Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Subject: search.filters.subject.Computational efficiency

Search Results

Now showing 1 - 10 of 17
  • No Thumbnail Available
    Item
    Implementation of comprehensive address generator for digital signal processor
    (2013) Ramesh Kini, R.M.; Sumam David, S.
    The performance of signal-processing algorithms implemented in hardware depends on the efficiency of datapath, memory speed and address computation. Pattern of data access in signal-processing applications is complex and it is desirable to execute the innermost loop of a kernel in a single-clock cycle. This necessitates the generation of typically three addresses per clock: two addresses for data sample/coefficient and one for the storage of processed data. Most of the Reconfigurable Processors, designed for multimedia, focus on mapping the multimedia applications written in a high-level language directly on to the reconfigurable fabric, implying the use of same datapath resources for kernel processing and address generation. This results in inconsistent and non-optimal use of finite datapath resources. Presence of a set of dedicated, efficient Address Generator Units (AGUs) helps in better utilisation of the datapath elements by using them only for kernel operations; and will certainly enhance the performance. This article focuses on the design and application-specific integrated circuit implementation of address generators for complex addressing modes required by multimedia signal-processing kernels. A novel algorithm and hardware for AGU is developed for accessing data and coefficients in a bit-reversed order for fast Fourier transform kernel spanning over log 2 N stages, AGUs for zig-zag-ordered data access for entropy coding after Discrete Cosine Transform (DCT), convolution kernels with stored/streaming data, accessing data for motion estimation using the block-matching technique and other conventional addressing modes. When mapped to hardware, they scale linearly in gate complexity with increase in the size. © 2013 Copyright Taylor and Francis Group, LLC.
  • No Thumbnail Available
    Item
    Efficient assessment of structural reliability in presence of random and fuzzy uncertainties
    (American Society of Mechanical Engineers (ASME), 2014) Balu, A.S.; Rao, B.N.
    This paper presents an efficient uncertainty analysis for estimating the possibility distribution of structural reliability in presence of mixed uncertain variables. The proposed method involves high dimensional model representation for the limit state function approximation, transformation technique to obtain the contribution of the fuzzy variables to the convolution integral and fast Fourier transform for solving the convolution integral. In this methodology, efforts are required in evaluating conditional responses at a selected input determined by sample points, as compared to full scale simulation methods, thus the computational efficiency is accomplished. The proposed method is applicable for structural reliability estimation involving any number of fuzzy and random variables with any kind of distribution. Copyright © 2014 by ASME.
  • No Thumbnail Available
    Item
    An efficient cuckoo search algorithm based multilevel thresholding for segmentation of satellite images using different objective functions
    (Elsevier Ltd, 2016) Suresh, S.; Lal, S.
    Satellite image segmentation is challenging due to the presence of weakly correlated and ambiguous multiple regions of interest. Several bio-inspired algorithms were developed to generate optimum threshold values for segmenting such images efficiently. Their exhaustive search nature makes them computationally expensive when extended to multilevel thresholding. In this paper, we propose a computationally efficient image segmentation algorithm, called CSMcCulloch, incorporating McCulloch's method for lévy flight generation in Cuckoo Search (CS) algorithm. We have also investigated the impact of Mantegna?s method forlévy flight generation in CS algorithm (CSMantegna) by comparing it with the conventional CS algorithm which uses the simplified version of the same. CSMantegna algorithm resulted in improved segmentation quality with an expense of computational time. The performance of the proposed CSMcCulloch algorithm is compared with other bio-inspired algorithms such as Particle Swarm Optimization (PSO) algorithm, Darwinian Particle Swarm Optimization (DPSO) algorithm, Artificial Bee Colony (ABC) algorithm, Cuckoo Search (CS) algorithm and CSMantegna algorithm using Otsu's method, Kapur entropy and Tsallis entropy as objective functions. Experimental results were validated by measuring PSNR, MSE, FSIM and CPU running time for all the cases investigated. The proposed CSMcCulloch algorithm evolved to be most promising, and computationally efficient for segmenting satellite images. Convergence rate analysis also reveals that the proposed algorithm outperforms others in attaining stable global optimum thresholds. The experiments results encourages related researches in computer vision, remote sensing and image processing applications. © 2016 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Security bound enhancement of remote user authentication using smart card
    (Elsevier Ltd, 2017) Madhusudhan, R.; Hegde, M.
