Dr. N. Radhika has done her Post Doctorate in the Department of Computer Science and Engineering, Indian Institute of Technology, Madras, in the domain of Wireless Sensor Networks (Smart grids), and her Doctorate from Government College of Technology, Coimbatore in the area of Mobile Adhoc Network. She is currently working as Professor in the Department of Computer Science and Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore and also holds the position of Academic Co-ordinator at the School of Engineering, Coimbatore Campus. She has around 60 papers in National, International Journals and Conferences to her credit. Her patent named “Multi secured dropping of spoofed packet at the gateway of unauthorized networks” – is filed and under second stage of evaluation. She is a reviewer of several Scopus indexed journals including Springer. She has received best paper award for her research papers. Her thrust area of research includes Mobile Adhoc networks, Wireless Sensor Networks, Smart Grids and Software Defined Networks. Dr.Radhika is currently guiding B. Tech. and M. Tech. students, as well as Research Scholars in her thrust areas.


Publication Type: Journal Article
Year of Publication Publication Type Title
2016 Journal Article V. Manjusha and N. Radhika, “A performance analysis of black hole detection mechanisms in ad HOC networks”, Advances in Intelligent Systems and Computing, vol. 398, pp. 433-443, 2016.[Abstract]

A continuous infrastructure-less, self-configured collection of mobile devices connected as a network without wires is termed as mobile ad hoc network (MANET). Dynamic topology, shared physical medium, and distributed operations are some of the characteristics of MANETs due to which they are highly vulnerable to security threats. Black hole attack is a kind of attack that compromises security by redirecting the entire traffic to a node that is not actually present in the network. This paper aims to detect black hole using three detection schemes, i.e., Time-based threshold detection schemes, DRI table with cross checking scheme, and distributed cooperative mechanism. Comparative analyses on all three schemes are done to find out which one detects black hole more accurately. The measurements are taken on the light of packet delivery ratio, throughput, energy consumption and end-to-end delay. Simulation is performed using Network Simulator-2 (NS2). © Springer India 2016.

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2016 Journal Article L. V. Priyanka Muddamsetty and N. Radhika, “Effect of heat treatment on the wear behaviour of functionally graded LM13/B4C composite”, Tribology in Industry, vol. 38, pp. 108-114, 2016.[Abstract]

Aluminium alloy reinforced with boron carbide (10 wt.%) was fabricated using stir casting method followed by centrifugal casting and the cylindrical specimen with dimension 150 x 150 x 15 mm was obtained. The composite specimens were heat treated at various aging temperatures and aging time for property improvement. Solution treatment was done at 525 °C for 5 hrs. Taguchi’s method was used for designing the plan of experiments and L27 orthogonal array was formulated for the analysis of data. The wear test was conducted on the outer periphery of centrifugally cast Functionally Graded composites using pin-on-disc tribometer. Optimization of parameters such as applied load (10 N, 20 N, 30 N), agingtemperature (150 °C, 175 °C, 200 °C) and aging time (2 hrs, 6 hrs, 10 hrs) was done using Signal-to-Noise ratio. “Smaller-the-better” criterion was used for analyzing the results. Results ended up with a conclusion that aging time (92.19%) had major influence on tribological behavior followed by aging temperature (5.36%) and applied load (1.95%). Scanning Electron Microscope (SEM) analysis was performed to understand the wear mechanism in heat treated specimens. © 2016 Published by Faculty of Engineering. More »»
2016 Journal Article N. Radhika, “Mechanical Properties and Abrasive Wear Behaviour of Functionally Graded Al-Si12Cu/Al2O3 Metal Matrix Composite”, Transactions of the Indian Institute of Metals, pp. 1-13, 2016.[Abstract]

Mechanical properties and abrasive wear behaviour of functionally graded Al-Si12Cu/Al2O3 metal matrix composite fabricated under centrifugal casting technique was investigated and compared with unreinforced aluminium alloy. Hollow cylindrical component with dimensions 150 × 150 × 16 mm was produced under the centrifuging speed of 1200 rpm by incorporating 10 wt% Al2O3 particles of size 30–50 µm. The distribution of the Al2O3 reinforcement particles at outer, middle and inner surfaces in matrix was examined through the microstructural analysis. Hardness and tensile strength of the aluminium alloy and functionally graded composite were tested through microhardness tester and universal testing machine respectively. Abrasive wear of aluminium alloy and functionally graded composite was tested through dry abrasion tester for various loads and speeds on outer, middle and inner surfaces of composite specimens. Scanning electron microscopy analysis was carried out on the fractured tensile specimens and worn out specimens. The results revealed that particles were segregated more on the outer periphery and less on the inner periphery. The mechanical properties and the abrasive wear resistance of the functionally graded material were found higher than the unreinforced alloy. The wear rate was found to increase with increase in load, speed and for the distance from the outer periphery of the casting. The worn out surfaces revealed more cutting and ploughing as a result of three body abrasion wear caused by silica sand particles. © 2016 The Indian Institute of Metals - IIM

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2016 Journal Article N. Radhika and Raghu, R., “Development of functionally graded aluminium composites using centrifugal casting and influence of reinforcements on mechanical and wear properties”, Transactions of Nonferrous Metals Society of China (English Edition), vol. 26, pp. 905-916, 2016.[Abstract]

Functionally graded Al/B4C, Al/SiC, Al/Al2O3 and Al/TiB2 composites with constant 12% (mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB2 composite exhibits less wear rate. © 2016 The Nonferrous Metals Society of China. More »»
2016 Journal Article J. Dinesh, G. Ashraf, M., and N. Radhika, “Fabrication and characterization of Al LM25/TiB2 in-situ composites”, ARPN Journal of Engineering and Applied Sciences, vol. 11, pp. 6001-6005, 2016.[Abstract]

