Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
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Item An Efficient Bandwidth Management algorithm for WiMAX (IEEE 802.16) wireless network: EBM allocation algorithm(2012) Gupta, A.; Chandavarkar, B.R.IEEE 802.16 WiMAX (Worldwide Interoperability for Microwave Access) consists of five service classes with different priorities. The priority of real time traffic is higher than that of non-real time traffic. Since bandwidth is limited, it must be allocated in advance to guarantee the throughput of real time traffic in WiMAX network. But WiMAX standard does not provide any algorithm for dynamic allocation of bandwidth to these services. In this paper, a dynamic bandwidth allocation algorithm for WiMAX called Efficient Bandwidth Management (EBM) is proposed. In EBM the bandwidth will be increased in the upcoming frames when the allocated bandwidth is not sufficient to transfer the data. On the other side if the allocated bandwidth is more, then the bandwidth will be decreased in the upcoming frames so that the other services can use this excess bandwidth. This bandwidth increase or decrease is proportional to the remaining data in the queue. EBM increase the throughput of real time traffic as the bandwidth is handled efficiently. The proposed algorithm is implemented in ns-2 and results are compared with traditional IEEE 802.16 WiMAX. The simulation results show that EBM algorithm gives better result for real-time traffic. © 2012 IEEE.Item A green greedy process scheduler for cloud data centers(Institute of Electrical and Electronics Engineers Inc., 2014) Karthik, C.; Gupta, A.; Chandrasekaran, K.In this paper we have addressed a major problem in current day data centers- power consumption. Power consumption in data centers has become a major problem these days, both from economic and environmental perspective. Various factors affect the power consumption, one of them being the scheduling of tasks on the data center servers. Basically we achieved a real-time simulation of two cloud scheduling algorithms and compared the power efficiency of the two algorithms in terms of two main temperature parameters of the servers-idle temperature and critical temperature. We assumed that we were given all the task parameters such as running time etc. and then we calculated a final temperature that a system will reach on running that particular task. Then we decided which system could accommodate that task based on that systems critical temperature and chose the best system among those based on a score proposed in the paper. © 2014 IEEE.Item IntelliSearch: A search engine based on Big Data analytics integrated with crowdsourcing and category-based search(Institute of Electrical and Electronics Engineers Inc., 2015) Lakhani, A.; Gupta, A.; Chandrasekaran, K.Big Data is the technology that has changed the world. Its powerful abilities to process the data and generate the valuable data out of that has challenged the saying wisdom can be only possessed by those who have souls. Though the big data analytics is quite successful in mining the value out of the large pool of data but Big Data alone is not enough in case of web-analytics. The existing search engines lack the category based search feature and a standard ranking system for website. Crowdsourcing by involving active online community on internet is changing the shape of web applications by refining the data and improving the recommendations for the products. The paper discusses about the search engines, web-analytics toolbars and crowdsourcing to improve the web-analytics. The paper also discusses how integration of crowdsourcing with Big Data Analytics can result in 'IntelliSearch', a robust and reliable search engine. © 2015 IEEE.Item Comparative study on sensitivities of different geometries of plastic optical fiber(Optica Publishing Group (formerly OSA), 2016) Ganesh, S.; Sai Shankar, M.; Kishore, P.V.N.; Abdul Hakeem, P.V.; Gupta, A.; Divya, G.This article discusses a comparative study on sensitivities of different geometries of Plastic optical fiber (POF). The evanescent field modulation decides the sensitivities of fiber geometries. Sensitivity increases with the increase of U-bents. © OSA 2016.Item Influence of perforation pattern in Direct Strength Method of upright design(Structural Stability Research Council, 2021) Jeyapragasam, J.V.V.; Gupta, A.; Harisanth, K.S.; Jayachandran, S.A.The Direct Strength Method design of thin-walled cold-formed steel members is recently extended to perforated members and implemented in AISI-2016 specification. Albeit the background research is well constructed for discrete perforations, it requires more attention to pattern perforations. Perhaps the range of upright cross-sections and perforation shapes available in the market are patented, is the main reason for the lack of experimental data in this research