77 research outputs found
Author Correction Large spontaneous exchange bias in a weak ferromagnet Pb 6 Ni 9 (TeO 6 ) 5 (Scientific Reports, (2017), 7, 1, (8300), 10.1038/s41598-017-09056-w)
No full textIn the original version of this Article, Binoy Krishna Hazra and S. Srinath were incorrectly affiliated with ‘Department of Physics, Indian Institute of Technology Tirupati, TIRUPATI, 517506, India’. The correct affiliation is listed below School of Physics, University of Hyderabad, Hyderabad, 500046, India This error has now been corrected in the PDF and HTML versions of the Article, and in the accompanying Supplementary Information file. © 2019, The Author(s)
Borane catalysed ring opening and closing cascades of furans leading to silicon functionalized synthetic intermediates
No full textThe conversion of renewable biomass resources to synthetically valuable chemicals is highly desirable, but remains a formidable challenge in regards to the substrate scope and reaction conditions. Here we present the development of tris(pentafluorophenyl)borane-catalysed conversion of furans via ring-opening and closing cascade processes to afford silicon-functionalized synthetic chemicals under transition metal-free conditions. The furan ring-opening with hydrosilanes is highly efficient (TON up to 2,000) and atom-economical without forming any byproduct to give rise to α-silyloxy-(Z)-alkenyl silanes. Additional equivalents of silane smoothly induce a subsequent B(C6 F5)3 -catalysed cyclization of initially formed olefinic silane compounds to produce anti-(2-alkyl)cyclopropyl silanes, another versatile synthon being potentially applicable in the synthesis of natural products and pharmacophores. © The Author(s) 2016113121sciescopu
Artificial Neural Network Training Using Differential Evolutionary Algorithm for Classification
No full textInvestigations on structural and electrical parameters of p-Si/ MgxZn1-xO thin film heterojunction diodes grown by RF magnetron sputtering technique
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Potato Leaf Disease Detection Using YOLOv8n with a Handheld Device
No full text<p><span>This study addresses the urgent need for timely detection of leaf diseases in agriculture to mitigate potential crop losses and subsequent negative impacts on the global economy. We propose a deep learning-based technique for potato leaf disease recognition, utilizing the Ultralytics YOLOv8n model trained on PlantVillage datasets, with the aim of enabling detection using handheld devices like mobile phones or Internet of Things (IoT) devices. Evaluation metrics including precision, recall, F1-score, mean Average Precision (mAP) at different Intersection Over Union (IOU) thresholds demonstrate the robust performance of the model, with high values across all metrics, such as precision (94.57%), recall (94.164%), F1-score (97.297%), and mAP (94.367%). These outcomes underscore the efficacy of the YOLOv8n model in accurately finding diseased regions within potato leaves. The potential applications of this approach extend beyond disease detection alone, with implications for precision farming and crop management. Overall, this research contributes to advancing technologies aimed at improving agricultural productivity, resilience, and economic sustainability through efficient disease management strategies.</span></p>
Autonomous Guidance for Asteroid Descent using Successive Convex Optimisation: Dual Quaternion Approach
No full textWith the onset of the age of space travel, asteroid missions have been steadily gaining interest. The pristine nature of asteroids due to their preserved state since the formation of the Solar System is an opportunity to unravel many mysteries about the Solar System. Also with the ever-growing need for resources, asteroids prove to be a plentiful source. With the discovery of asteroids in the close vicinity of our planet and a probable threat to the preservation of life, a need for defence missions has also arisen. The ever-growing need for better computational speed and accuracy has led to the development of new representations for attitude and position of the spacecraft in the past. The usual methods of representations of position and attitude (pose) are the Cartesian coordinates and quaternions. A recent development is the simultaneous representation of the pose of the spacecraft using dual quaternions which are eight-dimensional vectors. In this thesis, an attempt to incorporate these state-of-the-art guidance technologies to asteroid missions has been made. The novelty in this thesis is, using dual quaternions for SC pose and attitude representation to autonomously guide the spacecraft for mapping an asteroid and perform a touch and go descent using sampling-based motion predictive optimisation and successive convexification respectively. After