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Entropy, Volume 14, Issue 12 (December 2012), Pages 2375-2625

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Editorial

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Open AccessEditorial Natural/Unconventional Computing and Its Philosophical Significance
Entropy 2012, 14(12), 2408-2412; doi:10.3390/e14122408
Received: 31 October 2012 / Accepted: 1 November 2012 / Published: 27 November 2012
Cited by 2 | PDF Full-text (139 KB) | HTML Full-text | XML Full-text
Abstract
In this special issue we present a selection of papers from the Symposium on Natural/Unconventional Computing and its Philosophical Significance, held during the AISB/IACAP 2012 World Congress in Birmingham (UK). This article is an editorial, introducing the special issue of the journal [...] Read more.
In this special issue we present a selection of papers from the Symposium on Natural/Unconventional Computing and its Philosophical Significance, held during the AISB/IACAP 2012 World Congress in Birmingham (UK). This article is an editorial, introducing the special issue of the journal with the selected papers and the research program of Natural/Unconventional Computing. Full article

Research

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Open AccessArticle Expectation Values and Variance Based on Lp-Norms
Entropy 2012, 14(12), 2375-2396; doi:10.3390/e14122375
Received: 4 August 2012 / Revised: 13 November 2012 / Accepted: 14 November 2012 / Published: 26 November 2012
Cited by 7 | PDF Full-text (480 KB) | HTML Full-text | XML Full-text
Abstract
This analysis introduces a generalization of the basic statistical concepts of expectation values and variance for non-Euclidean metrics induced by Lp-norms. The non-Euclidean Lp means are defined by exploiting the fundamental property of minimizing the Lp deviations that [...] Read more.
This analysis introduces a generalization of the basic statistical concepts of expectation values and variance for non-Euclidean metrics induced by Lp-norms. The non-Euclidean Lp means are defined by exploiting the fundamental property of minimizing the Lp deviations that compose the Lp variance. These Lp expectation values embody a generic formal scheme of means characterization. Having the p-norm as a free parameter, both the Lp-normed expectation values and their variance are flexible to analyze new phenomena that cannot be described under the notions of classical statistics based on Euclidean norms. The new statistical approach provides insights into regression theory and Statistical Physics. Several illuminating examples are examined. Full article
Open AccessArticle Entropy-Based Block Processing for Satellite Image Registration
Entropy 2012, 14(12), 2397-2407; doi:10.3390/e14122397
Received: 8 October 2012 / Revised: 14 November 2012 / Accepted: 19 November 2012 / Published: 27 November 2012
Cited by 1 | PDF Full-text (27538 KB) | HTML Full-text | XML Full-text
Abstract
Image registration is an important task in many computer vision applications such as fusion systems, 3D shape recovery and earth observation. Particularly, registering satellite images is challenging and time-consuming due to limited resources and large image size. In such scenario, state-of-the-art image [...] Read more.
Image registration is an important task in many computer vision applications such as fusion systems, 3D shape recovery and earth observation. Particularly, registering satellite images is challenging and time-consuming due to limited resources and large image size. In such scenario, state-of-the-art image registration methods such as scale-invariant feature transform (SIFT) may not be suitable due to high processing time. In this paper, we propose an algorithm based on block processing via entropy to register satellite images. The performance of the proposed method is evaluated using different real images. The comparative analysis shows that it not only reduces the processing time but also enhances the accuracy. Full article
Open AccessArticle The Extension of Statistical Entropy Analysis to Chemical Compounds
Entropy 2012, 14(12), 2413-2426; doi:10.3390/e14122413
Received: 23 August 2012 / Revised: 25 September 2012 / Accepted: 26 November 2012 / Published: 28 November 2012
Cited by 3 | PDF Full-text (524 KB) | HTML Full-text | XML Full-text
Abstract
Statistical entropy analysis (SEA) quantifies the dilution and concentration of conservative substances (e.g., heavy metals) in a system. In this paper, the SEA concept is extended (eSEA) to make it applicable to systems in which the chemical speciation is of particular importance. [...] Read more.
