Semi-Symmetric Metric Connection on a 3-Dimensional Trans-Sasakian Manifold

The object of the present paper is to study the nature of curvature tensor, Ricci tensor, scalar curvature and Weyl conformal curvature tensors with respect to a semi-symmetric metric connection on a 3-dimensional trans-Sasakian manifold.We have given an example regarding it

A high performance position sensorless surface permanent magnet synchronous motor drive based on flux angle

A position sensorless Surface Permanent Magnet Synchronous Motor (SPMSM) drive based on flux angle is presented in this paper. The motor equations are written in rotor fixed d-q reference frame. A PID controller is used to process the speed error to generate the reference torque current keeping the magnetizing current fixed. The estimated stator flux using Recurrent Neural Network (RNN) is used to find out the rotor position. The flux angle and the reference current phasor angle are used in vector rotator to generate the reference phase currents. Hysteresis current controller block controls the switching of the 3-phase inverter to apply voltage to the motor stator. Simulation studies on different operating conditions indicate the acceptability of the drive system. The drive system only requires a speed transducer and is free from position sensor requirement. The proposed control scheme is robust under load torque disturbances and motor parameter variations. It is also simple and low cost to implement in a practical environment

High Precision Techniques for Imaging through Turbulence

Imaging through a turbulent medium, such as the atmosphere or the wavy surface of water, is highly desired in many scientific and military applications. This is a very challenging task due to the time-varying shifts and blurs captured in the images. This thesis deals with the geometrical restoration of such images captured as video sequences. These ordinarily undesirable geometrical distortions also act as information compressors and can be exploited to extract further bandwidth from the images to produce high-quality images from their lower resolution counterparts. The research investigations cover both the atmospheric as well as underwater imaging.First, a simple and robust method is reviewed and improved upon to restore warped frames using motion vector fields (shiftmaps) obtained through a motion estimation technique. The centroid of the pixel shiftmaps is then calculated to generate individual restoration shiftmaps for each warped frame. The centroid shiftmap is updated iteratively to take the restored frames closer to their likely ground-truth. Furthermore, the image restoration method is made predictive by the use of a generalized regression neural network (GRNN), where the pixel shiftmaps amongst successive frames are used for training the network to determine the underlying warping functions, which in turn, are used to predict the upcoming warped frame. Moreover, the accurate motionanalysis along with video stabilization method is utilized for reliable segmentation of video frames into stable and moving components and subsequently stabilizing frames, keeping real moving objects unaltered. Motivated by the successful application of GRNN in warp prediction, finally, a new and more efficient target tracking algorithm is proposed that works based on determining the centre and the area of moving objects, using those features for GRNN training, and employing the trained network to estimate the objects’ locations in the next frame. Both the accuracy and the potential of the proposed algorithms have been investigated. The results presented are of both theoretical and practical interest and offer new efficient tools for substantial improvement of infrastructure of machine vision-based systems in general and of intelligent surveillance systems in particular

Novel Meandered Line EBG Filters with Significant Size Reduction Using Sine Tapering

Tapering electromagnetic bandgap (EBG) structures is a common method in designing microstrip filters with different periodic structures. A novel technique for tapering EBG structures with the amplitude coefficients obtained from the sine function has been illustrated. This method deduces mellifluous coefficients that improves the performance with reasonable stopband width, preferable insertion loss level, and much-minimized passband ripples compared to similar designs with other tapering methods (e.g., binomial distribution, Chebyshev distribution, and conventional cosine tapering). It also offers tandem use of tapered EBG structures, leading to the novel meandered transmission line tandem design that significantly reduces the length of the filter; more than 40% is possible, compared to the uniform and conventional tapered designs. Size reduction on such a large scale will benefit the designers with the limited space issues

Vector control of a position sensorless SPMSM drive with RNN based stator flux estimator

A position sensorless Surface Permanent Magnet Synchronous Motor (SPMSM) drive based on single layer Recurrent Neural Network (RNN) is presented in this paper. The motor equations are written in rotor fixed d-q reference frame. A PID controller is used to process the speed error to generate the reference torque current keeping the magnetizing current fixed. The RNN estimator is used to estimate flux components along the stator fixed stationary axes. The flux angle and the reference current phasor angle are used in vector rotator to generate the reference phase currents. Hysteresis current controller block controls the switching of the three phase inverter to apply voltage to the motor stator. Simulation studies on different operating conditions indicate the acceptability of the drive system. The proposed estimator can be used to accurately measure the motor fluxes and rotor angle over a wide speed range. The proposed control scheme is robust under load torque disturbances and motor parameter variations. It is also simple and low cost to implememnt in a practical environmen

A Centroid Algorithm for Stabilization of Turbulence-Degraded Underwater Videos

This paper addresses the problem of stabilizing underwater videos with non-uniform geometric deformations or warping due to a wavy water surface. It presents an improved method to correct these geometric deformations of the frames, providing a high-quality stabilized video output. For this purpose, a non-rigid image registration technique is employed to accurately align the warped frames with respect to a prototype frame and to estimate the deformation parameters, which in turn, are applied in an image dewarping technique. The prototype frame is chosen from the video sequence based on a sharpness assessment. The effectiveness of the proposed method is validated by applying it on both synthetic and real- world sequences using various quality metrics. A performance comparison with an existing method confirms the higher efficacy of the proposed method

Number 2

ABSTRACT This paper proposes a position sensorless vector control methodology for Synchronous Reluctance Motor (SynRM) drive. In this control scheme, instead of a conventional Six Switch Three Phase (SSTP) inverter a Four Switch Three Phase (FSTP) inverter is used. The reduction of the number of power switches from six to four improves the cost-effectiveness, volumecompactness and reliability of the three phase inverters. The control system estimates the motor stator flux and its position using a Recurrent Neural Network (RNN). A simulation model of the drive system is developed and analyzed in order to validate the proposed approach. The robustness of the drive system is tested for different operating conditions. Simulation results show that the proposed drive system provides a fast speed response and good disturbance rejection capability

Thin Domain Wide Electrode (TDWE) Phantoms for Electrical Impedance Tomography (EIT)

Electrical Impedance Tomography (EIT) is a nonlinear ill posed inverse problem which is very prone to modeling errors. 2D-EIT reconstructs the spatial distribution of the object impedance profile comparing the measurements of boundary voltage data collected from a 3D object with the calculated data generated from an absolute 2D domain in computer. As the 2D-EIT assumes current conduction in two dimensional plane of EIT electrode array, the 2D EIT systems working with a practical 3D phantom produce some error and hence the forward modeling should be modified accordingly. On the other hand, the 3D error can be reduced by using long electrodes but in long electrode system, the electrode to electrode gap (EEGR) ratio required to be maintained to attain a good sensitivity is found difficult. In this direction the thin domain wide electrode (TDWE) phantoms are proposed for electrical impedance tomography (EIT) to reduce the 3D error by maintaining the required EEGR. A LabVIEW based multifrequency EIT instrumentation has been developed and a number of TDWE phantoms with different inhomogeneity configurations have been studied. Absolute impedance images reconstructed in EIDORS, demonstrate that developed TDWE phantom improves image quality by reducing the 3D error