Real-time sensing of static displacement and vibrations using HOM interference based quantum sensor

Hong-Ou-Mandel (HOM) interference, bunching of two indistinguishable photons on a balanced beam-splitter, has emerged as a promising tool for quantum sensing. The interference dip-width, thus the spectral-bandwidth of interfering pair-photons, highly influences the resolution of HOM-based sensors. Typically, the pair-photons bandwidth, generated through parametric down-conversion, is increased using bulky and expensive ultrafast lasers, limiting their use outside the lab. Here we show the generation of pair-photons with flexible spectral-bandwidth even using single-frequency, continuous-wave diode laser enabling high-precision, real-time sensing. Using 1-mm-long periodically-poled KTP crystal, we produced degenerate, high-brightness, paired-photons with spectral-bandwidth of 163.42$\pm$1.68 nm resulting in a HOM-dip width of 4.01$\pm$0.04 $\mu$m to measure a displacement of 60 nm, and vibration amplitude of $205\pm0.75$ nm with increment (resolution) of $\sim$80 nm, and frequency of 8 Hz. Deployment of Fisher-information and maximum likelihood estimator enables optical delay measurement as small as 4.97 nm with precision (Cram\'er-Rao bound) and accuracy of 0.89 and 0.54 nm, respectively. The 17$\times$ enhancement of Fisher-information for the use of 1 mm crystal over 30 mm empowers the HOM-based sensor achieving any arbitrary precision (say $\sim$5 nm) in small number of iterations ($\sim$3300) and time (19 minutes); establishing it's capability for real-time, precision-augmented, in-field quantum sensing applications

Cytomegalovirus colitis in a human immunodeficiency virus seropositive individual with moderately severe immunodeficiency

Colitis is the most common extraocular manifestation of cytomegalovirus (CMV) infection in human immunodeficiency virus (HIV) infected patients. CMV disease is usually seen in HIV-infected patients with CD4+ counts less than 50/ mm3 . There are documented reports of CMV gastrointestinal disease in patients with CD4+ count greater than 50 cells/L. A 46-year-old man with HIV1 infection on irregular antiretroviral treatment presented with low grade fever, abdominal pain and vomitings. He is a known alcoholic. Physical examination revealed pallor, evidence of malnutrition and tenderness in the abdomen. Laboratory investigations revealed mild anaemia; CD4+ count was 240 cells/L. Fundus examination of the patient was normal. Contrast enhanced computed tomography (CECT) of the abdomen revealed dilated small bowel loops, thickening of wall of splenic flexure and thickening of caecal and terminal ileal wall with mild narrowing. As anti-CMV antibodies (IgM) and CMV real time-polymerase chain reaction (PCR) tested positive, patient was treated with intravenous ganciclovir for 14 days followed by oral valganciclovir and patient showed remarkable improvement. Our case highlights the fact that CMV colitis can also occur in patients with relatively preserved CD4+ counts especially if co-morbid conditions like alcoholism co-exist

Beach Morphological Characteristics and Coastal Processes Along Dakshina Kannada Coast, West Coast of India

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Study on interventions to reduce vibration transmission to power tiller operator

Present study focuses on interventions to reduce vibration transmitted to power tiller operator. In this study two operations (namely: standing mode and transportation) and three forward speeds (1.0, 1.5 and 2.0 kmh-1) were selected. In both selected operations vibration magnitudes were maximum at 2.0 kmh-1. In the standing mode vibration magnitudes in x, y and z direction were 5.83, 1.37 and 2.36 ms -2 at 2.0 kmh-1. In transportation vibration magnitudes were 6.81, 1.49, 2.82 ms-2 respectively in x, y and z direction at 2.0 kmh-1. The selection of vibration isolators were done on the basis of the transmissibility curves and the isolation region. The selected isolators were installed at interface between engine and the chassis. These interventions along with previously developed bush and sheet type interventions reduced vibrations up to 50.24, 69.06 and 59.08 % at 1.0, 1.5 and 2.0 kmh-1 in stationary mode. In transportation vibration reduction were 52.96, 65.98 and 36.67 % at 1.0, 1.5 and 2.0 kmh-1, respectively. The vibration reduction were high in stationary mode than transportation mode because in stationary mode vibration comes only from the engine but in transportation vibration comes from engine and the surface profile as well

