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Kalman filtering for linear singular systems subject to round-robin protocol

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Control Theory and Technology 2024年第4期22卷 543-551页

作者： Ashna Goel Shovan Bhaumik Nutan Kumar Tomar department of Mathematics Indian Institute of Technology PatnaPatnaBihar801106India department of Electrical Engineering Indian Institute of Technology PatnaPatnaBihar801106India

This paper introduces a Kalman-type recursive state estimator for a class of discrete-time stochastic linear singular systems where the measurements are carried part by part periodically following a scheduling *** consider that the system is in a network with limited allotted bandwidth,which refers to a situation where the total available bandwidth for data transmission through the network is *** limitation can occur for various reasons,such as network congestion,resource allocation policies,or bandwidth limitations imposed by network *** such networks,the entire measurement vector cannot be transmitted to the estimator ***,managing a network with a limited allotted bandwidth requires careful planning,monitoring,and implementing some scheduling strategies to optimize the use of measured data while estimating the system *** show that a scheduling method,namely,round-robin protocol,is suitable for singular systems to deal with such a *** upper bound of the prior error covariance is studied via a periodic Riccati equation(PRE).To retain the boundedness of prior error covariance,the stability of the PRE is examined by the observability properties of the round-robin-induced ***,a simulation example is presented to show the effectiveness of the designed filtering scheme.

关键词： Networked control systems Communication constraints Round-robin protocol Singular systems Filtering

Sliding mode controller design for frequency regulation in an interconnected power system

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Protection and Control of Modern Power Systems 2021年第1期6卷 77-88页

作者： Anand Kumar Md Nishat Anwar Shekhar Kumar department of Electrical Engineering National Institute of Technology PatnaPatnaBiharIndia

In this paper, a Sliding mode controller design method for frequency regulation in an interconnected power system is presented. A sliding surface having four parameters has been selected for the load frequency control (LFC) system model. In order to achieve an optimal result, the parameter of the controller is obtained by grey wolf optimization (GWO) and particle swarm optimization (PSO) techniques. The objective function for optimization has been considered as the integral of square of error of deviation in frequency and tie-line power exchange. The method has been validated through simulation of a single area as well as a multi-area power system. The performance of the Sliding mode controller has also been analyzed for parametric variation and random loading patterns. The performance of the proposed method is better than recently reported methods. The performance of the proposed Sliding mode controller via GWO has 88.91% improvement in peak value of frequency deviation over the method of Anwar and Pan in case study 1 and similar improvement has been observed over different case studies taken from the literature.

关键词： Load frequency control Sliding mode control(SMC) Grey wolf optimization Particle swarm optimization Multi-area power system

Effects of the COVID-19 pandemic on semen quality in male partners of infertile couples: a hospitalbased observational study

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Asian Journal of Andrology 2023年第2期25卷 240-244页

作者： Tribhuwan Kumar Kamlesh Jha Md Zabihullah Kumari Neelu Yogesh Kumar Kumar Siddharth department of Physiology All India Institute of Medical SciencesPatna 801507BiharIndia Akshat Spandan Clinic Patna 801507BiharIndia

The effects of the coronavirus disease 2019(COVID-19)pandemic on male fertility have received considerable attention because human testes contain high levels of angiotensin-converting enzyme-2 receptors,through which severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)can *** studies showed decreases in semen quality during and after recovery from ***,no semen quality studies have examined the effects of widespread subclinical and mild disease,as well as changes in lifestyle,psychosocial behavior,intake of dietary supplements,and *** cross-sectional study compared semen quality parameters in male partners of infertile couples between men who underwent semen analysis before the COVID-19 pandemic(prepandemic group)and men who underwent semen analysis during the pandemic period(pandemic group);the analysis sought to clarify the overall effects of the *** participants in the pandemic group had experienced clinically overt *** the 239 participants,mean body weight(P=0.001),mean body mass index(P<0.001),median sperm concentration(P=0.014),total sperm count(P=0.006),and total percentages of motile(P=0.013)and abnormal cells(P<0.001)were significantly greater in the pandemic group(n=137)than those in the prepandemic group(n=102).Among abnormal cells,the percentages of cells with excess residual cytoplasm(P<0.001),head defects(P<0.001),and tail defects(P=0.015)were significantly greater in the pandemic group than those in the prepandemic *** the exception of morphology,the overall semenogram results were better in the pandemic group than those in the prepandemic group.