The Al LM25/TiB2 (10 wt %) composite is fabricated using in-situ process by stir casting method. LM25 alloy is melted in a graphite crucible at 8000C using electric furnace in argon gas atmosphere and a mixture of K2TiF6 and KBF4 is added to the melt gradually through the hopper attached at the top of the furnace. The melt is stirred with the aid of mechanical stirrer which rotates at 200 rpm for 40 minutes intermittently. The reaction between K2TiF6 and KBF4 in those conditions results in the formation of TiB2. This melt is poured in the stainless steel mould which is preheated at 2000C and the obtained casting have dimension 100 mm length and 20 mm diameter. The composite specimens are then machined according to the specification requirement of the experiments. All the specimens are polished using emery sheets of grade 1/0 and 2/0 followed by velvet polisher. The specimen used for microstructure analysis is further etched with Keller's reagent. Spectroscopy of LM25 alloy is carried out to observe its elemental composition. X-ray diffraction is used to ensure the formation of TiB2 during casting process. Inverted metallurgical microscope and Vickers hardness tester are used to study the microstructure and micro hardness of the fabricated composite respectively. The X-ray diffraction results revealed the formation of TiB2 particles in the fabricated composite. Microstructure analysis revealed uniform distribution of TiB2 in the aluminum matrix and Micro hardness test shows an increase in hardness of the composite (91HV) as compared to the un reinforced alloy (82HV) by 10%. © 2006-2016 Asian Research Publishing Network (ARPN). All rights reserved.

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2016 Journal Article N. Radhika and Raghu, R., “The mechanical properties and abrasive wear behavior of functionally graded aluminum/AlB2 composites produced by centrifugal casting”, Particulate Science and Technology, pp. 1-8, 2016.[Abstract]

Functionally graded aluminum composites reinforced with different average sized (15, 44, and 74 µm) aluminum diboride (AlB2) particles (10 wt%) have been fabricated through centrifugal casting process. The outer, middle, and inner surfaces of all the functionally graded composites were tested for their microhardness using a Vicker's hardness tester. The outer and inner zones of all the composites were investigated for their tensile strength using a universal testing machine. The abrasive wear test was conducted using dry abrasion tester on the outer region of the composites based on Taguchi's design of experiments, under the influence of parameters such as load, speed, and reinforcement size. The analysis of variance was performed and determined that load has major significance on the wear rate followed by reinforcement size and speed. Scanning electron microscopy analysis was performed on the worn-out surfaces and it was observed that outer surface of coarser particle reinforced composite with lesser scratches and minimum loss of material. More »»
2016 Journal Article N. Radhika and Raghu, R., “Effect of abrasive medium on wear behavior of Al/AlB2 functionally graded metal matrix composite”, Tribology Online, vol. 11, pp. 487-493, 2016.[Abstract]

Centrifugal casting process was applied for fabricating the functionally graded Aluminium/10% AlB2 composite under the centrifuging speed of 1200 rpm and hollow cylindrical (150 × 150 × 15 mm) component has been obtained. The outer, middle and inner surfaces of the FGM those were at the distance of 1 mm, 8 mm and 15 mm from the outer periphery were taken for three body abrasive wear test and the applied load was varied (33 N to 80 N) on these surfaces in the presence of silica sand and alumina as abrasive mediums. The wear test results showed that increase in load and increase in distance from the outer periphery of the FGM increases the wear rate. The surfaces of the FGM abraded with silica sand displays higher wear rate than the surfaces abraded through alumina. SEM analysis has been performed on the surfaces abraded by both medium and it was observed that severity of wear was less in the presence of alumina as abrasive medium during the abrasion test. More »»
2016 Journal Article and N. Radhika, “Greedy hop Algorithm for detecting shortest path in vehicular Networks”, International Journal of Control Theory and Applications, vol. 9, pp. 1125-1133, 2016.
2015 Journal Article N. Radhika, G. Chandran, K., Shivaram, P., and Karthik, K. T. Vijay, “Multi-objective optimization of EDM parameters using grey relation analysis”, Journal of Engineering Science and Technology, vol. 10, pp. 1-11, 2015.[Abstract]

This paper involves the multi-objective optimization of process parameters of AlSi10Mg/9 wt% alumina/3 wt% graphite in Electrical Discharge Machining for obtaining minimum surface roughness, minimum tool wear rate and maximum material removal rate. The important machining parameters were selected as peak current, flushing pressure and pulse-on time. Experiments were conducted by selecting different operating levels for the three parameters according to Taguchi’s Design of Experiments. The multi-objective optimization was performed using Grey Relation Analysis to determine the optimal solution. The Grey Relation Grade values were then analysed using Analysis of Variance to determine the most contributing input parameter. On analysis it was found that peak current, flushing pressure and pulse-on time had an influence of 61.36%, 17.81% and 8.09% respectively on the optimal solution.

