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Md. Shahabuddin

Publications and source records attributed to Md. Shahabuddin.

3 recordsLinked to original sources

Shifted Window Temporal Transformer for YOLO-Guided Phase Recognition in Laparoscopic Cholecystectomy Surgery

Intelligent operating rooms require accurate awareness of surgical workflow for better intra-operative decisions, teamwork, and surgical documentation. Therefore, accurately recognizing surgical phase during surgery is crucial. However, previous artificial intelligence-based methods provide fluctuating predictions for the transitions, restricting their clinical use. To address this challenge, we propose a clinically meaningful framework that integrates a Swin Transformer and Temporal Transformer Encoder (TTE) for effective surgical phase recognition and a parallel YOLOv11s network for real-time surgical instrument localization. To avoid phase flickering and to produce stable workflow predictions, a causal temporal smoothing is applied. The proposed framework is tested on the Cholec80 dataset for the simultaneous recognition of the surgical phases and instruments. The overall phase recognition accuracy of this model was 92%, and the macro average F1-score was 0.86. This performance surpasses CNN based methods such as EndoNet (81.7%) and SV-RCNet (85.3%), as well as temporal convolutional and transformer-based approaches including TeCNO (88.6%), Trans-SVNet (90.9%), and LoViT (91.5%). Besides, the module of instrument detection achieved mAP@0.5 = 0.863. The reliability of the results is confirmed, obtaining a high recognition rate of the workflows, and a high accuracy of the localization of the instruments. The proposed framework can serve as a foundation for intelligent surgical assistance, enriching situation awareness, and potential robotic surgery applications. Code will be made publicly available at: https://github.com/ac005sheekar/LapChol-Surgery-Swin-Cholec80

cs.CV↗

Fluxiod jumps coupled high critical current density of nano-Co3O4 doped MgB2

Polycrystalline MgB2 samples with 0, 2, 4 and 6 percent added nano-Co3O4 being synthesized by vacuum (10-5 Torr) annealing at 750 0C for three hours each are found to be nearly single phase with presence of only a small quantity of Mg/MgO in pristine sample and in addition the Co2O3 in doped compounds. All the samples exhibited clear and sharp diamagnetic transitions at around 38 K, in Zero-field-cooled (ZFC) magnetic susceptibility measurements with sizeable signal. The Field cooled (FC) measurements though having sharp transitions, but showed a very small signal, indicating high level of pinning centers in these samples. Further some of the doped samples exhibited Paramagnetic-Meissner-Effect (PME) in applied field of 5 Oe. The critical current density (Jc), being estimated by invoking Bean model for the pristine compound increase by nearly an order of magnitude for 2 and 4 percent nano-Co3O4 doping and later the same decreases sharply for 6 percent sample at nearly all studied temperatures and applied fields. Further the increased Jc (~ 10^8 A/cm2) is coupled with fluxiod jumps (T = 20 K and H = 1 T). Fluxiod Jumps are not seen in relatively low Jc pristine or 6 percent sample. This means the fluxiod-jumps are intrinsic only to the high Jc samples.

cond-mat.supr-con↗

Phase formation and superconductivity of Fe-tube encapsulated and vacuum annealed MgB2

We report optimization of the synthesis parameters viz. heating temperature (TH), and hold time (thold) for vacuum (10-5 torr) annealed and LN2 (liquid nitrogen) quenched MgB2 compound. These are single-phase compounds crystallizing in the hexagonal structure (space group P6/mmm) at room temperature. Our XRD results indicated that for phase-pure MgB2, the TH for 10-5 torr annealed and LN2 quenched samples is 750 0C. The right stoichiometry i.e., MgB2 of the compound corresponding to 10-5 Torr and TH of 750 0C is found for the hold time (thold) of 2.30 hours. With varying thold from 1- 4 hours at fixed TH (750 0C) and vacuum (10-5 torr), the c-lattice parameter decreases first and later increases with thold (hours) before a near saturation, while the a-lattice parameter first increase and later decreases beyond thold of 2.30 hours. c/a ratio versus thold plot showed an inverted bell shape curve, touching the lowest value of 1.141 which is reported value for perfect stoichiometry of MgB2. The optimized stoichimetric MgB2 compound exhibited superconductivity at 39.2 K with transition width of 0.6 K. In conclusion, the synthesis parameters for phase pure stoichimetric vacuum annealed MgB2 compound are optimized and are compared with widely reported Ta tube encapsulated samples.

cond-mat.supr-con↗