Statistical entropy analysis (SEA) quantifies the dilution and concentration of conservative substances (e.g., heavy metals) in a system. In this paper, the SEA concept is extended (eSEA) to make it applicable to systems in which the chemical speciation is of particular importance. The eSEA is applied to a simplified region used for crop farming. The extent to which the region concentrates or dilutes nitrogen compounds is expressed as the change in statistical entropy (DH). A detailed derivation for the calculation of DH is provided. The results are discussed for four variations of the crop farming system, showing that the efficiency of crop farming can be expressed by eSEA. Full article
(This article belongs to the Special Issue Concepts of Entropy and Their Applications)
Open AccessArticle Implications of the Cressie-Read Family of Additive Divergences for Information Recovery
Entropy 2012, 14(12), 2427-2438; doi:10.3390/e14122427
Received: 15 October 2012 / Revised: 20 November 2012 / Accepted: 27 November 2012 / Published: 3 December 2012
Cited by 4 | PDF Full-text (232 KB) | HTML Full-text | XML Full-text
Abstract
To address the unknown nature of probability-sampling models, in this paper we use information theoretic concepts and the Cressie-Read (CR) family of information divergence measures to produce a flexible family of probability distributions, likelihood functions, estimators, and inference procedures. The usual case [...] Read more.
To address the unknown nature of probability-sampling models, in this paper we use information theoretic concepts and the Cressie-Read (CR) family of information divergence measures to produce a flexible family of probability distributions, likelihood functions, estimators, and inference procedures. The usual case in statistical modeling is that the noisy indirect data are observed and known and the sampling model-error distribution-probability space, consistent with the data, is unknown. To address the unknown sampling process underlying the data, we consider a convex combination of two or more estimators derived from members of the flexible CR family of divergence measures and optimize that combination to select an estimator that minimizes expected quadratic loss. Sampling experiments are used to illustrate the finite sample properties of the resulting estimator and the nature of the recovered sampling distribution. Full article
Open AccessArticle Electro-Kinetic Pumping with Slip Irreversibility in Heat Exchange of CSP-Powered Bio-Digester Assemblies
Entropy 2012, 14(12), 2439-2455; doi:10.3390/e14122439
Received: 5 September 2012 / Revised: 13 October 2012 / Accepted: 26 November 2012 / Published: 4 December 2012
Cited by 2 | PDF Full-text (776 KB) | HTML Full-text | XML Full-text
Abstract
Parametric studies of the effects of slip irreversibility in concentrating solar power (CSP)-powered bio-digester assemblies are investigated. Complexities regarding the identification of the appropriate electro-kinetic phenomena for certain electrolyte phases are reviewed. The application of exergy analysis to the design of energy [...] Read more.
Parametric studies of the effects of slip irreversibility in concentrating solar power (CSP)-powered bio-digester assemblies are investigated. Complexities regarding the identification of the appropriate electro-kinetic phenomena for certain electrolyte phases are reviewed. The application of exergy analysis to the design of energy conversion devices, like solar thermal collectors, for the required heat of formation in a downdraft waste food bio-digester, is discussed. Thermal management in the silicon-based substrate of the energy system is analyzed. The rectangular-shaped micro-channels are simulated with a finite-volume, staggered coupling of the pressure-velocity fields. Entropy generation transport within the energy system is determined and coupled with the solution procedure. Consequently, the effects of channel size perturbation, Reynolds number, and pressure ratios on the thermal performance and exergy destruction are presented. A comparative analysis of the axial heat conduction for thermal management in energy conversion devices is proposed. Full article
(This article belongs to the Special Issue Exergy: Analysis and Applications)
Open AccessArticle Entropy and Gravity
Entropy 2012, 14(12), 2456-2477; doi:10.3390/e14122456
Received: 26 October 2012 / Revised: 22 November 2012 / Accepted: 23 November 2012 / Published: 4 December 2012
Cited by 3 | PDF Full-text (369 KB) | HTML Full-text | XML Full-text
Abstract
The effect of gravity upon changes of the entropy of a gravity-dominated system is discussed. In a universe dominated by vacuum energy, gravity is repulsive, and there is accelerated expansion. Furthermore, inhomogeneities are inflated and the universe approaches a state of thermal [...] Read more.
