3,321 research outputs found

    Fractal-cluster theory and thermodynamic principles of the control and analysis for the self-organizing systems

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    The theory of resource distribution in self-organizing systems on the basis of the fractal-cluster method has been presented. This theory consists of two parts: determined and probable. The first part includes the static and dynamic criteria, the fractal-cluster dynamic equations which are based on the fractal-cluster correlations and Fibonacci's range characteristics. The second part of the one includes the foundations of the probable characteristics of the fractal-cluster system. This part includes the dynamic equations of the probable evolution of these systems. By using the numerical researches of these equations for the stationary case the random state field of the one in the phase space of the DD, HH, FF criteria have been obtained. For the socio-economical and biological systems this theory has been tested.Comment: 37 pages, 20 figures, 4 table

    Partitioning de Bruijn Graphs into Fixed-Length Cycles for Robot Identification and Tracking

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    We propose a new camera-based method of robot identification, tracking and orientation estimation. The system utilises coloured lights mounted in a circle around each robot to create unique colour sequences that are observed by a camera. The number of robots that can be uniquely identified is limited by the number of colours available, qq, the number of lights on each robot, kk, and the number of consecutive lights the camera can see, \ell. For a given set of parameters, we would like to maximise the number of robots that we can use. We model this as a combinatorial problem and show that it is equivalent to finding the maximum number of disjoint kk-cycles in the de Bruijn graph dB(q,)\text{dB}(q,\ell). We provide several existence results that give the maximum number of cycles in dB(q,)\text{dB}(q,\ell) in various cases. For example, we give an optimal solution when k=q1k=q^{\ell-1}. Another construction yields many cycles in larger de Bruijn graphs using cycles from smaller de Bruijn graphs: if dB(q,)\text{dB}(q,\ell) can be partitioned into kk-cycles, then dB(q,)\text{dB}(q,\ell) can be partitioned into tktk-cycles for any divisor tt of kk. The methods used are based on finite field algebra and the combinatorics of words.Comment: 16 pages, 4 figures. Accepted for publication in Discrete Applied Mathematic

    Multicanonical Study of Coarse-Grained Off-Lattice Models for Folding Heteropolymers

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    We have performed multicanonical simulations of hydrophobic-hydrophilic heteropolymers with two simple effective, coarse-grained off-lattice models to study the influence of specific interactions in the models on conformational transitions of selected sequences with 20 monomers. Another aspect of the investigation was the comparison with the purely hydrophobic homopolymer and the study of general conformational properties induced by the "disorder" in the sequence of a heteropolymer. Furthermore, we applied an optimization algorithm to sequences with up to 55 monomers and compared the global-energy minimum found with lowest-energy states identified within the multicanonical simulation. This was used to find out how reliable the multicanonical method samples the free-energy landscape, in particular for low temperatures.Comment: 11 pages, RevTeX, 10 Postscript figures, Author Information under http://www.physik.uni-leipzig.de/index.php?id=2

    Fisher information approach to non-equilibrium phase transitions in quantum XXZ spin chain with boundary noise

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    We investigated quantum critical behaviours in the non-equilibrium steady state of a XXZXXZ spin chain with boundary Markovian noise using the Fisher information. The latter represents the distance between two infinitesimally close states, and its superextensive size scaling witnesses a critical behaviour due to a phase transition, since all the interaction terms are extensive. Perturbatively in the noise strength, we found superextensive Fisher information at anisotropy Δ1|\Delta|\leqslant1 and irrational arccosΔπ\frac{\arccos\Delta}{\pi} irrespective of the order of two non-commuting limits, i.e. the thermodynamic limit and the limit of sending arccosΔπ\frac{\arccos\Delta}{\pi} to an irrational number via a sequence of rational approximants. From this result we argue the existence of a non-equilibrium quantum phase transition with a critical phase Δ1|\Delta|\leqslant1. From the non-superextensivity of the Fisher information of reduced states, we infer that this non-equilibrium quantum phase transition does not have local order parameters but has non-local ones, at least at Δ=1|\Delta|=1. In the non-perturbative regime for the noise strength, we numerically computed the reduced Fisher information which lower bounds the full state Fisher information, and is superextensive only at Δ=1|\Delta|=1. Form the latter result, we derived local order parameters at Δ=1|\Delta|=1 in the non-perturbative case. The existence of critical behaviour witnessed by the Fisher information in the phase Δ<1|\Delta|<1 is still an open problem. The Fisher information also represents the best sensitivity for any estimation of the control parameter, in our case the anisotropy Δ\Delta, and its superextensivity implies enhanced estimation precision which is also highly robust in the presence of a critical phase

    Knowledge-generating Efficiency in Innovation Systems: The relation between structural and temporal effects

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    Using time series of US patents per million inhabitants, knowledge-generating cycles can be distinguished. These cycles partly coincide with Kondratieff long waves. The changes in the slopes between them indicate discontinuities in the knowledge-generating paradigms. The knowledge-generating paradigms can be modeled in terms of interacting dimensions (for example, in university-industry-government relations) that set limits to the maximal efficiency of innovation systems. The maximum values of the parameters in the model are of the same order as the regression coefficients of the empirical waves. The mechanism of the increase in the dimensionality is specified as self-organization which leads to the breaking of existing relations into the more diversified structure of a fractal-like network. This breaking can be modeled in analogy to 2D and 3D (Koch) snowflakes. The boost of knowledge generation leads to newly emerging technologies that can be expected to be more diversified and show shorter life cycles than before. Time spans of the knowledge-generating cycles can also be analyzed in terms of Fibonacci numbers. This perspective allows for forecasting expected dates of future possible paradigm changes. In terms of policy implications, this suggests a shift in focus from the manufacturing technologies to developing new organizational technologies and formats of human interaction

    Practical implementation of mutually unbiased bases using quantum circuits

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    The number of measurements necessary to perform the quantum state reconstruction of a system of qubits grows exponentially with the number of constituents, creating a major obstacle for the design of scalable tomographic schemes. We work out a simple and efficient method based on cyclic generation of mutually unbiased bases. The basic generator requires only Hadamard and controlled-phase gates, which are available in most practical realizations of these systems. We show how complete sets of mutually unbiased bases with different entanglement structures can be realized for three and four qubits. We also analyze the quantum circuits implementing the various entanglement classes.Comment: 5 pages, 2 color figures. Comments welcome
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