Faculty Publications
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Item Gradient-oriented directional predictor for HEVC planar and angular intra prediction modes to enhance lossless compression(Elsevier GmbH journals@elsevier.com, 2018) Shilpa Kamath, S.; Aparna., P.; Antony, A.Recent advancements in the capture and display technologies motivated the ITU-T Video Coding Experts Group and ISO/IEC Moving Picture Experts Group to jointly develop the High-Efficiency Video Coding (HEVC), a state-of-the-art video coding standard for efficient compression. The compression applications that essentially require lossless compression scenarios include medical imaging, video analytics, video surveillance, video streaming etc., where the content reconstruction should be flawless. In the proposed work, we present a gradient-oriented directional prediction (GDP) strategy at the pixel level to enhance the compression efficiency of the conventional block-based planar and angular intra prediction in the HEVC lossless mode. The detailed experimental analysis demonstrates that the proposed method outperforms the lossless mode of HEVC anchor in terms of bit-rate savings by 8.29%, 1.65%, 1.94% and 2.21% for Main-AI, LD, LDP and RA configurations respectively, without impairing the computational complexity. The experimental results also illustrates that the proposed predictor performs superior to the existing state-of-the-art techniques in the literature. © 2018 Elsevier GmbHItem Pixelwise improvised blend of predictors in HEVC lossless mode(Elsevier GmbH, 2020) Shilpa Kamath, S.; Aparna., P.; Antony, A.The commendable work by the two video coding pioneers ISO/IEC and ITU-T, to handle the next-generation of multimedia services has led to the evolution of High Efficiency Video Coding (HEVC) standard. The lossless mode of HEVC is essential when no loss in fidelity is desired to aide most of the real-world applications like video analytics, web collaboration, remote desktop sharing, etc. The proposed work intends to improvise the HEVC intra prediction scheme through the application of the heuristic history-based blend of predefined sub-predictors, while in lossless mode. The prime element of the locally adaptive mechanism is the derivation of the penalizing factors that are imposed on the sub-predictors, based on the neighborhood residuals. The experimental analysis highlights that the proposed method outperforms the lossless mode of HEVC anchor and the prevalent state-of-the-art prediction techniques in terms of savings in bit-rate which is achieved without any increase in run-time. © 2019 Elsevier GmbHItem Evaluation of piezoelectric behavior and biocompatibility of poly(vinylidene fluoride) ultrafine fibers with incorporated talc nanosheets(John Wiley and Sons Inc, 2022) Shetty, S.; SelvaKumar, S.; Salehi, S.; Pellert, A.; Scheibel, M.; Scheibel, T.; Anandhan, S.Herein, we fabricated biocompatible ultrafine fibers based on talc nanosheets (TNS)/PVDF composites that can exhibit robust electromechanical responses. Piezoresponse force microscopy (PFM) was extensively used to decode various characteristics, including ferroelectric and piezoelectric coefficients. The 0.5 wt% TNS dispersed ultrafine fibers exhibited well-defined ferroelectric characteristics with an enhanced piezoelectric coefficient (d33) of ≈43.3 pm/V compared to 10 pm/V measured for the pristine PVDF ultrafine fibers. It was observed that the piezoelectric coefficient values strongly depended on the morphology and electroactive phase fraction of the ensuing composite ultrafine fiber. The advantage of a high aspect ratio and surface charges offered by TNS alongside electrospinning augmented the composite ultrafine fiber's piezoelectric response. Further, in-vitro cytotoxicity of the TNS/PVDF composite ultrafine fibers was examined using BALB/3T3 fibroblasts based on ISO Standard 10993-5. Importantly, the new composite fibers showed no cytotoxic response and the exposed fibroblasts showed excellent viability. Thus, these fabricated TNS/PVDF piezoelectric ultrafine fibers are well suited for applications in bioelectronics, especially as flexible wearable electronic devices, including sensors. © 2022 Wiley Periodicals LLC.Item Utilization of rice husk and de-oiled cashew nut shell cake agro-wastes to produce ISO standard pellets and its synergistic behavior(Elsevier Ltd, 2025) Suriyakumar, S.; Mahalingam, H.; Ruben Sudhakar, R.S.The biomass pellet market is experiencing rapid growth, playing a critical role in addressing the escalating energy demand and environmental challenges. In India, pellets are predominantly produced from agricultural residues like rice husk, sawdust, straw, corn stalk, sugarcane bagasse, and groundnut shells. Among these, rice husk (RH) pellets are limited by their high ash content, low calorific value, and high moisture requirements during the pelletization process. These limitations can be effectively mitigated through rice husk co-pelletization with deoiled cashew nut shell cake (CC) that remains unexplored in the literature. This study aims to develop rice husk–cashew nut shell (RH-CC) blend pellets by identifying the optimal blend ratio and pelletizing parameters based on their physical and mechanical properties. RH-CC pellets showed that increasing CC addition to RH improved the bulk density, durability and calorific value. The optimization was performed using the desirability functional approach, based on ISO standards. The optimized conditions for 6, 8 and 10 mm pellets were identified as 84, 88, and 81 °C respectively, at a pressure of 180 MPa and 57 % CC blend for which the results are bulk densities of 684, 693, and 652 kg/m3 respectively, pellet durability of 97.1 %, moisture content ranging from 5.4 to 6.3 wt%, and calorific value of 16.7 MJ/kg belonging to I2 category. Additionally, TGA studies were performed to investigate the synergy of the pellets. Utilizing untreated rice husk in RH-CC pellets provides a sustainable alternative to fossil fuels, helping to reduce stubble burning and offering farmers additional income while supporting a cleaner energy future. © 2025 Elsevier Ltd