    Distribution of resources and services via open network has becoming latest trend in information technology. This is provided by many service provider servers. In open network, hackers can easily obtain the communication data. Therefore, open networks and servers demand the security to protect data and information. Hence, network security is most important requirement in distributed system. In this security system, authentication is considered as the fundamental and essential method. Recently many remote user authentication schemes are proposed. In 2012, WANG Ding et al. proposed a remote user authentication scheme, in which the author stated that the scheme provides protection against offline password guessing, impersonation and other known key attacks. By cryptanalysis we have identified that, WANG Ding et al.'s scheme does not provide user anonymity, once the smart card is stolen. This scheme is also susceptible to offline password guessing attack, server masquerading attack, stolen smart card attack and insider attack. Further, this scheme still has problem with proper perfect forward secrecy and user revocation. In order to fix these security weaknesses, an enhanced authentication scheme is proposed and analysed using the formal verification tool for measuring the robustness. From the observation of computational efficiency of the proposed scheme, we conclude that the scheme is more robust and easy to implement practically. © 2017
  • No Thumbnail Available
    Item
    Two-Dimensional CS Adaptive FIR Wiener Filtering Algorithm for the Denoising of Satellite Images
    (Institute of Electrical and Electronics Engineers, 2017) Suresh, S.; Lal, S.
    In the recent years, researchers are quite much attracted in designing two-dimensional (2-D) adaptive finite-impulse response (FIR) filters driven by an optimization algorithm to self-adjust the filter coefficients, with applications in different domains of research. For signal processing applications, FIR Wiener filters are commonly used for noisy signal restorations by computing the statistical estimates of the unknown signal. In this paper, a novel 2-D Cuckoo search adaptive Wiener filtering algorithm (2D-CSAWF) is proposed for the denoising of satellite images contaminated with Gaussian noise. Till date, study based on 2-D adaptive Wiener filtering driven by metaheuristic algorithms was not found in the literature to the best of our knowledge. Comparisons are made with the most studied and recent 2-D adaptive noise filtering algorithms, so as to analyze the performance and computational efficiency of the proposed algorithm. We have also included comparisons with recent adaptive metaheuristic algorithms used for satellite image denoising to ensure a fair comparison. All the algorithms are tested on the same satellite image dataset, for denoising images corrupted with three different Gaussian noise variance levels. The experimental results reveal that the proposed novel 2D-CSAWF algorithm outperforms others both quantitatively and qualitatively. Investigations were also carried out to examine the stability and computational efficiency of the proposed algorithm in denoising satellite images. © 2008-2012 IEEE.
  • No Thumbnail Available
    Item
    A secure and enhanced elliptic curve cryptography-based dynamic authentication scheme using smart card
    (John Wiley and Sons Ltd vgorayska@wiley.com Southern Gate Chichester, West Sussex PO19 8SQ, 2018) Madhusudhan, R.; Hegde, M.; Memon, I.
    In remote system security, 2-factor authentication is one of the security approaches and provides fundamental protection to the system. Recently, numerous 2-factor authentication schemes are proposed. In 2014, Troung et al proposed an enhanced dynamic authentication scheme using smart card mainly to provide anonymity, secure mutual authentication, and session key security. By the analysis of Troung et al's scheme, we observed that Troung et al' s scheme does not provide user anonymity, perfect forward secrecy, server's secret key security and does not allow the user to choose his/her password. We also identified that Troung et al's scheme is vulnerable to replay attack. To fix these security weaknesses, a robust authentication scheme is proposed and analyzed using the formal verification tool for measuring the robustness. From the observation of computational efficiency of the proposed scheme, we conclude that the scheme is more secure and easy to implement practically. © © 2018 John Wiley & Sons, Ltd.
  • No Thumbnail Available
    Item
    Image despeckling with non-local total bounded variation regularization
    (Elsevier Ltd, 2018) Padikkal, P.; Banothu, B.