The effect of gravity upon changes of the entropy of a gravity-dominated system is discussed. In a universe dominated by vacuum energy, gravity is repulsive, and there is accelerated expansion. Furthermore, inhomogeneities are inflated and the universe approaches a state of thermal equilibrium. The difference between the evolution of the cosmic entropy in a co-moving volume in an inflationary era with repulsive gravity and a matter-dominated era with attractive gravity is discussed. The significance of conversion of gravitational energy to thermal energy in a process with gravitational clumping, in order that the entropy of the universe shall increase, is made clear. Entropy of black holes and cosmic horizons are considered. The contribution to the gravitational entropy according to the Weyl curvature hypothesis is discussed. The entropy history of the Universe is reviewed. Full article
(This article belongs to the Special Issue Modified Gravity: From Black Holes Entropy to Current Cosmology)
Open AccessArticle Maximum Entropy Gibbs Density Modeling for Pattern Classification
Entropy 2012, 14(12), 2478-2491; doi:10.3390/e14122478
Received: 25 September 2012 / Revised: 19 October 2012 / Accepted: 30 November 2012 / Published: 4 December 2012
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Abstract
Recent studies have shown that the Gibbs density function is a good model for visual patterns and that its parameters can be learned from pattern category training data by a gradient algorithm optimizing a constrained entropy criterion. These studies represented each pattern [...] Read more.
Recent studies have shown that the Gibbs density function is a good model for visual patterns and that its parameters can be learned from pattern category training data by a gradient algorithm optimizing a constrained entropy criterion. These studies represented each pattern category by a single density. However, the patterns in a category can be so complex as to require a representation spread over several densities to more accurately account for the shape of their distribution in the feature space. The purpose of the present study is to investigate a representation of visual pattern category by several Gibbs densities using a Kohonen neural structure. In this Gibbs density based Kohonen network, which we call a Gibbsian Kohonen network, each node stores the parameters of a Gibbs density. Collectively, these Gibbs densities represent the pattern category. The parameters are learned by a gradient update rule so that the corresponding Gibbs densities maximize entropy subject to reproducing observed feature statistics of the training patterns. We verified the validity of the method and the efficiency of the ensuing Gibbs density pattern representation on a handwritten character recognition application. Full article
(This article belongs to the Special Issue Maximum Entropy Production)
Figures

Open AccessArticle Improving Classical Authentication over a Quantum Channel
Entropy 2012, 14(12), 2531-2549; doi:10.3390/e14122531
Received: 28 April 2012 / Revised: 28 July 2012 / Accepted: 26 November 2012 / Published: 11 December 2012
Cited by 3 | PDF Full-text (307 KB) | HTML Full-text | XML Full-text
Abstract
We propose a quantum protocol to authenticate classical messages that can be used to replace Wegman–Carter’s classical authentication scheme in quantum key distribution (QKD) protocols. We show that the proposed scheme achieves greater conditional entropy of the seed for the intruder given [...] Read more.
We propose a quantum protocol to authenticate classical messages that can be used to replace Wegman–Carter’s classical authentication scheme in quantum key distribution (QKD) protocols. We show that the proposed scheme achieves greater conditional entropy of the seed for the intruder given her (quantum) observation than the classical case. The proposed scheme is suitable for situations where the shared symmetric key used in authentication becomes dangerously short (due to noise or eavesdropping), and there is a threat that it might be completely consumed without being replaced. Our protocol is an improvement over a classical scheme by Brassard and takes advantage of quantum channel properties. It is motivated by information-theoretical results. We stress that the proposed authentication protocol can also be used as an independent authentication protocol that is not a part of a QKD. However by adopting it, QKD becomes a fully quantum protocol. We prove that quantum resources can improve both the secrecy of the key generated by the PRG and the secrecy of the tag obtained with a hidden hash function. We conclude that the proposed quantum encoding offers more security than the classical scheme and, by applying a classical result, we show that it can be used under noisy quantum channels. Full article
Open AccessArticle Entropy Stress and Scaling of Vital Organs over Life Span Based on Allometric Laws
Entropy 2012, 14(12), 2550-2577; doi:10.3390/e14122550
Received: 28 September 2012 / Revised: 22 November 2012 / Accepted: 26 November 2012 / Published: 12 December 2012
Cited by 5 | PDF Full-text (746 KB) | HTML Full-text | XML Full-text
Abstract
Abstract: Past theories on total lifetime energy expenditures and entropy generation in biological systems (BS) dealt with whole systems, but the recent literature suggests that the total metabolic rate of a BS,q̇body (W) is a sum of product of specific metabolic [...] Read more.
