[Re] Double Sampling Randomized Smoothing

This paper is a contribution to the reproducibility challenge in the field of machine learning, specifically addressing the issue of certifying the robustness of neural networks (NNs) against adversarial perturbations. The proposed Double Sampling Randomized Smoothing (DSRS) framework overcomes the limitations of existing methods by using an additional smoothing distribution to improve the robustness certification. The paper provides a clear manifestation of DSRS for a generalized family of Gaussian smoothing and a computationally efficient method for implementation. The experiments on MNIST and CIFAR-10 demonstrate the effectiveness of DSRS, consistently certifying larger robust radii compared to other methods. Also various ablations studies are conducted to further analyze the hyperparameters and effect of adversarial training methods on the certified radius by the proposed framework

Message queue telemetry transport and lightweight machine-to-machine comparison based on performance efficiency under various scenarios

Internet of things (IoT) is been advancing over a long period of time in many aspects. For data transfer between IoT devices in a wireless sensor network, various IoT protocols are proposed. Among them, the most widely used are constrained application protocol (CoAP) and message queue telemetry transport (MQTT). Overcoming the limitations of CoAP, lightweight machine-to-machine (LwM2M) framework was designed above CoAP. Recent statistics show that LwM2M and MQTT are the widely used, but LwM2M is still less used than MQTT. Our paper is aimed at comparing both MQTT and LwM2M on the basis of performance efficiency, which will be achieved by sending same file through both protocols to the server. Performance efficiency will be calculated in two scenarios, i) when the client makes a connection with the server i.e., while initial connection and ii) while sending data file to server i.e., while data transfer. Both the protocols will be tested on the number of packets sent and the variability of packet size throughout the session. Experimental results indicated that LwM2M outperformed MQTT in both above scenarios by almost 69%. Therefore, we concluded by stating that LwM2M is best choice over MQTT, but MQTT can still be used in some situations if necessary

HeRoSwarm: Fully-Capable Miniature Swarm Robot Hardware Design With Open-Source ROS Support

Experiments using large numbers of miniature swarm robots are desirable to teach, study, and test multi-robot and swarm intelligence algorithms and their applications. To realize the full potential of a swarm robot, it should be capable of not only motion but also sensing, computing, communication, and power management modules with multiple options. Current swarm robot platforms developed for commercial and academic research purposes lack several of these critical attributes by focusing only on a few of these aspects. Therefore, in this paper, we propose the HeRoSwarm, a fully-capable swarm robot platform with open-source hardware and software support. The proposed robot hardware is a low-cost design with commercial off-the-shelf components that uniquely integrates multiple sensing, communication, and computing modalities with various power management capabilities into a tiny footprint. Moreover, our swarm robot with odometry capability with Robot Operating Systems (ROS) support is unique in its kind. This simple yet powerful swarm robot design has been extensively verified with different prototyping variants and multi-robot experimental demonstrations

Evolution and Final Fates of a Rotating 25 M⊙_{\odot} Pop III star

In this proceeding, we present the 1-dimensional stellar evolution of two rotating population III (Pop III) star models, each having a mass of 25 M$_{\odot}$ at the zero-age main-sequence (ZAMS). The slowly rotating model has an initial angular rotational velocity of 10 per cent of the critical angular rotational velocity. In contrast, the rapidly rotating model has an initial angular rotational velocity of 70 per cent of the critical angular rotational velocity. As an effect of rotationally enhanced mixing, we find that the rapidly rotating model suffers an enormous mass loss due to the deposition of a significant amount of CNO elements toward the surface after the main-sequence phase. We also display the simulated light curves as these models explode into core-collapse supernovae (CCSNe).Comment: Resubmitted after incorporating minor revision, Part of 3$^{rd}$ BINA conference proceeding

Recent observations of peculiar Gamma-ray bursts using 3.6 m Devasthal Optical Telescope (DOT)

