Optical and infrared studies of herbig Ae/Be stars
subject: Physics
description: The work makes use of the unprecedented capability of the Gaia mission to study various properties of Herbig Ae/Be stars. We placed the Herbig Ae/Be stars in the Gaia color-magnitude diagram and accurately estimated their age and mass. The mass accretion rate is calculated from Hα line flux measurements of 106 HAeBe stars. The mass accretion rate is found to decay exponentially with the age of Herbig Ae/Be stars. Further, the immediate neighborhood of two Herbig Ae/Be stars, V1787 Ori and IL Cep, are studied using the astrometric and photometric data from the Gaia mission. We discovered a low mass binary companion to V1787 Ori using the analysis of distance and proper motion values from Gaia DR2. The mass ratio of the coeval binary system is found to be 0.23. Such a skewed mass ratio system is rarely identified in Herbig Ae/Be binary systems. The method of identification and characterization of the V1787 Ori wide binary system opens up the possibility of identifying more such systems. The HBe star IL Cep tells a much more complex story. The star is identified with a cluster of low mass stars associated with it. We identified 79 co-moving stars that are coeval to IL Cep, within 2 pc radius, from the analysis of Gaia EDR3 astrometry. The triggered star formation process called the "Rocket effect" caused by a massive star HD 216658 is identified to be the cause of the clustered star formation near IL Cep. The effect of this process is demonstrated for the first time using the proper motion data from Gaia. The immediate neighborhood of Herbig Ae/Be stars is identified as the formation region of long-chain carbon molecules such as Fullerenes and Polycyclic Aromatic Hydrocarbons.
creator: Roy, Arun - 1881303
publisher: CHRIST (Deemed to be University)
language: English
type: PhD

Optical Character Recognition (OCR) based Vehicle's License Plate Recognition System Using Python and OpenCV
subject: Computer vision; Image processing; License plate; Optical Character Recognition (OCR); Python programming
description: License Platform Detection is a computer technology that enables us to identify digital images on the platform automatically. Different operations are covered in this system, such as imaging, number pad locations, alphanumeric character truncation and OCR. The final objective of the system is to construct and create efficient image processing procedures and techniques to position a licensing platter on the Open Computer View Library picture. It was used and implemented the K-NN algorithm and python programming language. The technology can be used in different industries such as security, highway speed detection, lighting violations, manuscript documents, automatic charging system, etc. Auto plate recognition is an integrated technology which identifies the auto licence plate. Auto plate auto recognition. Multiple applications include complex safety systems, public spaces, parking and urban traffic control. Automatic Vehicle License Plate Recognition (AVLPR) has undesirable aspects because of many effects, such as light and speed. This work presents an alternative technique to leverage free software for the implementation of AVLPR systems including Python and the Open Computer Vision (openCV). 2021 IEEE.
creator: Samantaray M.; Biswal A.K.; Singh D.; Samanta D.; Karuppiah M.; Joseph N.P.
source: Proceedings of the 5th International Conference on Electronics, Communication and Aerospace Technology, ICECA 2021, pp. 849-853.
publisher: Institute of Electrical and Electronics Engineers Inc.
date: 2021-01-01
rights: Restricted Access
relation: ISBN: 978-166543524-6
format: Online
language: English
type: Conference paper
coverage: Samantaray M., Udayanath (Auto) College of Sc. Tech., Dept. of ITM, Odisha, India; Biswal A.K., Siksha 'o' Anusandhan University, Dept.of CSE, Odisha, India; Singh D., Siksha 'o' Anusandhan University, Dept.of CSE, Odisha, India; Samanta D., Siksha 'o' Anusandhan University, Dept. of CA, Odisha, India; Karuppiah M., SRM Institute of Science and Technology, Department of CSE, Ghaziabad, India; Joseph N.P., CHRIST University, Department of Computer Science, Bangalore, India

Optical Character Recognition system with Projection Profile based segmentation and Deep Learning Techniques
subject: Deep Learning; Document detection; line level segmentation; OCR; Optical Character Recognition; Projection Profiling; VGG16; word level segmentation
description: Optical character recognition is the solution to convert text from printed or scanned documents into editable data. This project is aimed at building a Optical character recognition system that recognizes digital text. A document is first detected using contour-based detection technique without altering the angle of the image and is segmented into lines, once the lines are segmented the words embedded in them are extracted. This segmentation is done using projection profiling method. Characters are then segmented words with vertical projection profiling from the extracted words. These characters are fed into an image recognition model for recognition. The recognition model is CNN based deep learning model. Modified VGG16 architecture is used here to extract maximum features from the images and then classify them. To train the model a dataset is created from a repository of digital character dataset. The dataset consists of images of 153 font variants. 2022 IEEE.
creator: Arockia Rexi F.; Jacob L.
source: Proceedings - 2022 4th International Conference on Advances in Computing, Communication Control and Networking, ICAC3N 2022, pp. 12-16.
publisher: Institute of Electrical and Electronics Engineers Inc.
date: 2022-01-01
rights: Restricted Access
relation: ISBN: 978-166547436-8
format: Online
language: English
type: Conference paper
coverage: Arockia Rexi F., Christ University, Department of Data Science, Lavasa, Pune, India; Jacob L., Christ University, Department of Data Science, Lavasa, Pune, India