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2015 Journal Article N. Radhika, Vijaykarthik, K. T., and Shivaram, P., “Adhesive wear behaviour of aluminium hybrid metal matrix composites using genetic algorithm”, Journal of Engineering Science and Technology, vol. 10, pp. 258-268, 2015.[Abstract]

<p>This paper involves the optimisation of the process parameters for the aluminium/alumina/graphite hybrid metal matrix composite to obtain the least wear rate during dry sliding process. The tribological properties of the composite have been studied and discussed. Experiments were carried out using pin-on-disc tribometer by varying the parameters such as load, velocity, distance &amp; the alumina composition of the composite and the wear rate for each input configuration was calculated. Using this empirical data, the regression equation was obtained using Artificial Neural Networks and this function was then optimised using Genetic Algorithm. The least wear rate was obtained for the composite with an alumina composition of 5 wt% © School of Engineering, Taylor’s University.</p>

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2015 Journal Article N. Radhika and Raghu, R., “Evaluation of dry sliding wear characteristics of LM 13 Al/B4C composites”, Tribology in Industry, vol. 37, pp. 20-28, 2015.[Abstract]

<p>The present paper labels the wear behaviour of the manufactured LM 13 aluminium/B4C metal matrix composites synthesized by means of liquid metallurgy technique. The B4C particles with size 33 μm diversified for the range of 0, 4, 8 and 12 wt-% were incorporated in the composite. The wear behaviour of the composites was studied as per L16 orthogonal array using pin-on-disc tribometer for various sliding conditions by varying the parameters such as load, velocity, sliding distance and wt-% of the reinforcement. Smaller-the-better characteristic was selected as the objective of the developed model and the optimum level of each parameter was detected. The influence of the parameters on the wear rate was known through analysis of variance. Regression model was developed and checked for adequacy using confirmation experiments. Scanning electron microscope analysis was done to study the worn morphologies of composite surface. The experimental results disclose that load was the major influencing parameter on the wear behaviour followed by wt-% of reinforcement, velocity and sliding distance. The worn-out surface interprets that rise in load yields a transition in the wear mechanism. The confirmatory results evident that Taguchi’s design as efficient statistical model by supporting the regression results with less error. © 2015 Published by Faculty of Engineering.</p>

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2015 Journal Article Ka Vignesh and N. Radhika, “Energy and location aware cluster routing protocol for wireless sensor networks (ELACRP)”, International Journal of Applied Engineering Research, vol. 10, pp. 12733-12744, 2015.[Abstract]

<p>This paper proposes an ensemble protocol called Energy and Location Aware Cluster Routing Protocol (ELACRP) for wireless sensor networks. The location information model and energy consumption model are adapted. The neighbor node election operation is initiated once when the network is deployed. The cluster head selection mechanism is performed based on the residual energy of sensor nodes. The cluster head mechanism chooses the sensor node having maximum residual energy. Clustering is performed based on the nodes location information conceived from the GPS location information. The metrics number of packets delivered to the sink, energy utilization rate, the energy standard deviation and average hops are taken to compare the performance of the ELACRP with AELAR protocol [13]. Simulations are performed using NS2 and the outcome results depicts that the proposed ELACRP performs better than that of AELAR protocol [13] in terms of the chosen performance metrics. © Research India Publications</p>

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2015 Journal Article N. Radhika and Raghu, R., “Dry sliding wear behaviour of aluminium Al-Si12Cu/TiB2 metal matrix composite using response surface methodology”, Tribology Letters, vol. 59, pp. 1-9, 2015.[Abstract]

Abstract An aluminium Al-Si12Cu/TiB2 metal matrix composite was fabricated using the liquid metallurgy route, and its dry sliding wear characteristics were investigated under various sliding parameters. The titanium diboride (TiB2) particles (10 wt%, average size 50-60 μm) were incorporated into the matrix and its microstructural characteristic was examined. A five-level central composite design experiment was developed using response surface methodology; parameters such as load, velocity and sliding distance were varied in the range of 10-50 N, 1-5 m/s and 500-2500 m, respectively. Dry sliding wear tests were performed as per the experimental design using a pin-on-disc tribometer at room temperature. Significance tests, analyses of variance and confirmatory tests were performed to validate the developed model. Study of the microstructural characteristics revealed uniform dispersion of the reinforcement particles throughout the composite. The regression result showed that the developed model performed well in relating the wear process parameters with the response and predicting the wear behaviour of the composite. The surface plot showed that wear rate increased with increasing load at all velocities and distances, and decreased with increasing sliding distance. In the case of velocity, the wear rate decreased initially, increasing after the transition velocity had been reached. Scanning electron microscopy analysis revealed severe wear at a high load due to a higher level of deformation of the composite surface. © 2015 Springer Science+Business Media New York.

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2015 Journal Article N. Radhika and Raghu, R., “Experimental investigation on abrasive wear behavior of functionally graded aluminum composite”, Journal of Tribology, vol. 137, 2015.[Abstract]

<p>Functionally graded Al-Si12Cu/10 wt.% B4Cp metal matrix composite (MMC) has been fabricated under stir casting process followed by horizontal centrifugal casting method. The casting of length 170 mm, outer diameter 160 mm, and thickness 16 mm was obtained under the centrifugal speed of 1000 rev min-1. The microstructural evaluation was carried out on the surfaces at distance of 3, 6, 9, and 11 mm from the outer periphery of the casting to ensure the distribution of reinforcement particles, and the surfaces at same distance were tested for its hardness using microhardness tester. The microstructural results revealed that surface at a distance of 3 mm from the outer periphery has reinforcement concentration of 32% and surface at a distance of 11 mm has reinforcement concentration of 3%. The hardness of the surface was improved considerably according to the reinforcement concentration. The three-body abrasive wear test was conducted on the composite specimens as per L16 orthogonal array for parameters such as the load, speed, time, and reinforcement concentration. Each parameter was varied for four levels and the optimum level of each parameter was found out through signal-to-noise ratio analysis using "smaller-the-better" characteristics. The signal-to-noise ratio analysis revealed that load was the dominant parameter on the abrasive wear behavior followed by reinforcement concentration, speed, and time. The analysis of variance (ANOVA) result indicates the parameter that affects the response significantly and results were agreed with signal-to-noise ratio analysis. The regression equation was developed and results were validated using confirmation experiments. The worn-out surfaces were examined using scanning electron microscope (SEM) for observing the wear mechanism. Copyright © 2015 by ASME.</p>

