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according to the obvious deficiencies of the regional division of the traditional gray level-average gray level two-dimensional histogram, an improved two-dimensional Otsu's threshold segmentation method and its fast algorithms based on gray level-gradient two-dimensional histogram are given. The results show that this method can be better resistant to(More)
We examine mode couplings in chiral fiber grating (CFG) with N-fold rotation symmetry in the cross section and show how the angular momentum matching condition in couplings determines the generation and conversion of orbital angular momentum (OAM) beams. Then we discuss interactions of OAM and spin angular momentum in single- and double-helix long-period(More)
We propose a more accurate and efficient reconstruction method used in testing large aspheric surfaces with annular subaperture interferometry. By the introduction of the Zernike annular polynomials that are orthogonal over the annular region, the method proposed here eliminates the coupling problem in the earlier reconstruction algorithm based on Zernike(More)
The present technique of recycling waste wires and cables is the cable granulator technique. The cable granulator mostly adopt mechanical method to cut and grind cable wastes into short pieces and then use screen separation process to get metal (mainly copper) and insulating material (mainly plastic). However, cutting and grinding process causes serious(More)
This paper presents a novel balanced dual-band bandpass filter with in-band common-mode suppression via multiple transmission zeros from the doubly short-ended coupled line. Through the analysis of coupled line structures, the transmission zeros in the differential- and common-mode equivalent circuits are extensively studied. In differential-mode, the(More)
A novel humidity sensor with high sensitivity, short response time and excellent reproducibility was developed. The sensor utilized single-port surface acoustic wave resonator (SAWR) with high resonance frequency as basic component. The silicone-containing polyelectrolyte was electro sprayed onto SAWR surface to form humidity-sensitive film with(More)
We developed a high-index-contrast photonic structure for improving the light extraction efficiency of light-emitting diodes (LEDs) by a self-assembly approach. In this approach, a two-dimensional grating can be non-lithographically integrated on the top of virtually any types of LEDs with controlled structural parameters and material indices. As a proof of(More)
Model of echo-to-interference ratio of bistatic sonar in shallow water was set up. Transmission loss of direct blasts at receiver were calculated with coherent multipaths transmission model based on ray theory in shallow water. Bistatic target strength of Simple BeTSSi-submarine versus azimuthal and bistatic angles were obtained by using Kirchhoff(More)