This paper studies microgrids where loads are supplied by parallel connected inverters controlled by decentralized active power/voltage frequency and reactive power/voltage magnitude droop control laws. The implementation of droop control laws for sharing of power between inverters has been known to present stability problems particularly for large values of active power/voltage frequency droop...

The rapidly developing theory of complex networks indicates that real networks are not random, but have a highly robust large-scale architecture, governed by strict organizational principles. Here, we focus on the properties of biological networks, discussing their scale-free and hierarchical features. We illustrate the major network characteristics using examples from the metabolic network of ...

Phenomena in a champaign covering diverse areas, from Internet topology to human acquaintance networks, seem to be described by the same statistical framework. It appears that so-called power law distributions are found anywhere that researchers care to look for. The observation has escaped the confines of academia and has been popularized, among others, by a leading scientist in the field [Bar...

In a previous study, we showed that the 1992 men's world record running times in the 100 m to 200 km could be represented accurately by the equation T = cDn, where T is the calculated record time for distance D, and c and n are positive constants. Here, we extend that to cover the years 1925-65 at 10-year intervals and 1970-95 in 5-year intervals for distances of 100 m to 10 km. Values of n for...

Takayasu et al. [1] have revisited the question of stochastic processes with multiplicative noise, which have been studied in several different contexts over the past decades. We focus on the regime, found for a generic set of control parameters, in which stochastic processes with multiplicative noise produce intermittency of a special kind, characterized by a power law probability density dist...

The United States and Iran as former allies turned into adversaries after the Islamic Revolution of 1979. Since then the United States has tried to contain Iran as a state considered to be a threat to the U.S. national security. The U.S. Congress has also acted in line with the administrations’ policies and in some cases directed the administration to take a tougher stance toward Iran. A review...

Exergy analysis is based on combined first and second laws of thermodynamics and is a useful tool to analyze the energy systems in a better and more realistic way than an energy analysis, based on the first law of thermodynamics. Combination of exergy from thermodynamics with conventional concepts from engineering economy which is referred to as thermo-economy (exergo-economy) is a valuable too...