Optical characterization of oxadiazoles analogues doped PMMA film for photonic application
subject: Absorption spectra; Energy band gap; Extinction coefficient; NLO applications; Refractive index
description: In the present study, newly synthesized nitrobenzene derivatives (PBT and PBF) doped poly(methyl methacrylate) films were prepared using spin coating techniques, and their optical properties were analyzed. The absorption spectra of various weight percentages (0.02%, 0.1%, 0.2%, and 0.3%) of nitrobenzene derivative-doped polymer films were recorded using a UVvisible spectrometer. From the absorption spectra, optical properties such as refractive index, band gap energy, extinction coefficient, and dielectric constant were calculated. The effect of doping on the optical properties of PMMA was investigated, with results revealing normal dispersive behavior from the refractive index and extinction coefficient. Atomic force microscopy and scanning electron microscopy images indicated that the synthesized films have a low degree of roughness and a smooth surface. Additionally, the nonlinear optical properties of the PBF-doped polymer film were investigated, and the ? value was determined to be 7.403cm/W. Overall, the findings suggest that PBF-doped polymer films are promising candidates for photonic applications. Indian Association for the Cultivation of Science 2024.
creator: Joshi S.S.; Shelar V.M.; Shridhar A.H.; Dhannur S.H.; Refat M.S.; Alsuhaibani A.M.; Naik L.
source: Indian Journal of Physics
publisher: Springer
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 9731458
format: Online
language: English
type: Article
coverage: Joshi S.S., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Shelar V.M., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Shridhar A.H., Department of Chemistry, SVM Arts, Science and Commerce College Illkal, Karnataka, Ilkal, India; Dhannur S.H., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Refat M.S., Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia; Alsuhaibani A.M., Department of Physical Sport Sciences, College of Sport Sciences and Physical Activity, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia; Naik L., Department of Physics, CHRIST University, Karnataka, Bengaluru, 560029, India

Optical characterization of oxadiazoles analogues doped PMMA film for photonic application
subject: Absorption spectra; Energy band gap; Extinction coefficient; NLO applications; Refractive index
description: In the present study, newly synthesized nitrobenzene derivatives (PBT and PBF) doped poly(methyl methacrylate) films were prepared using spin coating techniques, and their optical properties were analyzed. The absorption spectra of various weight percentages (0.02%, 0.1%, 0.2%, and 0.3%) of nitrobenzene derivative-doped polymer films were recorded using a UVvisible spectrometer. From the absorption spectra, optical properties such as refractive index, band gap energy, extinction coefficient, and dielectric constant were calculated. The effect of doping on the optical properties of PMMA was investigated, with results revealing normal dispersive behavior from the refractive index and extinction coefficient. Atomic force microscopy and scanning electron microscopy images indicated that the synthesized films have a low degree of roughness and a smooth surface. Additionally, the nonlinear optical properties of the PBF-doped polymer film were investigated, and the ? value was determined to be 7.403cm/W. Overall, the findings suggest that PBF-doped polymer films are promising candidates for photonic applications. Indian Association for the Cultivation of Science 2024.
creator: Joshi, Suraj Sunil; Shelar, Vikas M.; Shridhar, A.H.; Dhannur, Sikandar H.; Refat, Moamen S.; Alsuhaibani, Amnah Mohammed; Naik, Lohit
source: Indian Journal of Physics;Volume;99;Issue;5;pp.1615-1625
publisher: Springer
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 9731458;
format: online
language: English
type: Article
coverage: Joshi S.S., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Shelar V.M., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Shridhar A.H., Department of Chemistry, SVM Arts, Science and Commerce College Illkal, Karnataka, Ilkal, India; Dhannur S.H., Department of Physics, M.S. Ramaiah University of Applied Sciences, Karnataka, Bengaluru, 560058, India; Refat M.S., Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia; Alsuhaibani A.M., Department of Physical Sport Sciences, College of Sport Sciences and Physical Activity, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia; Naik L., Department of Physics, CHRIST University, Karnataka, Bengaluru, 560029, India