A Parallel Military Dog based Algorithm for Clustering Big data in Cognitive Industrial Internet of Things

With the advancement of wireless communication, internet of things, and big data, high performance data analytic tools and algorithms are required. Data clustering, a promising analytic technique is widely used to solve the IoT and big data based problems, since it does not require labeled datasets. Recently, meta-heuristic algorithms have been efficiently used to solve various clustering problems. However, to handle big data sets produced from IoT devices, these algorithm fail to respond within desired time due to high computation cost. This paper presents a new meta-heuristic based clustering method to solve the big data problems by leveraging the strength of MapReduce. The proposed methods leverages the searching potential of military dog squad to find the optimal centroids and MapReduce architecture to handle the big data sets. The optimization efficacy the proposed method is validated against 17 benchmark functions and the results are compared with 5 other recent algorithms namely, bat, particle swarm optimization, artificial bee colony, multiverse optimization, and whale optimization algorithm. Further, a parallel version of the proposed method is introduced using MapReduce (MR-MDBO) for clustering the big datasets produced from industrial IoT. Moreover, the performance of MR-MDBO is studied on 2 benchmark UCI datasets and 3 real IoT based datasets produced from industry. The F-measure and computation time of the MR-MDBO is compared with the 6 other state-of-the-art methods. The experimental results witness that the proposed MR-MDBO based clustering outperforms the other considered algorithms in terms of clustering accuracy and computation times

Astreaks: Astrometry of NEOs with trailed background stars

The detection and accurate astrometry of fast-moving near-Earth objects (NEOs) has been a challenge for the follow-up community. Their fast apparent motion results in streaks in sidereal images, thus affecting the telescope's limiting magnitude and astrometric accuracy. A widely adopted technique to mitigate trailing losses is non-sidereal tracking, which transfers the streaking to background reference stars. However, no existing publicly available astrometry software is configured to detect such elongated stars. We present Astreaks, a streaking source detection algorithm, to obtain accurate astrometry of NEOs in non-sidereal data. We validate the astrometric accuracy of Astreaks on 371 non-sidereally tracked images for 115 NEOs with two instrument set-ups of the GROWTH-India Telescope. The observed NEOs had V-band magnitude in the range [15, 22] with proper motion up to 140$^{\prime\prime}$/min, thus resulting in stellar streaks as high as 6.5$^\prime$ (582 pixels) in our data. Our method obtained astrometric solutions for all images with 100% success rate. The standard deviation in Observed-minus-Computed (O-C) residuals is 0.52$^{\prime\prime}$, with O-C residuals <2$^{\prime\prime}$(<1$^{\prime\prime}$) for 98.4% (84.4%) of our measurements. These are appreciable, given the pixel scale of $\sim$0.3$^{\prime\prime}$ and $\sim$0.7$^{\prime\prime}$ of our two instrument set-ups. This demonstrates that our modular and fully-automated algorithm helps improve the telescope system's limiting magnitude without compromising astrometric accuracy by enabling non-sidereal tracking on the target. This will help the NEO follow-up community cope with the accelerated discovery rates and improved sensitivity of the next-generation NEO surveys. Astreaks has been made available to the community under an open-source license.Comment: 10 pages, 7 figure

Multi-wavelength observations of multiple eruptions of the recurrent nova M31N 2008-12a

We report the optical, UV, and soft X-ray observations of the $2017-2022$ eruptions of the recurrent nova M31N 2008-12a. We infer a steady decrease in the accretion rate over the years based on the inter-eruption recurrence period. We find a ``cusp'' feature in the $r'$ and $i'$ band light curves close to the peak, which could be associated to jets. Spectral modelling indicates a mass ejection of 10$^{-7}$ to 10$^{-8}$ M$_{\odot}$ during each eruption, and an enhanced Helium abundance of He/He$_{\odot}$ $\approx$ 3. The super-soft source (SSS) phase shows significant variability, which is anti-correlated to the UV emission, indicating a common origin. The variability could be due to the reformation of the accretion disk. A comparison of the accretion rate with different models on the $\rm M_{WD}$$-\dot{M}$ plane yields the mass of a CO WD, powering the ``H-shell flashes'' every $\sim$ 1 year to be $>1.36$ M$_{\odot}$ and growing with time, making M31N 2008-12a a strong candidate for the single degenerate scenario of Type Ia supernovae progenitor.Comment: Submitted to AJ, 22 pages, 14 figures, 5 table