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2015 Journal Article S. K. Raj, Thanudas, B., N. Radhika, and Smitha, V. S., “Satellite-TCP: A Flow Control Algorithm for Satellite Network”, Indian Journal of Science and Technology, vol. 8, no. 17, 2015.[Abstract]

Objective: In this world of advanced technology, satellite communication is the basis for all data communications. TCP was designed to be flexible and robust but it cannot perform efficiently over the satellite links with long delay. The major objective of our work is to propose a novel flow control algorithm for satellite network to prevent the heavy degradation in the network performance due to long propagation delay, high bit error rate and bandwidth asymmetry. Methods: A strong flow control mechanism is necessary to eliminate the network performance degradation due to the satellite link characteristics like long propagation delay, high bit error rate and bandwidth asymmetry. Satellite-TCP is a flow control mechanism based on the negative acknowledgement strategy and connection splitting. The satellite link utilization is monitored and the active connections are assigned with the window values. The window values were considered as it can easily reflect the available bandwidth in the satellite links. Findings: The major problems affecting the performance in satellite links are long propagation delay, high bit error rate and bandwidth asymmetry. The proposed Flow Control Algorithm called Satellite-TCP is based on controlling the flow of Negative Acknowledgement packets (NACK), according to the level of congestion at the network. The two main modules in the proposed system include an enhanced TCP flow control mechanism and a data loss recovery mechanism. Among this the flow control is based on link utilization measurements and throughput calculation techniques. Data loss recovery strategy is based on Negative Acknowledgements coming from the receiver side. In this way, we can decrease the amount of packet loss in the network and even eliminate the packet loss, sometimes. Satellite-TCP adopts a window growth strategy to accelerate the speed of increase in the size of congestion window. The flow control mechanism not only enhanced the throughput of forward link but also greatly reduced the bandwidth occupancy rate in back-ward link in the satellite network. This in turn increases the overall performance of the satellite link. Improvements: If we add a priority based strategy to the new flow control mechanism, it can judge the network performance according to the data loss. Moreover we are expecting that, if we add a priority bit based strategy to the new flow control mechanism, it will help to distinguish the specific reasons for data loss and can take corresponding flow control strategies. While considering the throughput and loss rate, Satellite –TCP is showing excellent performance in the case of forward link but it performs poor in the case of backward link. So we are planning to extend our work in such a way that it will perform well in the case of backward link also. More »»
2015 Journal Article V. Midhun and N. Radhika, “Investigation of mechanical behaviour and tribological properties of coir and sugarcane bagasse fibers filled epoxy composites”, International Journal of Applied Engineering Research, vol. 10, pp. 37076-37081, 2015.[Abstract]

<p>Now a days the usage of natural fiber as reinforcement in polymers has gained significance due to its environmental nature like light weight, high strength, nearby obtainable and also reasonably economical. This current investigational study targets at learning the weight percentage of hybrid natural fiber reinforcement polymer composite material of coir and sugarcane bagasse fibers (10%, 15%) with epoxy resin as matrix in structural applications. The composite specimen was fabricated using hand lay-up practice to the dimension of 115mm x115mmx5mm. The mechanical properties like tensile strength and shore D hardness were approved out from the samples cut from the fabricated composite specimens. The tribological performance of hybrid polymer composite (7% of coir+3% of bagasse) filled epoxy composites were studied by means of Pin on Disc apparatus under dry sliding conditions. Major control factors mostly influencing the wear rate are recognized and the effect of wear constraints like load 10, 20, 30(N), sliding speed 1, 2,3(m/s), and sliding distance 500, 1000, 1500(m) on the sliding wear rate were examined by varying with three levels. A design of experiments based on the Taguchi technique was achieved to attain data in a precise way. An orthogonal array and Analysis of Variance (ANOVA) were practiced to examine the effect of process constraints on sliding wear behavior of these composites. Results revealed that hybrid polymer composite with (7% of coir+3% of bagasse) filled epoxy composites has the best tensile strength and shore D hardness number. Tribological results exposed that sliding distance have straight influence on wear rate (52.6%), pursued by sliding velocity (16.9%) and normal load (8.2%). © Research India Publications.</p>

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2015 Journal Article N. Radhika and .Raghu, R., “Mechanical and tribological properties of functionally graded aluminium/zirconia metal matrix composite synthesized by centrifugal casting”, International Journal of Materials Research, vol. 106, pp. 1174-1181, 2015.
2015 Journal Article N. Radhika, “Prediction of Tool Condition During Turning of aluminium/alumina/graphite Hybrid Metal Matrix Composites Using Machine Learning Approach”, Journal of Engineering Science and Technology, vol. 10, pp. 1310–1325, 2015.[Abstract]

Aluminium/alumina/graphite hybrid metal matrix composites manufactured using stir casting technique was subjected to machining studies to predict tool condition during machining. Fresh tool as well as tools with specific amount of wear deliberately created prior to machining experiments was used. Vibration signals were acquired using an accelerometer for each tool condition. These signals were then processed to extract statistical and histogram features to predict the tool condition during machining. Two classifiers namely, Random Forest and Classification and Regression Tree (CART) were used to classify the tool condition. Results showed that histogram features with Random Forest classifier yielded maximum efficiency in predicting the tool condition. This machine learning approach enables the prediction of tool failure in advance, thereby minimizing the unexpected breakdown of tool and machine.