Optical design studies for national large optical-IR telescope
subject: 10-m class telescope; NLOT; segmented mirror telescope; telescope design
description: A 1012 m class national large optical-IR telescope (NLOT) is envisaged to meet the growing scientific requirements in astronomy and astrophysics. Telescopes of such dimensions can only be made by segmenting the primary mirror, as it eases a more prominent primary mirrors fabrication, transportation, operation, and maintenance process. This paper presents the various optical designs analyzed for NLOT that can be fabricated using the India TMT Optics Fabrication Facility (ITOFF) at the Centre for Research and Education in Science and Technology (CREST) campus. We present the primary mirror segmentation details, its ideal optical performance, and study each designs advantages and technical complexities. Based on the above analysis, we have narrowed it down to an optimal design, and its performance analysis is also discussed. Indian Academy of Sciences 2024.
creator: Padikal V.; Hasan A.; Valsan V.; Sriram S.; Kurian A.; Unni V.C.; Basheer A.; Panchal P.; Gopinathan M.; Remya B.S.; Chand T.
source: Journal of Astrophysics and Astronomy, Vol-45, No. 1
publisher: Springer
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 2506335
format: Online
language: English
type: Article
coverage: Padikal V., Department of Physics and Electronics, Christ University, Bengaluru, 560029, India, Department of Biosciences, Newcastle University, Newcastle, NE1 7RU, United Kingdom; Hasan A., Department of Physics and Electronics, Christ University, Bengaluru, 560029, India, Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Valsan V., Department of Physics and Electronics, Christ University, Bengaluru, 560029, India; Sriram S., Department of Physics and Electronics, Christ University, Bengaluru, 560029, India, Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Kurian A., Department of Physics and Electronics, Christ University, Bengaluru, 560029, India; Unni V.C., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Basheer A., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Panchal P., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Gopinathan M., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Remya B.S., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India; Chand T., Optics and Photonics Division, Indian Institute of Astrophysics, Koramangala, Bengaluru, 560034, India

Optical Properties of Magnetic Quantum Dots
description: The delta-like dispersion of the density of states (DoS) enable quantum dots (QD) to display optical and electronic properties comparable with those of real atoms. The discrete electronic structure of QDs akin to that of atoms is formed due to the effect of quantum confinement (QCE). In the case of magnetic quantum dots (MQD), the QDs are incorporated with magnetic impurities such as Mn atom, rare earth elements etc., by which the QDs undergo significant changes in optical and electronic properties by lifting their degeneracies (Zeeman effect). The combination of fluorescent and magnetic entities opens up opportunities for synthesizing two-in-one nanocomposites beneficial for multi-functional, multi-targeting, and multi-theranostic tools. Optical properties of QDs consisting of magnetic impurities, such as the absorption coefficient, oscillator strength, and refractive index are discussed in this chapter. 2023 selection and editorial matter, Amin Reza Rajabzadeh, Seshasai Srinivasan, Poushali Das, and Sayan Ganguly.
creator: John V.L.; Vinod T.P.
source: Magnetic Quantum Dots for Bioimaging, pp. 71-90.
publisher: CRC Press
date: 2023-01-01
rights: Restricted Access
relation: ISBN: 978-100088103-5; 978-103232146-2
format: Online
language: English
type: Book chapter
coverage: John V.L., Department of Chemistry, CHRIST (Deemed to be University), Bangalore, India; Vinod T.P., Department of Chemistry, CHRIST (Deemed to be University), Bangalore, India

Optical properties of MnTe2 few-layer quantum dots
subject: DFT; MnTe2; Photoluminescence; QDs
description: Quantum dots (QDs) are gaining attention as a possible emissive material that might be used in flexible optoelectronic and photonic systems. In the present work, the temperature-dependent photoluminescence (TDPL) property of manganese di-telluride (MnTe2) QDs was investigated. The room-temperature PL is attributed to the abrupt breakage of the large-area MnTe2 nanosheets by ultrasonication, which integrates defect-mediated localized trap states inside the electronic bandgap. As a result, deliberately generated defect states ultimately generate such PL emission of QDs. Density functional theory (DFT) results further validate the experimental interpretations of the origin of TDPL. In addition, through an in-situ liquid diffusion approach, the QDs were also integrated into a NaCl matrix. Due to light scattering properties, the hybrid crystals exhibit fluorescence centres at various excitation wavelengths. These results suggest that these MnTe2 QDs can be used as an effective basis for future flexible optoelectronic applications. 2024 Elsevier B.V.
creator: Ninan G.G.; Varghese M.; Gowda C.C.; Bylappa Y.; Nag A.; Balachandran M.; Junior L.R.; Tromer R.; Galvao D.S.; Tiwary C.S.; Kumbhakar P.
source: Optical Materials, Vol-159
publisher: Elsevier B.V.
date: 2025-01-01
rights: Restricted Access
relation: ISSN: 9253467; CODEN: OMATE
format: Online
language: English
type: Article
coverage: Ninan G.G., Department of Physical Sciences and Mathematics, St. Francis de Sales College (Autonomous), Electronics City, Karnataka, Bengaluru, 560100, India, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Varghese M., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Gowda C.C., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India; Bylappa Y., Department of Life Science, CHRIST (Deemed to be University), Bangalore, 560029, India; Nag A., Department of Life Science, CHRIST (Deemed to be University), Bangalore, 560029, India; Balachandran M., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Junior L.R., Institute of Physics, University of Brasilia, DF, Brasilia, 70910-970, Brazil; Tromer R., Applied Physics Department, State University of Campinas, SP, Campinas, 13083-970, Brazil; Galvao D.S., Applied Physics Department, State University of Campinas, SP, Campinas, 13083-970, Brazil; Tiwary C.S., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India, Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India; Kumbhakar P., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India, Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India

