Performance of statistical inference for block classification in reducing blocking artefact in video coded images

This paper presents a performance study of four statistical test algorithms used to identify smooth image blocks in order to filter the reconstructed image of a video coded image. The four algorithms considered are the Coefficient of Variation (CV), Exponential Entropy of Pal and Pal (E), Shannon's (Logarithmic) Entropy (H), and Quadratic Entropy (Q). These statistical algorithms are employed to distinguish between smooth and textured blocks in a reconstructed image. The linear filtering is carried out on the smooth blocks of the image to reduce the blocking artefact. The rationale behind applying the filter on the smooth blocks only is that the blocking artefact is visually more prominent in the smooth region of an image rather than in the textured region.

Quantifying minimum monolith size and solute dilution from multi-compartment percolation sampler data

Preferential flow affects solute transport in natural soils, leading to high spatiotemporal variation of concentration. A multicompartment solute sampler (MCS), yielding multiple breakthrough curves at a given depth, can monitor tracer movement in a heterogeneous soil. We present a technique to estimate from MCS data whether a soil monolith is sufficiently large to capture preferential flow, which is a necessity for tracer breakthrough curves to be representative. For several soils, we estimate that an MCS should be larger than 0.1 to 0.2 m². We also expand dilution theory to analyze the concentration variations of a tracer passing the control plane monitored by the MCS, in addition to the conventional plume spreading analysis. We characterize the set of locally observed breakthrough curves by the entropy-based dilution index. For given first and second-central moment, the spatially uniform log-normal breakthrough curve maximizes the dilution index. The ratio between observed and maximum dilution index is denoted reactor ratio. For a 300-compartment solute sampler, covering an area of 0.75 m², we compute a reactor ratio of 0.665, compared with 0.04 for stochastic-convective and 1 for convective-dispersive transport. With a single, large collector the reactor ratio would be 0.958, severely underestimating concentration variations. Large collector areas are clearly inadequate to estimate dilution. Values of the dilution index and the reactor ratio for individual sampling compartments indicate efficient longitudinal mixing in most but not all cases, and considerable spatial variation of the leaching process.

Texture recognition by using GLCM and various aggregation functions

We discuss the problem of texture recognition based on the grey level co-occurrence matrix (GLCM). We performed a number of numerical experiments to establish whether the accuracy of classification is optimal when GLCM entries are aggregated into standard metrics like contrast, dissimilarity, homogeneity, entropy, etc., and compared these metrics to several alternative aggregation methods.We conclude that k nearest neighbors classification based on raw GLCM entries typically works better than classification based on the standard metrics for noiseless data, that metrics based on principal component analysis inprove classification, and that a simple change from the arithmetic to quadratic mean in calculating the standard metrics also improves classification.

Thermodynamics of lipophilic drug binding to intestinal fatty acid binding protein and permeation across membranes

Intestinal fatty acid binding protein (I-FABP) is present at high levels in the absorptive cells of the intestine (enterocytes), where it plays a role in the intracellular solubilization of fatty acids (FA). However, I-FABP has also been shown to bind to a range of non-FA ligands, including some lipophilic drug molecules. Thus, in addition to its central role in FA trafficking, I-FABP potentially serves as an important intracellular carrier of lipophilic drugs. In this study we provide a detailed thermodynamic analysis of the binding and stability properties of I-FABP in complex with a series of fibrate and fenamate drugs to provide an insight into the forces driving drug binding to I-FABP. Drug binding and selectivity for I-FABP are driven by the interplay of protein−ligand interactions and solvent processes. The Gibbs free energies (ΔG°) determined from dissociation constants at 25 °C ranged from −6.2 to −10 kcal/mol. The reaction energetics indicate that drug binding to I-FABP is an enthalpy−entropy driven process. The relationship between I-FABP stability and drug binding affinity was examined by pulse proteolysis. There is a strong coupling between drug binding and I-FABP stability. The effect of an I-FABP protein sink on the kinetics and thermodynamics of tolfenamic acid permeation across an artificial phospholipid membrane were investigated. I-FABP significantly decreased the energy barrier for desorption of tolfenamic acid from the membrane into the acceptor compartment. Taken together, these data suggest that the formation of stable drug−I-FABP complexes is thermodynamically viable under conditions simulating the reactant concentrations likely observed in vivo and maybe a significant biochemical process that serves as a driving force for passive intestinal absorption of lipophilic drugs.

