Faculty Publications
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Publications by NITK Faculty
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Item Influence of news on individual confidence bias in stock markets(Association for Computing Machinery acmhelp@acm.org, 2016) Mukund, Y.R.; Naresh, V.; Patil, S.; Chandrasekaran, K.; Vijaya, V.; Gnanamurthy, R.K.The Phenomenon of stock markets is a complex one and is something which, has attracted researchers and statisticians for a long time. Complex statistics have long dominated this field where the prediction models are usually stochastic. The advent of machine learning gave us a new way of looking at the problem. Much work has been done in analyzing the stock market to predict the stock index of a particular or-ganization. However, most of the work done is based on the previous stock data and other statistical parameters. Our work, uses data such as the online news articles about a particular company and aims to help a trader conclude the market sentiment towards that company through sentiment analysis. The online raw data is obtained through crawling and is indexed, weighted and subject to sentiment analysis to output the final sentiment of the market. It is found that the Naive-Bayesian Classifier is the more suitable op-tion among the Decision Tree and Random Forests for the task of sentiment analysis. The Final Sentiment Factor ar-rived at, is found to reect the real time market sentiment quite accurately. It is also shown that the sentiment factor can be used as an input to a more complex analysis model. This new model, performs better than the existing models.Item Effect of FSW on microstructure and hardness of AA6061/SiC/fly ash MMCs(Elsevier Ltd, 2018) Patil, S.; Narendranath, S.; Dupadu, D.In this study 6 mm thick plates of aluminum matrix composites (AMCs) composed of AA6061/SiC (10 Wt. %) /fly ash (7.5 Wt. %) were butt welded using friction stir welding (FSW. Microstructural characterization of weld joints was conducted by using optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the weld revealed the presence of four different zones like nugget zone (NZ), thermo mechanically affected zone (TMAZ), heat affected zone (HAZ) and base metal (BM). Nugget zone reveals homogenous distribution of fly ash and SiC particles. Rotating effect of FSW tool results in breaking of some array of grains present in the parent AMCs. Needle like phases present in the parent AMCs eliminated successfully by the incorporation of fly ash particles. Higher hardness is observed in the nugget zone compared to other zones. © 2018 Elsevier Ltd. All rights reserved.Item Study on microstructure and tensile properties of fly ash AMCs welded by FSW(American Institute of Physics Inc. subs@aip.org, 2018) Patil, S.; Narendranath, S.; Dupadu, D.Aluminum matrix composite (AMCs) constitute a new class of light weight and high strength materials which have widespread applications in almost all engineering sectors. But the cost of AMCs is the only barrier to increase their applications still. Hence there is a huge demand for the composites containing low cost reinforcement with less weight, keeping this in mind, in the present work, Friction stir welding (FSW) of AA6061/SiC/fly ash was carried out successfully. Microstructural study on the welded specimens was performed using optical microscopy (OM) and scanning electron microscopy (SEM). Results indicate that fly ash particles were uniformly distributed in the weld nugget area because of the stirring action of the FSW tool also promoted the grain refinement of the matrix material with complete elimination of clusters present in matrix material which resulting in sound welds without any defects for AA6061/SiC/fly ash composites. 82% of joint efficiency is obtained for selected AMCs. Transverse tensile test results showed that all welds fractured in HAZ. © 2018 Author(s).Item Micro-Architectural support for High Availability of NoC-based MP-SoC(Institute of Electrical and Electronics Engineers Inc., 2019) Singh, R.; Ranga, S.V.; Patil, S.; Krishna, M.; Mehta, M.; Anoop, M.N.; Nandy, S.K.; Haldar, C.; Narayan, R.; Neumann, F.; Baufreton, P.In this paper, we focus on increasing the availability of Multi-Processor System on Chip (MP-SoC) for executing user applications, even when some components of the system are faulty. A Network-on-Chip (NoC) provides high bandwidth communication substrate for the multitude of components/modules in such MP-SoCs. Health of such MP-SoC, and hence its availability, is largely dependent on the health of the NoC. We consider an NoC comprising a bidirectional toroidal mesh interconnection of routers. We use a distributed built-in-self-test to identify faulty communication links. We use information so obtained to determine healthy subsystems that can be made available for executing user applications. This feature is key for enhancing availability of MP-SoCs. We realize this feature as a micro-architectural enhancement in MP-SoC that incurs an insignificant hardware overhead of less than 2%. Latency incurred for analyzing availability of MP-SoC is also insignificant. We functionally validate our proposal by emulating the system on a FPGA device and demonstrate increase in availability of the MP-SoC. © 2019 IEEE.Item Studies on microstructure and mechanical characteristics of as cast AA6061/SiC/fly ash hybrid AMCs produced by stir casting(Elsevier Ltd, 2020) Patil, S.; Narendranath, S.; Dupadu, D.Fly ash has been receiving the extensive concentration as a strong reinforcing element for Aluminum Matrix Composites (AMCs) to strengthen the properties and cut the price of manufacturing. AA6061 reinforced with various weight percentages of fly ash particulates and a constant weight percentage of SiC were prepared by stir casting technique as it is one of the simplest and cost-effective method for producing AMCs. Wettability of SiC and Fly ash particles with the aluminum was enhanced by fly ash itself. The microstructure, hardness and tensile properties of manufactured AMCs were analyzed. Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) discovered a harmonized dispersion of SiC and fly ash particles with superior bonding with the matrix material. The inclusion of fly ash particles in to aluminum matrix enhanced the microhardness and Ultimate Tensile Strength (UTS) of the AMCs. © 2019 Elsevier Ltd. All rights reserved.Item Efficient Traffic Signboard Recognition System Using Convolutional Networks(Springer, 2020) Mothukuri, S.K.P.; Tejas, R.; Patil, S.; Darshan, V.; Koolagudi, S.G.In this paper, a smart automatic traffic sign recognition system is proposed. This signboard recognition system plays a vital role in the automated driving system of transport vehicles. The model is built based on convolutional neural network. The German Traffic Sign Detection Benchmark (GTSDB), a standard open-source segmented image dataset with forty-three different signboard classes is considered for experimentation. Implementation of the system is highly focused on processing speed and classification accuracy. These aspects are concentrated, such that the built model is suitable for real-time automated driving systems. Similar experiments are carried in comparison with the pre-trained convolution models. The performance of the proposed model is better in the aspects of fast responsive time. © Springer Nature Singapore Pte Ltd. 2020.Item Effect of traverse speed on joint characteristics of FSWed HAMCs(Elsevier Ltd, 2020) Patil, S.; Narendranath, S.; Dupadu, D.The present work describes the evolution of microstructure and enhancement of mechanical properties of friction stir welded AA6061/SiC/FA Hybrid AMCs (HAMCs). Various joints were produced using different traverse speed from 30 mm/min to 80 mm/min. Microstructural analysis was carried out using Optical microscopy and scanning electron microscopy. Mechanical characteristics such as ultimate tensile strength (UTS) and microhardness (Hv) were studied. Sound quality joints were obtained by FSW without any defects. Results showed that the microstructure zones are divided in to nugget zone, thermomechanically affected zone, heat affected zone and base material zone. Uniform and fine grain formation took place at traverse speed of 60 mm/min indicating sufficient amount of heat input at this speed. Accordingly maximum joint efficiency of 90% is obtained at this traverse speed. © 2020 Elsevier Ltd. All rights reserved.Item Saltwater corrosion behaviour of equal channel angular pressed AZ80/91 Mg alloys(Elsevier Ltd, 2021) Hebbale, A.M.; Naik, G.M.; Badiger, R.I.; Bellubbi, S.; Patil, S.; Narendranath, S.In this study, AZ80/91 Mg alloys were used to comprehend the electrochemical corrosion behaviour of coarse-grained and fine-grained Mg alloys in different concentration of NaCl solution as well as in the marine environment. The inadequate studies of the corrosion response of ECAPed AZ80 and AZ91 Mg alloy in a different environment were noticed. Accordingly, the current research presents and compares the corrosion behaviour of AZ80/91 Mg alloys in 2.5 wt% NaCl, 3.5 wt% NaCl solution and Natural Sea Water. Influence of corrosion media on coarse and fine-grained AZ80/91 Mg alloys was discussed in the results and discussion section. Corrosion attack of AZ80/91 Mg alloys under the above environment, increased with increase in chloride ion concentration and decreased with the ECAP passes. © 2021 Elsevier Ltd. All rights reserved.Item Synthesis of GDC electrolyte material for IT-SOFCs using glucose & fructose and its characterization(Elsevier B.V., 2017) Medisetti, S.; Ahn, J.; Patil, S.; Goel, A.; Bangaru, Y.; Sabhahit, G.V.; Babu, G.U.B.; Lee, J.-H.; Prasad Dasari, H.P.Nano-powder of gadolinium-doped-ceria (GDC, Ce0.9Gd0.1O2) has been synthesized using a novel sol–gel method with glucose and fructose as organic additives. The main objective of the present study is to find the suitability of this synthesis method in synthesizing ceria-based SOFC electrolyte materials and evaluate its performance. The average crystallite/particle size obtained from XRD, TEM, BET surface area was found to be 4–12 nm. The phase was found to be cubic fluorite from XRD and further the structure and the nature of oxygen vacancies was confirmed using Raman spectroscopy. Dilatometer studies illustrated two shrinkage maxima (450 °C and 1450 °C). The ionic conductivity measurements were done using DC four-probe method on the GDC electrolyte sintered at 1500 °C. The sintered sample showed an ionic conductivity of 1.13E?02 Scm?1 at a temperature of 700 °C in the air, and the activation energy is 1.02 eV. The present study reveals that this synthesis method can be adaptable for synthesizing SOFC electrolyte materials. © 2017 Elsevier B.V.Item Process parameter optimization for FSW of AA6061/SiC/fly ash AMCs using Taguchi technique(ICE Publishing subscriptions@icepublishing.com, 2018) Patil, S.; Narendranath, S.; Dupadu, D.In this research work, aluminum matrix composite (AMC) plates were welded using friction stir welding (FSW). AMCs contain AA6061 as a base metal with silicon carbide (SiC) and fly ash particles as reinforcements. The FSW process parameters considered in this work were tool rotational speed (revolutions/minute), tool traverse speed (millimeters/minute) and tool tilt angle (degrees). The Taguchi L9 orthogonal array was considered for optimizing the process parameters. Tensile strength and hardness were the two output responses obtained by analyzing joint efficiency and signal/noise ratio. An analysis of variance (Anova) study was conducted to identify the percentage contribution of each process parameter to the output responses. The Anova study concluded that among the three process parameters, tool rotational speed was the most dominant parameter in deciding the tensile strength and hardness of the FSW joints, followed by traverse speed and tool tilt angle. At the end, the results were validated by conducting additional experiments. © 2018 ICE Publishing: All rights reserved.