Multiwavelength Observations of Multiple Eruptions of the Recurrent Nova M31N 2008-12a

We report the optical, UV, and soft X-ray observations of the 2017–2022 eruptions of the recurrent nova M31N 2008-12a. We find a cusp feature in the r′ - and i′ -band light curves close to the peak, which could be related to jets. The geometry of the nova ejecta based on morpho-kinematic modeling of the Hα emission line indicates an extended jet-like bipolar structure. Spectral modeling indicates an ejecta mass of 10−7–10−8 M ⊙ during each eruption and an enhanced helium abundance. The supersoft source phase shows significant variability, which is anticorrelated to the UV emission, indicating a common origin. The variability could be due to the reformation of the accretion disk. We infer a steady decrease in the accretion rate over the years based on the intereruption recurrence period. A comparison of the accretion rate with different models on the MWD–Ṁ plane yields the mass of a CO white dwarf, powering the H-shell flashes every ∼1 yr, to be >1.36 M ⊙ and growing with time, making M31N 2008-12a a strong candidate for the single degenerate scenario of the Type Ia supernovae progenitor

IndicLLMSuite: A Blueprint for Creating Pre-training and Fine-Tuning Datasets for Indian Languages

Despite the considerable advancements in English LLMs, the progress in building comparable models for other languages has been hindered due to the scarcity of tailored resources. Our work aims to bridge this divide by introducing an expansive suite of resources specifically designed for the development of Indic LLMs, covering 22 languages, containing a total of 251B tokens and 74.8M instruction-response pairs. Recognizing the importance of both data quality and quantity, our approach combines highly curated manually verified data, unverified yet valuable data, and synthetic data. We build a clean, open-source pipeline for curating pre-training data from diverse sources, including websites, PDFs, and videos, incorporating best practices for crawling, cleaning, flagging, and deduplication. For instruction-fine tuning, we amalgamate existing Indic datasets, translate/transliterate English datasets into Indian languages, and utilize LLaMa2 and Mixtral models to create conversations grounded in articles from Indian Wikipedia and Wikihow. Additionally, we address toxicity alignment by generating toxic prompts for multiple scenarios and then generate non-toxic responses by feeding these toxic prompts to an aligned LLaMa2 model. We hope that the datasets, tools, and resources released as a part of this work will not only propel the research and development of Indic LLMs but also establish an open-source blueprint for extending such efforts to other languages. The data and other artifacts created as part of this work are released with permissive licenses

Far-Ultraviolet to Near-Infrared Observations of SN 2023ixf: A high energy explosion engulfed in complex circumstellar material

We present early-phase panchromatic photometric and spectroscopic coverage spanning far-ultraviolet (FUV) to the near-infrared (NIR) regime of the nearest hydrogen-rich core-collapse supernova in the last 25 years, SN~2023ixf. We observe early `flash' features in the optical spectra due to a confined dense circumstellar material (CSM). We observe high-ionization absorption lines Fe II, Mg II in the ultraviolet spectra from very early on. We also observe a multi-peaked emission profile of H-alpha in the spectrum beginning ~16 d, which indicates ongoing interaction of the SN ejecta with a pre-existing shell-shaped CSM having an inner radius of ~ 75 AU and an outer radius of ~140 AU. The shell-shaped CSM is likely a result of enhanced mass loss ~ 35 - 65 years before the explosion assuming a standard Red-Supergiant wind. Spectral modeling of the FUV, NUV, and the optical spectra during 9-12 d, using the radiative transfer spectrum synthesis code TARDIS indicates that the supernova ejecta could be well represented by a progenitor elemental composition greater than solar abundances. Based on early light curve models of Type II SNe, we infer that the nearby dense CSM confined to ~7+-3e14~cm(~45 AU) is a result of enhanced mass loss ~1e-(3.0+-0.5) Msol/yr two decades before the explosion.Comment: Submitted to AAS Journals, 4 figures, 2 table