the development and verification of these algorithms, different scenarios have been designed to find out the robustness of the dynamic successive convexification method. The scenarios have been run by both the Cartesian quaternion and dual quaternion based algorithms. They are found to behave similarly in their results, besides the latter being computationally more expensive as proved by different theses so far. The algorithm performs better than the one developed by Szmuk et al. (2017), but faces difficulties with badly scaled problems as is the nature of missions to asteroids. The software used for the thesis is ECOS, which faces numerical problems in these mission scenarios even when the problem is feasible and has an optimal result. The availability of a solution to the optimal control problem depends on the scaling of the penalty weights used in the cost function to penalise virtual controls and trust region, which are used to prevent infeasibility and bound the problem, respectively. It also depends on finding an appropriate final time for the descent along with the number of nodes for discretisation. This research proves, that successive convexification indeed provides a speedy solution for an autonomous precision descent but needs further work to make it robust and stable. The outcome of this thesis is to carry out further research to understand the complex relations, between the scale of the problem, simulation parameters for the optimal control problem and final time to make the algorithm robust and safe for an autonomous mission. Another important future research prospect is to incorporate the sampling based model predictive optimisation, for the SC to autonomously map the target body and help in selecting a landmark for a descent.Aerospace Engineerin
Study of thickness and uniformity of oxide passivation with DI-O3 on silicon substrate for electronic and photonic applications
No full textMagnanimous Kunti by Samaresh Basu/ সমরেশ বসুর কলমে মনস্বিনী কুন্তী
No full textSamaresh Basu wrote a number of books based on Puran-Mahabharata under the pseudonym Bhramar and Kalkoot. Such as, ‘Shamba (1978)’, ‘Juddher Sesh Senapati (1984)’, ‘Prachetas (1984)’, \u27Pritha (1986)\u27, ‘Antim Pranay (1987)’ etc. ‘Pritha’ was published in the magazine \u27Prasad\u27 under the pseudonym \u27Bhramar\u27. In such books, the author analyzed the traditional story of the Puranas in a new perspective.
One of the memorable Panchakanyas in Puranas, Empress Kunti has been recreated in the light of the author\u27s spirit in this book. In the present article we will discuss how the character of Kunti has been recreated by Samaresh Basu in \u27Pritha\u27.
At the beginning of the story, before reaching the context of Kunti, the author undertakes a very realistic analysis of heaven-hell, Gods-demons, Samhita era-Puranic era, male-female relationship, marriage customs, child birth and the position of women in society. Then he explained the solitude, self-immolation and transition of Kunti from a feminist perspective.
The story of love-marriage-motherhood-heroism-restraint-pain-sacrifice of this remarkable female character of Mahabharata has been captured in a new way in the unique writing of Kalkoot. Inventing many thoughtful arguments the author tried to establish the father-son relationship between Yudhisthira-Vidura and Karna-Durbasha. How the author incarnated new contexts in the familiar story of Mahabharata and how he made it acceptable by arranging relevant arguments in favour of his new thoughts – this essay will try to elaborate these points
Gearbox Fault Detection Using Synchro-squeezing Transform
No full textAbstractThis paper presents a novel fault-detection method for gearbox vibration signatures using synchro-squeezing transform (SST). Premised upon the concept of time-frequency (TF) reassignment, SST provides a sharp representation of signals in TF plane compared to many popular TF methods. Additionally, it can also extract the individual components, called intrinsic mode functions or IMFs, of a non-stationary multi-component signal, akin to empirical mode decomposition. The rich mathematical structure based on continuous wavelet transform makes SST a promising candidate for gearbox diagnosis. This work utilizes the decomposing power of SST to extract the IMFs from gearbox signals. For robust detection of faults in gear-motors, a fault detection technique based on time-varying autoregressive coefficients of IMFs as features is utilized. Sequential Karhunen-Loeve transform is employed on the condition indicators to select the appropriate window sizes on which SST can be applied. Laboratory experimental data obtained from drivetrain diagnostics simulator provides test bed to demonstrate the robustness of the proposed algorithm
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