Online system identification of mini cropped delta UAVs using flight test methods

Saderla, Subrahmanyam,Kim, Yoonsoo,Ghosh, A.K. Elsevier 2018 Aerospace science and technology Vol.80 No.-

<P><B>Abstract</B></P> <P>The current manuscript presents the longitudinal and lateral directional online parameter estimation of two unmanned aerial vehicles (UAVs) using sequential Least Squares formulation in frequency domain. The two fixed wing UAVs share a similar cropped delta planform and differ in their cross sectional geometries, one with a rectangular and the other being a reflex airfoil cross sections respectively. Recursive Fourier Transform algorithm has been used to convert the flight data in time domain to frequency domain which is measured by means of a dedicated on-board data acquisition system capable of on-board logging and telemetry to ground station. The combination of Sequential Least Squares with Recursive Fourier Transform (SLS-RFT) in frequency domain can be used to carry out online parameter estimation. An attempt has been made to check the applicability of the current method to estimate parameters from the generated flight data of the two UAVs using both conventional as well as random control inputs. Results showed that the parameters estimated, using SLS-RFT, from the linear flight data are consistent and in close agreement with the obtained parameters from full scale wind tunnel testing of UAVs. It was also observed that the estimates from the manoeuvres with multistep control inputs converged faster compared to the parameters obtained from the manoeuvres with slow varying control surface deflections. The time varying linear aerodynamic parametric model of SLS-RFT was able to capture the dynamics of the flights with nonlinear aerodynamics. Certain limitations of the current online system identification method were also observed with estimating parameters from the flight data of UAVs performing near stall manoeuvres. The estimated parameters using SLS-RFT are also compared with the results obtained from batch methods namely classical Maximum Likelihood (ML) and neural based Neural–Gauss–Newton (NGN) methods.</P>

Molecular methods for diagnosis of microbial pathogens in muga silkworm, Antheraea assamensis Helfer (Lepidoptera: Saturniidae)

Gangavarapu Subrahmanyam 한국잠사학회 2023 International Journal of Industrial Entomology Vol.47 No.1

The Indian golden muga silkworm, Antheraea assamensis Helfer is an economically important wild silkworm endemic to Northeastern part of India. In recent years, climate change has posed a threat to muga silk production due to the requirement that larvae be reared outdoors. Since the muga silkworm larvae are exposed to the vagaries of nature, the changing climate has increased the incidence of microbial diseases in the rearing fields. Accurate diagnosis of the disease causing pathogens and its associated epidemiology are prerequisites to manage the diseases in the rearing field. Although conventional microbial culturing methods are widely used to identify pathogenic bacteria, they would not provide meaningful information on a wide variety of silkworm pathogens. The information on use of molecular diagnostic tools in detection of microbial pathogens of wild silk moths is very limited. A wide range of molecular and immunodiagnostic techniques including denaturing gradient gel electrophoresis (DGGE), random amplified polymorphism (RAPD), 16S rRNA/ITSA gene sequencing, multiplex polymerase chain reaction (M-PCR), fluorescence in situ hybridization (FISH), immunofluorescence, and repetitive-element PCR (Rep-PCR), have been used for detecting and characterizing the pathogens of insects with economic significance. Nevertheless, the application of these molecular tools for detecting and typing entomopathogens in surveillance studies of muga silkworm rearing is very limited. Here, we discuss the possible application of these molecular techniques, their advantages and major limitations. These methods show promise in better management of diseases in muga ecosystem.

