A new approach for design of an efficient FPGA-based reconfigurable convolver for image processing

The Journal of Supercomputing - Two-dimensional convolution plays a fundamental role in different image processing applications. Image convolving with different kernel sizes enriches the overall...     

The Role of Inhibitors' Molecular Structure on Asphaltene Deposition in Reservoir Conditions

Abstract

Due to the lack of research on the effects of inhibitors on asphaltene flocculation in reservoir conditions, operational application of inhibitors in the petroleum industry has not been clearly investigated. In previous studies, molecular structures and the effectiveness of prevalent inhibitors were investigated and other parameters such as cost and environmental issues were also considered.

The proposed inhibitor was tested over a wide variety of Iranian asphaltenic crude oils and optimized quantities of the inhibitor were studied in detail. Moreover, qualitative and quantitative effects of the proposed inhibitor were tested on crude oils in atmospheric conditions and the effect of the proposed inhibitor on asphaltene flocculation and deposition at reservoir conditions was investigated. The amounts of change in onset pressure point due to injection of the inhibitor were measured at reservoir conditions. The proposed inhibitor is in good agreement with reservoir conditions.     

Subsurface diffuse optical tomography can localize absorber and fluorescent objects but recovered image sensitivity is nonlinear with depth

Subsurface tomography with diffuse light has been investigated with a noncontact approach to characterize the performance of absorption and fluorescence imaging. Using both simulations and experiments, the reconstruction of local subsurface heterogeneity is demonstrated, but the recovery of target size and fluorophore concentration is not linear when changes in depth occur, whereas the mean position of the object for experimental fluorescent and absorber targets is accurate to within 0.5 and 1.45 mm when located within the first 10 mm below the surface. Improvements in the linearity of the response with depth appear to remain challenging and may ultimately limit the approach to detection rather than characterization applications. However, increases in tissue curvature and/or the addition of prior information are expected to improve the linearity of the response. The potential for this type of imaging technique to serve as a surgical guide is highlighted.     

Transient performance improvement of model reference adaptive control: LMI‐based resetting

In this paper, a resetting mechanism is proposed to enhance the transient performance of model reference adaptive control. While the suggested method has a simple structure, it is capable of taking into account both the desired steady‐state behavior and the transient response, simultaneously. Whenever the transient specification is not satisfying, there is a jump in the controller parameters. This jump is determined by designing an optimal reset law. At the reset times, the after‐reset values of parameters are calculated based on a minimization problem. The considered cost function is a mixed H₂/H_∞ criterion, which minimizes the tracking error. The optimization problem is converted to an LMI formulation, and the reset law is designed by solving this LMI at certain reset times. To verify the effectiveness of the proposed approach, simulation results are presented.