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392 results on '"Singh, Nitesh"'

2. A stochastic moving ball approximation method for smooth convex constrained minimization

Author

Singh, Nitesh Kumar and Necoara, Ion

Subjects
Mathematics - Optimization and Control
Abstract

In this paper, we consider constrained optimization problems with convex, smooth objective and constraints. We propose a new stochastic gradient algorithm, called the Stochastic Moving Ball Approximation (SMBA) method, to solve this class of problems, where at each iteration we first take a gradient step for the objective function and then perform a projection step onto one ball approximation of a randomly chosen constraint. The computational simplicity of SMBA, which uses first-order information and considers only one constraint at a time, makes it suitable for large-scale problems with many functional constraints. We provide a convergence analysis for the SMBA algorithm using basic assumptions on the problem, that yields new convergence rates in both optimality and feasibility criteria evaluated at some average point. Our convergence proofs are novel since we need to deal properly with infeasible iterates and with quadratic upper approximations of constraints that may yield empty balls. We derive convergence rates of order $\mathcal{O} (k^{-1/2})$ when the objective function is convex, and $\mathcal{O} (k^{-1})$ when the objective function is strongly convex. Preliminary numerical experiments on quadratically constrained quadratic problems demonstrate the viability and performance of our method when compared to some existing state-of-the-art optimization methods and software., Comment: 28 pages

Published
2024

4. Mini-batch stochastic subgradient for functional constrained optimization

Author

Singh, Nitesh Kumar and Necoara, Ion

Subjects
Mathematics - Optimization and Control
Abstract

In this paper we consider finite sum composite convex optimization problems with many functional constraints. The objective function is expressed as a finite sum of two terms, one of which admits easy computation of (sub)gradients while the other is amenable to proximal evaluations. We assume a generalized bounded gradient condition on the objective which allows us to simultaneously tackle both smooth and nonsmooth problems. We also consider the cases of both with and without a strong convexity property. Further, we assume that each constraint set is given as the level set of a convex but not necessarily differentiable function. We reformulate the constrained finite sum problem into a stochastic optimization problem for which the stochastic subgradient projection method from [17] specializes to a collection of mini-batch variants, with different mini-batch sizes for the objective function and functional constraints, respectively. More specifically, at each iteration, our algorithm takes a mini-batch stochastic proximal subgradient step aimed at minimizing the objective function and then a subsequent mini-batch subgradient projection step minimizing the feasibility violation. By specializing different mini-batching strategies, we derive exact expressions for the stepsizes as a function of the mini-batch size and in some cases we also derive insightful stepsize-switching rules which describe when one should switch from a constant to a decreasing stepsize regime. We also prove sublinear convergence rates for the mini-batch subgradient projection algorithm which depend explicitly on the mini-batch sizes and on the properties of the objective function. Numerical results also show a better performance of our mini-batch scheme over its single-batch counterpart., Comment: 24 pages

Published
2024
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6. ALEXA-The Thinking Car

Author

Wankhade, Pranali, Barad, Vaishnavi, Samarth, Pankaj, Singh, Nitesh, Prasad, P.S., and Yadav, V.

Published
2017

7. Site-specific stable deterministic single photon emitters with low Huang-Rhys value in layered hexagonal boron nitride at room temperature

Author

Bhunia, Amit, Joshi, Pragya, Singh, Nitesh, Chakraborty, Biswanath, and Nair, Rajesh V

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics, Quantum Physics
Abstract

Development of stable room-temperature bright single-photon emitters using atomic defects in hexagonal-boron nitride flakes (h-BN) provides significant promises for quantum technologies. However, an outstanding challenge in h-BN is creating site-specific, stable, high emission rate single photon emitters with very low Huang-Rhys (HR) factor. Here, we discuss the photonic properties of site-specific, isolated, stable quantum emitter that emit single photons with a high emission rate and unprecedented low HR value of 0.6 at room temperature. Scanning confocal image confirms site-specific single photon emitter with a prominent zero-phonon line at ~578 nm with saturation photon counts of 105 counts/second. The second-order intensity-intensity correlation measurement shows an anti-bunching dip of ~0.25 with an emission lifetime of 2.46 ns. Low-energy electron beam irradiation and subsequent annealing are important to achieve stable single photon emitters.