India has been actively involved in the follow-up observations of optical afterglows of gamma-ray bursts (GRBs) for more than two decades, using the country's meter-class facilities such as the 1.04 m Sampurnanand Telescope, 1.3 m Devasthal Fast Optical Telescope, 2.01 m Himalayan Chandra Telescope along with many others in the country, utilizing the longitudinal advantage of the place. However, since 2016, Indian astronomers have embarked on a new era of exploration by utilizing the country's largest optical telescope, the 3.6 m Devasthal Optical Telescope (DOT) at the Devasthal Observatory of ARIES Nainital. This unique telescope has opened up exciting opportunities for transient study. Starting from the installation itself, the DOT has been actively performing the target of opportunity (ToO) observations, leading to many interesting discoveries. Notable achievements include the contributions towards the discovery of long GRB 211211A arising from a binary merger, the discovery of the most delayed optical flare from GRB 210204A along with the very faint optical afterglow (fainter than 25 mag in g-band) of GRB 200412B. We also successfully observed the optical counterpart of the very-high-energy (VHE) detected burst GRB 201015A using DOT. Additionally, DOT has been used for follow-up observations of dark and orphan afterglows, along with the observations of host galaxies associated with peculiar GRBs. More recently, DOT's near-IR follow-up capabilities helped us to detect the first near-IR counterpart (GRB 230409B) using an Indian telescope. In this work, we summarise the recent discoveries and observations of GRBs using the 3.6 m DOT, highlighting the significant contributions in revealing the mysteries of these cosmic transients.Comment: 16 pages, 2 figures, 1 table, accepted for publication in the Bulletin of Li\`ege Royal Society of Sciences as a part of 3$^{rd}$ Belgo-Indian Network for Astronomy and Astrophysics (BINA) workshop, 22-24 March 202

Tale of GRB 171010A/SN 2017htp and GRB 171205A/SN 2017iuk: Magnetar origin?

We present late-time optical follow-up observations of GRB 171010A/SN 2017htp ($z$ = 0.33) and low-luminosity GRB 171205A/SN 2017iuk ($z$ = 0.037) acquired using the 4K$\times$4K CCD Imager mounted at the 3.6m Devasthal Optical Telescope (3.6m DOT) along with the prompt emission data analysis of these two interesting bursts. The prompt characteristics (other than brightness) such as spectral hardness, T$_{90}$, and minimum variability time-scale are comparable for both the bursts. The isotropic $X$-ray and kinetic energies of the plateau phase of GRB 171205A are found to be less than the maximum energy budget of magnetars, supporting magnetar as a central engine powering source. The new optical data of SN 2017htp and SN 2017iuk presented here, along with published ones, indicate that SN 2017htp is one of the brightest and SN 21017iuk is among the faintest GRB associated SNe (GRB-SNe). Semi-analytical light-curve modelling of SN 2017htp, SN 2017iuk and only known GRB associated superluminous supernova (SLSN 2011kl) are performed using the $\texttt{MINIM}$ code. The model with a spin-down millisecond magnetar as a central engine powering source nicely reproduced the bolometric light curves of all three GRB-SNe mentioned above. The magnetar central engines for SN 2017htp, SN 2017iuk, and SLSN 2011kl exhibit values of initial spin periods higher and magnetic fields closer to those observed for long GRBs and H-deficient SLSNe. Detection of these rare events at such late epochs also demonstrates the capabilities of the 3.6m DOT for deep imaging considering longitudinal advantage in the era of time-domain astronomy.Comment: Accepted for publication in New Astronomy; Received 21 April 2022, Revised 13 June 2022, Accepted 1 July 202

Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K×\times4K CCD Imager+3.6m DOT

