Modelling of surface roughness based on geometrical parameters of woven fabrics

A novel model has been developed for the surface roughness evaluation of woven fabrics, based on fabric geometrical parameters. The model is developed based on the properties of twenty five groups of woven fabrics consisting of five various weave structures and five different weft densities. The output of the model is validated through a set of subjective roughness pair-comparison tests. The model output is found to be in accordance with the roughness scale value which is obtained from subjective tests, to a reasonable extent. The statistical analysis of roughness results shows that the effect of fabric structural parameters such as weave structure and weft density is significant in the confidence range of 95%. This model can be utilized for the prediction of the roughness behavior of various types of woven fabrics. Bearing in mind the influence of fabric surface roughness on the comfort and aesthetic properties of cloths, the usage of the model is a guide for selecting the suitable fabric for various end uses

Measurement of yarn density in woven fabrics using fringe projection moiré techniques

Fringe projection Moiré, a novel, accurate and fast technique with high repeatability, has been developed in order to measure the yarn density in woven fabrics. In the experimental set-up, collimated laser beams illuminate a Ronchi grating to be projected on a fabric. In case the density of projected lines and fabric becomes the same, the desired moiré pattern is observed on the fabric. As a result, the measurement of the distance between grating and fabric can guide us to find out fabric yarn density by using simple equations. In this regard, twenty five groups of shirting woven fabrics consisting of five weave structures and five different weft densities have been tested. The results show that there is a high correlation (R2 =0.9932) between the data obtained from the new and the conventional methods

Polarization characterization of biological tissues using Stokes vector decomposition

A method is proposed for characterizing the polarization properties of a depolarizing anisotropic medium based on decomposition of the Stokes vector representing the light emerging from the medium. The exiting Stokes vector can be considered as being decomposed into two parts, namely a completely unpolarized and a completely polarized part. Then, the Mueller matrix representing the sample can be extracted as a superposition of two distinguishable parts. The differential Mueller formalism is applied to one part of the Muller matrix. Here, explicit expressions are presented for the extraction of polarization properties of the medium. Results indicate that the proposed method is a promising method for characterization of complicated media such as biological tissues

Singular value analysis of the Mueller matrix in comparison with eigenvalue analysis of the coherency matrix in polarization characterization of media

Singular values of the arbitrary Mueller matrix are determined to be indicators of some polarization properties of the medium such as depolarization and diattenuation. Whereas eigenvalue analysis of the coherency matrix may wrongly characterize media with simultaneous strong depolarization and diattenuation effects. The comparison between the patterns of changes in singular-value and eigenvalue trends of the coherency matrix in experimental Mueller matrices, shows that singular values of the Mueller matrix are more capable of discriminating media with close degrees of depolarization

Modelling of surface roughness based on geometrical parameters of woven fabrics

43-50A novel model has been developed for the surface roughness evaluation of woven fabrics, based on fabric geometrical parameters. The model is developed based on the properties of twenty five groups of woven fabrics consisting of five various weave structures and five different weft densities. The output of the model is validated through a set of subjective roughness pair-comparison tests. The model output is found to be in accordance with the roughness scale value which is obtained from subjective tests, to a reasonable extent. The statistical analysis of roughness results shows that the effect of fabric structural parameters such as weave structure and weft density is significant in the confidence range of 95%. This model can be utilized for the prediction of the roughness behavior of various types of woven fabrics. Bearing in mind the influence of fabric surface roughness on the comfort and aesthetic properties of cloths, the usage of the model is a guide for selecting the suitable fabric for various end uses

Measurement of yarn density in woven fabrics using fringe projection moiré techniques

203-207Fringe projection Moiré, a novel, accurate and fast technique with high repeatability, has been developed in order to measure the yarn density in woven fabrics. In the experimental set-up, collimated laser beams illuminate a Ronchi grating to be projected on a fabric. In case the density of projected lines and fabric becomes the same, the desired moiré pattern is observed on the fabric. As a result, the measurement of the distance between grating and fabric can guide us to find out fabric yarn density by using simple equations. In this regard, twenty five groups of shirting woven fabrics consisting of five weave structures and five different weft densities have been tested. The results show that there is a high correlation (R2 =0.9932) between the data obtained from the new and the conventional methods