Published
2023

10. Knowledge Graph Implementation to Enhance Micro-segmentation for Health Care

Author

Pandey, Arunanshu, Kumar, Shubham, Singh, Nitesh, Kacprzyk, Janusz, Series Editor, Gomide, Fernando, Advisory Editor, Kaynak, Okyay, Advisory Editor, Liu, Derong, Advisory Editor, Pedrycz, Witold, Advisory Editor, Polycarpou, Marios M., Advisory Editor, Rudas, Imre J., Advisory Editor, Wang, Jun, Advisory Editor, and Arai, Kohei, editor

Published
2024
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14. Purcell and collection efficiency enhancement of single NV- center emission coupled to an asymmetric Tamm structure

Author

Singh, Nitesh and Nair, Rajesh V

Subjects
Physics - Optics
Abstract

The resonant modes associated with engineered photonic structures of different spatial-dimension are essential to obtain bright on-demand single photon sources for quantum technologies. Negatively-charged nitrogen-vacancy (NV-) center in diamond is proposed as an excellent single photon source at room temperature. The possible optical readout of spin states in diamond makes it a good candidate for spin-photon interface. However, the poor light collection, feeble zero-phonon line, low emission rate, and the presence of broad phonon-induced emission limits the use of NV- center in quantum technologies. Here, we present a feasible, easy to fabricate, asymmetric Tamm structure coupled with single NV- center to enhance the emission rate of zero phonon line (ZPL) with better light collection efficiency. The asymmetric Tamm structure shows dual resonant mode with one of the modes coinciding with NV- ZPL wavelength of 640 nm. The quality factor (Q-factor) of the mode is 140 which is far better than the Q-factor of conventional Tamm structure and hence, better field intensity localization. We achieve four times Purcell enhancement along with an enhanced light collection efficiency of five times at 640 nm. The proposed structure is useful for generating bright single photons using NV- center and an efficient spin-photon interface.

Published
2022

15. Stochastic subgradient for composite optimization with functional constraints

Author

Necoara, Ion and Singh, Nitesh Kumar

Subjects
Mathematics - Optimization and Control
Abstract

In this paper we consider convex optimization problems with stochastic composite objective function subject to (possibly) infinite intersection of constraints. The objective function is expressed in terms of expectation operator over a sum of two terms satisfying a stochastic bounded gradient condition, with or without strong convexity type properties. In contrast to the classical approach, where the constraints are usually represented as intersection of simple sets, in this paper we consider that each constraint set is given as the level set of a convex but not necessarily differentiable function. Based on the flexibility offered by our general optimization model we consider a stochastic subgradient method with random feasibility updates. At each iteration, our algorithm takes a stochastic proximal (sub)gradient step aimed at minimizing the objective function and then a subsequent subgradient step minimizing the feasibility violation of the observed random constraint. We analyze the convergence behavior of the proposed algorithm for diminishing stepsizes and for the case when the objective function is convex or strongly convex, unifying the nonsmooth and smooth cases. We prove sublinear convergence rates for this stochastic subgradient algorithm, which are known to be optimal for subgradient methods on this class of problems. When the objective function has a linear least-square form and the constraints are polyhedral, it is shown that the algorithm converges linearly. Numerical evidence supports the effectiveness of our method in real problems., Comment: 32 pages, initial version July 2021

Published
2022

21. Synthetically Encapsulated \& Self-Organized Transition Metal Oxide Nano Structures inside Carbon Nanotubes as Robust Li-ion Battery Anode Materials

Author

Kapoor, Aakanksha, Patrike, Apurva L., Singh, Nitesh, Thauer, Elisa, Ottmann, Alexander, Klingeler, Rudiger, Ogale, Satishchandra, and Bajpai, A.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report a comprehensive study on the electrochemical performance of four different Transition Metal Oxides encapsulated inside carbon nanotubes (CNT). Irrespective of the type of oxide-encapsulate, all these samples exhibit superior cyclic stability as compared to the bare-oxide. Innovative use of camphor during sample synthesis enables precise control over the morphology of these self-organized carbon nanotube structures, which in turn appears to play a crucial role in the magnitude of the specific capacity. A comparative evaluation of the electrochemical data on different samples bring forward interesting inferences pertaining to the morphology, filling fraction of the oxide-encapsulate, and the presence of oxide nano-particles adhering outside the filled CNT. Our results provides useful pointers towards the optimization of critical parameters, thus paving the way for using these synthetically encapsulated and self-organized carbon nanotube structures as anode materials for Li-ion batteries, and possibly other electrochemical applications.

