Faculty Publications
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Publications by NITK Faculty
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Item Web service clustering and data mining in SOA system(IGI Global, 2017) Mukherjee, S.; Nath, A.The success of the web depended on the fact that it was simple and ubiquitous. Over the years, the web has evolved to become not only the repository for accessing information but also for storing software components. This transformation resulted in increased business needs and with the availability of huge volumes of data and the continuous evolution in Web services functions derive the need of application of data mining in the Web service domain. Here we focus on applying various data mining techniques to the cluster web services to improve the Web service discovery process. We end this with the various challenges that are faced in this process of data mining of web services. © 2017, IGI Global. All rights reserved.Item Learner centered design approach for E-learning using 3D virtual tutors(IEEE Computer Society help@computer.org, 2013) Mukherjee, S.; Singhal, H.; Jha, P.; Kokane, A.; Rastogi, P.; Mittal, R.; Guddeti, G.Most of the existing E-learning system designs have focused on the development of feature-rich, but usable systems with little effort in motivating students to develop interest in the teaching-learning process. This paper discusses the learner centered design approach for web-based tutoring to motivate young learners using 3D virtual tutors in a requirement-based, flexible pedagogical model. Students can choose course(s) and the study-mode. In the guided mode, the student is mentored by a human tutor, whereas a student in un-guided mode is tutored by 3D avatar. The student has access to study materials, educational videos and applets that are provided by the tutors, the student also has access to forums for doubt clearing and online assignments to be submitted for tutors' evaluation. Tutors can track students' progress using online quiz and reports modules. Further, tutors have access to teaching aids like online chat system and whiteboard-based teaching in a virtual classroom environment. © 2013 IEEE.Item Ember: A smartphone web browser interface for the blind(Association for Computing Machinery, 2014) Jassi, I.S.; Ruchika, S.; Pulakhandam, S.; Mukherjee, S.; Ashwin, T.S.; Guddeti, G.R.M.Ember is a smartphone web browser interface designed exclusively for the blind user. The Ember keypad enables blind users to type using their knowledge of Braille. The interface is intuitive to the blind user because the layout consists of a very few large targets and remains consistent throughout the application. The verbal command option provides another dimension for user-interface interaction. Twelve out of thirteen users found that Ember verbal command navigation was easier than using a traditional web browser. Ten out of thirteen users found it faster to use the Ember tactile method of navigation compared to a traditional web browser. The learning rate for both the tactile and verbal command methods was faster compared to the learning rate associated with a traditional web browser layout. Finally it was seen that five out of five users found it significantly faster to use the Ember keypad compared to the QWERTY keypad. © 2014 ACM.Item A hybrid algorithm for disparity calculation from sparse disparity estimates based on stereo vision(Institute of Electrical and Electronics Engineers Inc., 2014) Mukherjee, S.; Guddeti, G.R.M.In this paper, we have proposed a novel method for stereo disparity estimation by combining the existing methods of block based and region based stereo matching. Our method can generate dense disparity maps from disparity measurements of only 18% pixels of either the left or the right image of a stereo image pair. It works by segmenting the lightness values of image pixels using a fast implementation of K-Means clustering. It then refines those segment boundaries by morphological filtering and connected components analysis, thus removing a lot of redundant boundary pixels. This is followed by determining the boundaries' disparities by the SAD cost function. Lastly, we reconstruct the entire disparity map of the scene from the boundaries' disparities through disparity propagation along the scan lines and disparity prediction of regions of uncertainty by considering disparities of the neighboring regions. Experimental results on the Middlebury stereo vision dataset demonstrate that the proposed method outperforms traditional disparity determination methods like SAD and NCC by up to 30% and achieves an improvement of 2.6% when compared to a recent approach based on absolute difference (AD) cost function for disparity calculations [1]. © 2014 IEEE.Item Effective E-learning using 3D Virtual Tutors and WebRTC Based Multimedia Chat(Institute of Electrical and Electronics Engineers Inc., 2014) Kokane, A.; Singhal, H.; Mukherjee, S.; Guddeti, G.R.M.This paper discuss the novel implementation of Learner Centered Design Approach of E-learning System using 3D Virtual Tutors [1] and further enhances this work in facilitating young learners to interact with human tutors using WebRTC Based Multimedia Chat system. The present work adds three main features such as: Firstly, addition of live video lecture session by which students can interact with the tutor just like video call of Skype system. Secondly, the presentation of 3D virtual tutors' narrations of articles in the text form of live transcriptions of avatars' speech. Thirdly, introduction of timed quiz by which a real-life objective examination can be mimicked and thereby evaluating the performance of students. Lastly, we present a comparative evaluation of the original system and its improved version with respect to responses received from a large pool of young learners using the system. © 2014 IEEE.Item Entropy-difference based stereo error detection(Institute of Electrical and Electronics Engineers Inc., 2016) Mukherjee, S.; Cheng, I.; Guddeti, G.R.; Basu, A.Stereo depth estimation is error-prone; hence, effective error detection methods are