Complexity and non-separability of classical Liouvillian dynamics

We propose a simple complexity indicator of classical Liouvillian dynamics, namely the separability entropy, which determines the logarithm of an effective number of terms in a Schmidt decomposition of phase space density with respect to an arbitrary fixed product basis. We show that linear growth of separability entropy provides stricter criterion of complexity than Kolmogorov-Sinai entropy, namely it requires that dynamics is exponentially unstable, non-linear and non-markovian.Comment: Revised version, 5 pages (RevTeX), with 6 pdf-figure

The bounds of heavy-tailed return distributions in evolving complex networks

We consider the evolution of scale-free networks according to preferential attachment schemes and show the conditions for which the exponent characterizing the degree distribution is bounded by upper and lower values. Our framework is an agent model, presented in the context of economic networks of trades, which shows the emergence of critical behavior. Starting from a brief discussion about the main features of the evolving network of trades, we show that the logarithmic return distributions have bounded heavy-tails, and the corresponding bounding exponent values can be derived. Finally, we discuss these findings in the context of model risk

Model of mobile agents for sexual interactions networks

We present a novel model to simulate real social networks of complex interactions, based in a granular system of colliding particles (agents). The network is build by keeping track of the collisions and evolves in time with correlations which emerge due to the mobility of the agents. Therefore, statistical features are a consequence only of local collisions among its individual agents. Agent dynamics is realized by an event-driven algorithm of collisions where energy is gained as opposed to granular systems which have dissipation. The model reproduces empirical data from networks of sexual interactions, not previously obtained with other approaches.Comment: 6 pages, 8 figure

Carbon and oxygen in metal-poor halo stars

Carbon and oxygen are key tracers of the Galactic chemical evolution; in particular, a reported upturn in [C/O] towards decreasing [O/H] in metal-poor halo stars could be a signature of nucleosynthesis by massive Population III stars. We reanalyse carbon, oxygen, and iron abundances in thirty-nine metal-poor turn-off stars. For the first time, we take into account three-dimensional (3D) hydrodynamic effects together with departures from local thermodynamic equilibrium (LTE) when determining both the stellar parameters and the elemental abundances, by deriving effective temperatures from 3D non-LTE H$\beta$ profiles, surface gravities from Gaia parallaxes, iron abundances from 3D LTE Feii equivalent widths, and carbon and oxygen abundances from 3D non-LTE Ci and Oi equivalent widths. We find that [C/Fe] stays flat with [Fe/H], whereas [O/Fe] increases linearly up to $0.75$ dex with decreasing [Fe/H] down to $-3.0$ dex. As such [C/O] monotonically decreases towards decreasing [O/H], in contrast to previous findings, mainly by virtue of less severe non-LTE effects for Oi at low [Fe/H] with our improved calculations.Comment: 5 pages, 2 figures; published in A&A Letter

Hong Kong survey of adult oral health 1984

Parallel title in Chinese.published_or_final_versionX AppendicesList of FiguresList of TablesVI.1 Material 115I.3 Purpose of the Present Survey 14VI.2 Methods 116I.2 Dental Services in Hong Kong 13VI.3 Oral Health Related Knowledge, Beliefs, Values, and Behaviour 117I.1 Previous Epidemiologic Studies 7VI.4 Clinical Findings 121V Survey Findings - Clinical Data 72IV Findings - Questionnaire Data 30III Survey Findings - Sample Response 22II Material and Methods 17I Introduction 5IV.4 Denture Wearers 51V.4 Dental Fluorosis 89V.9 Periodontal Treatment Needs 101IV.3 Oral Health Conditions and Problems 50IV.2 Oral Health Care Practices 42IV.1 Oral Health Related Perceptions and Knowledge 30II.13 Data Processing and Analysis 22II.12 The Interviews and Examinations 22II.11 The Survey Site 21List of Figures ivII.10 Clinical Criteria and Procedures 21List of Tables vII.9 Examiner Calibration and Monitoring 21Acknowledgements 3II.8 The Clinical Examination 20Summary in English 2Summary in Chinese 4II.7 The Questionnaire 20VI Discussion 115II.6 Home Visitor Programme 19II.5 Recruitment of the Sample 19VII Goals For Oral Health Year 2000 128II.4 Sampling Method 18II.3 Sampling Frame 18VIII Conclusions and Recommendations 133II.2 Sample Size 17II.1 Survey Region 17IX Literature References 138V.3 Dental Caries Treatment Needs 84V.2 Dental Caries Status 74V.1 Teeth Present and Teeth Missing 72IV.6 Use of Professional Services 57V.5 Denture Possession and Requirement 91V.6 Dento-facial Anomalies 94V.7 Root Surface Caries 95V.8 Periodontal Status 99IV.5 Satisfaction With the Condition and Appearance of Teeth 5

Rogue waves and entropy consumption

Based on data from the Japan Sea and the North Sea the occurrence of rogue waves is analyzed by a scale dependent stochastic approach, which interlinks fluctuations of waves for different spacings. With this approach we are able to determine a stochastic cascade process, which provides information of the general multipoint statistics. Furthermore the evolution of single trajectories in scale, which characterize wave height fluctuations in the surroundings of a chosen location, can be determined. The explicit knowledge of the stochastic process enables to assign entropy values to all wave events. We show that for these entropies the integral fluctuation theorem, a basic law of non-equilibrium thermodynamics, is valid. This implies that positive and negative entropy events must occur. Extreme events like rogue waves are characterized as negative entropy events. The statistics of these entropy fluctuations changes with the wave state, thus for the Japan Sea the statistics of the entropies has a more pronounced tail for negative entropy values, indicating a higher probability of rogue waves.Comment: 6 pages, 6 figure