Optical follow-up observations of optical afterglows of gamma-ray bursts are crucial to probe the geometry of outflows, emission mechanisms, energetics, and burst environments. We performed the follow-up observations of GRB 210205A and ZTF21aaeyldq (AT2021any) using the 3.6m Devasthal Optical Telescope (DOT) around one day after the burst to deeper limits due to the longitudinal advantage of the place. This paper presents our analysis of the two objects using data from other collaborative facilities, i.e., 2.2m Calar Alto Astronomical Observatory (CAHA) and other archival data. Our analysis suggests that GRB 210205A is a potential dark burst once compared with the X-ray afterglow data. Also, comparing results with other known and well-studied dark GRBs samples indicate that the reason for the optical darkness of GRB 210205A could either be intrinsic faintness or a high redshift event. Based on our analysis, we also found that ZTF21aaeyldq is the third known orphan afterglow with a measured redshift except for ZTF20aajnksq (AT2020blt) and ZTF19abvizsw (AT2019pim). The multiwavelength afterglow modelling of ZTF21aaeyldq using the afterglowpy package demands a forward shock model for an ISM-like ambient medium with a rather wider jet opening angle. We determine circumburst density of $n_{0}$ = 0.87 cm$^{-3}$, kinetic energy $E_{k}$ = 3.80 $\times 10^{52}$ erg and the afterglow modelling also indicates that ZTF21aaeyldq is observed on-axis ($\theta_{obs} < \theta_{core}$) and a gamma-ray counterpart was missed by GRBs satellites. Our results emphasize that the 3.6m DOT has a unique capability for deep follow-up observations of similar and other new transients for deeper observations as a part of time-domain astronomy in the future.Comment: Accepted for Special Issue of Journal of Astrophysics and Astronomy, 2022, Astrophysical jets and observational facilities: National perspective, 05 -09 April 2021, ARIES Nainita

A long gamma-ray burst from a merger of compact objects

Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (>2 s) duration are produced by the core-collapse of massive stars, those of short (< 2 s) duration by the merger of two neutron stars (NSs). A third class of events with hybrid high-energy properties was identified, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented. Here we report observations of the exceptionally bright GRB211211A that classify it as a hybrid event and constrain its distance scale to only 346 Mpc. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (~1E42 erg/s) kilonova possibly formed in the ejecta of a compact binary merger.Comment: original version, accepted for publication after revisio

Molecular diagnosis of infectious diseases using cytological specimens

Pathologists have an important role in the diagnosis of infectious disease (ID). In many cases, a definitive diagnosis can be made using cytopathology alone. However, several ancillary techniques can be used on cytological material to reach a specific diagnosis by identifying the causative agent and consequently defining the management of the patient. This review aims to present the effectiveness of the application of molecular studies on cytological material to diagnose IDs and discuss the advantages and disadvantages of the various molecular techniques according to the type of cytological specimen and the infectious agents.info:eu-repo/semantics/publishedVersio

SN 2016iyc : a Type IIb supernova arising from a low-mass progenitor

In this work, photometric and spectroscopic analyses of a very low-luminosity Type IIb supernova (SN) 2016iyc have been performed. SN 2016iyc lies near the faint end among the distribution of similar supernovae (SNe). Given lower ejecta mass (Mej) and low nickel mass (MNi) from the literature, combined with SN 2016iyc lying near the faint end, one-dimensional stellar evolution models of 9–14 M⊙ zero-age main-sequence (ZAMS) stars as the possible progenitors of SN 2016iyc have been performed using the publicly available code mesa. Moreover, synthetic explosions of the progenitor models have been simulated, using the hydrodynamic evolution codes stella and snec. The bolometric luminosity light curve and photospheric velocities produced through synthetic explosions of ZAMS stars of mass in the range of 12–13 M⊙ having a pre-supernova radius R0 = (204–300) R⊙, with Mej = (1.89–1.93) M⊙, explosion energy Eexp = (0.28–0.35) × 1051 erg, and MNi &amp;lt; 0.09 M⊙, are in good agreement with observations; thus, SN 2016iyc probably exploded from a progenitor near the lower mass limits for SNe IIb. Finally, hydrodynamic simulations of the explosions of SN 2016gkg and SN 2011fu have also been performed to compare intermediate- and high-luminosity examples among well-studied SNe IIb. The results of progenitor modelling and synthetic explosions for SN 2016iyc, SN 2016gkg, and SN 2011fu exhibit a diverse range of mass for the possible progenitors of SNe IIb