Sarat Chandra Dass

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Situations with incomplete multivariate spatial data on a lattice are considered. The goal is to impute the missing data in the presence of edges or boundaries and recover the image. Two methods based on Bayesian hierarchical models that iterate between edge detection and spatial smoothing to impute the missing data within identified homogeneous regions are(More)
Segmentation is the basic and important step for digital image analysis and understanding. Segmentation of acne lesions in the visual spectrum of light is very challenging due to factors such as varying skin tones due to ethnicity, camera calibration and the lighting conditions. In this approach the color image is transformed into various color spaces. The(More)
Hierarchical mixture models arise naturally for clustering a heterogeneous population of objects where observations made on each object follow a standard mixture density. Hierarchical mixtures utilize complementary aspects of mixtures at different levels of the hierarchy. At the first (top) level, the mixture is used to perform clustering of the objects,(More)
In this paper we propose the maximum likelihood method of estimation for Delay Differential Equation Model governed by unknown delay and other parameters of interest. As an example we consider the Exponential Differential Equation Model. A grid based estimation framework is proposed. Our methodology estimates correctly the delay parameter as well as the(More)
This manuscript is concerned with parameter estimation of nonlinear dynamical system. Bayesian framework is very useful for parameter estimation, Metropolis-Hastings (MH) algorithm is proposed for constructing the posterior density, which is main working procedure of Bayesian analysis. Extended Kalman Filter (EKF) gives better results in non-linear(More)
Humans have distinctive and unique traits which can be used to distinguish them thus, acting as a form of identification. Biometrics identify people by measuring some aspect of individual's anatomy or physiology such as hand geometry or fingerprint which consists of a pattern of interleaved ridges and valleys. The year 2015 election in Nigeria was greeted(More)
We address the issue of parameter estimation for nonlinear dynamical systems obtained as a model for dengue disease incidence. A Bayesian framework of estimation is adopted. Parameter estimation is performed using a Metropolis Hastings algorithm in which the target distribution of the resulting Markov chain equals the posterior distribution of unknown(More)
Specular illumination in digital images is one of the main causes, affecting the performance of image analysis techniques. The causes of this artifact include shiny nature of the surface on which the light is falling and the intensity and distribution of light. In this paper, it is explained that how specularly illuminated spots in the color images of acne(More)
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