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61.
Detection of unanticipated faults for autonomous underwater vehicles using online topic models 下载免费PDF全文
Ben‐Yair Raanan James Bellingham Yanwu Zhang Mathieu Kemp Brian Kieft Hanumant Singh Yogesh Girdhar 《野外机器人技术杂志》2018,35(5):705-716
For robots to succeed in complex missions, they must be reliable in the face of subsystem failures and environmental challenges. In this paper, we focus on autonomous underwater vehicle (AUV) autonomy as it pertains to self‐perception and health monitoring, and we argue that automatic classification of state‐sensor data represents an important enabling capability. We apply an online Bayesian nonparametric topic modeling technique to AUV sensor data in order to automatically characterize its performance patterns, then demonstrate how in combination with operator‐supplied semantic labels these patterns can be used for fault detection and diagnosis by means of a nearest‐neighbor classifier. The method is evaluated using data collected by the Monterey Bay Aquarium Research Institute's Tethys long‐range AUV in three separate field deployments. Our results show that the proposed method is able to accurately identify and characterize patterns that correspond to various states of the AUV, and classify faults at a high rate of correct detection with a very low false detection rate. 相似文献
62.
Santhosh Kumar S. V. N. Palanichamy Yogesh Selvi M. Ganapathy Sannasi Kannan Arputharaj Perumal Sankar Pariserum 《Wireless Networks》2021,27(6):3873-3894
Wireless Networks - Wireless Sensor Networks (WSNs) is a collection of tiny distributed sensor nodes that have been used to sense the physical parameters of the environment where it has been... 相似文献
63.
Chatterjee Sheshadri Rana Nripendra P. Dwivedi Yogesh K. 《Information Systems Frontiers》2022,24(3):945-964
Information Systems Frontiers - Co-production and active participation of the consumers are considered to have enhanced the value co-creation activities that would ensure business benefits of a... 相似文献
64.
Capillary breakup extensional rheometry of associative and hydrolyzed polyacrylamide polymers for oil recovery applications 下载免费PDF全文
High molecular weight polymers used for heavy oil recovery exhibit viscoelasticity that can influence the oil recovery during chemical enhanced oil recovery. Different polymers having similar molecular weight and shear rheology may have different elongation flow behavior depending on their extensional properties. Displacing slugs are more likely to stretch than shear in tortuous porous media. Therefore, it is critical to seek an analytical tool that can characterize extensional parameters to improve polymer selection criteria. This article focuses on the extensional characterization of two polymers (hydrolyzed polyacrylamide and associative polymer) having identical shear behavior using capillary breakup extensional rheometer to explain their different porous media behavior. Maximum extensional viscosity at the critical Deborah number and Deborah number in porous media classified the associative polymer as the one having high elastic‐limit. Extensional characterization results were complemented by significantly higher pressure drop, marginally increased oil recovery of associative polymer in porous media. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46253. 相似文献
65.
Kiran S. Dalal Yogesh B. Wagh Yogesh A. Tayade Dipak S. Dalal Bhushan L. Chaudhari 《Catalysis Letters》2018,148(11):3335-3341
A green synthesis of 3-indolyl-3-hydroxy oxindoles was reported using hen egg white lysozyme (HEWL) in an aqueous ethanol. The HEWL promotes this reaction efficiently from various isatins and indoles under mild reaction conditions with yields up to 98% bearing good adaptability to varied substrates in the reaction. This conversion has provided a new strategy to synthesize 3-indolyl-3-hydroxy oxindole derivatives employing biocatalytic promiscuity of less explored lysozyme. Based on the experimental studies, the plausible reaction mechanism is proposed. 相似文献
Graphical Abstract
66.
Ali Abdallah Alalwan Nripendra P. Rana Yogesh K. Dwivedi Raed Algharabat 《Telematics and Informatics》2017,34(7):1177-1190
People worldwide are largely engaged and attached with the web 2.0 technology and Social media platforms. By the same token, businesses start looking at such technologies as effective mechanisms to interact more with their customers. Equally, the related issues of social media marketing have been also the focus of attention for academics and researchers to expand the current understanding about such phenomena over the marketing area. Accordingly, the main aim of this study is to systematically examine and review the current studies that have conducted over the related area of social media and marketing. By reviewing approximately 144 articles, the researchers were able to provide an overview of the main themes and trends covered by the relevant literature such as the role of social media on advertising, the electronic word of mouth, customers’ relationship management, and firms’ brands and performance. In this review, it has also studied the most common research approaches adopted to examine the related issues of social media marketing. Further discussion is also introduced followed by an explanation of the current review limitations and recommended directions to be examined by future studies. 相似文献
67.