Published
2020

28. Hybrid Energy Storage System

Author

Sharma, Rohini, primary, Singh, Nitesh, additional, Sharma, Aakash, additional, Sharma, Naina, additional, Singh, Manjeet, additional, and Pattnaik, Amruta, additional

Published
2023
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29. The heparin-binding hemagglutinin protein of Mycobacterium tuberculosis is a nucleoid-associated protein

Author

Keshavam, Chetkar Chandra, Naz, Saba, Gupta, Aanchal, Sanyal, Priyadarshini, Kochar, Manisha, Gangwal, Aakriti, Sangwan, Nitika, Kumar, Nishant, Tyagi, Ekta, Goel, Simran, Singh, Nitesh Kumar, Sowpati, Divya Tej, Khare, Garima, Ganguli, Munia, Raze, Dominique, Locht, Camille, Basu-Modak, Sharmila, Gupta, Meetu, Nandicoori, Vinay Kumar, and Singh, Yogendra

Published
2023
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31. Efficacy and adverse events profile of videolaryngoscopy in critically ill patients: subanalysis of the INTUBE study

Author

Anstey, Matthew, Colica, Sandra, Brewster, David, Simpson, Shannon, Regli, Adrian, O'Grady, Ross, Litton, Edward, Ferrier, Janet, Bartholdy, Roland, Tabah, Alexis, Bowen, David, Rowley, Rebecca, Gatward, Jonathan, Alonso, Julio, Varkey, Sneha, Palaniswamy, Vijayanand, Chimunda, Timothy, Reza, Syed T., Hossain, Mozaffer, Islam, Motiul, Hamid, Tarikul, Parotto, Matteo, Ajami, Samareh, Steel, Andrew, Del Sorbo, Lorenzo, Goffi, Alberto, Randall, Ian, Adhikari, Neill K.J., Mehesry, Tasneem H., Vera, Maria M., Bugedo, Guillermo, Labarca, Gonzalo, Silva, Monica, Ma, Wuhua, Li, Yongxing, Wu, Jiayan, Wu, Lun, Radivojević, Renata Curić, Matas, Marijana, Ivančan, Višnja, Pavlek, Mario, Mihaljević, Slobodan, Jumić, Aleksandra, Moguš, Mate, Tucić, Iva, Michalek, Pavel, Flaksa, Marek, Aguirre-Bermeo, Hernan, Tirape-Castro, Hugo, García Aguilera, Maria F., Montenegro, Diana Alvarez, Tutillo, Diego Morocho, Tutillo León, Jose A., Winiszewski, Hadrien, Piton, Gael, Aissaoui, Nadia, Augy, Jean-Loup, Champigneulle, Benoit, Zlotnik, Diane, Muller, Grégoire, Jacquier, Sophie, Hraiech, Sami, Guervilly, Christophe, Plantefeve, Gaetan, Contou, Damien, Ricard, Jean Damien, Besset, Sebastien, Colin, Gwenhael, Pouplet, Caroline, Mirouse, Adrien, Azoulay, Elie, Boissier, Florence, Frat, Jean-Pierre, Mercier, Emmanuelle, Salmon-Gandonnière, Charlotte, Lascarrou, Jean-Baptiste, Martin, Maelle, Ferre, Alexis, Legriel, Stephane, Bruel, Cedric, Philippard, Francois, Zarka, Jonathan, Chemouni, Frank, Hamzaoui, Olfa, Sztrymf, Benjamin, Brunin, Yannick, Pili-Floury, Sébastien, Constantin, Jean-Michel, Godet, Thomas, Maraffi, Tommaso, Dessap, Armand