of extensive numerical simulations in (1+1)-dimensions of the radial KPZ equation, starting from an initial circular substrate. We find that unlike the KPZ equation for flat substrates, the transition from linear to nonlinear universality classes is not sharp. Moreover, in the long-time limit the interface width exhibits logarithmic growth with the time, instead of saturation. We also find that evaporation dominates the growth process when the coefficient of the nonlinear term in the KPZ equation is small, and that the average radius of the interface decreases with time and reaches a minimum but not zero value.

cond-mat.stat-mech↗