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Polytropic gas cosmology and late-time acceleration

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Chinese Physics C 2024年第11期48卷 220-230页

作者： Safae Dahmani Himanshu Chaudhary Amine Bouali shibesh kumar jas pacif Taoufik Ouali Laboratory of Physics of Matter and Radiation Mohammed I UniversityBP 717OujdaMorocco Department of Applied Mathematics Delhi Technological UniversityDelhi 110042India pacif Institute of Cosmology and Selfology(PICS) SagaraSambalpur 768224OdishaIndia Department of Mathematics Shyamlal CollegeUniversity of DelhiDelhi-110032India Higher School of Education and Training Mohammed I UniversityBP 717OujdaMorocco

The accelerated expansion of the Universe has sparked significant interest in the mysterious concept of dark energy within *** theories have been proposed to explain dark energy,and many models have been developed to understand its origins and *** research explores cosmic expansion using the Polytropic Gas(PG)approach,which combines Dark Matter(DM)and Dark Energy(DE)into a single mysterious *** used the principles of general relativity and built our model within the homogeneous and isotropic framework of Friedmann-Lemaître-Robertson-Walker(FLRW)*** revised the Original Polytropic Gas(OPG)model to expand its applicability beyond the OPG,to theΛCDM *** model's parameters were carefully adjusted to reflect key cosmological features of the variable PG *** validate our model,we performed a Markov chain Monte Carlo analysis using recent Supernova data from the Pantheon+survey,36 observational data points,162 Gamma-Ray Bursts,and 24 binned Quasars distance modulus *** AIC and BIC criteria indicate that our model is slightly preferred over theΛCDM model based on observational *** also tested our model with data,Supernova,Gamma-Ray Bursts,and Quasars and found that it exhibits a transition from a quintessential to phantom *** Polytropic dark fluid model(PDFM)is a promising candidate that effectively addresses the interplay between cosmic acceleration and dark energy.

关键词： polytropic dark energy parametrization

Cosmological test of dark energy parametrizations within the framework of Horava-Lifshitz gravity via baryon acoustic oscillation

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Chinese Physics C 2024年第11期48卷 203-219页

作者： Himanshu Chaudhary shibesh kumar jas pacif Ujjal Debnath Farook Rahaman G.Mustafa pacif Institute of Cosmology and Selfology(PICS) SagaraSambalpur 768224OdishaIndia Department of Applied Mathematics Delhi Technological UniversityDelhi-110042India Department of Mathematics Shyamlal CollegeUniversity of DelhiDelhi-110032India Department of Mathematics Indian Institute of Engineering Science and TechnologyShibpurHowrah-711103India Department of Mathematics Jadavpur UniversityKolkata-700032India Department of Physics Zhejiang Normal UniversityJinhua 321004China

We conduct an investigation to explore late-time cosmic acceleration through various dark energy parametrizations(Wettrich,Efstathiou,and Ma-Zhang)within the Horava-Lifshitz gravity *** an alternative to general relativity,this theory introduces anisotropic scaling at ultraviolet *** primary objective is to constrain the key cosmic parameters and baryon acoustic oscillation(BAO)scale,specifically the sound horizon(rd),by utilizing 24 uncorrelated measurements of BAOs derived from recent galaxy surveys spanning a redshift range from z=0.106 to z=***,we integrate the most recent Hubble constant measurement by Riess in 2022(denoted as R22)as an extra *** the parametrizations of Wettrich,Efstathiou,and Ma-Zhang,our analysis of BAO data yields sound horizon results of r_(d)=148.1560±2.7688 Mpc,r_(d)=148.6168±10.2469 Mpc,and r_(d)=147.9737±10.6096 Mpc,*** the R22 prior into the BAO dataset results in r_(d)=139.5806±3.8522 Mpc,r_(d)=139.728025±2.7858 Mpc,and r_(d)=139.6001±2.7441 *** outcomes highlight a distinct inconsistency between early and late observational measurements,analogous to the H_(0) tension.A notable observation is that,when we do not include the R22 prior,the outcomes for rd tend to be in agreement with Planck and SDSS *** this,we conducted a cosmography test and comparative study of each parametrization within the Lambda Cold Dark Matter *** diagnostic analyses demonstrate that all models fit seamlessly within the phantom *** dark energy parametrizations predict an equation of state parameter close ω=-1,indicating a behavior similar to that of a cosmological *** statistical analysis indicates that neither of the two models can be ruled out based on the latest observational measurements.

