An introduction of the condition class space with continuous value discretization and rough set theory

The granularity of an information system has an incumbent effect on the efficacy of the analysis from many machine learning algorithms. An information system contains a universe of objects characterized and categorized by condition and decision attributes. To manage the concomitant granularity, a level of continuous value discretization (CVD) is often undertaken. In the case of the rough set theory (RST) methodology for object classification, the granularity contributes to the grouping of objects into condition classes with the same condition attribute values. This article exposits the effect of a level of CVD on the subsequent condition classes constructed, with the introduction of the condition class space—the domain within which the condition classes exist. This domain elucidates the association of the condition classes to the related decision outcomes—reflecting the inexactness incumbent when a level of CVD is undertaken. A series of measures is defined that quantify this association. Throughout this study and without loss of generality, the findings are made through the RST methodology. This further offers a novel exposition of the relationship between all the condition attributes and the RST‐related reducts (subsets of condition attributes). © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 173–191, 2006.     

Introduction and Elucidation of the Quality of Sagacity in the Extended Variable Precision Rough Sets Model

This paper introduces the quality of sagacity measure in the extended variable precision rough sets model - VPRS_l,u. The need for this measure is a direct consequence of the use of the associated l and u values. Moreover, different levels of miss-classification are allowed in the classification of objects to a decision class or its compliment. This measure attempts to take this into account, by acknowledging the classification of an object to the compliment of a decision class, as an appropriate (if not optimum) classification of that object. A consequence of the analysis is a discussion of the notion of open and closed worlds in VPRS_l,u.     

Use of inverse gas chromatography to quantify interactions in amine cured epoxy resins

Flory–Huggins interaction parameters, λ, were determined for a series of probes in an amine cured epoxy resin matrix (433–493 K) and its precursors (324–363 K) by inverse gas chromatography (IGC). Hildebrand–Scatchard theory was combined with Flory–Huggins theory in order to estimate infinte dilution solubility parameters (δ₂) for the matrix and its precursors at 298 K. It was shown that the value of the solubility parameter for the cured resin matrix lies between those of its precursors. Compared to the majority of published work, an unusual aspect of this application of IGC is that solubility parameters have been determined when the stationery phases are (i) small molecules and (ii) a highly crosslinked polymer. Moreover, all possible attempts have been made to ensure equilibrium conditions between probe and stationary phase, and compensation for asymmetry of peak profile has been applied in determining δ₂. The solubility parameters estimated by IGC are in good agreement with those calculated by other methods.     

Development and characterization of magnetorheological polymer gels

Magnetorheological materials have been used in many applications in recent years. To develop new materials, polyurethane and silicone polymer gels were investigated. Rheology is qualitatively controlled for each system by controlling the concentration of reactants and diluents. The resulting polymers have solid, gel, or liquid states, depending on the crosslinking and dilution. The gels were characterized through kinetic analysis. Differential scanning calorimetry (DSC) was used with analysis methods to find the kinetic properties for diluted and undiluted polyurethane systems. Heat of reaction, order of reaction, preexponential constant, and activation energy were obtained from the experimental DSC data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2733–2742, 2002     

Selective solvation of polystyrene in tetralin/cyclohexane mixtures

Refractive index increments and density increments have been measured at 307.6K for polystyrene in binary solvents of 1,2,3,4-tetrahydronaphthalene (tetralin, TET) and cyclohexane over the whole range of solvent composition. Comparison of these increments with the corresponding values obtained at dialysis equilibrium (i.e. at constant chemical potential of low molecular weight species) yielded the coefficients of selective adsorption (γ₁) of TET by the polymer. Positive values of γ₁ were exhibited at solvent compositions up to 78% (v/v) of the thermodynamically better solvent, TET. Theoretical curves of γ₁ vs. composition were calculated on the basis of, firstly, relevant interaction parameters and, secondly, interaction parameters in conjunction with solubility parameters. Both procedures afforded self-consistent results, which were, however, uniformly lower than the experimental values of γ₁.     

Styryl Dyes for Synthetic-polymer Fibres.

The synthesis of a series of dyes derived from reaction of 2-methyl-4-(N-ethyl-N-hydroxyethyl)amino, lidicyano-styrene with acid chlorides, chloroformates, isocyanates and isothiocyanates is described. Data relevant to dye characterization by electron-impact induced fragmentation is reported. Dyeing and fastness properties of the dyes on cellulose secondary acetate, cellulose triacetate, nylon 6.6 and polyester fibres are discussed in terms of dye structure. Comparison is made between some related dyes derived from 2-methyl-4-(N-ethyl-N-β-aminoethyljamino-β,βdicyanostyrene.