131 research outputs found

    Mixed finite difference method for singularly perturbed differential difference equations with mixed shifts via domain decomposition

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    AbstractIn this paper, a mixed finite difference method is proposed to solve singularly perturbed differential difference equations with mixed shifts, solutions of which exhibit boundary layer behaviour at the left end of the interval using domain decomposition. A terminal boundary point is introduced into the domain, to decompose it into inner and outer regions. The original problem is reduced to an asymptotically equivalent singular perturbation problem and with the terminal point the singular perturbation problem is treated as inner region and outer region problems separately. The outer region and the modified inner region problems are solved by mixed finite difference method. The method is repeated for various choices of the terminal point. To validate the computational efficiency of the method model examples have been solved for different values of perturbation, delay and advanced parameters. Convergence of the proposed scheme has also been investigated

    Special Second Order Non Symmetric Fitted Method for Singular Perturbation Problems

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    In this paper, we present a special second order non symmetric fitted difference method for solving singular perturbed two point boundary value problems having boundary layer at one end. We introduce a fitting factor in the special second order non symmetric finite difference scheme which takes care of the rapid changes occur that in the boundary layer. The value of this fitting factor is obtained from the theory of singular perturbations. The discrete invariant imbedding algorithm is used to solve the tridiagonal system obtained by the method. We discuss the existence and uniqueness of the discrete problem along with stability estimates and the convergence of the method. We present the maximum absolute errors in numerical results to illustrate the proposed method. Keywords: Singularly perturbed two-point boundary value problem, Boundary layer, Fitting factor, Maximum absolute erro

    Extensive Review on Laminated Bus Bar for Low and High Power Applications

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    This paper explains about wide range of applications for Laminated Bus Bar used for high and low power applications. Authors also explains ways to effective utilize laminated bus bar when compared to conventional bus bar. Laminated bus bars are designed with low stray inductance and high capacitance with a uniform current distribution in conducting plate. Parameters like Length, Width, material thickness and other miscellaneous parameters effect Laminated bus bar performance. With a proper design of Laminated bus bar it can best utilized, laminated bus bar are suitable for many low and high power applications which are discussed in this paper. Replacing conventional bus bar with laminated bus bar additional advantages are achieved like lighter weight, less space and lower maintenance

    Critical Computational Aspects of Near Infrared Circular Tomographic Imaging: Analysis of Measurement Number, Mesh Resolution and Reconstruction Basis

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    The image resolution and contrast in Near-Infrared (NIR) tomographic image reconstruction are affected by parameters such as the number of boundary measurements, the mesh resolution in the forward calculation and the reconstruction basis. Increasing the number of measurements tends to make the sensitivity of the domain more uniform reducing the hypersensitivity at the boundary. Using singular-value decomposition (SVD) and reconstructed images, it is shown that the numbers of 16 or 24 fibers are sufficient for imaging the 2D circular domain for the case of 1% noise in the data. The number of useful singular values increases as the logarithm of the number of measurements. For this 2D reconstruction problem, given a computational limit of 10 sec per iteration, leads to choice of forward mesh with 1785 nodes and reconstruction basis of 30×30 elements. In a three-dimensional (3D) NIR imaging problem, using a single plane of data can provide useful images if the anomaly to be reconstructed is within the measurement plane. However, if the location of the anomaly is not known, 3D data collection strategies are very important. Further the quantitative accuracy of the reconstructed anomaly increased approximately from 15% to 89% as the anomaly is moved from the centre to boundary, respectively. The data supports the exclusion of out of plane measurements may be valid for 3D NIR imaging

    Design and Implementation of Deep Learning Based Contactless Authentication System Using Hand Gestures