Mekontso, Jozwiak, Mathieu, Marin, Nathalie, Guitton, Christophe, Chudeau, Nicolas, Gros, Alexandre, Boyer, Alexandre, Papandreou, Eleni, Petsiou, Athanasia, Papanikolaou, Metaxia, Kyparissi, Aikaterini, Tileli, Maria, Makris, Alexandros, Tsiftsis, Dimitrios, El-Fellah, Nadia, Karametos, Ilias, Nakou, Evi, Chalkias, Athanasios, Arnaoutoglou, Eleni, Katsoulis, Panagiotis, Pouriki, Sofia, Vagdatli, Kyriaki, Dimitropoulou, Aikaterini, Kothekar, Amol, Baliga, Nishanth, Korula, Sara V., Philip, Sam, Singh, Lalit, Agrawal, Nipun, Jeswani, Deepak, Jeswani, Deepti, Jha, Simant, Singh, Nitesh, Bhattacharyya, Mahuya, Das, Amit, Kuragayala, Swarna D., Kesavarapu, Subba R., Shah, Bhagyesh, Kaushik, Shuchi, Sunil, Nilu, Gnanadurai, Kingsly, Singh, Atul K., Singh, Dinesh K., Khunteta, Sudhir, Gupta, Kulbhusahn, Sanyal, Rhik, Midya, Abhirup, Tyagi, Vijay N., Bendre, Prashant, Prashant, Kumar, Chaurasia, Satish, Mishra, Prasanna, Dash, Sampat, Sundrani, Omprakash, Lalwani, Jaya, Jain, Nikhilesh, Agrawal, Kehari, Ray, Banambar, Meher, Ranjan, Saravanabavan, Lakshmikanthcharan, Munusamy, Satheesh, Gupta, Manish, Ahmad, Meraj, Gopalakrishna, Kadarapura N., Suparna, Bharadwaj, Surath, Manimala R., Munta, Kartik, Jagiasi, Bharat, Srivastava, Anand, Sahu, Samir, Mrinal, Sircar, Kumar, Singh Sujeet, Shah, Mehul, Patel, Mayur, Bamane, Shrirang, Narkhede, Amit, Chawla, Rajesh, Chawla, Aakanksha, Maheshwarappa, Harish Mallapura, Manjunath, Ramya Ballekatte, Rahmani, Lua, Laffey, John G., Rona, Roberto, Benini, Annalisa, Russotto, Vincenzo, Rundo, Annalisa, Luzi, Annalisa, Esposito, Clelia, Nespoli, Moana R., Pradella, Andrea, Lungu, Ramona, Baccari, Laura, Chiumiento, Fernando, Mariano, Karim, Cotoia, Antonella, De Rosa, Silvia, Boni, Elisa, Palmese, Salvatore, Gammaldi, Renato, Spadaro, Savino, Santoro, Lida, Cracchiolo, Andrea N., Palma, Daniela M., Pinciroli, Riccardo, Giovannini, Ilaria, Calamai, Italo, Spina, Rosario, Cappellini, Iacopo, Tutino, Lorenzo, Bellissima, Agrippino, Maugeri, Jessica G., Riva, Ivano, Fabretti, Fabrizio, Brazzi, Luca, Sales, Gabriele, Montrucchio, Giorgia, Orsello, Alberto, Costamagna, Andrea, Canavosio, Federico G., Pelagalli, Lorella, Marcelli, Maria E., Cortegiani, Andrea, Tramarin, Jacopo, Musso, Stefania, Tarantino, Stefano, Di Giacinto, Ida, Licciardi, Anna L., Montini, Luca, De Pascale, Gennaro, Giacomucci, Angelo, Russo, Pierpaolo, Longhini, Federico, Garofalo, Eugenio, Ferluga, Massimo, Moro, Valeria, Cascella, Marco, Di Caprio, Barbara, Di Fenza, Raffaele, Nespoli, Francesca, Bassini, Ospedale E., Muttini, Stefano, Pezzi, Angelo, Elhadi, Muhammed, Ghula, Mohamed, Ahmed, Hazem Abdelkarem, Khaled, Ala, Elhadi, Ahmed, Alhadi, Abdulmueti, Mazlan, Mohd Z., Wan Hassan, Wan Mohd