SearcharxivSearch

arXiv subjects

Abdurrouf

Publications and source records attributed to Abdurrouf.

3 recordsLinked to original sources

Physics-Based Explainable AI for ECG Segmentation: A Lightweight Model

The heart's electrical activity, recorded through Electrocardiography (ECG), is essential for diagnosing various cardiovascular conditions. However, many existing ECG segmentation models rely on complex, multi-layered architectures such as BiLSTM, which are computationally intensive and inefficient. This study introduces a streamlined architecture that combines spectral analysis with probabilistic predictions for ECG signal segmentation. By replacing complex layers with simpler ones, the model effectively captures both temporal and spectral features of the P, QRS, and T waves. Additionally, an Explainable AI (XAI) approach is applied to enhance model interpretability by explaining how temporal and frequency-based features contribute to ECG segmentation. By incorporating principles from physics-based AI, this method provides a clear understanding of the decision-making process, ensuring reliability and transparency in ECG analysis. This approach achieves high segmentation accuracy: 97.00% for the QRS wave, 93.33% for the T wave, and 96.07% for the P wave. These results indicate that the simplified architecture not only improves computational efficiency but also provides precise segmentation, making it a practical and effective solution for heart signal monitoring.

cs.LG

To be, or not to be: Balmer breaks in high-z galaxies with JWST

Standard models of structure formation allow us to predict the cosmic timescales relevant for the onset of star formation and the assembly history of galaxies at high redshifts ($z > 10$). The strength of the Balmer break represents a well-known diagnostic of the age and star formation history of galaxies, which enables us to compare observations with contemporary simulations - thus shedding light on the predictive power of our current models of star formation in the early universe. Here, we measure the Balmer break strength for 23 spectroscopically confirmed galaxies at redshifts $6 \lesssim z \lesssim 12$ using public JWST NIRSpec data from the cycle 1 GO 1433 and GO 2282 programs (PI Coe), as well as public spectroscopic data from the JWST Deep Extragalactic Survey (JADES). We find that the range of observed Balmer break strengths agree well with that of current simulations given our measurement uncertainties. No cases of anomalously strong Balmer breaks are detected, and therefore no severe departures from the predictions of contemporary models of star formation. However, there are indications that the number of outliers in the observed distribution, both in direction of strong and weak Balmer breaks, is higher than that predicted by simulations.

astro-ph.GA

Discovery of a strong ionized-gas outflow in an AKARI-selected Ultra-luminous Infrared Galaxy at z = 0.5

In order to construct a sample of ultra-luminous infrared galaxies (ULIRGs, with infrared luminosity, $L_{\rm IR} > 10^{12}$ L$_{\odot}$) at 0.5 < z < 1, we are conducting an optical follow-up program for bright 90-$μ$m FIR sources with a faint optical (i < 20) counterpart selected in the AKARI Far-Infrared Surveyor (FIS) Bright Source catalog (Ver.2). AKARI-FIS-V2 J0916248+073034, identified as a ULIRG at z = 0.49 in the spectroscopic follow-up observation, indicates signatures of an extremely strong outflow in its emission line profiles. Its [OIII] 5007Å emission line shows FWHM of 1830 km s$^{-1}$ and velocity shift of -770 km s$^{-1}$ in relative to the stellar absorption lines. Furthermore, low-ionization [OII] 3726Å 3729Å doublet also shows large FWHM of 910 km s$^{-1}$ and velocity shift of -380 km s$^{-1}$. After the removal of an unresolved nuclear component, the long-slit spectroscopy 2D image possibly shows that the outflow extends to radius of 4 kpc. The mass outflow and energy ejection rates are estimated to be 500 M$_{\odot}$ yr$^{-1}$ and $4\times10^{44}$ erg s$^{-1}$, respectively, which imply that the outflow is among the most powerful ones observed in ULIRGs and QSOs at 0.3 < z < 1.6. The co-existence of the strong outflow and intense star formation (star formation rate of 990 M$_{\odot}$ yr$^{-1}$) indicates that the feedback of the strong outflow has not severely affect the star-forming region of the galaxy.

astro-ph.GA