Abstract: Past theories on total lifetime energy expenditures and entropy generation in biological systems (BS) dealt with whole systems, but the recent literature suggests that the total metabolic rate of a BS,q̇body (W) is a sum of product of specific metabolic rate q̇k,m (W/kg of organ k) of each vital life organ, k {k = brain, heart, kidney and liver, or abbreviated as BHKL, and rest of the organ mass (R)} and mass of each organ k (mk). Using this hypothesis, Kleiber’s law on metabolic rate of BS (q̇body) for animals of different sizes was validated. In this work, a similar procedure is adopted in estimating total entropy generation rate of whole human body (σ̇body, W/K) as a sum of product of specific entropy generation rate for each organ, σ̇k,m (W/{K kg of organ k·}) and the organ mass at any given age (t). Further integrating over life span for each organ (tlife), the lifetime specific entropy generated by organ k, σk,m,life (J of organ k/ {K kg organ k}) is calculated. Then lifetime entropy generation of unit body mass, σbody,M,life (J/{K kg body mass·}) is calculated as a sum of the corresponding values contributed by all vital organs to unit body mass and verified with previously published literature. The higher the σk,m,life , the higher the entropy stress level (which is a measure of energy released by unit organ mass of k as heat) and the irreversibility within the organ, resulting in faster degradation of organ and the consequent health problems for the whole BS. In order to estimate σ̇k (W/K of organ k), data on energy release rate (q̇) is needed over lifetime for each organ. While the Adequate Macronutrients Distribution Range (AMDR)/Adequate Intake (AI) publication can be used in estimating the energy intake of whole body vs. age for the human body, the energy expenditure data is not available at organ level. Hence the σk,m,life was computed using existing allometric laws developed for the metabolism of the organs, the relation between the mk of organ and body mass mB, and the body mass growth data mB(t) over the lifetime. Based on the values of σk, m, life, the organs were ranked from highest to lowest entropy generation and the heart is found to be the most entropy-stressed organ. The entropy stress levels of the other organs are then normalized to the entropy stress level (NESH) of the heart. The NESH values for organs are as follows: Heart: 1.0, Kidney: 0.92, Brain: 0.46, Liver: 0.41, Rest of BS: 0.027. If normalized to rest of body (R), NESR, heart: 37, Kidney: 34, Brain: 17, Liver: 15, Rest of BS: 1.0; so heart will fail first followed by kidney and other organs in order. Supporting data is provided. Full article
Open AccessArticle Reliability Analysis of Free Jet Scour Below Dams
Entropy 2012, 14(12), 2578-2588; doi:10.3390/e14122578
Received: 29 October 2012 / Revised: 3 December 2012 / Accepted: 11 December 2012 / Published: 14 December 2012
Cited by 1 | PDF Full-text (102 KB) | HTML Full-text | XML Full-text
Abstract
Current formulas for calculating scour depth below of a free over fall are mostly deterministic in nature and do not adequately consider the uncertainties of various scouring parameters. A reliability-based assessment of scour, taking into account uncertainties of parameters and coefficients involved, [...] Read more.
Current formulas for calculating scour depth below of a free over fall are mostly deterministic in nature and do not adequately consider the uncertainties of various scouring parameters. A reliability-based assessment of scour, taking into account uncertainties of parameters and coefficients involved, should be performed. This paper studies the reliability of a dam foundation under the threat of scour. A model for calculating the reliability of scour and estimating the probability of failure of the dam foundation subjected to scour is presented. The Maximum Entropy Method is applied to construct the probability density function (PDF) of the performance function subject to the moment constraints. Monte Carlo simulation (MCS) is applied for uncertainty analysis. An example is considered, and there liability of its scour is computed, the influence of various random variables on the probability failure is analyzed. Full article
Open AccessArticle Capacity Bounds and Mapping Design for Binary Symmetric Relay Channels
Entropy 2012, 14(12), 2589-2610; doi:10.3390/e14122589
Received: 1 September 2012 / Revised: 4 December 2012 / Accepted: 6 December 2012 / Published: 17 December 2012
Cited by 1 | PDF Full-text (313 KB) | HTML Full-text | XML Full-text
Abstract
Capacity bounds for a three-node binary symmetric relay channel with orthogonal components at the destination are studied. The cut-set upper bound and the rates achievable using decode-and-forward (DF), partial DF and compress-and-forward (CF) relaying are first evaluated. Then relaying strategies with finite [...] Read more.