关键词： dark energy parametrizations Horava-Lifshitz gravity baryon acoustic oscillation

A Novel Approach for Enhancement of Geometric and Contrast Resolution Properties of Low Contrast Images

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IEEE/CAA Journal of Automatica Sinica 2018年第2期5卷 628-638页

作者： Koushlendra kumar Singh Manish kumar Bajpai Rajesh kumar Pandey Department of Computer Science and Engineering National Institute of Technology Jamshedpur 831014 India Indian Institute of Information Technology Design & Manufacturing Jabalpur MP 482005 India Department of Mathematical Sciences In- dian Institute of Technology Varanasi U.P. 221005 India

The present work encompasses a new image enhancement algorithm using newly constructed Chebyshev fractional order differentiator. We have used Chebyshev polynomials to design Chebyshev fractional order differentiator. We have generated the high pass filter corresponding to it. The designed filters are applied for decomposing the input image into four bands and low-low(L-L) sub-band is updated using correction coefficients. Reconstructed image with updated L-L sub-band provides the enhanced image. The visual results obtained are encouraging for image enhancement. The applicability of the developed algorithm is illustrated on three different test *** effects of order of differentiation on the edges of images have also been presented and discussed.

关键词： Index Terms-Chebyshev polynomial based approximation contrast enhancement fractional order differentiator.

Fractionally Delayed Kalman Filter

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 169-177页

作者： Abhinoy kumar Singh Discipline of Electrical Engineering Indian Institute of Technology Indore

The conventional Kalman filter is based on the assumption of non-delayed measurements. Several modifications appear to address this problem, but they are constrained by two crucial assumptions: 1) the delay is an integer multiple of the sampling interval, and 2) a stochastic model representing the relationship between delayed measurements and a sequence of possible non-delayed measurements is known. Practical problems often fail to satisfy these assumptions, leading to poor estimation accuracy and frequent track-failure. This paper introduces a new variant of the Kalman filter, which is free from the stochastic model requirement and addresses the problem of fractional *** proposed algorithm fixes the maximum delay(problem specific), which can be tuned by the practitioners for varying delay possibilities. A sequence of hypothetically defined intermediate instants characterizes fractional delays while maximum likelihood based delay identification could preclude the stochastic model requirement. Fractional delay realization could help in improving estimation accuracy. Moreover, precluding the need of a stochastic model could enhance the practical applicability. A comparative analysis with ordinary Kalman filter shows the high estimation accuracy of the proposed method in the presence of delay.

关键词： Gaussian likelihood Kalman filter optimal Kalman gain randomly delayed measurements

Major Development Under Gaussian Filtering Since Unscented Kalman Filter

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1308-1325页

作者： Abhinoy kumar Singh IEEE Department of Electrical Engineering Indian Institute of Technology Indore

Filtering is a recursive estimation of hidden states of a dynamic system from noisy *** problems appear in several branches of science and technology,ranging from target tracking to biomedical monitoring.A commonly practiced approach of filtering with nonlinear systems is Gaussian *** early Gaussian filters used a derivative-based implementation,and suffered from several drawbacks,such as the smoothness requirements of system models and poor stability.A derivative-free numerical approximation-based Gaussian filter,named the unscented Kalman filter(UKF),was introduced in the nineties,which offered several advantages over the derivativebased Gaussian *** the proposition of UKF,derivativefree Gaussian filtering has been a highly active research *** paper reviews significant developments made under Gaussian filtering since the proposition of *** review is particularly focused on three categories of developments:i)advancing the numerical approximation methods;ii)modifying the conventional Gaussian approach to further improve the filtering performance;and iii)constrained filtering to address the problem of discrete-time formulation of process *** review highlights the computational aspect of recent developments in all three *** performance of various filters are analyzed by simulating them with real-life target tracking problems.

关键词： Bayesian framework cubature rule-based filtering Gaussian filters Gaussian sum and square-root filtering nonlinear filtering quadrature rule-based filtering unscented transformation

A Local Contrast Fusion Based 3D Otsu Algorithm for Multilevel Image Segmentation

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 200-213页

作者： Ashish kumar Bhandari Arunangshu Ghosh Immadisetty Vinod kumar Department of Electronics and Communication Engineering National Institute of Technology Patna

To overcome the shortcomings of 1 D and 2 D Otsu’s thresholding techniques, the 3 D Otsu method has been *** all Otsu’s methods, 3 D Otsu technique provides the best threshold values for the multi-level thresholding processes. In this paper, to improve the quality of segmented images, a simple and effective multilevel thresholding method is introduced. The proposed approach focuses on preserving edge detail by computing the 3 D Otsu along the fusion phenomena. The advantages of the presented scheme include higher quality outcomes, better preservation of tiny details and boundaries and reduced execution time with rising threshold levels. The fusion approach depends upon the differences between pixel intensity values within a small local space of an image;it aims to improve localized information after the thresholding process. The fusion of images based on local contrast can improve image segmentation performance by minimizing the loss of local contrast, loss of details and gray-level distributions. Results show that the proposed method yields more promising segmentation results when compared to conventional1 D Otsu, 2 D Otsu and 3 D Otsu methods, as evident from the objective and subjective evaluations.