Optical properties of MnTe2 few-layer quantum dots
subject: DFT; MnTe2; Photoluminescence; QDs
description: Quantum dots (QDs) are gaining attention as a possible emissive material that might be used in flexible optoelectronic and photonic systems. In the present work, the temperature-dependent photoluminescence (TDPL) property of manganese di-telluride (MnTe2) QDs was investigated. The room-temperature PL is attributed to the abrupt breakage of the large-area MnTe2 nanosheets by ultrasonication, which integrates defect-mediated localized trap states inside the electronic bandgap. As a result, deliberately generated defect states ultimately generate such PL emission of QDs. Density functional theory (DFT) results further validate the experimental interpretations of the origin of TDPL. In addition, through an in-situ liquid diffusion approach, the QDs were also integrated into a NaCl matrix. Due to light scattering properties, the hybrid crystals exhibit fluorescence centres at various excitation wavelengths. These results suggest that these MnTe2 QDs can be used as an effective basis for future flexible optoelectronic applications. 2024 Elsevier B.V.
creator: Ninan, Gisa Grace; Varghese, Meera; Gowda, Chinmayee Chowde; Bylappa, Yatheesharadhya; Nag, Anish; Balachandran, Manoj; Junior, Luiz Ribeiro; Tromer, Raphael; Galvao, Douglas Soares; Tiwary, Chandra Sekhar; Kumbhakar, Partha
source: Optical Materials;Volume;159;Issue;;Article No.;116619;
publisher: Elsevier B.V.
date: 01-01-2025
rights: Restricted Access; Hardcopy may be available in the library
relation: ISSN: 9253467; CODEN: OMATE
format: online
language: English
type: Article
coverage: Ninan G.G., Department of Physical Sciences and Mathematics, St. Francis de Sales College (Autonomous), Electronics City, Karnataka, Bengaluru, 560100, India, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Varghese M., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Gowda C.C., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India; Bylappa Y., Department of Life Science, CHRIST (Deemed to be University), Bangalore, 560029, India; Nag A., Department of Life Science, CHRIST (Deemed to be University), Bangalore, 560029, India; Balachandran M., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Junior L.R., Institute of Physics, University of Brasilia, DF, Brasilia, 70910-970, Brazil; Tromer R., Applied Physics Department, State University of Campinas, SP, Campinas, 13083-970, Brazil; Galvao D.S., Applied Physics Department, State University of Campinas, SP, Campinas, 13083-970, Brazil; Tiwary C.S., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India, Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India; Kumbhakar P., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India, Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India

Optical Resonator-Enhanced Random Lasing using Atomically Thin Aluminium-based Multicomponent Quasicrystals
subject: 2D quasicrystals (2D-QCs); Al70Co10Fe5Ni10Cu5; Optical resonator; Random lasing (RL)
description: Photon trapping inside a gain medium using a dispersed two-dimensional (2D) passive scatterer is an impetus to obtain incoherent random lasing (ic-RL) emission due to non-resonant feedback. An optical resonator (OR) can be used to influence such lasing thresholds. Non-noble nanomaterials-based quasicrystals (QCs) are an intriguing research prospect due to their potential surface plasmon resonance (SPR) property and ability to be exfoliated into 2D. In this work, an aluminium-based multicomponent alloy (Al70Co10Fe5Ni10Cu5) has been synthesized via the arc melting method. Thereafter, ultrasonication-based liquid phase exfoliation was used to obtain 2D quasicrystals (2D-QCs). The SPR-induced light scattering properties of synthesized 2D-QCs were exploited to obtain ic-RL from DCM dye gain medium under 532 nm, 10 ns, 10 Hz pulsed laser pumping. The plasmonic field enhancement property of 2D-QCs which enables the gain medium to absorb photons outside its peak absorption band has been demonstrated. The transition from ic-RL to OR-enhanced ic-RL and vice versa in the presence of resonator walls has been achieved by tweaking the device architecture. In this way, the ability of 2D-QCs to be potential passive scatterers and the controllability of lasing thresholds in the presence of an OR has been demonstrated. 2024 Elsevier Ltd
creator: Mandal N.; Kumbhakar P.; Dey A.; Kumbhakar P.; Chatterjee U.; J. S. de Matos C.; Prasad Yadav T.; Krishna Mukhopadhyay N.; Biswas K.; Kochat V.; Sekhar Tiwary C.
source: Optics and Laser Technology, Vol-175
publisher: Elsevier Ltd
date: 2024-01-01
rights: Restricted Access
relation: ISSN: 303992; CODEN: OLTCA
format: Online
language: English
type: Article
coverage: Mandal N., School of Nanoscience and Technology, Indian Institute of Technology Kharagpur, 721302, India; Kumbhakar P., Department of Physics and Electronics, Christ University, Karnataka, Bangalore, 560029, India; Dey A., Nanoscience Laboratory, Department of Physics, National Institute of Technology, West Bengal, Durgapur, 713209, India; Kumbhakar P., Nanoscience Laboratory, Department of Physics, National Institute of Technology, West Bengal, Durgapur, 713209, India; Chatterjee U., Laser Laboratory, Dept. of Physics, The University of Burdwan, Burdwan, 713104, India; J. S. de Matos C., MackGraphe, Mackenzie Presbyterian Institute, S PauloSP, 01302-907, Brazil, School of Engineering, Mackenzie Presbyterian University, S PauloSP, 01302-907, Brazil; Prasad Yadav T., Department of Physics, Faculty of Science, University of Allahabad, Prayagraj, 211002 UP, India; Krishna Mukhopadhyay N., Department of Metallurgical Engineering, Indian Institute of Technology (BHU), UP, Varanasi, 221005, India; Biswas K., Department of Materials Science and Engineering, Indian Institute of Technology, UP, Kanpur, India; Kochat V., School of Nanoscience and Technology, Indian Institute of Technology Kharagpur, 721302, India; Sekhar Tiwary C., School of Nanoscience and Technology, Indian Institute of Technology Kharagpur, 721302, India