domain. Available literature reports a pool of numerical data resulting from finite element analysis accounting the parameters such as cross-section shape, thickness, perforation shape, the spacing between perforations, member lengths, etc. These numerical models are mainly calibrated with the experimental results of fixed end columns. It should be noted that the fixed end columns are not influenced by the shift of effective centroid. Using such results in developing analytical equations will end up with the ignorance of effective centroid shift. The systematic experiments on perforated compression members in the view of simply supported boundary conditions are scarce. Therefore, experimental results with respect to flexural boundary conditions are reported herein. With the results of experiments, the influence of perforations is rationally assessed for local, distortional and flexural buckling about minor axis. The interaction between the modes is also observed and reported. The DSM design procedure recommended in the AISI-2016 is validated with the experimental results and summarized for the safe and economic design of uprights. © 2021 Proceedings of the Annual Stability Conference Structural Stability Research Council 2021, SSRC 2021. All rights reserved.Item The Impact of Perforation Orientation on Buckling Behaviour of Storage Rack Uprights(Springer Science and Business Media Deutschland GmbH, 2023) Sensy, K.; Gupta, A.; Swaminathan, K.; Vijaya Vengadesh Kumar, J.Industrial storage rack uprights are the most widely used framed structures of thin-walled cold-formed steel members which are meant for the depot of palletized goods. The sensibility of uprights towards local buckling, distortional buckling, global buckling or interaction between these buckling modes in the presence of perforations results in complex behaviour of the uprights. The sustainability of the uprights in terms of the perforations, cross-section geometry, buckling and complexity might be difficult to design through the existing analytical methods alone. The test-based design being expensive leads to the necessity of an analysis-based design approach. The limited analytical methods available in the literature focus on orthogonal perforations and there is no systematic study available in terms of perforation orientation which would imply a minimum net section. This article sheds light effect of increased perforated width due to orientation which directly influences the elastic local critical buckling load calculations. The parametric analysis using finite element software is systematically done for the simple rack section with orthogonal cross-section elements having two idealized transverse web perforations of square and rectangular shape oriented at an angle other than orthogonal angles. The pre-validated FE model is used in this study, and thus the critical elastic buckling loads are procured for various perforation orientations. The CUFSM buckling analysis is done by using the reduced thickness expression recommended in the literature and compared with the FE results. The applicability of reduced thickness equations in accounting perforations in the view of perforation orientation is compared and summarized. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Prediction of Hydrodynamic Coefficients of Stratified Porous Structure Using Artificial Neural Network (ANN)(Springer Science and Business Media Deutschland GmbH, 2023) Gupta, A.; Shilna, K.; Karmakar, D.The breakwater is designed to offer tranquility in the harbor to protect the offshore facilities and also to prevent coastal erosion. The use of soft computing approaches in coastal engineering helps to solve the nonlinear problems and predicts the hydrodynamic performance of the device. In the present study, the artificial neural networks (ANNs) with different topologies are considered to predict the hydrodynamic coefficients for the wave interaction with the stratified porous breakwater. The experimental study is performed to determine the reflection and transmission coefficient for the horizontally stratified porous structure with three layers of different porosity and width of the structure. The hydrodynamic performance is analyzed by considering the feed-forward back-propagation neural network, and the results are compared for different numbers of hidden nodes. Further, the root mean square error (RMSE) and coefficient of correlation (CC) are considered to assess the ability of ANN topologies to predict the transmission coefficient. The numerical results obtained using ANN are noted to fall within the range that represents the network’s ability to predict accurate results. The study performed will provide an insight in the design and analysis of the stratified porous breakwater in the nearshore regions. