Building and querying e-catalog networks using P2P and data summarisation techniques

One of the critical issues in Web-based e-commerce has been how to efficiently and effectively integrate and query heterogeneous, diverse e-catalogs. We propose an integration framework for building and querying catalogs. Our approach is based on a hybrid of peer-to-peer data sharing paradigm and Web-services architecture. Peers in our system serve as domain-specific data integration mediators. Links between peers are established based on the similarity of the domain they represent. The relationships are used for routing queries among peers. As the number of catalogs involved grow larger, the need for filtering irrelevant data sources will become increasingly high. We apply a summarisation technique to summarise the content of catalogs. The summaries are used to pre-selecting data sources that are relevant to a user query. We use terms e-catalog and catalog interchangeably.     

Inverse gas chromatography characterization of polyaniline complexes: application to volatile organic compounds sensing

Surface thermodynamic characteristics of two polyaniline complexes with inorganic and organic acids were investigated using inverse gas chromatography technique. Thirteen solutes were injected into two separate chromatographic columns packed with polyaniline (PANI) complexes as stationary phases without any chromatographic support. The retention volumes of these solutes were measured to show their strong retention with both PANI complexes, particularly the xylene isomers: ortho, meta and para. The free energy of adsorption, $\Updelta G_{a}$ Δ G a , consisting of dispersive term $\Updelta G_{a}^{d}$ Δ G a d and the acid–base interaction term, $\Updelta G_{a}^{s}$ Δ G a s was also determined showing that it is mainly based on its dispersive contribution. The dispersive surface energy of hydrochloric acid polyaniline complex is ranging from 70.39 mJ/m² at 130 °C to 65.75 mJ/m² at 150 °C while the surface energy of dodecylbenzenesulfonic acid polyaniline complex has shown slight upper difference ranging from 70.90 to 66.23 mJ/m² in the same temperature’s interval, thus reflecting a behavior comparable to that of high surface energy materials. Furthermore, the obtained PANI complexes powders were characterized using fourier transform infrared spectrometry, Raman spectroscopy, UV–visible, XRF and SEM techniques. The measured retention volumes were combined with linear solvation energy relationship (LSER), called Abraham law, to determine physicochemical parameters describing dispersive, polar and acid–base properties, the surface of both polyaniline was found out exhibiting a basic nature.     

A nonstationary model of newborn EEG

The detection of seizure in the newborn is a critical aspect of neurological research. Current automatic detection techniques are difficult to assess due to the problems associated with acquiring and labelling newborn electroencephalogram (EEG) data. A realistic model for newborn EEG would allow confident development, assessment and comparison of these detection techniques. This paper presents a model for newborn EEG that accounts for its self-similar and nonstationary nature. The model consists of background and seizure submodels. The newborn EEG background model is based on the short-time power spectrum with a time-varying power law. The relationship between the fractal dimension and the power law of a power spectrum is utilized for accurate estimation of the short-time power law exponent. The newborn EEG seizure model is based on a well-known time-frequency signal model. This model addresses all significant time-frequency characteristics of newborn EEG seizure which include; multiple components or harmonics, piecewise linear instantaneous frequency laws and harmonic amplitude modulation. Estimates of the parameters of both models are shown to be random and are modelled using the data from a total of 500 background epochs and 204 seizure epochs. The newborn EEG background and seizure models are validated against real newborn EEG data using the correlation coefficient. The results show that the output of the proposed models have a higher correlation with real newborn EEG than currently accepted models (a 10% and 38% improvement for background and seizure models, respectively).     

Modeling of Thermo-Hydro-Viscoelastic Behavior of a Partially Saturated Ceramic Material During Drying

A mathematical model to simulate the drying of a partially saturated ceramic material has been developed. The investigated problem involves coupling equations considering heat, mass, and mechanical aspects. Transport in unsaturated porous medium includes two mean mechanisms: convection for liquid and gases, and molecular diffusion in the gas mixture.

Viscoelastic rheology is applied by using the generalized Maxwell model in which the relaxation modulus depends on time and moisture content. The numerical resolution is performed to foresee the variation of moisture content, shrinkage, liquid pressure, gas pressure, temperature, and mechanical stresses during drying. The model was validated partially for porcelain material in classical convective drying. Simulation results showed the importance of using a viscoelastic model with two dependent variables in evaluating the developed mechanical stresses. The Von Mises criterion is used as a crack initiation criterion, which allows localizing the area of risk of the material's fracture.     

THE SIGNIFICANCE OF CRACK TIP DEFORMATION FOR SHORT AND LONG FATIGUE CRACKS

Abstract— The behaviour of physical short mode I cracks under constant amplitude cyclic loading was investigated both numerically and experimentally. A dynamic two-dimensional elastic-plastic finite element technique was utilised to simulate cyclic crack tip plastic deformation. Different idealisations were investigated. Both stationary and artificially advanced long and short cracks were analysed. A parameter which characterises the plastically deformed crack tip zone, the strain field generated within that zone and the opening and closure of the crack tip were considered. The growth of physically short mode I cracks under constant amplitude fully reversed fatigue loading was investigated experimentally using conventional cast steel EN-9 specimens. Based on a numerical analysis, a crack tip deformation parameter was devised to correlate fatigue crack propagation rates.     

Reactions with 2-Oxo-4-thioxo-1,2,3,4-tetrahydrobenzo[f]isoquinoline and 1,2,3,4-tetrahydro-benzo[f]-isoquinoline-2,4-dione

Alkylation of 2-oxo-4-thioxo-1,2,3,4-tetrahydro-benzo[f]isoquinoline 2 gave at first the S-alkyl derivatives, then the S- and O-dialkyl derivatives were formed. Compound 2 and its alkyl derivatives coupled with aryldiazonium salts. The S-methyl derivatives of 2 , on acid hydrolysis, gave 1,2,3,4-tetrahydro-benzo[f]isoquinoline-2,4-dione 10 , which coupled with diazonium salts. 10 gave a monochloro and a monobromo derivative. 10 reacted also with p-nitrosodimethylaniline and the product was hydrolysed to the triketo compound 14 , which condensed with o-phenylenediamine to give the quinoxaline derivative 15 .