Quantifying Noise of Dynamic Vision Sensor

Dynamic visual sensors (DVS) are characterized by a large amount of background activity (BA) noise, which it is mixed with the original (cleaned) sensor signal. The dynamic nature of the signal and the absence in practical application of the ground truth, it clearly makes difficult to distinguish between noise and the cleaned sensor signals using standard image processing techniques. In this letter, a new technique is presented to characterise BA noise derived from the Detrended Fluctuation Analysis (DFA). The proposed technique can be used to address an existing DVS issues, which is how to quantitatively characterised noise and signal without ground truth, and how to derive an optimal denoising filter parameters. The solution of the latter problem is demonstrated for the popular real moving-car dataset.Comment: 5 pages, 4 figures, submitted to the IEEE Signal Processing Letter

Constrained flow around a magnetic obstacle

Many practical applications exploit an external local magnetic field -- magnetic obstacle -- as an essential part of their constructions. Recently, it has been demonstrated that the flow of an electrically conducting fluid influenced by an external field can show several kinds of recirculation. The present paper reports a 3D numerical study whose some results are compared with an experiment about such a flow in a rectangular duct.Comment: accepted to JFM, 26 pages, 14 figure

Theory of the Lorentz force flowmeter

A Lorentz force flowmeter is a device for the contactless measurement of flow rates in electrically conducting fluids. It is based on the measurement of a force on a magnet system that acts upon the flow. We formulate the theory of the Lorentz force flowmeter which connects the measured force to the unknown flow rate. We first apply the theory to three specific cases, namely (i) pipe flow exposed to a longitudinal magnetic field, (ii) pipe flow under the influence of a transverse magnetic field and (iii) interaction of a localized distribution of magnetic material with a uniformly moving sheet of metal. These examples provide the key scaling laws of the method and illustrate how the force depends on the shape of the velocity profile and the presence of turbulent fluctuations in the flow. Moreover, we formulate the general kinematic theory which holds for arbitrary distributions of magnetic material or electric currents and for any velocity distribution and which provides a rational framework for the prediction of the sensitivity of Lorentz force flowmeters in laboratory experiments and in industrial practice.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58171/2/njp7_8_299.pd

APPLICATION OF A GETE GAS MODEL TO THE INVESTIGATION OF KINETIC CHARACTERISTICS OF LOCAL HETEROGENEOUS SYSTEMS AT THE EXAMPLE OF CALCULATIONS OF MEMBRANE PENETRABILITY AND THER-MOSORPTION SPECTRUMS

The expression for the calculation of penetrability of homogeneous-microheterogeneous membranes has been obtained. The influence of wall heterogeneities of micropores on sorption and diffusion of lateral interacting molecules in them has been investigated. The joint influence of the base heterogeneity and lateral interaction of adatoms on thermosorption spectrums has been also investigated. Methodical bases for the calculation of kinetic characteristics of processes in microheterogeneous systems "gas-solid body" and in condensed phases have been developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Numerical simulation of a longitudinal Lorentz force flowmeter for turbulent flows in a circular pipe

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