N., Hasan, Shahnaz, Jamaluddin, Muhamad F.H., Samat, Noryani Mohd, Ismail, Muhamad A., Alias, Anita, Hwa, Ngu Pei, Irtiza, Ismail Nahla, Khalidah, Hapiz, Kiok, Lee Chew, Nordin, Norbaniza Mohd, Wan Ismail, Wan N., Ali, Mohd N., Sánchez-Hurtado, Luis, Toledo-Salinas, Otoniel, Landaverde, Antonio, Sosa, Miguel A., Gonzalez, Mayra Martinez, Lopez Nava, Claudia L., San Juan Roman, Nandyelly, Gonzalez, Maria, Espinoza, Missael, González, Daira, Flores, Fernando, Pantoja Leal, Jesus N., Loza Gallardo, Luis R., Young, Paul, Mistry, Ravi, Browne, Alexander, Crone, Petra, Chandwani, Juhi, Hossein, Sazzad, Koul, Salman S., Aman, Rubina, Ali, Syed M., Akhtar, Shazia N., Jankowski, Milosz, Bielanski, Piotr, Mudyna, Wojciech, Franczyk, Pawel, Galkin, Piotr, Skowronski, Lukasz, Gaszynski, Tomasz, Piegat, Mariusz, Catorze, Nuno, Pinto, Marcia, Leonor, Tiago, Fernandes, Marco, Campos, Patricia, Aragão, Irene, Costa, Paulo F., Franco, Daniela G., Basto, Marta, Nogueira, Carla, Cunha, Rui P., Costa, Vasco, Lomivorotov, Vladimir, Nikitenko, Artem, Belsky, Vladislav, Furman, Mikhail, Magomedov, Marat, Baturova, Vera, Karelov, Alexey, Marova, Nadezhda, Almekhlafi, Ghaleb, Alghamdi, Adnan, Maseda, Emilio, Suarez de la Rica, Alejandro, Gonzalez, Jesus Flores, Ruiz, Miryam Pérez, Roca, Oriol, Santafe, Manel, Fernandez, Gemma Goma, Escudero-Acha, Patricia, González-Castro, Alejandro, Agvald-Öhman, Christina, Broman, Lina, Spangfors, Martin, Hannesdottir, Katrin, Persson, Elin, Rosell, Jon, Sperber, Jesper, Ohlsson, Annika, Von Seth, Magnus, Pedrotti, Niccolò, Wahlstrom, Carl, Meirik, Maria, Bandert, Anna, Krog, Ditte, Kuo, Lu-Cheng, Shin, Ming-Hann, Chien, Jung-Yien, Ku, Shih-Chi, Ruan, Sheng-Yuan, Huang, Chun-Kai, Yeh, Yu-Chang, Chao, Anne, Wang, Kuo-Chuan, Chiu, Ching-Tang, Lee, Chien-Chang, Chou, Nai-Kuan, Szakmany, Tamas, Jones, Benjamin, Jones, Laura, Della Torre, Valentina, Sinah, Ayush, Quayle, Alice, Cheetham, Olivia, Syed, Yadullah, Mensah, Kwabena, Edmunds, Christopher, Kaye, Callum T., Bauer, Philippe R., Odeyemi, Yewande E., Nates, Joseph, Laserna, Andres, Mosier, Jarrod, Hypes, Cameron, Gottesman, Eric, Mastroianni, Fiore, Fein, Daniel G., Zhao, Dawn, Fonseca Fuentes, Xavier E., Gallo de Moraes, Alice, Sandefur, Benjamin J., Khan, Akram, Matos, Dubier, Kaufman, David A., Lehr, Andrew, Bigatello, Luca, Bonney, Iwona, Lascarrou, Jean Baptiste, Tassistro, Elena, Antolini, Laura, Bauer, Philippe, Szułdrzyński, Konstanty, Camporota, Luigi, Putensen, Christian, Pelosi, Paolo, Sorbello, Massimiliano, Higgs, Andy, Greif, Robert, Grasselli, Giacomo, Valsecchi, Maria G., Fumagalli, Roberto, Foti, Giuseppe, Caironi, Pietro, Bellani, Giacomo, and Myatra, Sheila N.

