Symbolic framework for linear active circuits based on port equivalence using limit variables

Published versio

Unified Description for Network Information Hiding Methods

Until now hiding methods in network steganography have been described in arbitrary ways, making them difficult to compare. For instance, some publications describe classical channel characteristics, such as robustness and bandwidth, while others describe the embedding of hidden information. We introduce the first unified description of hiding methods in network steganography. Our description method is based on a comprehensive analysis of the existing publications in the domain. When our description method is applied by the research community, future publications will be easier to categorize, compare and extend. Our method can also serve as a basis to evaluate the novelty of hiding methods proposed in the future.Comment: 24 pages, 7 figures, 1 table; currently under revie

Topological fractal networks introduced by mixed degree distribution

Several fundamental properties of real complex networks, such as the small-world effect, the scale-free degree distribution, and recently discovered topological fractal structure, have presented the possibility of a unique growth mechanism and allow for uncovering universal origins of collective behaviors. However, highly clustered scale-free network, with power-law degree distribution, or small-world network models, with exponential degree distribution, are not self-similarity. We investigate networks growth mechanism of the branching-deactivated geographical attachment preference that learned from certain empirical evidence of social behaviors. It yields high clustering and spectrums of degree distribution ranging from algebraic to exponential, average shortest path length ranging from linear to logarithmic. We observe that the present networks fit well with small-world graphs and scale-free networks in both limit cases (exponential and algebraic degree distribution respectively), obviously lacking self-similar property under a length-scale transformation. Interestingly, we find perfect topological fractal structure emerges by a mixture of both algebraic and exponential degree distributions in a wide range of parameter values. The results present a reliable connection among small-world graphs, scale-free networks and topological fractal networks, and promise a natural way to investigate universal origins of collective behaviors.Comment: 14 pages, 6 figure

Renormalization: the observable-state model

The usual mathematical formalism of quantum field theory is non-rigorous because it contains divergences that can only be renormalized by non-rigorous mathematical methods. The purpose of this paper is to present a method of subtraction of this divergences using the formalism of decoherence. This is achieved by replacing the standard renormalization method by a projector on a well defined Hilbert subspace. In this way a list of problems of the standard formalism disappears while the physical results of QFT remains valid. From it own nature, this formalism can be used in non-renormalizable theories.Comment: 23 page

Capital mobility and financial repression in Italy, 1960-1990 : a public finance perspective

After significant headway towards liberalization of capital movements in the early 1960s, European governments resorted massively to capital controls in the turmoil of the demise of the Bretton Woods system. In some countries (Italy among others), what looked like a temporary backlash against incipient financial globalisation caused an escalation of domestic and external controls, leading to a comprehensive and long-lasting regime of financial repression. Why financial repression was so hard to dismantle, in spite of its widely recognized distortionary impact? Why did governments stick so long to sub-optimal policy instruments? By concentrating on the Italian case, this paper argues that a public finance approach may provide an answer to such questions. More specifically, following the literature on the political economy of capital controls and the fiscal implications of financial repression, the paper suggests that policies increasing revenues from implicit taxation may be regarded as an attempt to postpone the structural change in the established fiscal policy regime that capital liberalization necessarily entailed. As capital controls (and financial repression, more generally) substantially contributed to ease the government's budget constraint under conditions of structural deficit and rapidly rising debt, liberalization was expected to exacerbate fiscal problems. The paper illustrates the policy measures deployed to increase seigniorage revenues, grant implicit subsidies to the government and enforce financial protectionism. It also provides for the first time an estimation of the economic relevance of revenues from financial repression, which proved to be of a magnitude comparable to revenues from seigniorage. High revenues from implicit taxation (relative to GDP) can be considered a rough approximation of the cost of financial liberalization and may explain why the process of financial reform was slow and controversial

Distribution of "level velocities" in quasi 1D disordered or chaotic systems with localization

The explicit analytical expression for the distribution function of parametric derivatives of energy levels ("level velocities") with respect to a random change of scattering potential is derived for the chaotic quantum systems belonging to the quasi 1D universality class (quantum kicked rotator, "domino" billiard, disordered wire, etc.).Comment: 11 pages, REVTEX 3.