Category Archives: Theory

Game Theory – Correlated Equilibrium

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“In game theory, a correlated equilibrium is a solution concept that is more general than the well known Nash equilibrium. It was first discussed by mathematician Robert Aumann (1974). The idea is that each player chooses his/her action according to his/her observation of the value of the same public signal. A strategy assigns an action to every possible observation a player can make. If no player would want to deviate from the recommended strategy (assuming the others don’t deviate), the distribution is called a correlated equilibrium.” – from Wikipedia

In the following case of study, the concepts of game theory, Nash equilibrium and correlated equilibrium are used to reach the goal.

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Approximation algorithm for partial set cover

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The set cover problem (SCP)  is a classical question in combinatorics, computer science and complexity theory.

Briefly, a set of elements and a set of sets that contains different elements are given. Each set has an associated cost. The goal is cover every elements paying the less cost possible.

The partial set cover is a slightly different problem, in which is required to cover at least a given percentage of items paying the less cost possible. The problem is known to be NP-complete, but using approximation good results can be achieved with ease. In the following we analyze the correctness of a greedy approximation algorithm for partial set cover.

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Petri network

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The attached PDF contains a project done during Capacity Planning exam at University. It analyzes the mechanisms behind Petri Networks and focuses particularly on application within queue networks modeling. I’ve used QPME (Queueing Petri net Modeling Environment) software to analyze a simple system, but it cover all basis to work on a more complex system. Tutorial on QPME’s usage can be found [here]

PDF

SIMULATION FILE

Schumann Resonator

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The Schumann resonances (SR) are a set of spectrum peaks in the extremely low frequency (ELF) portion of the Earth‘s electromagnetic field spectrum. Schumann resonances are global electromagnetic resonances, excited by lightning discharges in the cavity formed by the Earth’s surface and the ionosphere.

(from Wikipedia http://en.wikipedia.org/wiki/Schumann_resonances)

Schumann resonances are claimed to provide equilibrium between people and Earth, since the main frequency (7.83Hz) has a wavelength of 38000Km (about the circumference of the Earth). Most of scientific community argued that a body small like the human one can’t obtain advantages from this frequency. Despite of this, some audiophiles (in which I also agree) says that when in presence of a Schumann resonance the music listening is more relaxed.

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