Digital image splicing detection technique using optimal threshold based local ternary pattern

Multimedia Tools and Applications - Digital images were considered as authentic proof of evidence some years ago but advancement in technology has made image tampering an easy task for every user....     

Cobalt substituted ZnO thin films: a potential candidate for spintronics

Cobalt doped zinc oxide thin films have been deposited using spray pyrolysis method. These single phasic films exhibited [100] preferential texture and small decrease in the lattice parameter on cobalt substitution. The films having different Co concentration have almost similar surface morphology and microstructure. These Zn_1?x Co _x O (x ≤ 0.10) thin films distinctly showed ferromagnetic character at room temperature. The optical transmission measurements of these films clearly proved that in these films Co substitutes for Zn²⁺ and exists in +2 state. Based on the optical, structural and magnetic measurements, the possibility of occurrence of ferromagnetic ordering due to cobalt clustering is ruled out in these spray-pyrolyzed films. A correlation of the observed ferromagnetic behavior in these Zn_1?x Co _x O films with structural change resulting from the addition of Co is presented in this paper.     

Neurodynamics for auditory stream segregation: tracking sounds in the mustached bat's natural environment

During navigation and the search phase of foraging, mustached bats emit approximately 25 ms long echolocation pulses (at 10-40 Hz) that contain multiple harmonics of a constant frequency (CF) component followed by a short (3 ms) downward frequency modulation. In the context of auditory stream segregation, therefore, bats may either perceive a coherent pulse-echo sequence (PEPE...), or segregated pulse and echo streams (P-P-P... and E-E-E...). To identify the neural mechanisms for stream segregation in bats, we developed a simple yet realistic neural network model with seven layers and 420 nodes. Our model required recurrent and lateral inhibition to enable output nodes in the network to 'latch-on' to a single tone (corresponding to a CF component in either the pulse or echo), i.e., exhibit differential suppression by the alternating two tones presented at a high rate (> 10 Hz). To test the applicability of our model to echolocation, we obtained neurophysiological data from the primary auditory cortex of awake mustached bats. Event-related potentials reliably reproduced the latching behaviour observed at output nodes in the network. Pulse as well as nontarget (clutter) echo CFs facilitated this latching. Individual single unit responses were erratic, but when summed over several recording sites, they also exhibited reliable latching behaviour even at 40 Hz. On the basis of these findings, we propose that a neural correlate of auditory stream segregation is present within localized synaptic activity in the mustached bat's auditory cortex and this mechanism may enhance the perception of echolocation sounds in the natural environment.     

Acoustic diffraction by a rigid annular disk

Summary The subject of this paper is the problem of acoustic diffraction by a perfectly rigid annular disk. The method of solution rests on formulating the problem in terms of an integral equation which embodies the steady state wave equation as well as the boundary conditions. This Fredholm integral equation of the first kind is converted into four simultaneous integral equations of the second kind by using Williams' integral equation technique. These four integral equations are subsequently solved by the standard iterative procedure when the frequency of the incident wave is low and the inner radius of the annulus is small.