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2015 Journal Article N. Radhika and Raghu, R., “Parametric Study Of Dry Sliding Wear Behaviour Of Functionally Graded Al Lm25/Si3n4 Composite By Response Surface Methodology”, ADVANCED COMPOSITES LETTERS, vol. 24, pp. 130–136, 2015.
2015 Journal Article , ,, and N. Radhika, “Design of secure smart grid Architecture model using Damgardjurik cryptosystems”, Research Journal of Applied Sciences, Engineering and Technology, vol. 9, no. 10, pp. 895-901, 2015.[Abstract]

Smart grid is a paradigm shift from the traditional Power grid which promises to make the electric grid both energy efficient and Fault tolerant. Trade-off between Energy savings and Security is a critical issue in Smart grid architecture. Smart grid architecture requires a high level secure data exchanges between sensors like Phasor Measurement Units and Advanced Metering Infrastructures like Smart Meters. In this study a Secure Smart grid Architecture model is proposed for the Smart grid network. Initially DamgardJurik encryption algorithm is applied on the data from the Phasor Measurement Units and a digital signature is then attached to the encrypted text to provide further authentication. The digitally signed data is collected in Data centre where it is decrypted. The proposed architecture has been implemented in both software and hardware. The effectiveness of the system is verified by introducing an intruder in hardware implementation

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2015 Journal Article V. K. and N. Radhika, “An Improved role based trust management system based on Artificial bee Algorithms in wireless Networks,”, International journal of Applied sciences , Engineering and Technology, vol. 10, pp. 1175-1184, 2015.[Abstract]

The aim of this research study is to propose an improved role based trust management system for wireless
sensor networks. The objective is attained using an interactive artificial bee colony algorithm which is used for path
optimization. Also the purpose is to guarantee to provide robust and trustworthiness among the clusters formed in the wireless sensor network. The reputation among the sensor nodes is assured using the trust model. One of the main concerns of WSN, that have attracted research scholars, is the property to guarantee a less amount of security in a limited environment. Trust among the communicative nodes is one of the major issues that have to be given importance in wireless sensor network. A number of research works have concentrated on only Trust Management (TM) techniques without considering their roles. Existing trust management schemes do not provide significant reliability in all environments. In order to overcome these issues, Role Trust (RT) framework is presented, to select role for each nodes representing policies in a distributed authorized environment. RT integrates the features of rolebased access control and TM schemes. This feature is particularly applicable for attribute based access control. Role trust management schemes generate rules, identify and assure roles based on the rules generation process and then clusters are identified for each trust model. Along with the trust model, this study focuses on efficient data path with
reduced data loss. Hence, this study presents a novel Swarm Intelligence based Role Trust and Reputation Model (SIRTRM) to provide trust and reputation in WSNs. Simulations are carried out in NS2 environment and the results portrays the accuracy, robustness and lightness of the proposed model.

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2015 Journal Article T. V. and N. Radhika, “J-Botnet Detector: A Java based tool for HTTP Botnet detection”, Wseas Transactions on Advances in Engineering Education, 2015.
2015 Journal Article R. Kalaivani, Vinotha, V., and N. Radhika, “TBASR: Trust based anonymous secure routing protocol for manet in adversarial environment”, International Journal of Applied Engineering Research, vol. 10, pp. 18321-18331, 2015.[Abstract]

Mobile ad hoc networks (MANETs) are wireless and dynamic topology networks. The major issue of mobile ad hoc networks (MANETs) is to send data in secured manner from source to destination node in an adversarial (opponent) environment. Wireless networks are vulnerable to many attacks that are not secured and less-trustworthy. Existing research work focuses on developing the routing protocols for security enhancement in adversarial environment. These protocols are not secured in MANET environment. The existing protocol works on the basis of authentication, group signature, and onion routing. In this paper, the proposal of Trust based Anonymous Secure Routing for MANET in Adversarial environment is created to provide secured environment. TBASR protocol defends the neighbor nodes attacks by the way of key encryption and decryption through route-request and reply. Trust of the path is achieved by Asymmetric key encryption and that of the node is attained through group signature. It helps to detect intruders in the networks and avoids packet delay between intruder nodes. Onion Routing is used for obtaining anonymity during packet transmission. © Research India Publications.

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2015 Journal Article S. Anne and N. Radhika, “Strategy for overlap minimization in sensing area”, International Journal of Applied Engineering Research, vol. 10, pp. 29405-29416, 2015.[Abstract]

When the sensors are deployed without any strategy in the target area, it increases the detection of redundant data which thereby increases the processing load at the base station or the cluster heads. The redundant data does detected presents a challenge for real time sensor Applications which needs solutions. In order to reduce the redundant data, the overlap in the sensing area has to be minimized. In this paper a brute force and randomized algorithm are suggested as the possible solution to reduce excess overlaps. Implementation results have shown that randomized algorithm provides optimal solution. © Research India Publications.

