Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item An analytical model for intersystem handover(Institute of Electrical and Electronics Engineers Inc., 2003) Singh, B.; Aggarwal, K.K.; Kumar, S.Universal Mobile Telecommunication Systems (UMTS) shall be developed in such a way that it will support compatibility with an evolved Global System for Mobile Communications (GSM). In this paper, we investigate intersystem handover between GSM and UMTS based on Wideband Code Division Multiple Access (WCDMA) air-interface. A mathematical model is proposed to evaluate the handover performance. The handover initiation algorithm is based on the absolute value of averaged signal strength thresholds. Average number of handovers and handover initiation delay are used as performance measures. Based on numerical results, it is observed that handover initiation algorithm based on absolute thresholds induces large number of handovers near the cell boundary. Finally, threshold levels are optimized for given system parameters.Item A Multilingual Multimedia Indian Sign Language Dictionary Tool(Asian Federation of Natural Language Processing, 2008) Dasgupta, T.; Shukla, S.; Kumar, S.; Diwakar, S.; Basu, A.This paper presents a cross platform multilingual multimedia Indian Sign Language (ISL) dictionary building tool. ISL is a linguistically under-investigated language with no source of well documented electronic data. Research on ISL linguistics also gets hindered due to a lack of ISL knowledge and the unavailability of any educational tools. Our system can be used to associate signs corresponding to a given text. The current system also facilitates the phonological annotation of Indian signs in the form of HamNoSys structure. The generated HamNoSys string can be given as input to an avatar module to produce an animated sign representation. © 2008 Asian Federation of Natural Language Processing. All rights reserved.Item Fast response search and rescue robot, assisted low power WSN net for navigation and detection(IEEE Computer Society, 2013) Kumar, S.; Reddy, V.; Prakash, P.; Aparna., P.Our project is a remotely controlled robot capable of surveying disaster situations or act as a security countermeasure. It utilizes a stationary network of passive infrared sensor nodes interconnected through a multi-hop Zig bee network. The sensors are motion sensitive and using regional localization can be used for identifying the location of survivors or intruders based on the situation. The robot is controlled via a Wi-fi link which streams real time video back to the base station. The main processor is a TI Sitara AM335x ARM processor. It also acts as relay for the sensor data. Each node consists of three passive infrared detection circuits each covering a sector of 120 degrees and connects via the TI CC2530 ZNP chip. The raw PIR data is signal conditioned using an LM324 Op-amp. The nodes can be deployed easily due to their compact size. Their low power consumption and low cost makes them ideal for remote areas and can be deployed in large numbers. © 2013 IEEE.Item Theoretical and numerical study of symmetric, in-plane, free vibration of Timoshenko portal frame with open crack(Chinese Society of Theoretical and Applied Mechanics ICF13@cstam.org.cn, 2013) Satyavan, N.M.; Kumar, S.; Murigendrappa, S.M.The local flexibility introduced by cracks changes the vibration behaviour of the structure and by examining this change, crack severity can be identified. This paper presents the natural frequencies of symmetric, in-plane free-vibrations of Timoshenko portal frame with and without open crack for different boundary conditions. Cracked segment is modelled as two segments connected by a massless torsional spring. Considering appropriate compatibility requirements at the crack section in any one of segments and at the junction of two segments, the characteristic equations are established for corresponding boundary conditions and solved for natural frequencies by numerically. Crack location ranging from 20% to 70% of length of segment and crack size ranging from 20% to 60% of depth have been considered. Results obtained analytically are compared numerically using standard commercially available finite element software. The frame has been modelled by using quadratic quadrilateral shell elements and quarter-point singular elements are employed around the crack-tip. It is observed that as expected, with increase in crack depth the change in frequencies of the frame with and without crack increases. The maximum difference between the analytical and numerical results is 7.09% for all the cases considered, which proves usefulness