Optical Spectroscopy of Classical Be Stars in Old Open Clusters
subject: (Galaxy:) open clusters and associations: general; Be; stars: emission-line; techniques: spectroscopic
description: We performed the optical spectroscopy of 16 classical Be stars in 11 open clusters older than 100 Myr. Ours is the first spectroscopic study of classical Be stars in open clusters older than 100 Myr. We found that the H? emission strength of most of the stars is less than 40 in agreement with previous studies. Our analysis further suggests that one of the stars, [KW97] 35-12, might be a weak H? emitter in nature, showing H? equivalent width of ?0.5 Interestingly, we also found that the newly detected classical Be star LS III +47 37b might be a component of the possible visual binary system LS III +47 37, where the other companion is also a classical Be star. Hence, the present study indicates the possible detection of a binary Be system. Moreover, it is observed that all 16 stars exhibit a lesser number of emission lines compared to classical Be stars younger than 100 Myr. Furthermore, the spectral type distribution analysis of B-type and classical Be stars for the selected clusters points out that the existence of CBe stars can depend on the spectral type distribution of B-type stars present in these clusters. 2023. National Astronomical Observatories, CAS and IOP Publishing Ltd.
creator: Kashyap Jagadeesh M.; Mathew B.; Paul K.T.; Banerjee G.; Bhattacharyya S.; Anusha R.; Kumar S P.
source: Research in Astronomy and Astrophysics, Vol-23, No. 3
publisher: Institute of Physics
date: 2023-01-01
rights: Restricted Access
relation: ISSN: 16744527
format: Online
language: English
type: Article
coverage: Kashyap Jagadeesh M., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Main Road, Bengaluru, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Main Road, Bengaluru, India; Paul K.T., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Main Road, Bengaluru, India; Banerjee G., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Main Road, Bengaluru, India; Bhattacharyya S., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Main Road, Bengaluru, India; Anusha R., Department of Physics and Astronomy, University of Western Ontario, London, N6A 3K7, ON, Canada; Kumar S P., Indian Institute of Astrophysics, Koramangala, Bengaluru, India

Optical Spectroscopy of Classical Be Stars in The Galaxy
subject: Physics and Electronics
description: A classical Be (Be hereafter) star is a special type of massive B-type main newlinesequence star surrounded by a geometrically thin, equatorial, gaseous, decretion disc orbiting the central star. Spectra of Be stars show emission lines of different elements. Studying these lines provide an excellent opportunity to understand the geometry and kinematics of the circumstellar newlinedisc and properties of the central star itself. Be stars, thus provide excellent opportunities to study circumstellar discs. However, the disc formation mechanism in Be stars the Be phenomenon is still poorly understood. The present study focuses on studying a large sample of Be stars through newlineoptical spectroscopy and using two national optical telescope facilities. We performed the spectroscopic study of all major emission lines for a sample of 115 feld Be stars in the wavelength range of 3800 - 9000 using the 2.1-m HCT facility at Ladakh. To our knowledge, this is the frst study where near simultaneous spectra covering the whole spectral range of 3800 - 9000 has been studied for over 100 feld Be stars. We, therefore, produce an atlas of emission lines for Be stars which will be a valuable resource for researchers involved in Be star research. We made use of the unprecedented capability of the Gaia mission to re-estimate the extinction parameter (AV ) for these stars. The estimated AV values are used for extinction correction in the analysis of Balmer decrement (D34 and D54) for our program stars. D34 in our sample ranges between 0.1 and 9.0, whereas the corresponding D54 value mostly (and#8776; 70%) ranges between 0.2 and 1.5, clustering somewhere near 0.8 and#8722; 1.0. Our study indicates that Be star discs are generally optically thick in nature in majority of the cases. Through comparative study with the literature, we also noticed that the Hand#945; EW values in Be stars are usually lower than -40 Further from our analysis, it appears that the emission strength of Hand#945;, P1…
creator: Banerjee, Gourav
source: Author's Submission
publisher: Christ(Deemed to be University)
date: 2023-01-01
contributor: Mathew, Blesson
rights: Open Access
relation: 61000297
format: PDF
language: English
type: PhD