Simulations for the flow of viscoplastic fluids in a cavity driven by the movement of walls by Lattice Boltzmann Method

Siva Subrahmanyam Mendu,Prasanta Kumar Das 한국유변학회 2020 Korea-Australia rheology journal Vol.32 No.3

The current paper is focused on analyzing the flow of viscoplastic fluid in a cavity that is driven by the two walls. The Lattice Boltzmann method (LBM) is used to solve the discrete Boltzmann equation. To represent the stress-strain rate relationship of viscoplastic fluids, the Bingham Papanastasiou constitutive model is considered. Cavity flow filled with Bingham fluids is considered for validating the present LBM code. After successful validation of the code, the analysis is extended for three dissimilar wall motions- simultaneous and opposed movement of the parallel facing walls, and the simultaneous motion of non-facing walls. The flow dynamics of Bingham fluid is influenced by Reynolds and Bingham numbers which can be studied using velocity and streamline plots. Subsequently, the yielded and un-yielded zones in a cavity have been effectively tracked using the limiting condition of yield stress. Further, the effect of wall motion on the variation of those zones inside a cavity has been studied. Finally, the drag coefficient for considered wall motions is presented.

Trends, Characteristics and inter - face of Prinary and Secondary Poverty in Urbam India

D Subrahmanyam 한국지역학회 1998 지역연구 Vol.14 No.1

This paper examines the policy implications of poverty in terms of its forms: primary and secondary poverty and brings out the synergetic relationship between the reduction of primary and secondary poverty in Urban India. The paper also demonstrates the influence that the alleviation of secondary poverty exerts on the alleviation of the primary poverty and it pinpoints the macro-level policy implications and suggests envisaged strategy for poverty alleviation applicable to the developing world.

Secant Method for Economic Dispatch with Generator Constraints and Transmission Losses

Chandram, K.,Subrahmanyam, N.,Sydulu, M. The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.1

This paper describes the secant method for solving the economic dispatch (ED) problem with generator constraints and transmission losses. The ED problem is an important optimization problem in the economic operation of a power system. The proposed algorithm involves selection of minimum and maximum incremental costs (lambda values) and then the evaluation of optimal lambda at required power demand is done by secant method. The proposed algorithm has been tested on a power system having 6, 15, and 40 generating units. Studies have been made on the proposed method to solve the ED problem by taking 120 and 200 units with generator constraints. Simulation results of the proposed approach were compared in terms of solution quality, convergence characteristics, and computation efficiency with conventional methods such as lambda iterative method, heuristic methods such as genetic algorithm, and meta-heuristic methods like particle swarm optimization. It is observed from different case studies that the proposed method provides qualitative solutions with less computational time compared to various methods available in the literature.

Improved Pre-prepared Power Demand Table and Muller's Method to Solve the Profit Based Unit Commitment Problem

Chandram, K.,Subrahmanyam, N.,Sydulu, M. The Korean Institute of Electrical Engineers 2009 Journal of Electrical Engineering & Technology Vol.4 No.2

This paper presents the Improved Pre-prepared Power Demand (IPPD) table and Muller's method as a means of solving the Profit Based Unit Commitment (PBUC) problem. In a deregulated environment, generation companies (GENCOs) schedule their generators to maximize profits rather than to satisfy power demand. The PBUC problem is solved by the proposed approach in two stages. Initially, information concerning committed units is obtained by the IPPD table and then the subprob-lem of Economic Dispatch (ED) is solved using Muller's method. The proposed approach has been tested on a power system with 3 and 10 generating units. Simulation results of the proposed approach have been compared with existing methods and also with traditional unit commitment. It is observed from the simulation results that the proposed algorithm provides maximum profit with less computational time compared to existing methods.

Finding Probabilistic Skyline Points by using Dimensionality Reduction and Boundary detection Approach in Distributed Environment

Vijaya Saradhi.T,Kodukula Subrahmanyam,Debnath Bhattacharyya,Tai-hoon Kim 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.8

A skyline of a n-dimensional data contains the data objects that are not dominated by any other data object on all dimensions. However, as the number of data dimensions increases the probability of domination points become very low, accordingly the number of points in the skyline becomes large. Also skyline search space has been identified as the key problem in real-time multidimensional databases. None of the traditional search techniques include the use of dimensionality reduction to optimize the search space. Skyline query computation on the server consecutively reduces the amount of data transferred between the server sites. Traditional static lower bound and upper bound probability computation will increase the number of non-dominance points. In this proposed work, an optimized skyline boundary detection algorithm is used to filter the skyline objects and pruning the local probability. Also, global probability computation was improved on the large skyline databases in order to minimize the search space and storage .The experimental results show that the efficiency of the proposed approach compared to traditional static skyline bound techniques in terms of time and search space are concerned.