of the data.Item Traitor-traceable key pre-distribution based on visual secret sharing(2013) Kumar, S.; Jaipal, P.B.J.; Sen Gupta, S.; Ungrapalli, V.R.In this paper, we study the problem of traitor-traceable key pre-distribution for general access structures. We propose a new scheme for key pre-distribution using visual secret sharing, where the keys are generated based on certain combinatorial block designs. Our scheme naturally extends for general access structures, and provides a flexible many-to-one function using visual secret sharing concepts to efficiently avoid the problem of pixel expansion. In addition, our proposal accommodates a simple traitor-tracing functionality for video broadcast applications; using efficient PBIBD based combinatorial constructs and visual secret sharing based on random grids. In effect, our scheme provides a novel technique for secure video and image broadcast, using general access structures to reduce collusions, trace forgery, and identify traitors in case there is a collusion. We duly analyze and discuss the efficiency of our scheme for varying number of users in the broadcast network. © 2013 Springer-Verlag.Item Multiple aggregator multiple chain routing protocol for heterogeneous wireless sensor networks(2013) Harichandan, P.; Jaiswal, A.; Kumar, S.Wireless sensor nodes are deployed to gather useful information from the field but their constraint on battery power leads us to think about energy efficient routing protocols so that they can operate over longer periods of time. We study the advantages of having multiple chains in a network with each chain's topmost node (called the aggregator) collecting the data from the nodes beneath it and transmitting it to the sink. In the proposed scheme, a chain in each region works as PEGASIS. We also study how considering heterogeneity in the network can improve the lifetime of a network by a significant period. We assume that a fraction of the nodes in the network possess additional energy. We show by simulations that the introduction of heterogeneity into the network results in a greater lifetime, compared to those of the classical data aggregation schemes, with the duration increasing with the amount of additional energy considered. © 2013 IEEE.Item Synergestic approach for the simultaneous estimation of heat transfer coefficient and heat flux using fin from steady state heat transfer experiments(Begell House Inc., 2015) Kumar, H.; Kumar, S.; Srinivasa Sagar, K.; Gnanasekaran, N.This paper reports simultaneous estimation of heat transfer coefficient and heat flux from natural convection fin heat transfer. The experimental setup contains rectangular mild steel fin of dimensions (250×154×6 mm) and an aluminium base plate of dimensions (250×150×8 mm). A slot of 4mm depth is created at the center of aluminium plate along its length (250mm) and mild steel fin is press fitted into this slot. Eighteen calibrated K-type thermocouples are used to record the temperature of the base plate and the fin. Beneath the base plate, a heater is placed with the dimensions of the base plate. To restrict the heat loss, bottom and sides of the heater are insulated with glass wool. Steady state experiments are carried out for different heat input. The problem considered is an inverse problem where in heat transfer coefficient and heat flux can be estimated simultaneously for the given temperature data from experiments/surrogate data. The forward model uses Asymptotic Computational Fluid Dynamics (ACFD) to obtain temperature distribution for the assumed inputs (heat transfer coefficient and heat flux). A powerful Markov Chain Monte Carlo method along with Metropolis-Hastings algorithm is used to minimize the objective function. Finally, the estimated values of heat transfer coefficient and heat flux are reported in terms of mean. © 2021, Begell House Inc. All rights reserved.Item Soil classification using airborne hyperspectral data employing various approaches(Asian Association on Remote Sensing Sh1939murai@nifty.com, 2017) George, J.K.; Kumar, V.; Tarun, B.; Kumar, S.; Senthil Kumar, A.S.Hyperspectral remote sensing technology is one of the advance technology for detailed land cover feature extraction. Hyperspectral datasets contain large number of contiguous spectral bands with a narrow spectral bandwidth which enables identification of peculiar absorption features for distinguishing different type of soils. The potential of Airborne Visible Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) data was tested for distinguishing black and red soils in the ICRISAT area near Hyderabad, Telangana. The AVIRIS-NG data captured