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2015 Journal Article A. Ambika devi and N. Radhika, “Performance Analysis of Enablers and disablers in cloud”, International Journal of Engineering Research , 2015.
2015 Journal Article V. V.V., N. Radhika, and Vanitha, V., “Intruder Detection and Prevention in a Smart Grid Communication System”, ICSGT 2015 Procedia Technology, vol. 21, pp. 393 - 399, 2015.[Abstract]

Abstract Smart Grid is an electrical network that uses digital and other advanced technology to monitor and manage the transport of electricity from all generating sources to meet the varying demand of the end-users. The important nodes of the Smart Grid are the phasor measurement unit(PMU),Smart meter(SM) and phasor data concentrator(PDC). All PMU's within substation will form a communication network with a gate-way node called phasor data concentrator which updates data from PMU's within the cluster range. Proper management of data exchange between PMU's and PDC's are an essential thing to meet in the concept of Smart Grid. In this paper we are considering \{PMU\} as a sensor node and \{PDC\} as a central node and the data is exchanged between this nodes. Proposed intrusion detection algorithm, Packet loss avoidance using Time Division Multiple Access (TDMA) protocol and security algorithm improves system security in response to malicious attacks. Network simulator \{NS2\} is used to create simulation scenario for detecting attacks. Hardware is tested using \{LPC2148\} microcontrollers and Zigbee.

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2015 Journal Article G. N., V.V., V., and N. Radhika, “A Novel Approach in Demand Side Management for Smart Home”, ICSGT 2015 Procedia Technology, vol. 21, pp. 526 - 532, 2015.[Abstract]

Abstract The development of smart grid technology acts as new brain to the power generation and distribution network. Through this technology, the network is not only going to get integrated and turn communicable all over the country but also the demand will be monitored by the control centers and at peak time the usage of electricity is going to cost higher than the nominal rate with intimation given to the customer through sms and mail. Hence it's time for the consumers to act smart or else they will end up receiving highly billed statements. This project presents an idea of having a power hub which has control over all the loads individually. The hub detects the peak time demand and reduces the load usage by switching off unwanted loads with a priority that is being set by the consumer based on game theory's algorithm which schedules load usage by creating several possible schedule vector for consumers such that demand is never raised. This could be done both individually and among multiple users of a community or area. The power hub can also monitor our energy usage and creates an order of importance among the loads, thus providing intelligence to the consumers.

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2014 Journal Article N. Radhika and Subramanian, Rb, “Effect of ageing time on mechanical properties and tribological behaviour of aluminium hybrid composite”, International Journal of Materials Research, vol. 105, pp. 875-882, 2014.[Abstract]

Aluminium/alumina/graphite hybrid metal matrix composites prepared by using the stir casting technique were heat treated to enhance mechanical properties such as strength, hardness and wear resistance. The present study evaluates the effect of ageing time on the hardness, tensile strength and tribological behaviour of both unreinforced Al-Si10Mg alloy and aluminium hybrid metal matrix composites. Results for composite samples were compared with those of as-cast samples. Results showed that heat treated samples of alloy and composite showed higher hardness, tensile strength and tribological properties compared to both as-cast alloy and composite. Among the different ageing times employed, specimens aged for 4 hours showed maximum mechanical and tribological properties. Investigations of the worn surfaces were carried out using scanning electron microscopy to understand the wear mechanism.

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2014 Journal Article N. Radhika, Vaishnavi, A., and Chandran, G. K., “Optimisation of dry sliding wear process parameters for aluminium hybrid metal matrix composites”, Tribology in Industry, vol. 36, pp. 188-194, 2014.[Abstract]

The advancement in today's technology calls for the usage of superior material. A metal matrix composite has a unique characteristics to combine the various properties of the different materials present in the matrix composition, which enables it to be used for various high temperature applications where constrains could be overcome. The present study investigates the influence of applied load, sliding velocity and temperature on wear rate of AlSi10Mg alloy reinforced with 3 wt-% graphite and 9 wt-% alumina which was fabricated through liquid metallurgy route. The wear rate of this hybrid composite was investigated by performing dry sliding wear test on a pin-on-disc wear tester. The experiment was conducted for a constant sliding distance of 1500m. The influence of the various parameters on the wear rate was studied using Taguchi's Design of Experiment. An L9 orthogonal array was used for analysis of data. Signal-to-Noise ratio and Analysis of Variance were used to determine the ranking and percentage effect of input process parameters on wear rate respectively. Results revealed that load has the highest contribution on wear rate followed by temperature and sliding velocity. Worn-out wear surfaces were analysed using scanning electron microscope. © 2014 Published by Faculty of Engineering.

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2014 Journal Article V. Sureshkumar, T. Reddy, S., Malepati, A., and N. Radhika, “A query adaptive fuzzy based dynamic sampling algorithm to manage power consumption in wireless sensor networks”, International Journal of Applied Engineering Research, vol. 9, pp. 4283-4296, 2014.[Abstract]

<p>Wireless sensor networks (WSNs) have received a great deal of researcher's attention in recent years due to its wide applications. These low-powered sensing devices are to be deployed densely and randomly in application environment. Since nodes are powered by batteries, the lifetime of the sensor node is strongly dependent on its battery lifetime. Hence energy saving in sensor nodes has received great amount of interest, thereby increasing the lifetime of the nodes. This paper includes various approaches to solve the drawbacks of SMAC and also to optimize the energy consumption of sensor nodes. This could be achieved by using dynamic sampling algorithm based on the application of the sensor nodes. This proposed algorithm reduces the energy consumption in S-MAC by addressing to its problem which indirectly increases the lifetime of sensor nodes. © Research India Publications.</p>

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2014 Journal Article N. Radhika, Sudhamshu, A. R., and G. Chandran, K., “Optimization of electrical discharge machining parameters of aluminium hybrid composites using Taguchi method”, Journal of Engineering Science and Technology, vol. 9, pp. 502-512, 2014.[Abstract]

Metal matrix composites utilises the combined properties of the constituent material that finds applications in various fields. The present study investigates the influence of peak current, flushing pressure and pulse-on time on Electrical Discharge Machining of AlSi10Mg alloy reinforced with 3 wt% graphite and 9 wt% alumina hybrid metal matrix composites. Taguchi's Design of Experiment was used to analyse the machining characteristics of hybrid composites. Analysis of Variance and Signal-to-Noise ratio were used to determine the influence of input process parameters on the surface roughness, material removal rate and tool wear rate. Signal to Noise ratio and Analysis of Variance revealed that peak current was the most influential parameter on surface roughness followed by pulse on time and flushing pressure. For material removal rate, the major parameter was flushing pressure followed by peak current and pulse on time. The most significant parameter of tool wear rate was pulse on time followed by peak current and flushing pressure. Interaction terms also have significant effect on their output responses. © School of Engineering, Taylor's University.

