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Integrating Memristor-Based Median Filtering at the Sensor Front-End for Biomedical Image Enhancement

2026-01-01T00:00:00Z

Title: Integrating Memristor-Based Median Filtering at the Sensor Front-End for Biomedical Image Enhancement Authors: Hindoliya, Lokesh Kumar; Jyoti, Kumari; Paul, Animesh; Kumar, Mohit; Yadav, Saurabh; Pachori, Ram Bilas; Mukherjee, Shaibal Abstract: Camera sensors often struggle to capture images in low-light conditions, leading to reduced brightness, contrast, and color fidelity, and increased noise that degrades the performance. Many methods have emerged for image enhancement but they often require slow processing and blur image, making them imperfect for real-world scenarios. This paper presents the first-ever Y2O3-based transmission gate memristor comparator-based median filter (TG-MCBMF) for on-sensor image enhancement in biomedical imaging systems such as X-ray, computed tomography (CT), and magnetic resonance imaging (MRI), designed using Verilog-A. The current system performs front-end noise suppression directly at the sensor output stage, effectively removing salt and pepper (SAP) noise that is introduced during signal acquisition from sensors. The denoised images were reconstructed in MATLAB, and performance was evaluated using quality assessment metrics such as peak signal-to-noise ratio (PSNR), mean square error (MSE), and mean absolute error (MAE). The proposed filter demonstrated superior performance compared to traditional methods such as adaptive median filter (AMF), switch median (SM), and threshold and weighted median filter (TWMF), achieving PSNR values of 46.36 dB for brain CT and 43.84 dB for COVID-19 X-ray, alongside reduced MSE and MAE values of 1.5 and 29.53 for brain CT and 2.67 and 43.84 for COVID-19 X-ray, respectively. The findings indicate the potential of memristor-based filters for next-generation biomedical sensors. © 2017 IEEE.

3 D-HQAM Constellation Design and Performance Evaluation Under AWGN

2026-01-01T00:00:00Z

Title: 3 D-HQAM Constellation Design and Performance Evaluation Under AWGN Authors: Sukhsagar; Bhatia, Vimal Abstract: This letter proposes a simple and effective method for constructing higher-order three-dimensional (3D) signal constellations. The proposed approach introduces a novel 3D hexagonal quadrature amplitude modulation (3D-HQAM) scheme, where constellation points are systematically arranged in a 3D signal space to form structured lattice configurations. To address the increased decision complexity resulting from a larger number of constellation points, a dimension reduction (DR) technique is introduced, allowing the derivation of an analytical approximation of symbol error probability (SEP) under additive white Gaussian noise (AWGN) conditions. Theoretical SEPs closely match simulation results, thereby validating accuracy of the proposed method. The minimum Euclidean distance (MED) of the 3D constellations shows a minimum increase of 12.14% over 2D constellation for 8-HQAM, reaching up to 160.81% for 1024-HQAM constellations. This significant improvement in MED leads to enhanced error performance. Additionally, the average SEP performance of the proposed system is analyzed over Rayleigh faded channel. Therefore, the proposed 3D constellations are promising candidates for high-quality and reliable next-generation digital communication systems. © 2012 IEEE.

Scalable oxide-based memcapacitive crossbar arrays for 1 Kb neuromorphic memory

2025-01-01T00:00:00Z

Title: Scalable oxide-based memcapacitive crossbar arrays for 1 Kb neuromorphic memory Authors: Paul, Animesh; Yadav, Saurabh; Hindoliya, Lokesh Kumar; Dubey, Mayank; Mukherjee, Shaibal Abstract: Memcapacitors are being investigated as potential candidates for high-density data storage. However, developing high-density memcapacitive devices for complex applications is challenging due to higher cycle-to-cycle (C2C) and device-to-device (D2D) variations. In this work, we demonstrate the fabrication of high-density (32 × 32) memcapacitor crossbar arrays achieving device sizes as small as 10 µm × 10 µm using yttrium oxide (Y2O3) as the switching material, deposited via dual ion beam sputtering system. The arrays exhibit low C2C variability (1.01% for VSET and 2.56% for VRESET) and low D2D variability (1.70% for VSET and 4.83% for VRESET). The Y2O3-based crossbar arrays also display robust switching behavior, with a high on/off current ratio (IRATIO > 150), excellent endurance (∼18 000) cycles, long retention ∼160 000 s) and low power consumption of 17 pW. Electrochemical impedance spectroscopy has been utilized to examine the electrical behavior, providing insights into device performance. Neuromorphic functionalities are further demonstrated through potentiation (learning) and depression (forgetting) mechanisms. Moreover, a (16 × 16) array subset is employed to electrically encode random alphabet patterns and exhibit neuromorphic learning capabilities, underscoring the potential of these devices for analog and neuromorphic applications. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.

Bilayer Mos2 Based Memristive Crossbar Array for Neuromorphic Applications

2024-01-01T00:00:00Z

Title: Bilayer Mos2 Based Memristive Crossbar Array for Neuromorphic Applications Authors: Yadav, Saurabh; Patel, Chandrabhan; Chaudhary, Sumit; Paul, Animesh; Ghodke, Shruti Sandip; Mukherjee, Shaibal Abstract: Memristors offer considerable potential to further biological synapse modeling and are frequently utilized to simulate biological synapses due to their typical neuron-synapse-like metal-insulator-metal (MIM) sandwich structure. However, the memristor's poor stability and high switching voltage limit its wider application to the biological synapse mimicking. High-density and highly efficient neuromorphic computing capabilities is required for the realization of multi-functional neuromorphic computing integrated with 3D RRAM technology. Therefore, in this study, we have successfully fabricated a bilayer MoS2-based Memristive Crossbar Array (MCA) using Au/MoS2/Au configuration. This work not only exhibits non-volatile bipolar resistive switching characteristics with an impressive endurance of 240 cycles and a remarkable retention time of up to 3×104seconds, but also showed excellent operational uniformity with a coefficient of variation limited to 4.57 % and 2.52 % for RESET and SET voltages, respectively. © 2024 IEEE.