in 432 narrow contiguous bands (346–2505 nm) with spectral sampling of 5 nm bandwidth and a 4m ground pixel size was used in this study. The dataset was first spectrally subsetted by identification and removal of bad bands and was atmospherically corrected by converting it to surface reflectance using FLAASH. The data was finally georeferenced using the Internal Geometry Module (IGM) parameters. Optimal spectral bands from the reflectance data were selected on the basis of different characteristics of various soils. Data dimensionality reduction technique Minimum Noise Fraction (MNF) was also performed to extract noise free components. Total five classes including red and black soils were considered for land cover classification. Pixel based classification techniques such as Spectral Angle Mapper(SAM) and Support Vector Machine (SVM) were performed on the reflectance as well as MNF transformed data. SVM was also performed on data containing noise free MNF components and the selected optimal spectral bands. In the resultant classified output of reflectance data, SVM classifier provided higher accuracy and was able to classify black and red soil in a better way than SAM technique. The results also suggested that use of MNF components and specific spectral bands altogether improvised the classification of black and red soil. © 2017 ACRS. All rights reserved.Item Kinect Based Real Time Gesture Recognition Tool for Air Marshallers and Traffic Policemen(Institute of Electrical and Electronics Engineers Inc., 2017) Prakash, A.; Swathi, R.; Kumar, S.; Ashwin, T.S.; Guddeti, G.R.M.The Microsoft Kinect which is a motion sensing input device presents a very straightforward and affordable approach to facilitate real-time user interaction. Although a lot of research has been conducted on the application of Kinect to gaming and virtual reality environments, its relevance to real-world scenarios has not been explored much. The features provided by the driver platforms such as OpenNI and Microsoft Kinect Software Development Kit (SDK) for development using Kinect coupled with the motion sensing ability of Kinect, presents a unique opportunity for extending the scope of the Kinect sensor. This paper proposes a system for automatically recognizing the road traffic control gestures of police officers and air marshalling commands by ground personnels. This system is aimed for selflearning, training and testing these officers to equip them with the skills to tackle real-world situations. Since these applications are very crucial and performing accurate gestures are of at most importance, this system will prove to be very essential. Experimental results also demonstrate that our system is robust and effective and is suitable for real-time application. © 2016 IEEE.Item Enhancing tribological performance of Ti-6Al-4V using pin on disc setup(American Institute of Physics Inc. subs@aip.org, 2018) Kumar, D.; Lijesh, K.P.; Deepak, K.B.; Kumar, S.Titanium (Ti) alloy Ti-6Al-4V (Ti64), possesses a inimitable combination of mechanical, physical and corrosion properties, which makes them desirable for applications like aerospace, automobile, chemical and energy industries devices etc. However this alloy of Ti exhibits poor tribological (friction and wear) properties, which limits their full fledged implementation. However, the tribological behavior of T164 can be enhanced by providing a coating or a protective layer on it, which posses superior tribological properties. It is hypothesized that by a layer of alumina on the can be deposited on the surface of Ti64, by sliding them in dry-ambient condition using Pin On Disk (POD) machine. To validate the hypothesis, experiments were performed for different normal loading conditions of 13.7N, 68.7N and 109.9N at sliding speed of 0.01m/s and for a sliding distance of 1000m. The tribological performance of the experiments, were evaluated by measuring Coefficient of Friction (COF) and weight loss values. To understand the tribological mechanism and behaviour, In-situ analysis was performed on the pin using (i) Scanning Electron Microscopy (SEM) to understand the wear morphology, and (ii) Energy Dispersive Analysis of X Ray (EDAX) to estimate the deposition of alumina on surface of the pins. Based on the obtained results, the most favorable experimenting condition required for deposition of alumina over Ti64 will be identified. Finally, experiment on POD will be repeated for the selected experimenting condition and will be continued for the worst tribological condition. The obtained COF and wear values after performing the experiment will be presented. © 2018 Author(s).