Optical Spectroscopy of Classical be stars in the galaxy /
subject: Physics
creator: Gourav Banerjee - 1942082
publisher: CHRIST (Deemed to be University)
date: 2023-07-06
language: English
type: PhD

Optical spectroscopy of Gaia detected protostars with DOT: Can we probe protostellar photospheres?
subject: orion; Protostars; star formation
description: Optical spectroscopy offers the most direct view of the stellar properties and the accretion indicators. Standard accretion tracers, such as H ? , H ? and Ca II triplet lines, and most photospheric features fall in the optical wavelengths. However, these tracers are not readily observable from deeply embedded protostars because of the large line of sight extinction (Av? 50 100 mag) toward them. In some cases, however, it is possible to observe protostars at optical wavelengths if the outflow cavity is aligned along the line-of-sight that allows observations of the photosphere, or the envelope is very tenuous and thin, such that the extinction is low. In such cases, we not only detect these protostars at optical wavelengths, but also follow up spectroscopically. We have used the HOPS catalog (Furlan et al. in 2016) of protostars in Orion to search for optical counterparts for protostars in the Gaia DR3 survey. Out of the 330 protostars in the HOPS sample, an optical counterpart within 2 ? ? is detected for 62 of the protostars. For 17 out of 62 optically detected protostars, we obtained optical spectra (between 5500 and 8900 using nt Object Spectrograph and Camera (ADFOSC) on the 3.6-m Devasthal Optical Telescope (DOT) and Hanle Faint Object Spectrograph Camera (HFOSC) on 2-m Himalayan Chandra Telescope (HCT). We detect strong photospheric features, such as the TiO bands in the spectra (of 4 protostars), hinting that photospheres can form early in the star-formation process. We further determined the spectral types of protostars, which show photospheres similar to a late M-type. Mass accretion rates derived for the protostars are similar to those found for T-Tauri stars, in the range of 10 - 7 10 - 8M? yr - 1 . 2023, Indian Academy of Sciences.
creator: Narang M.; Manoj P.; Tyagi H.; Nayak P.K.; Sharma S.; Surya A.; Banerjee B.; Mathew B.; Ghosh A.; Verma A.
source: Journal of Astrophysics and Astronomy, Vol-44, No. 2
publisher: Springer
date: 2023-01-01
rights: Restricted Access
relation: ISSN: 2506335
format: Online
language: English
type: Article
coverage: Narang M., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India, Academia Sinica Institute of Astronomy and Astrophysics, 11F of Astro-Math Bldg., No.1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan; Manoj P., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India; Tyagi H., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India; Nayak P.K., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India, Institute of Astrophysics, Pontificia Universidad Catolica de Chile, Av. Vicu MacKenna 4860, Santiago, 7820436, Chile; Sharma S., Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, 263 001, India; Surya A., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India; Banerjee B., Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai, 400005, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Ghosh A., Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, 263 001, India; Verma A., Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, 263 001, India

Optical spectroscopy of Galactic field classical Be stars
subject: Circumstellar matter; Stars: Emission-line, Be; Techniques: Spectroscopic
description: In this study, we analyse the emission lines of different species present in 118 Galactic field classical Be stars in the wavelength range of 3800-9000 We re-estimated the extinction parameter (AV) for our sample stars using the newly available data from Gaia DR2 and suggest that it is important to consider AV while measuring the Balmer decrement (i.e. D34 and D54) values in classical Be stars. Subsequently, we estimated the Balmer decrement values for 105 program stars and found that ?20 per cent of them show D34 ? 2.7, implying that their circumstellar disc are generally optically thick in nature. One program star, HD 60855 shows H? in absorption - indicative of disc-less phase. From our analysis, we found that in classical Be stars, H? emission equivalent width values are mostly lower than 40 which agrees with that present in literature. Moreover, we noticed that a threshold value of ?10of H? emission equivalent width is necessary for FeII emission to become visible. We also observed that emission line equivalent widths of H?, P14, FeII 5169, and OI 8446for our program stars tend to be more intense in earlier spectral types, peaking mostly near B1-B2. Furthermore, we explored various formation regions of Ca II emission lines around the circumstellar disc of classical Be stars. We suggest the possibility that Ca II triplet emission can originate either in the circumbinary disc or from the cooler outer regions of the disc, which might not be isothermal in nature. 2021 Oxford University Press. All rights reserved.
creator: Banerjee G.; Mathew B.; Paul K.T.; Subramaniam A.; Bhattacharyya S.; Anusha R.
source: Monthly Notices of the Royal Astronomical Society, Vol-500, No. 3, pp. 3926-3943.
publisher: Oxford University Press
date: 2021-01-01
rights: All Open Access; Green Open Access
relation: ISSN: 358711; CODEN: MNRAA
format: Online
language: English
type: Article
coverage: Banerjee G., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Main Road, Bangalore, 560029, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Main Road, Bangalore, 560029, India; Paul K.T., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Main Road, Bangalore, 560029, India; Subramaniam A., Indian Institute of Astrophysics, Koramangala, Bangalore, 560034, India; Bhattacharyya S., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Main Road, Bangalore, 560029, India; Anusha R., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Main Road, Bangalore, 560029, India