Published
2023
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33. Guillain-Barre Syndrome and its Prognosis with Hyponatremia

Author

Jerin Romeo, Hemant Mahur, D P Singh, Nitesh Pansari, Heeralal Verma, Pavan Kumar KT

Subjects
Not available, Medicine
Abstract

Introduction: Guillain Barre Syndrome (GBS) can be described as a collection of clinical syndrome that manifest as an acute inflammatory polyradiculopathy with resultant weakness and diminished reflexes. The hyponatremia is a recognized association of GBS and is also known to occur after the administration of intravenous infusion of gamma globulin (IVIG); a treatment often used in management of GBS. Hyponatremia in GBS is very often overlooked entity even though it is well established. The purpose of this study was to document serum sodium concentration in GBS patients before and during management procedures (including IVIG), positive pressure ventilation (PPV) and to assess whether hyponatremia is a predictor of poor outcome. Methodology: All patients (>2 years of age) diagnosed as Guillain-Barre Syndrome (GBS) fulfilling the criteria as modified by Asbury, admitted in the Medicine and Pediatric department of RNT Medical College and Associated Hospital, Udaipur from January 2014 to July 2015 were included in this study. After obtaining clinical history, electrophysiologic studies were performed to determine the GBS subtype. Serum electrolytes were determined at the time of admission of patient and during course of treatment (day 1 and day 3). Results: A total of 50 patients were studied. Male preponderance was observed with the maximum number (38.00%) of patients below 16 years age group and was seen in the months of April to June. All patients received physiotherapy and the nine patients who developed respiratory failure were put on mechanical ventilation. Six patients required mechanical ventilation inspite of intravenous immunoglobulin (IVIG) therapy. Eight patients received intravenous methylprednisolone (MPS). The mean duration of hospitalization was 8.66 days. Bulbar weakness and need for ventilatory support were higher in GBS with hyponatremia (6 v/s 3). Serum sodium concentration was low (

Published
2023
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40. Paddy straw management: alternative strategies and emerging technology for sustainable ecosystem

Author

PARSHAD, Jagdish, primary, KUMAR, Ravinder, additional, CHHOKAR, Vinod, additional, PATIL, Nagaraj, additional, BENIWAL, Vikas, additional, SINGH, Namita, additional, KUMAR, Ajay, additional, SINGH, Nitesh, additional, YOGI, Rajesh, additional, KUMAR, Mukesh, additional, VIKRAM, Prashant, additional, CHAUHAN, Avnish, additional, and KUMAR, Anil, additional

Published
2024
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41. 3d Transition Metals and Oxides within Carbon Nanotubes by Co-Pyrolysis of Metallocene & Camphor: High Filling Efficiency and Self-Organized Structures

Author

Kapoor, Aakanksha, Singh, Nitesh, Dey, Arka Bikash, Nigam, A. K., and Bajpai, Ashna

Subjects
Condensed Matter - Materials Science
Abstract

We demonstrate that a single zone furnace with a modified synthesis chamber design is sufficient to obtain metal (Fe, Co or Ni) filled carbon nanotubes (CNT) with high filling efficiency and controlled morphology. Samples are formed by pyrolysis of metallocenes, a synthesis technique that otherwise requires a dual zone furnace. Respective metallocene in all three cases are sublimed in powder form, a crucial factor for obtaining high filling efficiency. While Fe@CNT is routinely produced using this technique, well-formed Ni@CNT or Co@CNT samples are reported for the first time. This is achieved by sublimation of nickelocene (or cobaltocene) in combination with 'camphor'. These samples exhibit some of the highest saturation magnetization (Ms) values, at least an order of magnitude higher than that reported for Ni or Co filled CNT, by aerosol assisted pyrolysis. The results also elucidate on why Ni or Co@CNT are relatively difficult to obtain by pyrolyzing powder metallocene alone. Overall, a systematic variation of synthesis parameters provides insights for obtaining narrow length and diameter distribution and reduced residue particles outside filled CNT - factors which are important for device related applications. Finally, the utility of this technique is demonstrated by obtaining highly aligned forest of Fe2O3@CNT, wherein Fe2O3 is a functional magnetic oxide relevant to spintronics and battery applications.

Published
2017

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