    A non-local total bounded variational (TBV) regularization model is proposed for restoring images corrupted with data-correlated speckles and linear blurring artifacts. The energy functional of the model is derived using maximum a posteriori (MAP) estimate of the noise probability density function (PDF). The non-local total bounded variation prior regularizes the model while the data fidelity is derived using the MAP estimator of the noise PDF. The computational efficiency of the model is improved using a fast numerical scheme based on the Augmented Lagrange formulation. The proposed model is employed to restore ultrasound (US) and synthetic aperture radar (SAR) images, which are usually speckled and blurred. The numerical results are presented and compared. Furthermore, a detailed theoretical study of the model is performed in addition to the experimental analysis. © 2017 Elsevier Ltd
  • No Thumbnail Available
    Item
    A novel DNA based password authentication system for global roaming in resource-limited mobile environments
    (Springer, 2020) Madhusudhan, R.; Shashidhara R
    Mobile environments are highly vulnerable to security threats and pose a great challenge for the wireless and mobile networks being used today. Because the mode of a wireless channel is open, these networks do not carry any inherent security and hence are more prone to attacks. Therefore, designing a secure and robust protocol for authentication in a global mobile network is always a challenging. In these networks, it is crucial to provide authentication to establish a secure communication between the Mobile User (MU), Foreign Agent (FA) and Home Agent (HA). In order to secure communication among these entities, a number of authentication protocols have been proposed. The main security flaw of the existing authentication protocols is that attackers have the ability to impersonate a legal user at any time. Moreover, the existing authentication protocols in the literature are exposed to various kind of cryptographic attacks. Besides, the authentication protocols require larger key length and more computation overhead. To remedy these weaknesses in mobility networks, DNA (Deoxyribo Nucleic Acid) based authentication scheme using Hyper Elliptic Curve Cryptosystem (HECC) is introduced. It offers greater security and allows an MU, FA and HA to establish a secure communication channel, in order to exchange the sensitive information over the radio link. The proposed system derive benefit from HECC, which is smaller in terms of key size, more computational efficiency. In addition, the security strength of this authentication system is validated through widely accepted security verification tool called ProVerif. Further, the performance analysis shows that the DNA based authentication system using HECC is secure and practically implementable in the resource-constrained mobility nodes. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
  • No Thumbnail Available
    Item
    An improved user authentication scheme for electronic medical record systems
    (Springer, 2020) Madhusudhan, R.; Nayak, C.S.
    Electronic Medical Record (EMR) systems is a part of e-healthcare system, which is developing rapidly. In this, it is possible to deliver medical services among multiple participants over a network without physical presence. Since sensitive data is transmitted over public channels, it is very much required to maintain the secrecy of that data. This is achieved by mutual authentication between the participants. For this, various schemes for authentication with smart cards have been proposed. Han et al. proposed one such biometrics-based scheme for the same purpose using hash functions along with symmetric key encryption and elliptic curve cryptography. From cryptanalysis of their scheme, we have pointed out weaknesses viz. no user anonymity, user and server impersonation, man-in-the-middle attack. These security issues have been presented in this article. To overcome these attacks, a scheme has been proposed in this article. Since it does not use symmetric key encryption, the proposed scheme reduces the computational complexity as can be seen in the comparison provided. The security analysis of the proposed scheme, along with BAN (Burrows-Abadi-Needham) logic has been explained in detail. Comparison of the proposed scheme with related schemes with respect to computation cost, execution time and performance is demonstrated. This proves that the proposed scheme performs well in terms of security as well as computational efficiency. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
  • No Thumbnail Available
    Item
    On Newton’s Midpoint-Type Iterative Scheme’s Convergence
    (Springer, 2022) Krishnendu, R.; Saeed, M.; George, S.; Padikkal, J.
    This paper introduce new three step iterative schemes with order of convergence five and six for solving nonlinear equations in Banach spaces. The proposed scheme’s convergence is assessed using assumptions on the operator’s derivatives up to order two. Unlike earlier studies, the convergence study of these methods are not based on the Taylor’s expansion. Numerical examples and Basin of attractions are given in this study © 2022, The Author(s), under exclusive licence to Springer Nature India Private Limited.