arXiv subjects

Adib Rahman

Publications and source records attributed to Adib Rahman.

4 recordsLinked to original sources

arXiv2026

Adaptive Temporal Dynamics for Personalized Emotion Recognition: A Liquid Neural Network Approach

Emotion recognition from physiological signals remains challenging due to their non-stationary, noisy, and subject-dependent characteristics. This work presents, to the best of our knowledge, the first comprehensive application of liquid neural networks for EEG-based emotion recognition. The proposed multimodal framework combines convolutional feature extraction, liquid neural networks with learnable time constants, and attention-guided fusion to model temporal EEG dynamics with complementary peripheral physiological and personality features. Dedicated subnetworks are used to process EEG features and auxiliary modalities, and a shared autoencoder-based fusion module is used to learn discriminative latent representations before classification. Subject-dependent experiments conducted on the PhyMER dataset across seven emotional classes achieve an accuracy of 95.45%, surpassing previously reported results. Furthermore, temporal attention analysis provides interpretable insights into emotion-specific temporal relevance, and t-SNE visualizations demonstrate enhanced class separability, highlighting the effectiveness of the proposed approach. Finally, statistical analysis of temporal dynamics confirms that the network self-organizes into distinct functional groups with specialized fast and slow neurons, proving it independently tunes learnable time constants and memory dominance to effectively capture complex emotion artifacts.

eess.SP↗

arXiv2025

Quasi-BICs due to symmetry mismatch in architected elastic plates

We report the existence of quasi-bound modes in the continuum (quasi-BICs) in architected elastic plates based on a square lattice. The structure consists of topologically trivial and nontrivial lattices, forming an interface and maintaining C2 symmetry. Carefully engineered interface gives rise to center quasi-BICs. We show how the mismatch in symmetry between the Bloch modes of the lattice and the defect modes confine them at the defect center, resulting in quasi-BICs. Our analysis begins with a square lattice-based spring-mass system. Finite element simulations on an architected plate comprising of slender curved and straight beams to achieve the desired stiffness variation predict quasi-BICs analogous to those in the discrete model. These predictions are validated with Laser Doppler vibrometry based experiments, confirming the presence of a quasi-BIC in the structure. The concept of quasi-BICs arising from modal symmetry mismatch paves the way for achieving localized modes in elastic structures, with potential applications as resonators.

cond-mat.mes-hall↗

arXiv2023

Observation of elastic bound modes in the continuum in architected beams

We report the experimental observation of an elastic bound mode in the continuum (BIC) in a compact region of an architected beam. We consider a long slender beam with rigid masses attached at periodic intervals, with a compact segment bounded by four protruding side beams. The key idea is to seek a mode where the side beams move out-of-phase with the compact region, thereby nullifying the forces and moments outside this region and resulting in a bound mode. The structure is modeled using Euler-Bernoulli beam theory and the side beams are designed by imposing equilibrium constraints required for a BIC. Multiple BICs are found in the compact region, and for each BIC, we find a one-parameter family of BIC supporting side beam designs. The predictions are verified by three-dimensional finite element simulations, followed by their experimental observation using laser Doppler vibrometry in a macro-scale structure. Our approach allows to achieve BICs in an arbitrary sized compact region of the architected beam. Our findings may open avenues for confining elastic wave energy in compact regions for applications in sensors and resonators.

physics.class-ph↗

arXiv2022

Bound modes in the continuum based phononic waveguides

We analytically predict and numerically demonstrate the existence of a family of bound modes in the continuum (BICs) in bi-layered spring mass chains. A coupled array of such chains is then used to illustrate transversely bound waves propagating along a channel in a lattice. We start by considering the compact region formed by coupling two spring mass chains with defects and predict bound modes arising due to reflection symmetries in this region. Dispersion analysis of a waveguide consisting of an array of appropriately coupled bi-layered chains reveals the presence of a branch having bound modes in the passband. Finally, detailed numerical analyses verify the existence of a BIC and its propagation through the waveguide at passband frequencies without energy leakage. The framework allows to achieve BICs and their propagation, for any arbitrary size and location of the compact region. Such BICs open avenues for novel classes of resonators with extremely high $Q$ factors due to zero energy leakage and allow for guiding confined waves in structures without requiring bandgaps.

cond-mat.mes-hall↗