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2014 Journal Article N. Radhika, R., S., and A., S., “Analysis of chip formation in machining aluminium hybrid composites”, E3 Journal of Scientific Research, vol. 2, pp. 09-15, 2014.
2014 Journal Article N. Radhika, Praveen, G., and P Rathan, G., “Study of wear behaviour of Al/(Al2O3P and SiCP) hybrid metal matrix composities”, Malaysian Journal of Science, vol. 33, 1 vol., pp. 78–88, 2014.
2014 Journal Article T. Raviteja, N. Radhika, and Raghu, R., “Fabrication and Mechanical Properties of Stir Cast Al-Si12Cu/B4C Composities”, International Journal of Research in Engineering and Technology, vol. 3, no. 7, pp. 343-346, 2014.
2014 Journal Article S. N Prabhakar, N. Radhika, and Raghu, R., “Analysis of Tribological Behavior of Aluminium/B 4 C Composite Under Dry Sliding Motion”, Procedia Engineering, vol. 97, pp. 796-807, 2014.[Abstract]

This present study deals with the fabrication of aluminium/boron carbide metal matrix composite and investigation on its tribological behavior. The composite incorporated with 5 wt% of boron carbide particles with an average size 33 μmwas fabricated through stir casting process. The microstructure of this composite was examined and uniform distribution of reinforced particles in the matrix was observed. Wear experiments were conducted on pin-on-disc tester based on Taguchi's L27 orthogonal array using three process parameters such as applied load, sliding velocity and distance; each varied for three levels. Loads of 10 N, 20 N, 30 N; velocities of 1 m/s, 2 m/s, 3 m/s and distances of 1000 m, 1500 m, 2000 m were considered for analyzing the wear behavior of composite. Optimum parameters were found out using Signal-to-Noise ratio by choosing ‘Smaller-the-better’ characteristics for wear rate and coefficient of friction. Influence of individual parameter and their interactions on the responses was predicted using Analysis of Variance. Results depicted that both wear rate and coefficient of friction increases with load and decreases with velocity and distance. Worn out surfaces of the composite specimen were analyzed using Scanning Electron Microscope for predicting the wear mechanism. It was observed that, severe delamination occurred as applied load increased from 10 N to 30 N. This tribological analysis can be utilized to replace the conventional automotive materials with aluminium metal matrix composites having better wear characteristics.

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2014 Journal Article N. Radhika, .Shivaram, P., and Karthik, K. T. V., “Multi-objective optimization in electric discharge machining of aluminium composite”, Tribology in Industry, vol. 36, pp. 428-436, 2014.
2014 Journal Article N. Radhika and .Raghu, R., “Statistical modeling and analysing of wear behaviour of LM25 Al/B4C/Gr hybrid composites”, International Journal of Applied Engineering Research, vol. 9, pp. 8773-8776, 2014.
2014 Journal Article V. Sureshkumar and N. Radhika, “Energy Efficient Mobility Prediction Based Localization Algorithm for Mobile Sensor Networks”, Research Journal of Applied Sciences, Engineering and Technology, vol. 8, no. 4, pp. 571-577, 2014.[Abstract]

Aim of study is to develop energy efficient mobility prediction based localization algorithm for mobile sensor networks. Mobile sensors are being deployed in the environment like underwater sea monitoring, where they can move to any location to meet coverage requirements. Sensor networks choose to follow data centric approach to track the exact location of the nodes. Location information should be identified for application tasks and network operations. Novel localization algorithms need to be developed for mobile sensor networks with high accuracy and minimal energy consumption. The proposed localization algorithm for mobile sensor networks uses the mobility prediction localization and Mobility Prediction Localization (MPL) algorithm with Maximum Likelihood Estimation (MLE) technique for low and high accuracy respectively. The performance analysis shows that proposed MPL and MPL along with MLE achieve accuracy above 95.5% in the simulated environment. This study also analyses the number of anchor nodes to be deployed to achieve desired level of accuracy. The proposed algorithm uses minimal number of nodes for tracking while rest are in sleep mode for energy saving, thereby increasing lifetime of the nodes.

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2014 Journal Article N. Radhika and K Raj, S., “Link Failure Localization in All-Optical Network”, International Journal of Advanced Research in Computer Science and Software Engineering, vol. 4, no. 5, 2014.
2014 Journal Article N. Radhika and Thejiya, V., “Trust based Solution for Mobile Ad-hoc Networks”, International Journal of Advanced Research in Computer Science and Software Engineering, vol. 4, 2014.
Publication Type: Book
Year of Publication Publication Type Title
2016 Book S. K. Vasudevan, Vasudevan, S., Velusamy, K., and N. Radhika, Dictionary of Computer Science. New Delhi : IK International Publishing, 2016, p. 306.[Abstract]

Very often we encounter words from the computing world whose precise meaning tends to elude us! More and more computer jargons are cropping up almost every other day. This dictionary is conceptualized realizing this need for access to a ready reference resource. The authors have strived to develop this dictionary of computer terminologies in a novel way. It does not only give the pithy meaning, connotation or context, but it also includes witty cartoons and simple images and diagrams to make its usage a “learn and fun” experience. With its exciting way of treatment of the terminologies, this dictionary will be useful to anybody who has to deal with computers in a day to day activity. This could be students of all grades, teachers, parents, professionals and so on.

