Athota K.,JNTUH College of Engineering |
Athota K.,University of Hyderabad |
StalinBabu G.,AITAM |
Negi A.,University of Hyderabad
Communications in Computer and Information Science | Year: 2012
Wireless Mesh Networks(WMNs) with multiradio multichannel capability have received much attention from research community. Routing in WMNs has been active area of research for many years. Routing metrics that have been proposed for WMN provide better path selection in comparision with hop count which is popular in wired networks. Expected Transmission Time (ETT) was proposed as better metric as compared to ETX so as to give weighting to throughput. Weighted Cumulative ETT(WCETT) allows accounting for concatenated links that interfere when using the same channel. Adhoc on demand distance vector (AODV) is a popular routing protocol design for MANETs which is also considered applicable as a routing protocol for WMNs. Further, an extension of AODV may support Multiple Radios and Multiple channels. In this paper we integrate WCETT and AODV to realize better routing for WMNs. We attempt to study and investigate performance of above said routing metrics using simulations from NS2 simulator. © 2012 Springer-Verlag.
Prasad P.M.K.,GMR Institute of Technology |
Kumar M.N.V.S.S.,AITAM |
Sasi Bhushana Rao G.,Andhra University
Smart Innovation, Systems and Technologies | Year: 2015
The X-ray bone images are extensively used by the medical practitioners to detect the minute fractures as they are painless and economical compared to other image modalities. This paper proposes a parameterized design of biorthogonal wavelet based on the algebraical construction method. In order to assign the characters of biorthogonal wavelet, there are two kinds of parameters which are introduced in construction process. One is scale factor and another one is sign factor. In edge detection, the necessary condition of wavelet design is put forward and two wavelet filers are built. The simulation results show that the parameterized design of biorthogonal wavelet is simple and feasible. The biorthogonal wavelet zbo6.6 performs well in detecting the edges with better quality. The various performance metrics like Ratio of Edge pixels to size of image (REPS), peak signal to noise ratio (PSNR) and computation time are compared for various biorthogonal wavelets. © Springer India 2015.
Prasan U.D.,AITAM |
Murugappan S.,Annamalai University
International Journal of Applied Engineering Research | Year: 2016
Vehicular Ad Hoc Networks is a class of special wireless ad-hoc network with the characteristics of high node mobility and fast topology changes. The Vehicular Networks can provide wide variety of services, range from safety-related warning systems to improved navigation mechanisms as well as information and entertainment applications. So lot of research work is being conducted to study the problems related to the vehicular communications including network architecture, protocols, routing algorithms, as well as security issues. In order to stimulate the ‘beginners in research’, here we present a paper on an overview of Vehicular Ad-hoc Networks. VANETs comprise vehicle-to-vehicle and vehicle-to-infrastructure communications based on wireless local area network technologies. The distinctive set of candidate applications, resources, and the environment make the VANET a unique area of wireless communication. Due to their unique characteristics such as high dynamic topology and predictable mobility, VANETs attract so much attention of both academia and industry. In this paper, we provide an overview of the main aspects of VANETs from a research perspective. This paper starts with the basic architecture of networks, then discusses research issues and general research methods, and ends up with the analysis on challenges and applications of VANETs. © 2016, Research India Publications.
Raja Kishor D.,Jawaharlal Nehru Technological University |
Cybernetics and Information Technologies | Year: 2016
The present work proposes hybridization of Expectation-Maximization (EM) and K-means techniques as an attempt to speed-up the clustering process. Even though both the K-means and EM techniques look into different areas, K-means can be viewed as an approximate way to obtain maximum likelihood estimates for the means. Along with the proposed algorithm for hybridization, the present work also experiments with the Standard EM algorithm. Six different datasets, three of which synthetic datasets, are used for the experiments. Clustering fitness and Sum of Squared Errors (SSE) are computed for measuring the clustering performance. In all the experiments it is observed that the proposed algorithm for hybridization of EM and K-means techniques is consistently taking less execution time with acceptable Clustering Fitness value and less SSE than the standard EM algorithm. It is also observed that the proposed algorithm is producing better clustering results than the Cluster package of Purdue University.
Bidikar B.,Andhra University |
Rao G.S.,Andhra University |
Ganesh L.,ANITS |
Procedia Computer Science | Year: 2016
The time delay of GPS link1 (L1) and link2 (L2) signals in ionosphere is one of the propagation path effects caused when the signal is travelling from satellite to receiver. The absence of the Selective Availability (SA) made the ionospheric delay as the predominant accuracy limiting factor for GPS. As the density of the ionized plasma varies, the velocity of the GPS signals differs from the velocity of light. Due to this the GPS radio frequency (RF) signals experience the group delay or phase advance. Hence the one way time transfer of the GPS is affected, inturn resulting in pseudorange error varying from few meters to tens of meters at zenith. To correct the GPS range measurements this delay is estimated using conventional Code Range technique which models the Total Electron Content (TEC). In this method the TEC is an additional parameter to be calculated and the accuracy of the TEC depends on the inter channel biases and solar activity. To overcome this, an orthogonal decomposition algorithm is proposed in this paper. The proposed algorithm decomposes the coefficient matrix derived from the linear combination of GPS measurements. The proposed algorithm not only avoids TEC calculation but also minimizes complex computations. The comparative analysis of the estimates of the proposed algorithm and conventional method are presented in this paper. The proposed algorithm is implemented and estimates are validated for the ephemerides data collected on 07th April 2015 from the Dual Frequency GPS (DFGPS) receiver located in the Department of Electronics and Communications Engineering (ECE), Andhra University College of Engineering (AUCE), Visakhapatnam (Lat:17.730N/Long:83.3190E). The proposed algorithm can be implemented for precise navigation and tracking applications like Category I (CAT I) precision approach (PA), Precise Point Positioning (PPP), geographic information systems (GIS) and Real Time Kinematic (RTK) positioning. © 2016 The Authors. Published by Elsevier B.V.