Optimal allocation algorithm of marketing resources based on improved random forest
subject: allocation algorithm; Improved random forest; marketing; resource optimization
description: Random Forest algorithm is an ensemble learning algorithm that classifies data by combining multiple decision trees. It has a wide range of applications and is not easy to overfit. It has a wide range of applications in medicine, bioinformatics, management and other fields. By studying the Cobb-Douglas sales function, it is found that it can only analyze the static allocation of marketing resources, but cannot describe the dynamic changes. Enterprise marketing resource management runs through the enterprise management from beginning to end. The research on marketing resource management is helpful for enterprises to grasp and control the whole process of marketing resource management from the overall and overall level, and has important theoretical value and reality for enterprise marketing management activities. significance. In the vast majority of enterprises in our country, the size of advertising promotion expenses and the number of salesmen is often determined based on the experience and subjective assumptions of decision makers, so it is difficult to say that they are optimized. This paper starts with determining the optimal advertising budget and the number of salespeople, and conducts applied research on the optimal allocation of marketing resources. 2023 IEEE.
creator: Winster Praveenraj D.D.; Hussein L.; Tomar R.S.; Margarat G.S.; Vimala M.; Krishnaraj V.
source: 2023 2nd International Conference on Smart Technologies for Smart Nation, SmartTechCon 2023, pp. 809-813.
publisher: Institute of Electrical and Electronics Engineers Inc.
date: 2023-01-01
rights: Restricted Access
relation: ISBN: 979-835030541-8
format: Online
language: English
type: Conference paper
coverage: Winster Praveenraj D.D., School of Business and Management, Christ (Deemed to be University), Bangalore, India; Hussein L., College of Technical Engineering, The Islamic University, Najaf, Iraq; Tomar R.S., Department of Computer Science & Engineering, IES College Of Technology, MP, Bhopal, 462044, India; Margarat G.S., New Prince Shri Bhavani College Of Engineering And Technology, India; Vimala M., Department of Electronics and Communication Engineering, P.S.R Engineering College, Tamilnadu, India; Krishnaraj V., Department of Mathematics, Sona College of Technology, Tamilnadu, Salem, India

Optimal Allocation of Renewable Sources with Battery and Capacitors in Radial Feeders for Reliable Power Supply Using Pathfinder Algorithm
subject: Distribution network; Energy storage system; Islanding mode; Multi-objective optimization; Pathfinder algorithm; Renewable energy
description: Allocating renewable energy systems (RESs) in an electrical distribution system (EDS) is crucial to achieving various objectives. However, their intermittency presents several challenges. In this connection, an efficient meta-heuristic pathfinder algorithm (PFA) is employed to determine the optimal location and size of photovoltaic (PV) and wind turbine (WT) systems, along with energy storage systems (ESS) and capacitor banks (CB) for both grid and islanding modes of operations. An objective function was formulated for loss reduction, greenhouse gas (GHG) emissions, and voltage profile improvement. The simulation results for the IEEE 33-bus EDS system are shown for two cases: grid-connected and islanding. The computational effectiveness of the PFA was compared with that reported in the literature. The PFA results showed an outstanding ability to resolve difficult optimisation problems. In addition, the optimal size of the RES when the network operates in the grid-connected mode can significantly improve the performance. The real power losses and GHG emissions were reduced by 48.49 % and 67.75% with PV systems and the other, respectively, whereas WT systems they are reduced to 69.68 % and 67.85 %, respectively. However, a combination of ESS, CB, and PV/WT can render the EDN sustainable for the islanding mode of operations. The Author(s).
creator: Sreenivasulu Reddy D.; Janamala V.
source: Journal of Solar Energy Research, Vol-8, No. 4, pp. 1651-1662.
publisher: University of Tehran
date: 2023-01-01
rights: Restricted Access
relation: ISSN: 25883097
format: Online
language: English
type: Article
coverage: Sreenivasulu Reddy D., Department of Electrical and Electronics Engineering, School of Engineering and Technology, CHRIST (Deemed to be University), Karnataka, Bangalore, 560074, India; Janamala V., Department of Electrical and Electronics Engineering, School of Engineering and Technology, CHRIST (Deemed to be University), Karnataka, Bangalore, 560074, India