A Dependency analysis for Information Security and Risk Management

B. Chaitanya Krishna,Kodukula Subrahmanyam,Tai-hoon Kim 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

Today major issue in IT Sector is security, now a day in every field software products are using at the same time users are struggles for their information and data security. Normally software engineers developed good software and test the all aspects and deliver to the user but they cannot bother about minuet problems because they think that those problems cannot impact the product output. But in the run time environment those problems create major problems and display the wrong outputs. Software hackers also using these minuet problems hacked the system and spoil the data. There are so many methods are available for information security and risk management but those are not universally accepted methods. In this paper I proposed a novel method for information security and risk management. Using this method to develop application very well and if any hidden mistakes are there in development stage those risks are identified in run time environment and reduce risk and provide security to the data.

Physicochemical process of non-thermal plasma at gas-liquid interface and synergistic effect of plasma with catalyst

Chandana L.,Ray Debjyoti,Subrahmanyam Ch 한국물리학회 2022 Current Applied Physics Vol.36 No.-

An atmospheric-pressure plasma jet (APPJ) was directly irradiated at a gas-liquid interface under ambient conditions. The reactive oxygen species (ROS) like hydroxyl radicals (•OH), hydrogen peroxide (H2O2) and ozone (O3) and also reactive nitrogen species (RNS) such as nitrogen oxides (NOx) and nitric acid (HNO3) formed during the plasma discharge were quantified under various experimental parameters. In a chemical dosimetry method, terephthalic acid (TA) was employed for the quantification of •OH and titanium sulfate was used to quantify the H2O2. Quantitative determination of NO3 − was carried out by using Ion chromatography (IC). The changes in the solution pH were studied during the plasma treatment. Strong acidification along with the production of dominant reactive nitrogen species and ozone formation were observed with air. The effect of various gases, gas flow rate, various applied voltage and catalyst were studied to optimize the experimental conditions for the best performance. The influence of catalyst Fe2+ salt, TiO2 on the formation of reactive species were studied. The efficiency of the plasma device for the degradation of crystal violet (CV) was also investigated with TiO2 and Fe2+ salt.

A Novel Dr.KSM Approach for Information Security and Risk Management in Health Care Systems

B.Chaitanya Krishna,Kodukula Subrahmanyam,S.S.N.Anjaneyulu,Tai-hoon Kim 보안공학연구지원센터 2015 International Journal of Bio-Science and Bio-Techn Vol.7 No.4

At Present times, A common person focus on their health issues not only for themselves but also for their family because health is a wealth. In the modern days most of the people are working and they spending 40% to 50% of the income on their health issues not only for themselves but also for their family. By this the rate of population arrival to the Hospitals are increasing day-by-day. So the hospitals have to be reliable towards the patients. The records of the patients and the medication details are to be maintained correctly. There may be many risks in the software that they use. So any health organizations are struggles to display the patient electronically measured health records and what they use medication outside. So every time common people are lose their health information. If the common people know the about their previous health records they reduce their money and take the first aid immediately. In this paper we suggest a new approach to risk assessment for health care systems. As risk assessment is a Qualitative approach, there are no exact techniques to solve such risks. Lack of risk assessment techniques leads to failure in the system and organization as the people don’t find interest to come if once the organization fails in any of the issues. Our new method mainly focuses on the risk management for health care organizations. Today’s health care industry faces a number of emerging risk issues related to health care reform, the shift from fee-for-services to outcomes-based compensation, the use of electronic medical records and the management of human capital. Therefore our method has put forth a Risk management technique for the Risk assessment.