Sharif Digital Repository

The proper orthogonal decomposition (POD) method is used and assessed as a fast technique for estimation of aerodynamics data with variation of some aerodynamics parameters. In this way, four extensions to the POD method are considered for steady viscous/inviscid compressible aerodynamic applications. The first extension is a coupling between the POD method with a cubic spline interpolation, as introduced for inviscid flows. The second and the third ones are essentially new techniques which are introduced here for the first time. In these methods, some additional calibrations (including a kind of filtering and reprojection) are needed to achieving more accurate estimations. The so-called... 

A major challenge in automatic irrigation of extensive agricultural fields is large scale soil moisture monitoring. Proper orthogonal decomposition (POD) is a widespread data-driven dimension reduction technique which can be combined with QR pivoting method for estimation of high-dimensional signals and optimal sensor placement. However, it requires computation of tailored basis functions which should be extracted from known training data. This is feasible for problems with constant features such as face recognition. However, using fixed bases (and probably fixed sensor selection) may not be an appropriate approach for estimation of signals with time-variant features. This paper demonstrates... 

MIMO radar is the next generation radar which transmits arbitrary waveforms at each one of its apertures. It has been shown that the design of waveforms for MIMO radars in order to synthesize a desired spatial beampattern is mapped into a waveform correlation matrix R design in the narrowband case. As of now, given a desired beampattern or estimated locations information of targets, calculating R has been modeled as an optimization problem like semi-definite programming. Also, in some special cases like rectangular beampattern, closed-form solutions for R has been proposed. In this paper, we introduce a fast algorithm which is capable of designing R in order to achieve more arbitrary... 

Atomic force microscope (AFM) is one of the most versatile and powerful devices capable of producing high-resolution images of nanomaterial. Many researchers are widely investigating to improve the scanning speed and image quality of AFM by proposing different techniques. Here, we aim to present a novel approach based on the smooth orthogonal decomposition for the estimation of the surface topography in AFM. The technique proposed in this research not only eliminates the need for a closed-loop controller but also acquires the surface three-dimensional shape (topography) very quickly and accurately. The proposed technique relies on the fact that in the tapping mode of atomic force microscopy,...