desirable. Most such existing methods depend on characteristics of the stereo matching cost curve, making them unduly dependent on functional details of the matching algorithm. As a remedy, we propose a novel error detection approach based solely on the input image and its depth map. Our assumption is that, entropy of any point on an image will be significantly higher than the entropy of its corresponding point on the image's depth map. In this paper, we propose a confidence measure, Entropy-Difference (ED) for stereo depth estimates and a binary classification method to identify incorrect depths. Experiments on the Middlebury dataset show the effectiveness of our method. Our proposed stereo confidence measure outperforms 17 existing measures in all aspects except occlusion detection. Established metrics such as precision, accuracy, recall, and area-under-curve are used to demonstrate the effectiveness of our method. © 2016 IEEE.Item Towards Evaluating Multipath TCP using Linux Tools and Utilities(Association for Computing Machinery, 2023) Tahiliani, M.; Khan, D.; Rakshit, A.; Mukherjee, S.Multipath TCP (MPTCP) is a transport protocol standardized in RFC 8684 and is an ongoing research topic at IETF. The implementation of MPTCP is under active development in the Linux network community. Performing experiments with MPTCP using the Linux network stack requires installing external tools and utilities. This paper analyzes the tools and utilities that are popularly used for MPTCP experimentation using the Linux network stack. Subsequently, using these tools and utilities, we perform a deep-dive analysis of the implementation of the connection establishment phase of MPTCP in the Linux kernel by conducting experiments and comparing whether this implementation is in line with the RFC. We leverage Linux network namespaces to perform experiments because they provide a lightweight alternative to setting up physical testbeds or virtual machines. Moreover, it makes our experiments easily reproducible across different Linux platforms. Our experiments show that the Linux implementation of the connection establishment phase of MPTCP closely follows RFC 8684. © 2023 ACM.Item Depth-Based Selective Blurring in Stereo Images Using Accelerated Framework(3D Research Center 3drc@kw.ac.kr, 2014) Mukherjee, S.; Guddeti, R.M.R.Abstract: We propose a hybrid method for stereo disparity estimation by combining block and region-based stereo matching approaches. It generates dense depth maps from disparity measurements of only 18 % image pixels (left or right). The methodology involves segmenting pixel lightness values using fast K-Means implementation, refining segment boundaries using morphological filtering and connected components analysis; then determining boundaries’ disparities using sum of absolute differences (SAD) cost function. Complete disparity maps are reconstructed from boundaries’ disparities. We consider an application of our method for depth-based selective blurring of non-interest regions of stereo images, using Gaussian blur to de-focus users’ non-interest regions. Experiments on Middlebury dataset demonstrate that our method outperforms traditional disparity estimation approaches using SAD and normalized cross correlation by up to 33.6 % and some recent methods by up to 6.1 %. Further, our method is highly parallelizable using CPU–GPU framework based on Java Thread Pool and APARAPI with speed-up of 5.8 for 250 stereo video frames (4,096 × 2,304). © 2014, 3D Research Center, Kwangwoon University and Springer-Verlag Berlin Heidelberg.Item Artificial neural network based modeling to evaluate methane yield from biogas in a laboratory-scale anaerobic bioreactor(Elsevier Ltd, 2016) Nair, V.V.; Dhar, H.; Kumar, S.; Thalla, A.K.; Mukherjee, S.; Wong, J.W.C.The performance of a laboratory-scale anaerobic bioreactor was investigated in the present study to determine methane (CH4) content in biogas yield from digestion of organic fraction of municipal solid waste (OFMSW). OFMSW consists of food waste, vegetable waste and yard trimming. An organic loading between 40 and 120 kg VS/m3 was applied in different runs of the bioreactor. The study was aimed to focus on the effects of various factors, such as pH, moisture content (MC), total volatile solids (TVS), volatile fatty acids (VFAs), and CH4 fraction on biogas production. OFMSW witnessed high CH4 yield as 346.65 L CH4/kg VS added. A target of 60–70% of CH4 fraction in biogas was set as an optimized condition. The experimental results were statistically optimized by application of ANN model using free forward back propagation in MATLAB environment. © 2016 Elsevier LtdItem New insights into the structure-nonlinear mechanical property relations for graphene allotropes(Elsevier Ltd, 2016) Sun, H.; Mukherjee, S.; Daly, M.; Krishnan, A.; Karigerasi, M.H.; Singh, C.V.A vast array of two-dimensional (2D) graphene allotropes have been reported to possess remarkable electronic, thermal, and magnetic properties. However, our understanding of their structure-mechanical-property relationship is far from complete. In this study, we performed extensive density functional theory calculations to evaluate the mechanical properties of 11 different graphene allotropes, comprising structures with solely sp2 hybridized bonds and both sp and sp2 hybridized bonds. A complete set of nonlinear anisotropic elastic constants up to the fifth order are determined for these structures. Energetics of the deformation of these allotropes have been analyzed to mathematically establish a relationship between the sum of the second order nonlinear elastic constants and the area density. Empirical relationships have been obtained for predicting theYoung's moduli, Poisson's ratios and the ultimate tensile strengths (UTS) of the allotropes using their area densities and the sizes of the carbon rings. Furthermore, comparison with traditional engineering materials reveals that 2D graphene allotropes expand the available material-property space by occupying a new region with both high Young's modulus and a high UTS, as well as a high UTS and low density. © 2016 Elsevier Ltd