Optimal allocation of solar photovoltaic distributed generation in electrical distribution networks using Archimedes optimization algorithm
subject: Archimedes optimization algorithm; Composite load modelling; Distributed generation; Electrical distribution network; Solar photovoltaic system
description: This paper proposes to resolve optimal solar photovoltaic (SPV) system locations and sizes in electrical distribution networks using a novel Archimedes optimization algorithm (AOA) inspired by physical principles in order to minimize network dependence and greenhouse gas (GHG) emissions to the greatest extent possible. Loss sensitivity factors are used to predefine the search space for sites, and AOA is used to identify the optimal locations and sizes of SPV systems for reducing grid dependence and GHG emissions from conventional power plants. Experiments with composite agriculture loads on a practical Indian 22-bus agricultural feeder, a 28-bus rural feeder and an IEEE 85-bus feeder demonstrated the critical nature of optimally distributed SPV systems for minimizing grid reliance and reducing GHG emissions from conventional energy sources. Additionally, the voltage profile of the network has been enhanced, resulting in significant reductions in distribution losses. The results of AOA were compared to those of several other nature-inspired heuristic algorithms previously published in the literature, and it was observed that AOA outperformed them in terms of convergence and redundancy when solving complex, non-linear and multivariable optimization problems. The Author(s) 2022.
creator: Janamala V.; Rani K.R.
source: Clean Energy, Vol-6, No. 2, pp. 1036-1052.
publisher: Oxford University Press
date: 2022-01-01
rights: All Open Access; Gold Open Access
relation: ISSN: 25154230
format: Online
language: English
type: Article
coverage: Janamala V., Department of Electrical and Electronics Engineering, School of Engineering and Technology, CHRIST (Deemed to be University), Karnataka, Bangalore, 560 074, India; Rani K.R., Department of Electrical & Electronics Engineering, R.V.R. & J.C. College of Engineering, Andhra Pradesh, Guntur, 522 019, India

Optimal arrangement of ration items into container using modified forest optimization algorithm
subject: Container loading; Fair Price Shop; Modified Forest Optimization algorithm; Shrewd framework; Smart City
description: Planning a shrewd framework for loading the ration goods into the container is one of the significant objectives in the mission of smart city advancement in India. This optimal container loading system is designed for the arrangement of ration goods into the container using Modified Forest Optimization algorithm for safe and secure delivery. The effectiveness of the proposed approach has been demonstrated using BR datasets and compared with different optimization algorithms. From the experiment, it is observed that the proposed Modified Forest Optimization algorithm is implemented in java meets the objective of loading the ration items into the container in an optimal fashion. Further, it is observed that the order of arrangement predicted by the proposed algorithm is found to be optimal than other competitive optimization algorithms. 2020, Engg Journals Publications. All rights reserved.
creator: Ravichandran S.K.; Sasi A.
source: Indian Journal of Computer Science and Engineering, Vol-11, No. 4, pp. 334-346.
publisher: Engg Journals Publications
date: 2020-01-01
rights: All Open Access; Gold Open Access
relation: ISSN: 9765166
format: Online
language: English
type: Article
coverage: Ravichandran S.K., School of Engineering and Technology, Department of Computer Science and Engineering, Christ University, Bengaluru, Karnataka, India; Sasi A., School of Engineering, Department of Computer Science and Engineering Presidency University, Bengaluru, Karnataka, India

Optimal benchmarking of quality of service and quality of experience metrics for telecom service providers using a slack based measure in data envelopment analysis
subject: Computer Science
description: With new devices and new network technologies coming up, it has become an inevitable task to provide services of a minimum quality. Setting feasible Service Level Agreements (SLAs) is the need of the hour. This, being a part of network provisioning and providing the best possible Quality of Service (QoS) is very vital and helps improve user perceived quality or the Quality of Experience (QoE). QoE evaluation helps Internet Service Providers (ISPs) understand their user satisfaction better and this goes hand in hand with providing adequate network QoS. Moreover, in this era of competition, the ISPs themselves will have to be evaluated based on their QoE and QoS metrics to know their true position in the market in terms of performance against their peers/competitors. This evaluation is usually done on a per-metric basis. However, we see from current performance data that all the ISPs fare well on some metrics and need improvement in the others. It is a fact that no ISP fares bad on all given metrics and leads to an understanding that per-metric based evaluation may be a biased form of newlineevaluating performance. Hence, this research has attempted to use an intelligent, robust newlinemathematical technique called the Data Envelopment Analysis (DEA) with its Slack newlineBased Measure (SBM) approach. DEA is a proven, tested and tried technique that is in newlineuse in major industries even today. Being a multiple criterion evaluation methodology newlinebased on linear programming, it works well on multiple outputs and multiple inputs. DEA gives the overall, relative efficiency of the ISPs which gives us the true position of the provider against its peers. The Slack Based Measure provides the Output Slacks that show the potential improvement that the lagging ISPs can make to be in par with their peers/competitors. The Output targets that are provided by the technique can be used as benchmarks for SLAs.
creator: S,Gracia
source: Author's Submission
publisher: Christ(Deemed to be University)
date: 2024-11-08
contributor: Beaulah, Soundarabai P
rights: Open Access
relation: 61000349
format: PDF
language: English
type: PhD