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Your search keyword '"Sarkar, Saikat"' showing total 43 results
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43 results on '"Sarkar, Saikat"'

3. SoccerKDNet: A Knowledge Distillation Framework for Action Recognition in Soccer Videos

Author

Bose, Sarosij, Sarkar, Saikat, and Chakrabarti, Amlan

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

Classifying player actions from soccer videos is a challenging problem, which has become increasingly important in sports analytics over the years. Most state-of-the-art methods employ highly complex offline networks, which makes it difficult to deploy such models in resource constrained scenarios. Here, in this paper we propose a novel end-to-end knowledge distillation based transfer learning network pre-trained on the Kinetics400 dataset and then perform extensive analysis on the learned framework by introducing a unique loss parameterization. We also introduce a new dataset named SoccerDB1 containing 448 videos and consisting of 4 diverse classes each of players playing soccer. Furthermore, we introduce an unique loss parameter that help us linearly weigh the extent to which the predictions of each network are utilized. Finally, we also perform a thorough performance study using various changed hyperparameters. We also benchmark the first classification results on the new SoccerDB1 dataset obtaining 67.20% validation accuracy. Apart from outperforming prior arts significantly, our model also generalizes to new datasets easily. The dataset has been made publicly available at: https://bit.ly/soccerdb1, Comment: Accepted to 10th Springer PReMI 2023

Published
2023

22. Possible charge ordering and anomalous transport in graphene/graphene quantum dot heterostructure

Author

Gómez Pérez, Inmaculada Jénnifer, Roy, Rajarshi, Holec, David, Michal, Lukáš, Hemzal, Dušan, Sarkar, Saikat, Gundam, Sandeep Kumar, Nečas, David, Dhankhar, Meena, Kaushik, Preeti, Zajickova, Lenka, Gómez Pérez, Inmaculada Jénnifer, Roy, Rajarshi, Holec, David, Michal, Lukáš, Hemzal, Dušan, Sarkar, Saikat, Gundam, Sandeep Kumar, Nečas, David, Dhankhar, Meena, Kaushik, Preeti, and Zajickova, Lenka

Abstract

[Abstract] Observations of superconductivity and charge density waves (CDW) in graphene have been elusive thus far due to weak electron–phonon coupling (EPC) interactions. Here, we report a unique observation of anomalous transport and multiple charge ordering phases at high temperatures (T1 ∼ 213K, T2 ∼ 325K) in a 0D−2D van der Waals (vdW) heterostructure comprising of single layer graphene (SLG) and functionalized (amine) graphene quantum dots (GQD). The presence of functionalized GQD contributed to charge transfer with shifting of the Dirac point ∼ 0.05 eV above the Fermi level (ab initio simulations) and carrier density n ∼ −0.3 × 1012 cm−2 confirming p-doping in SLG and two-fold increase in EPC interaction was achieved. Moreover, we elucidate the interplay between electron–electron and electron–phonon interactions to substantiate high temperature EPC driven charge ordering in the heterostructure through analyses of magnetotransport and weak anti-localization (WAL) ramework. Our results provide impetus to investigate strongly correlated phenomena such as CDW and superconducting phase transitions in novel graphene based heterostructures.

Published
2024

23. Possible charge ordering and anomalous transport in graphene/graphene quantum dot heterostructure

Author

Roy, Rajarshi, Holec, David, Michal, Lukáš, Hemzal, Dušan, Sarkar, Saikat, Sandeep Kumar, Gundam, Nečas, David, Dhankhar, Meena, Kaushik, Preeti, Jénnifer Gómez, I., Zajíčková, Lenka, Roy, Rajarshi, Holec, David, Michal, Lukáš, Hemzal, Dušan, Sarkar, Saikat, Sandeep Kumar, Gundam, Nečas, David, Dhankhar, Meena, Kaushik, Preeti, Jénnifer Gómez, I., and Zajíčková, Lenka

Abstract

Observations of superconductivity and charge density waves (CDW) in graphene have been elusive thus far due to weak electron-phonon coupling (EPC) interactions. Here, we report a unique observation of anomalous transport and multiple charge ordering phases at high temperatures ( T1 ∼ 213K , T2 ∼ 325K ) in a 0D−2D van der Waals (vdW) heterostructure comprising of single layer graphene (SLG) and functionalized (amine) graphene quantum dots (GQD). The presence of functionalized GQD contributed to charge transfer with shifting of the Dirac point ∼ 0.05 eV above the Fermi level (ab initio simulations) and carrier density n ∼ − 0.3 × 1012 cm−2 confirming p-doping in SLG and two-fold increase in EPC interaction was achieved. Moreover, we elucidate the interplay between electron-electron and electron-phonon interactions to substantiate high temperature EPC driven charge ordering in the heterostructure through analyses of magnetotransport and weak anti-localization (WAL) framework. Our results provide impetus to investigate strongly correlated phenomena such as CDW and superconducting phase transitions in novel graphene based heterostructures.