Capacity bounds for a three-node binary symmetric relay channel with orthogonal components at the destination are studied. The cut-set upper bound and the rates achievable using decode-and-forward (DF), partial DF and compress-and-forward (CF) relaying are first evaluated. Then relaying strategies with finite memory-length are considered. An efficient algorithm for optimizing the relay functions is presented. The Boolean Fourier transform is then employed to unveil the structure of the optimized mappings. Interestingly, the optimized relay functions exhibit a simple structure. Numerical results illustrate that the rates achieved using the optimized low-dimensional functions are either comparable to those achieved by CF or superior to those achieved by DF relaying. In particular, the optimized low-dimensional relaying scheme can improve on DF relaying when the quality of the source-relay link is worse than or comparable to that of other links. Full article
(This article belongs to the Special Issue Information Theory Applied to Animal Communication)
Open AccessArticle A Finite-Time Thermal Cycle Variational Optimization with a Stefan–Boltzmann Law for Three Different Criteria
Entropy 2012, 14(12), 2611-2625; doi:10.3390/e14122611
Received: 16 October 2012 / Revised: 5 December 2012 / Accepted: 5 December 2012 / Published: 17 December 2012
Cited by 1 | PDF Full-text (118 KB) | HTML Full-text | XML Full-text
Abstract
This work shows the power of the variational approach for studying the efficiency of thermal engines in the context of the Finite Time Thermodynamics (FTT). Using an endoreversible Curzon–Ahlborn (CA) heat engine as a model for actual thermal engines, three different criteria [...] Read more.
This work shows the power of the variational approach for studying the efficiency of thermal engines in the context of the Finite Time Thermodynamics (FTT). Using an endoreversible Curzon–Ahlborn (CA) heat engine as a model for actual thermal engines, three different criteria for thermal efficiency were analyzed: maximum power output, ecological function, and maximum power density. By means of this procedure, the performance of the CA heat engine with a nonlinear heat transfer law (the Stefan–Boltzmann law) was studied to describe the heat exchanges between the working substance and its thermal reservoirs. The specific case of the Müser engine for all the criteria was analyzed. The results confirmed some previous findings using other procedures and additionally new results for the Müser engine performance were obtained. Full article

Review

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Open AccessReview Is Endothelial Nitric Oxide Synthase a Moonlighting Protein Whose Day Job is Cholesterol Sulfate Synthesis? Implications for Cholesterol Transport, Diabetes and Cardiovascular Disease
Entropy 2012, 14(12), 2492-2530; doi:10.3390/e14122492
Received: 8 October 2012 / Revised: 28 November 2012 / Accepted: 4 December 2012 / Published: 7 December 2012
Cited by 7 | PDF Full-text (618 KB) | HTML Full-text | XML Full-text
Abstract
Theoretical inferences, based on biophysical, biochemical, and biosemiotic considerations, are related here to the pathogenesis of cardiovascular disease, diabetes, and other degenerative conditions. We suggest that the “daytime” job of endothelial nitric oxide synthase (eNOS), when sunlight is available, is to catalyze [...] Read more.
Theoretical inferences, based on biophysical, biochemical, and biosemiotic considerations, are related here to the pathogenesis of cardiovascular disease, diabetes, and other degenerative conditions. We suggest that the “daytime” job of endothelial nitric oxide synthase (eNOS), when sunlight is available, is to catalyze sulfate production. There is a striking alignment between cell types that produce either cholesterol sulfate or sulfated polysaccharides and those that contain eNOS. The signaling gas, nitric oxide, a well-known product of eNOS, produces pathological effects not shared by hydrogen sulfide, a sulfur-based signaling gas. We propose that sulfate plays an essential role in HDL-A1 cholesterol trafficking and in sulfation of heparan sulfate proteoglycans (HSPGs), both critical to lysosomal recycling (or disposal) of cellular debris. HSPGs are also crucial in glucose metabolism, protecting against diabetes, and in maintaining blood colloidal suspension and capillary flow, through systems dependent on water-structuring properties of sulfate, an anionic kosmotrope. When sunlight exposure is insufficient, lipids accumulate in the atheroma in order to supply cholesterol and sulfate to the heart, using a process that depends upon inflammation. The inevitable conclusion is that dietary sulfur and adequate sunlight can help prevent heart disease, diabetes, and other disease conditions. Full article
(This article belongs to the Special Issue Biosemiotic Entropy: Disorder, Disease, and Mortality)

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