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    Hand gestures based sign language digits have several contactless applications. Applications include communication for impaired people, such as elderly and disabled people, health-care applications, automotive user interfaces, and security and surveillance. This work presents the design and implementation of a complete end-to-end deep learning based edge computing system that can verify a user contactlessly using ‘authentication code’. The ‘authentication code’ is an ‘n’ digit numeric code and the digits are hand gestures of sign language digits. We propose a memory-efficient deep learning model to classify the hand gestures of the sign language digits. The proposed deep learning model is based on the bottleneck module which is inspired by the deep residual networks. The model achieves classification accuracy of 99.1% on the publicly available sign language digits dataset. The model is deployed on a Raspberry pi 4 Model B edge computing system to serve as an edge device for user verification. The edge computing system consists of two steps, it first takes input from the camera attached to it in real-time and stores it in the buffer. In the second step, the model classifies the digit with the inference rate of 280 ms, by taking the first image in the buffer as input.publishedVersio

    Numerical solution of differential – difference equations having an interior layer using nonstandard finite differences

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    This paper addresses the solution of a differential-difference type equation having an interior layer behaviour. A difference scheme is suggested to solve this equation using a non-standard finite difference method. Finite differences are derived from the first and second order derivatives. Using these approximations, the given equation is discretized. The discretized equation is solved using the algorithm for the tridiagonal system. The method is examined for convergence. Numerical examples are illustrated to validate the method. Maximum errors in the solution, in contrast to the other methods are organized to justify the method. The layer behaviour in the solution of the examples is depicted in graphs

    Kikuchi-Fujimoto disease presenting as pyrexia of unknown origin

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    Background: Kikuchi-Fujimoto disease, a benign self-limited lymphadenopathy is an uncommon cause of pyrexia of unknown origin (PUO). Methods: We retrospectively studied the case-records of 13 patients presenting with PUO who were diagnosed to have Kikuchi-Fujimoto disease on peripheral lymph node excision biopsy and report the salient clinical manifestations and histopathological findings in them. All of them received symptomatic treatment. Results: Their median age was 28 [interquartile range (IQR) 18.5-38.0] years. Women (11/13, 84.6%) were more frequently affected. All of them were human immunodeficiency virus (HIV) seronegative. Prior to presenting to us, two were being treated for lymph node tuberculosis with DOTS. Cervical lymph nodes were predominantly involved, the distribution being: right cervical (n=10, 76.9%); left cervical (n=4); and bilateral cervical (n=2). Axillary and generalized lymphadenopathy were rare being seen in 2 and 1 patient respectively. The median (IQR) erythrocyte sedimentation rate (n=11) was 53 (35-89) mm at the end of first hour. Salient histopathological features were paracortical patchy zones of eosinophilic fibrinoid necrosis with karyorrhectic debris, large numbers of histiocytes, including histiocytes with peripherally placed “crescentic” nuclei. Spontaneous regression of fever and lymphadenopathy was observed over a median (IQR) period of 8 (6.75-10.25) months in all of them. Conclusions: Kikuchi-Fujimoto disease is a rare but important cause of PUO presenting with peripheral lymphadenopathy. Women are most often affected and cervical lymph nodes are the most frequently involved site. Clinical suspicion and thoughtful collaboration between clinicians and pathologists are essential for accurate diagnosis, and to minimize unnecessary investigations and inappropriate aggressive treatment

    IMPLEMENTATION OF AN EFFICIENT AND OPTIMIZED VEDIC MULTIPLIER DESIGN USING REVERSIBLE LOGIC GATES

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    Multiplier design is always a challenging task; however many   designs are proposed, the user needs demands much more optimized ones. Vedic mathematics provides   some   algorithms that evaluate fast results, both in mental calculations or hardware design. Power dissipation is continuously reduced by the use of Reversible logic. The reversible Urdhva Tiryakbhayam Vedic multiplier is one such multiplier which is effective both in terms of speed and power. In this paper the modified design increase the performance by maintain the design functionality without any degradation. The Total Reversible Logic Implementation Cost (TRLIC) evaluate the proposed design. This multiplier has application over  designing Fast Fourier Transforms (FFTs) Filters and other applications of DSP like imaging, software defined radios, wireless communications.
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