A single gate Ⅲ-V junctionless tunnel field effect transistor (SG-JLTFET) has been reported which shows excellent dc characteristics at low power supply operation. This device has a thin uniformly n-type doped channel of GaSb i.e. gallium antimonide which is grown epitaxially over silicon substrate. The DC performance parameters such as ION, ION/IOFF, average and point subthreshold slope as well as device parameters for analog applications viz. transconductance gm, transconductance generation efficiency gm/ID, various capacitances and the unity gain frequency fT are studied using a device simulator. Along with examining its endurance to short channel effects, the performances are also compared with a Silicon Dual Gate Junctionless Tunnel FET (DG-JLTFET). The DC and small signal analog performance reflects that GaSb SG-JLTFET has immense purview for extreme high-frequency and low-power applications. 相似文献
68.
In this paper TCAD-based simulation of a novel insulated shallow extension (ISE) cylindrical gate all around (CGAA) Schottky barrier (SB) MOSFET has been reported,to eliminate the suicidal ambipolar behavior (bias-dependent OFF state leakage current) of conventional SB-CGAA MOSFET by blocking the metal-induced gap states as well as unwanted charge sharing between source/channel and drain/channel regions.This novel structure offers low barrier height at the source and offers high ON-state current.The ION/IoFF of ISE-CGAA-SB-MOS-FET increases by 1177 times and offers steeper subthreshold slope (~60 mV/decade).However a little reduction in peak cut off frequency is observed and to further improve the cut-off frequency dual metal gate architecture has been employed and a comparative assessment of single metal gate,dual metal gate,single metal gate with ISE,and dual metal gate with ISE has been presented.The improved performance of Schottky barrier CGAA MOSFET by the incorporation of ISE makes it an attractive candidate for CMOS digital circuit design.The numerical simulation is performed using the ATLAS-3D device simulator. 相似文献
69.
The present work is focused towards the lowering of the k value of deposited SiO2 thin films by varying solvent concentration i.e. ethanol in the range 4-10 ml. Porous low-k thin films were synthesized by using the sol-gel spinon technique. A non-ionic surfactant polysorbate 80 (Tween 80) was used as a porogen to generate the porosity in the film matrix. The lower values of refractive index and film density were measured to be 1.19 and 0.94 gm/cm3 respectively for 10 ml solvent concentration. Further, the lowest k value of 2.2 and highest porosity percentage of 58.5 % were obtained for the same film due to the dilution of coating solution at higher solvent concentration. The water contact angle of the film was observed to be increased to 106.3° which indicates the transformation of the deposited film surface from hydrophilic to hydrophobic. The change in chemical structure as an effect of solvent concentration is studied by using FTIR. From FTIR spectra the disappearance of Si-OH groups at higher solvent concentration reveals the increase in condensation rate. Overall in this study, the result shows the significant change in structural, chemical and optical properties of the deposited films at 10 ml solvent concentration. Such deposited porous thin films with lower k value and enhanced hydrophobicity can be used as an interlayer dielectric (ILD) for back end of line (BEOL) in CMOS technology. 相似文献
70.
Hasan SS Singh S Parikh RY Dharne MS Patole MS Prasad BL Shouche YS 《Journal of nanoscience and nanotechnology》2008,8(6):3191-3196
A bacterial mediated synthesis of copper/copper oxide nanoparticle composite is reported. A Gram-negative bacterium belonging to the genus Serratia was isolated from the midgut of Stibara sp., an insect of the Cerambycidae family of beetles found in the Northwestern Ghats of India. This is a unique bacterium that is quite specific for the synthesis of copper oxide nanoparticles as several other strains isolated from the same insect and common Indian mosquitoes did not result in nanoparticle formation. By following the reaction systematically, we could delineate that the nanoparticle formation occurs intracellularly. However, the process results in the killing of bacterial cells. Subsequently the nanoparticles leak out as the cell wall disintegrates. The nanoparticles formed are thoroughly characterized by UV-Vis, TEM, XRD, XPS and FTIR studies. 相似文献