关键词： coronavirus disease 2019 pandemic male infertility SARS-CoV-2 semen analysis

Defect induced room-temperature ferromagnetism and enhanced photocatalytic activity in Ni-doped ZnO synthesized by electrodeposition

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Chinese Physics B 2020年第10期29卷 566-572页

作者： Deepika Raju Kumar Ritesh Kumar Kamdeo Prasad Yadav Pratyush Vaibhav Seema Sharma Rakesh Kumar Singh Santosh Kumar College o f Commerce Arts and SciencePatna.BiharIndia Jaypee University o f Engineering and Technology GunaMadhya PradeshIndia Anugrah Narayan College PatnaBiharIndia Aryabhatta Knowledge University PatnaBiharIndia

Zn0.90Ni0.10O nanoparticles have been synthesized by single-bath two-electrode electrodeposition at constant voltage. X-ray diffraction, UV vis and photoluminescence studies reveal that a single-phase polycrystalline hcp wurtzite crystal structure of ZnO is evolved. The material consists of a large number of defects such as oxygen vacancy (Ov) and zinc interstitial (Zi). The magnetization study reveals that the sample exhibits room-temperature global ferromagnetism and the ferromagnetic ordering seems to be defect induced via bound magnetic polaron mechanism, and double exchange is also expected to have played role. Interesting optoelectronic properties have been found in the synthesized sample and the material seems to be a potential candidate to be used as a UV sensor. Such a transition metal doped ZnO based dilute magnetic semiconducting system exhibiting room-temperature ferromagnetism is likely to be first of its kind in the sense that such materials have not yet been reported to be synthesized by the simple method of electrodeposition to the best of our knowledge on the basis of ample literature review.

关键词： dilute magnetic semiconductors(DMS) bound magnetic polaron photoluminescence ferromagnetism

Axially Oriented Structured Porous Layers for Heat Transfer Enhancement in a Solar Receiver Tube

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Journal of Thermal Science 2021年第5期30卷 1643-1657页

作者： DAS Shefali VERMA Neha PATHAK Manabendra BHATTACHARYYA Suvanjan department of Mechanical Engineering Indian Institute of Technology PatnaPatna801103BiharIndia department of Mechanical Engineering BITS-PilaniPilani333031RajasthanIndia

The present work reports a numerical investigation of heat transfer and pressure drop characteristics in a solar receiver tube with different shaped porous media for laminar and low Reynolds number turbulent flow *** simulations have been performed with finite volume-based code ANSYS(v-2017)for different shapes of porous layers axially oriented in the *** plain-shaped porous medium fitted up to 50%of the tube shows better performance than other-shaped porous *** have also been performed for axially oriented structured porous media with different *** oriented structured porous medium develops a lateral flow disturbance enhancing the intermixing of the liquid and porous medium at their *** porous medium with a 3-crest configuration shows the best heat transfer performance among all the shapes of porous *** offers a maximum of 148%heat transfer enhancement compared to a half-filled plain porous layer,whereas it reports a maximum of 564%enhancement compared to the flow without a porous *** lateral flow tendency or the swirling effect helps better heat transfer performance in the axially oriented structured porous *** evaluation criterion(PEC)in all types of porous media is more in the transitional flow regime than in the laminar and turbulent flow *** the same operating conditions,the maximum value of the PEC in the present work is 120%higher than the maximum value of PEC for other-shaped porous media reported in the *** for Nusselt number have been developed for both laminar and turbulent flow regimes for three crests shaped porous medium.

关键词： porous medium structured porous layer heat transfer enhancement pressure drop performance evaluation criterion

Mathematical model for smoking： Effect of determination and education

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International Journal of Biomathematics 2015年第1期8卷 1-14页

作者： Anuradha Yadav Prashant K. Srivastava Anuj Kumar department of Mathematics School of Basic Sciences Indian Institute of Technology Patna Patna Bihar 13 India

We propose and analyze mathematical models to study the dynamics of smoking behavior under the influence of educational programs and also individual＇s determination to quit smoking. We establish the positivity and boundedness of the solutions in a biologically feasible region. A threshold value responsible for persistence of smoking is obtained and stability analysis on models is performed. We find that determination alone is not enough to eradicate smoking but it can reduce the prevalence of smoker population. Whereas the increase in education can possibly eradicate it. We performed numerical simulation for representative set of parameters to verify and discuss results obtained analytically.

