Improved Compressed Sensing Matrixes for Insulator Leakage Current Data Compressing

Insulator fault may lead to the accident of power network，thus the on-line monitoring of insulator is very significant. Low rates wireless network is used for data transmission of leakage current. Determination of the measurement matrix is the significant step for realizing the compressed sensing theory. This article comes up with new sparse matrices which can be used as compressed sensing matrices to make data compression and reconstruction of leakage current with the compressed sensing. This theory can achieve pretty good results. And then this article performs that the reconstitution effect is almost the same using the measurement matrix of Toeplitz matrix, circulant matrix or sparse matrix, as using a classical measurement matrix. DOI : http://dx.doi.org/10.11591/telkomnika.v12i6.141

Charting a course for chemistry

To mark the occasion of Nature Chemistry turning 10 years old, we asked scientists working in different areas of chemistry to tell us what they thought the most exciting, interesting or challenging aspects related to the development of their main field of research will be — here is what they said

Stability and drag reduction in transient channel flow of fibre suspension

Drag reduction features in the transition regime of channel flow with fibre suspension were analyzed in terms of the linear stability theory. The modified stability equation was obtained based on the slender-body theory and natural closure approximation. Results of the stability analysis show attenuating effects of fibre additives to the flow instability. For the cases leading to transition, drag reduction rate increases with the characteristic parameter H of fibres. The mechanism of drag reduction by fibres is revealed through the variation of velocity profile and the decrease of wall shear stress. The theoretical results are qualitatively consistent with some typical experiments