Published
2024

24. Molecular identification of ecologically relevant hoverflies (Diptera, Syrphidae) from eastern India.

Author

Kar, Oishik, Ghosh, Debjani, Mukherjee, Arka, Mukherjee, Koustav, Pramanik, Debdeep, Sarkar, Saikat, Sengupta, Jayita, Naskar, Atanu, and Banerjee, Dhriti

Subjects
LIFE cycles (Biology), CYTOCHROME oxidase, ENTOMOLOGY, DIPTERA, BAR codes
Abstract

Syrphid identification keys that cover all life cycle stages of the taxonomy are insufficient, and there are problems with the morphological identification of these flies. Cytochrome oxidase I (COI) is widely used for molecular identification and phylogenetic reconstruction. The study examined the effectiveness of COI in identifying 18 specimens containing 13 agriculturally important species of syrphids collected from different geo-climatic regions of West Bengal. Phylogenetic analysis was performed using Maximum Likelihood (ML) and Bayesian (BA) trees, which were almost congruent. Barcodes were generated for Dasysyrphus orsua and Eristalinus polychromata for the first time. This is the first study to use the COI for barcoding ecologically and agriculturally relevant syrphid flies from eastern India and their phylogeny. The findings contribute to the basic understanding of the diversity of syrphids across West Bengal and the molecular characterization of hoverflies, promoting their conservation and thus leading to the augmentation of crops. © 2024 Association for Advancement of Entomology. [ABSTRACT FROM AUTHOR]

Published
2024
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28. Enhancement of electron phonon coupling by modulation of out-of-plane oxygen functional groups in thermally annealed few layer graphene.

Author

Sarkar, Saikat, Roy, Rajarshi, and Chattopadhyay, Kalyan Kumar

Subjects
*FUNCTIONAL groups, *CHARGE density waves, *GRAPHENE, *X-ray photoelectron spectroscopy, *PHONONS
Abstract

Understanding some collective phenomena in two dimensional van der Waal structure has been recently on-trend. Particularly, in doped graphene, physics related to highly correlated electronic structures is extensively studied to explain the quantum behaviors like superconductivity (SC), charge density wave (CDW), etc. In this work, we investigate a latent feature of functionalized graphene, i.e., electron-phonon coupling (EPC), which is essential to achieve these symmetry-breaking states. This study demonstrates the role of oxygen functional groups (OFGs), incorporated in graphene lattice along out-of-plane direction, in increasing electron-phonon interaction. Two significant spectroscopic tools, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, are employed to measure this interaction. [ABSTRACT FROM AUTHOR]

Published
2024
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34. AN INVENTORY OF NECROPHAGOUS FLIES FROM INDIA

Author

OISHIK KAR, ., primary, NASKAR, ATANU, primary, PRAMANIK, DEBDEEP, primary, MUKHERJEE, KOUSTAV, primary, SARKAR, SAIKAT, primary, MUKHERJEE, ARKA, primary, GHOSH, DEBJANI, primary, SENGUPTA, JAYITA, primary, and BANERJEE, DHRITI, primary

Published
2022
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39. Analysis and Design of an Industrial Tower

Author

Banerjee, Debargha, primary, Ghosh, Uddipta, primary, Das, Debasish, primary, Nama, Puja, primary, Mandi, Sukhen, primary, Sarkar, Saikat, primary, Sarkar, Susama, primary, Chowdhury, Unnata Sen, primary, Barman, Bapi, primary, Das, Suman, primary, Dutta, Sibananda Prasad, primary, Bhattacharjee, Saikat, primary, and Goswami, Kishalay, primary

Published
2022
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43. Reinforcement Learning for Pass Detection and Generation of Possession Statistics in Soccer

Author

Sarkar, Saikat, Mukherjee, Dipti Prasad, and Chakrabarti, Amlan

Abstract

We propose a reinforcement learning (RL) based technique to detect passes from the video of a soccer match. The detection of passes determines ball possession statistics of a soccer match. A sequence of video frames is mapped to a sequence of states, such as ball with team A or team B or ball not possessed either by team A or B. The agent of RL learns the frame-to-state mapping and the optimal policy to decide the mapping task. We propose a novel reward function by utilizing contextual information of the soccer game in order to help the agent decide the optimal policy. In this context, the advantage of RL is in the integration of a reward system in choosing an action that maps a video frame of a soccer match to one of three possible states. Unlike competing methods, we design the RL model in a way so that explicit identification of team labels of players is not required. We introduce a deep recurrent $Q$ -network (DRQN) to learn the optimal policy. For efficient training of the DRQN, we have proposed decorrelated experience replay (DER), a strategy that selects important experiences based on the correlations of the experiences stored in the replay memory. Experimental results show that at least 5.75% and 2.1% better accuracy are achieved in calculating pass and possession statistics, respectively, compared to similar approaches.

Published
2023
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