Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item Satellite image contrast enhancement algorithm based on Plateau Histogram Equalization(Institute of Electrical and Electronics Engineers Inc., 2014) Raju, R.; Dwarakish, G.S.; Venkat Reddy, D.The quality of remotely sensed satellite images depends on the reflected electromagnetic radiation from earth surface features. Lack of consistent and similar amounts of energy reflected by different features from earth surface, results a low contrast satellite image. Enhancement of contrast is needed for satellite images to identify and extract objects from images, where features are essential in studying earth applications. In this paper, a new contrast enhancement technique for satellite images based on clipping or plateau histogram equalization has been proposed. The technique adopted Bi-Histogram Equalization with Plateau Limit (BHEPL) for image decomposition and Self-Adaptive Plateau Histogram Equalization (SAPHE) for threshold calculation. The proposed method has been compared with existing methods such as Histogram Equalization (HE), Brightness Preserving Bi-Histogram Equalization (BBHE), Minimum Mean Brightness Error Bi-Histogram Equalization (MMBEBHE), Dynamic Histogram Equalization (DHE), Bi-Histogram Equalization with Plateau Limit (BHEPL) and Self-Adaptive Plateau Histogram Equalization (SAPHE) with image quality measures such as Absolute Mean Brightness Error (AMBE) and Peak-Signal to Noise Ratio (PSNR). © 2014 IEEE.Item Implementation of a RTAI-Linux-based PLL and firing pulse generation for a laboratory TCSC(Institute of Electrical and Electronics Engineers Inc., 2014) Raju, R.; Shubhanga, K.N.This paper presents the implementation of a phase locked loop (PLL) using Real-Time Application Interface (RTAI) on Linux platform. This PLL has been employed to generate firing pulses for gating the thyristors of a thyristor controlled series capacitor (TCSC) developed in the laboratory. The working of the TCSC in the capacitive vernier mode is depicted through a set of oscilloscope plots. A detailed waveform analysis is also carried out to show the harmonic performance of the TCSC. © 2014 IEEE.Item Laboratory implementation of a thyristor controlled series capacitor(Institute of Electrical and Electronics Engineers Inc., 2015) Raju, R.; Shubhanga, K.N.In this paper, performance details of a thyristor controlled series capacitor (TCSC) implemented in a laboratory environment, are presented. The setup is not only simple, but also uses an open-source Linux-based real-time application interface (RTAI) software to realize a phase locked loop (PLL). With this PLL, the performance of the TCSC for the capacitor voltage and the line current reference signals, are compared. With the line current referencing, a non-ideal TCR inductor is found to offer a different fundamental TCSC reactance for a given firing angle command compared to the capacitor voltage referencing. Such a setup gives a better insight into TCSC operation and greatly augments the classroom studies. © 2015 IEEE.Item Effect of a non-ideal inductor on the performance of a laboratory TCSC and implementation of a current controller(Institute of Electrical and Electronics Engineers Inc., 2016) Raju, R.; Shubhanga, K.N.In this paper a procedure to estimate the effective resistance of a non-ideal inductor which is used to build a laboratory TCSC is presented. Having estimated the effective resistance, its influence on the performance of the TCSC is studied, not only through PSCAD/EMTDC-based simulation, but also by capturing the waveforms from the experimental setup. Further, a current controller is implemented on a real-time application interface (RTAI) platform, employing recursive Fourier-series-based current estimation technique. Case studies are presented to demonstrate the controller performance and its usefulness in augmenting the classroom teaching. © 2016 IEEE.