Investigating business cycle asymmetry for the G7 countries : evidence from over a century of data

In this paper we test for asymmetric behaviour of business cycles for the G7 countries, using the entropy-based test for asymmetry suggested by Racine and Maasoumi [Racine, J.S., & Maasoumi, E. (in press-a). A versatile and robust metric entropy test of time-reversibility, and other hypotheses, Journal of Econometrics; Racine, J.S., & Maasoumi, E. (in press-b). A robust entropy based test for asymmetry. Econometric Reviews.]. We find overwhelming evidence of symmetry. In only 14% of the cases, we find some evidence of asymmetric behaviour of GDP and per capita GDP. More importantly, the period marked by the flexible exchange rate regime, over which much of the empirical work for the G7 countries has been conducted, evidence suggests that the two GDP series are symmetric.

Can the electricity market be characterised by asymmetric behaviour?

In this paper, we test for asymmetric behaviour of industrial and residential electricity demand for the G7 countries, using the entropy-based test for symmetry suggested by [Racine, J., and Maasoumi, E., 2007. A versatile and robust metric entropy test of time-reversibility, and other hypotheses. Journal of Econometrics 138(2), 547–567; Racine, J., and Maasoumi, E., 2008. A robust entropy-based test of asymmetry for discrete and continuous processes. Econometric Reviews 28, 246–261], the Triples test of [Randles, R., Flinger, M., Policello, G., and Wolfe, D., 1980. An asymptotically distribution-free test for symmetry versus asymmetry. Journal of the American Statistical Association 75, 168–172] and the [Bai, J., and Ng, S., 2001. A consistent test for conditional symmetry in time series models. Journal of Econometrics 103, 225–258] test for conditional symmetry. Using data that spans over three decades, we find overwhelming evidence of conditional symmetry of residential and industrial electricity consumption. This finding implies that the use of econometric tests based on linear data generating processes is credible.

Physical theory of organisation and consequent neural model of spatio-temporal pattern acquisition

A neurone model (the FORMON) is proposed which provides a mathematical explanation for a range of psychological phenomena and has potential in Artificial Intelligence applications. A general definition of organisation in terms of entropy and information is formulated. The concept of microcodes is introduced to describe the physical nature of organisation. Spatio-temporal pattern acquisition and processing functions attributable to individual neurones are reviewed. The criterion for self-organisation in a neurone is determined as the maximisation of mutual organisation. A feedback control system is proposed to satisfy this criterion and provide an integrated long-term memory of spatio-temporal pattern. This pattern acquisition system is shown to be applicable to dendritic pattern recognition and axonal pattern generation. Provision is also made for adaptation, short-term memory and operant learning. An electro-chemical model of transmission and processing of neural signals is outlined to provide the pattern acquisition functions of the Formon model. A transverse magnetic mode of electrotonic propagation is postulated in addition to the transverse electromagnetic mode. Configurations of the Formon are categorised in terms of possible pattern processing functions. Connective architectures are proposed as self-organising models of acquisitive semantic and syntactic networks.

Available energy

A proposed new statement of the second law of thermodynamics - the transformation of energy to work is always inefficient with respect to available energy - is conceptually and pedagogically simpler than historical entropy-based statements. It has assisted in the discovery of a new general characterisation of steady (energy dissipative) states.

An abnormal-based approach to effectively detect DDOS attacks

Distributed Denial-of-Service (DDoS) attacks are a serious threat to the safety and security of cyberspace. In this paper we propose a novel metric to detect DDoS attacks in the Internet. More precisely, we use the function of order α of the generalized (Rényi) entropy to distinguish DDoS attacks traffic from legitimate network traffic effectively. In information theory, entropies make up the basis for distance and divergence measures among various probability densities. We design our abnormal-based detection metric using the generalized entropy. The experimental results show that our proposed approach can not only detect DDoS attacks early (it can detect attacks one hop earlier than using the Shannon metric while order  α =2, and two hops earlier than the Shannon metric while order α =10.) but can also reduce both the false positive rate and the false negative rate, compared with the traditional Shannon entropy metric approach.