关键词： Smoking determination education global stability Lyapunov function

Effect of induced magnetic field on natural convection in vertical concentric annuli

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Acta Mechanica Sinica 2012年第2期28卷 315-323页

作者： R.K.Singh A.K.Singh department of Mathematics Central University of BiharPatnaIndia department of Mathematics Banaras Hindu UniversityVaranasiIndia

In the present paper, we have considered the steady fully developed laminar natural convective flow in open ended vertical concentric annuli in the presence of a ra- dial magnetic field. The induced magnetic field produced by the motion of an electrically conducting fluid is taken into account. The transport equations concerned with the con- sidered model are first recast in the non-dimensional form and then unified analytical solutions for the velocity, induced magnetic field and temperature field are obtained for the cases of isothermal and constant heat flux on the inner cylin- der of concentric annuli. The effects of the various phys- ical parameters appearing into the model are demonstrated through graphs and tables. It is found that the magnitude of maximum value of the fluid velocity as well as induced magnetic field is greater in the case of isothermal condition compared with the constant heat flux case when the gap be- tween the cylinders is less or equal to 1.70 times the radius of inner cylinder, while reverse trend occurs when the gap between the cylinders is greater than 1.71 times the radius of inner cylinder. These fields are almost the same when the gap between the cylinders is equal to 1.71 times the radius of inner cylinder for both the cases. It is also found that as the Hartmann number increases, there is a flattening ten- dency for both the velocity and the induced magnetic field. The influence of the induced magnetic field is to increase the velocity profiles.

关键词： Natural convection Isothermal Heat flux Skin-friction Induced magnetic field Magnetohydrody- namics

Extension of Distribution Transformer Life in the Presence of Smart Inverter-based Distributed Solar Photovoltaic Systems

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 88-95页

作者： Kanhaiya Kumar Saran Satsangi Ganesh Balu Kumbhar department of Electrical and Electronics Engineering Motihari College of EngineeringMotihariBiharIndia department of Electrical Engineering National Institute of Technology(NIT)PatnaPatnaBiharIndia department of Electrical Engineering Indian Institute of Technology(IIT)RoorkeeRoorkeeUttarakhandIndia

A transformer is an essential but expensive power delivery equipment for a distribution *** many distribution utilities worldwide,a sizable percentage of transformers are near the end of their designed *** the same time,distribution utilities are adopting smart inverter-based distributed solar photovoltaic(SPV)systems to maximize renewable *** central objective of this paper is to propose a methodology to quantify the effect of smart inverter-based distributed SPV systems on the aging of distribution *** proposed method is first tested on a modified IEEE-123 node distribution *** that,the procedure is applied to a practical distribution system,i.e.,the Indian Institute of Technology(IIT)Roorkee campus,*** transformer aging models,alongside advanced control functionalities of grid-tied smart inverter-based SPV systems,are implemented in *** open-source simulation tool(OpenDSS)is used to model distribution *** analyze effectiveness of various inverter functionalities,time-series simulations are performed using exponential load models,considering daily load curves from multiple seasons,load types,current harmonics,*** show replacing a traditional inverter with a smart inverter-based SPV system can enable local reactive power generation and may extend the life of a distribution *** results demonstrate,simply by incorporating smart inverter-based SPV systems,transformer aging is reduced by 15%to 22%in comparison to SPV systems operating with traditional inverters.

关键词： Distribution transformer loss of life smart inverter functions solar photovoltaic systems thermal models Volt-VAr control

Severe progression of autoimmune hepatitis in a young COVID-19 adult patient: A case report

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Journal of Acute Disease 2022年第4期11卷 161-164页

作者： Neeraj Kumar Sushant Satyapriya Shaik Mohammad Tahaseen Kunal Singh Abhyuday Kumar department of Trauma&Emergency AIIMS PatnaBiharIndia801505 department of Anaesthesiology AIIMS PatnaBiharIndia801505 department of Medicine AIIMS PatnaBiharIndia801505

Rationale:The impact of COVID-19 in patients with autoimmune liver disease treated with immunosuppressive therapy has not been described so *** case report describes the clinical course of a patient with autoimmune hepatitis(AIH)who developed COVID-19 and the features of cytokine syndrome leading to its deterioration in our intensive care ***’s Concern:A 28-year-old male presented with generalized anasarca for two weeks and chronic liver disease for 8 ***:AIH and Covid-19 with features of cytokine storm ***:Intravenous furosemide,mannitol,syrup lactulose,steroids(prednisolone 40 mg),azathioprine 1 mg/kg body weight,rifaximin,vitamin K,and blood ***:The patient had hepatic encephalopathy and AIH and died on the 10th day after admission despite ventilatory support,sustained low-efficiency hemodialysis,and ***:The dramatic release of cytokines and the inflammatory‐immune responses not only alter the pathophysiology but also affects the onset and severity of disease progression in patients with AIH.

关键词： COVID-19 Autoimmune hepatitis Cytokine storm syndrome Immunosuppressant drugs Liver dysfunction