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Publication Type: Conference Paper
Year of Publication Publication Type Title
2015 Conference Paper S. M. Chandrabose and N. Radhika, “Analysis of the Machining Characteristics on Surface Roughness of Functionally Graded Aluminium Metal Matrix Composite”, in International Conference on ‘Advanced Engineering and Technology for Sustainable Development, Karpagam College of Engineering, Coimbatore, 2015, vol. 10, pp. 14856-14861.
2015 Conference Paper A. Suresh, Harish, K. V., N. Radhika, Samuel P., James R.K., Raj S., and B., P., “Particle Swarm Optimization over back propagation neural network for length of stay prediction”, in Procedia Computer Science ICICT 2014, 2015.[Abstract]

Length of stay of an inpatient reflects the severity of illness as well as the practice patterns of the hospital. Predicting the length of stay will provide a better perception of the different resources consumed in a healthcare system. Neural network trained using back propagation has been discerned as a successful prediction model in healthcare systems 1. In this paper, a robust stochastic optimization technique called Particle Swarm Optimization (PSO) is compared with back propagation for training. The algorithms were evaluated based on error convergence, sensitivity, specificity, positive precision value and accuracy and corresponding results are presented. © 2015 The Authors.

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2015 Conference Paper M. R. M. Veeramanickam and N. Radhika, “A study on educational games application model in E-learning cloud system”, in 2014 International Conference on Information Communication and Embedded Systems, ICICES 2014, S.A.Engineering College Chennai ,India, 2015.[Abstract]

Professional students are having experience of what they find more enjoyable in using Android games using internet and how they are learning through various application gives valuable information for the design of new model intended for them. In this paper, we explore new concept consist of games application design model in E-learning cloud using Cloud as a medium to reach end user students. What will be outcomes in regard to the user interface and contents of the learning environments under E-learning cloud development. In Addition, we present importance related to designing new Games application model in E-learning cloud through Simulation. So, we need to focus on what we want them to learn through games application. This gives is main concept of games application design model. © 2014 IEEE.

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2015 Conference Paper M. Divya M. and N. Radhika, “Design of secure Multilevel Architecture for last Mile communication in smart grid systems”, in ICSGT, 2015.
2015 Conference Paper A. Athavan and N. Radhika, “Memory optimized lifetime vehicle data acquisition framework”, in 2015 International Conference on Computing and Network Communications, CoCoNet 2015, 2015, pp. 602-606.[Abstract]

Data acquisition is done from road vehicles by many service providers for delivering various services to the end user. Apart from this, car manufacturers also collect a fair share of data which allows them to design better components and robust systems in future. But, the lifetime data acquisition, storage and processing leads to huge costs and lot of resources. Existing data collection procedure in road vehicles has limitations like huge memory requirements to store such volume of data, delay in accessing the data from vehicle for analysis and etc. Although remote connectivity and cloud storage facilities look promising, the transfer of large volume of data from vehicle to cloud storage is still a challenge. This paper describes a life-time data acquisition and storage framework for automobiles with reduced memory consumption and with possibility of quick access to data for analysis. The framework is tested using a sample application which collects lifetime data from OBD Socket of a car and stores it at a remote storage space. From this sample application, the memory requirements & efficiency of system are analyzed, compared with existing system and proven to be effective. © 2015 IEEE.

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2014 Conference Paper N. Radhika and .Raghu, R., “Statistical Modeling and Analysing of Wear Behaviour of LM25 Al/B4C/Gr Hybrid Composites’”, in International Conference on “Modeling, Optimisation and Computing, Noorul Islam University, Kumaracoil, Kanyakumari Dist, 2014.
2014 Conference Paper N. Radhika and Prabhakar, S., “Influence of Cutting Parameters on Surface Roughness of Aluminium Hybrid Composites”, in International Conference on “Modeling, Optimisation and Computing, Noorul Islam University, Kumaracoil, Kanyakumari Dist, India, 2014.
Publication Type: Conference Proceedings
Year of Publication Publication Type Title
2014 Conference Proceedings N. Radhika and .Raghu, R., “Three Body Abrasion Wear Behaviour of Functionally Graded Aluminium/B4C Metal Matrix Composite Using Design of Experiments”, International Conference on 12th Global Congress on Manufacturing and Management, vol. 97. VIT University, Vellore, pp. 713–722, 2014.
2014 Conference Proceedings N. Radhika, Prabhakar, N. S., and .Raghu, R., “Analysis of Tribological Behaviour of Aluminium/ B4C Composite Under Dry Sliding Motion”, International Conference on “12th Global Congress on Manufacturing and Management, vol. 97. VIT University, Vellore, India, pp. 796-807, 2014.


Lecture Series

Mr. S. Nithin and Dr. N. Radhika, “Centralized Control Station for Smart Grid Test Bed based on Windows Embedded XP 2007 and Ebox 4861S", the Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering series, Vol.0117. [Scopus Indexed]

Patent Filed

Multi secured dropping of spoofed packets at the gateway for unauthorized networks with number 1855/CHE/2010.   Awaiting second stage of Experimental Review this year.

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