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Energy Efficient Coverage Optimization in Mobile Wireless Sensor Network Using Grey Wolf Algorithm(Institute of Electrical and Electronics Engineers Inc., 2023) Gupta, A.; Mamatha, K.M.; Manjappa, M.The issue of decreased coverage rate in Mobile Wireless Sensor Networks (MWSNs), caused by mobile sensor nodes being randomly placed inside a monitoring area. Additionally, it becomes extremely important to utilise a sensor node's energy very effectively due to the finite energy of sensor nodes. Hence, to provide optimised positions for the sensor nodes while using the energy of sensor nodes adeptly authors propose an energy efficient coverage algorithm. Initially, article focus on optimal placement of the sensor nodes within a area to achieve the maximum coverage and later authors have focused on improvising the network lifetime. Article presents a combination of Grey Wolf Optimization and Virtual Force algorithm for optimization of coverage in MWSN. Further, to improve the network lifetime, a GWO-based clustering algorithm is presented using distance and energy as a parameter. The algorithms are implemented and simulated on Matlab. The efficiency of the presented algorithm is observed comparing with other Swarm Intelligence (SI) based optimization algorithms, like GWO, VFA, Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Ant-lion Optimization (ALO) and the results of the GWO-based clustering is compared with the traditional LEACH algorithm and energy-balanced clustering based on PSO. Simulation results demonstrate that the presented algorithms outperform the considered algorithms. © 2023 IEEE.Item A Review on Carotid Ultrasound Atherosclerotic Tissue Characterization and Stroke Risk Stratification in Machine Learning Framework(Current Medicine Group LLC 1 info@phl.cursci.com, 2015) Sharma, A.M.; Gupta, A.; Kumar, P.K.; Rajan, J.; Saba, L.; Nobutaka, I.; Laird, J.R.; Nicolades, A.; Suri, J.S.Cardiovascular diseases (including stroke and heart attack) are identified as the leading cause of death in today’s world. However, very little is understood about the arterial mechanics of plaque buildup, arterial fibrous cap rupture, and the role of abnormalities of the vasa vasorum. Recently, ultrasonic echogenicity characteristics and morphological characterization of carotid plaque types have been shown to have clinical utility in classification of stroke risks. Furthermore, this characterization supports aggressive and intensive medical therapy as well as procedures, including endarterectomy and stenting. This is the first state-of-the-art review to provide a comprehensive understanding of the field of ultrasonic vascular morphology tissue characterization. This paper presents fundamental and advanced ultrasonic tissue characterization and feature extraction methods for analyzing plaque. Additionally, the paper shows how the risk stratification is achieved using machine learning paradigms. More advanced methods need to be developed which can segment the carotid artery walls into multiple regions such as the bulb region and areas both proximal and distal to the bulb. Furthermore, multimodality imaging is needed for validation of such advanced methods for stroke and cardiovascular risk stratification. © 2015, Springer Science+Business Media New York.Item Carotid inter-adventitial diameter is more strongly related to plaque score than lumen diameter: An automated tool for stroke analysis(John Wiley and Sons Inc. P.O.Box 18667 Newark NJ 07191-8667, 2016) Saba, L.; Araki, T.; Krishna Kumar, P.; Rajan, J.; Lavra, F.; Ikeda, N.; Sharma, A.M.; Shafique, S.; Nicolaïdes, A.; Laird, J.R.; Gupta, A.; Suri, J.S.Purpose: To compare the strength of correlation between automatically measured carotid lumen diameter (LD) and interadventitial diameter (IAD) with plaque score (PS). Methods: Retrospective study on a database of 404 common carotid artery B-mode sonographic images from 202 diabetic patients. LD and IAD were computed automatically using an advanced computerized edge detection method and compared with two distinct manual measurements. PS was computed by adding the maximal thickness in millimeters of plaques in segments taken from the internal carotid artery, bulb, and common carotid artery on both sides. Results: The coefficient of correlation was 0.19 (p < 0.007) between LD and PS, and 0.25 (p < 0.0006) between IAD and PS. After excluding 10 outliers, coefficient of correlation was 0.25 (p < 0.0001) between LD and PS, and 0.38 (p < 0.0001) between IAD and PS. The precision of merit of automated versus the two manual measurements was 96.6% and 97.2% for LD, and 97.7% and 98.1%, for IAD, respectively. Conclusions: Our automated measurement system gave satisfying results in comparison with manual measurements. Carotid IAD was more strongly correlated to PS than carotid LD in this population sample of Japanese diabetic patients. © 2016 Wiley Periodicals, Inc.
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