关键词： 1D Otsu 2D Otsu 3D Otsu image fusion local contrast multi-level image segmentation

Control of Non-Deterministic Systems With μ-Calculus Specifications Using Quotienting

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IEEE/CAA Journal of Automatica Sinica 2021年第5期8卷 953-970页

作者： Samik Basu Ratnesh kumar the Department of Computer Science Iowa State UniversityIowa 50011-3060 USA the Department of Electrical and Computer Engineering Iowa State UniversityIowa 50011-3060 USA

The supervisory control problem for discrete event system(DES) under control involves identifying the supervisor, if one exists, which, when synchronously composed with the DES,results in a system that conforms to the control specification. In this context, we consider a non-deterministic DES under complete observation and control specification expressed in action-based propositional μ-calculus. The key to our solution is the process of quotienting the control specification against the plan resulting in a new μ-calculus formula such that a model for the formula is the supervisor. Thus the task of control synthesis is reduced a problem of μ-calculus satisfiability. In contrast to the existing μ-calculus quotienting-based techniques that are developed in deterministic setting, our quotienting rules can handle nondeterminism in the plant models. Another distinguishing feature of our technique is that while existing techniques use a separate μ-calculus formula to describe the controllability constraint(that uncontrollable events of plants are never disabled by a supervisor), we absorb this constraint as part of quotienting which allows us to directly capture more general state-dependent controllability constraints. Finally, we develop a tableau-based technique for verifying satisfiability of quotiented formula and model generation. The runtime for the technique is exponential in terms of the size of the plan and the control specification. A better complexity result that is polynomial to plant size and exponential to specification size is obtained when the controllability property is state-independent. A prototype implementation in a tabled logic programming language as well as some experimental results are presented.

关键词： Discrete event systems(DES) non-deterministic plant μ-calculus supervisory control

A Context Sensitive Multilevel Thresholding Using Swarm Based Algorithms

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IEEE/CAA Journal of Automatica Sinica 2019年第6期6卷 1471-1486页

作者： Shreya Pare Anil kumar Varun Bajaj Girish kumar Singh PDPM Indian Institute of Information Technology Design and Manufacturing Jabalpur 482005MPIndia Institute of Technology Roorkee Uttarakhand 247667India

In this paper, a comprehensive energy function is used to formulate the three most popular objective functions:Kapur's, Otsu and Tsalli's functions for performing effective multilevel color image thresholding. These new energy based objective criterions are further combined with the proficient search capability of swarm based algorithms to improve the efficiency and robustness. The proposed multilevel thresholding approach accurately determines the optimal threshold values by using generated energy curve, and acutely distinguishes different objects within the multi-channel complex images. The performance evaluation indices and experiments on different test images illustrate that Kapur's entropy aided with differential evolution and bacterial foraging optimization algorithm generates the most accurate and visually pleasing segmented images.

关键词： Color image segmentation Kapur's entropy multilevel thresholding Otsu method swarm based optimization algorithms Tsalli's entropy

Mathematical Study of A Memory Induced Biochemical System

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IEEE/CAA Journal of Automatica Sinica 2018年第6期5卷 1142-1149页

作者： Mithun kumar Ghosh Tridip Sardar Xianbing Cao Priti kumar Roy Centre for Mathematical Biology and Ecology Department of MathematicsJadavpur University Department of Mathematics Dinabondhu Andrews College College of Science Beijing Technology and Business University

In this work, to study the effect of memory on a bi-substrate enzyme kinetic reaction, we have introduced an approach to fractionalize the system, considering it as a threecompartmental model. Solutions of the fractionalized system are compared with the corresponding integer-order model. The equilibrium points of the fractionalized system are derived analytically. Their stability properties are discussed from numerical aspect. We determine the changes of the substances due to the changes of "memory effect". The effect is discussed critically from the perspective of product formation. We have also analyzed the memory induced system with a control measure in view of optimizing the product. Our numerical result reveals that the solutions of the fractionalized system, when it is free from memory, are in good agreement with the integer-order *** is noticed that the effect of memory influences the reaction in the forward direction and assists in yielding the product more quickly. However, an extensive use of memory makes the system slower, but introduction of a control input makes the reaction faster. It is possible to overcome the slowness of the reaction due to the undue effect of memory by appropriate use of a control measure.

关键词： Bi-substrate enzymatic reaction compartmental system control theoretic approach fractional-order differential equations memory effect