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Elastic and Optoelectronic Properties of kCdF3:ab initio Calculations through LDA/GGA/TB-mBJ within FP-LAPW Method

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Chinese Physics Letters 2015年第1期32卷 108-112页

作者： k. Ephraim babu N. Murali k. Vijaya babu B. kishore babu V. Veeraiah Modelling and Simulation in Materials Science Laboratory Department of Physics Andhra University Visakhapatnam 530003 Andhra Pradesh India Department of Engineering Chemistry A UCE(A) Andhra University Visakhapatnam 530003 Andhra Pradesh India

Ab initio calculations are performed on the electronic, structural, elastic and optical properties of the cubic per- ovskite kCdF3. Tile kohn Sham equations are solved by applying the full potential linearized augmented plane wave （FP-LAPW） method. The exchange correlation effects are included through the local density approximation （LDA ）, generalized gradient approximation （GGA） and modified Becke-Johnson （mBJ） exchange potential The calculated lattice constant is in good agreement with the experimental result. The elastic properties such as elastic constants, anisotropy factor, shear modulus, Young＇s modulus and Poisson＇s ratio are calculated. kCdF3 is ductile and elastically anisotropic. The calculations of the electronic band structure, density of states （DOS） and charge density show that this compound has an indirect energy band gap （M-F） with a mixed ionic and covalent bonding. The contribution of the different bands is analyzed from the total and partial density of states curves. Optical response of the dielectric functions, optical reflectivity, absorption coefficient, real part of optical conductivity, refractive index, extinction coefficient and electron energy loss, are presented for the energy range of O-40eV. The compound kCdF3 can be used for high-frequency optical and optoelectronic devices.

关键词： GGA Cd Elastic and Optoelectronic Properties of kCdF3:ab initio Calculations through LDA/GGA/TB-mBJ within FP-LAPW Method LDA FP

Brain Tumor Segmentation through Level Based Learning Model

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Computer Systems Science & Engineering 2023年第1期44卷 709-720页

作者： k.Dinesh babu C.Senthil Singh Department of Electronics and Communication Engineering Adhi College of Engineering and Technology631605India Department of Electronics and Communication Engineering Infant Jesus College of EngineeringVallanaduThoothukudi628851India

Brain tumors are potentially fatal presence of cancer cells over a human brain,and they need to be segmented for accurate and reliable planning of *** process must be carried out in different regions based on which the stages of cancer can be accurately *** patients exhibit a different level of challenge in terms of cancer or tumors detection as the Magnetic Resonance Imaging(MRI)images possess varying sizes,shapes,positions,and *** scanner used for sensing the location of tumors cells will be sub-jected to additional protocols and measures for accuracy,in turn,increasing the time and affecting the performance of the entire *** this view,Convolutional Neural Networks deliver suitable models for efficient segmentation and thus delivered promising *** previous strategies and models failed to adhere to diversity of sizes and shapes,proving to be a well-established solution for detecting tumors of bigger *** tend to be smaller in size and shape during their premature stages and they can easily evade the algorithms of Convolutional Neural Network(CNN).This proposal intends to furnish a detailed model for sensing early stages of cancer and hence perform segmentation irrespective of the current size and shape of *** size of networks and layers will lead to a significant weightage when multiple kernel sizes are involved,especially in multi-resolution *** the other hand,the proposed model is designed with a novel approach including a dilated convolution and level-based learning *** the convolution process is dilated,the process of feature extraction deals with multiscale objective and level-based learning eliminates the shortcoming of previous models,thereby enhancing the quality of smaller tumors cells and *** level-based learning approach also encapsulates the feature recon-struction processes which highlights the sensing of small-scale tumors ***,segmenting t

关键词： Glioma detection segmentation smaller tumour growth machine learning feature analysis

Effect of Phase Shifted Frequency Modulation on Two Level Atom-Field Interaction

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Communications in Theoretical Physics 2012年第3期57卷 468-472页

作者： k.V.Priyesh Ramesh babu Thayyullathil Department of Physics Cochin University of Science and Technology

We have studied the effect of phase shifted frequency modulation on two level atom with field interaction using Jaynes-Cummings *** the frequency of the interacting field is sinusoidally varying with time with a constant *** to the presence of phase in the frequency modulation,the variation of population inversion with time is different from the standard *** are no exact collapses and revivals in the variation of population inversion but it oscillates sinusoidally with *** coherent field atom interaction the population inversion behaves as in the case of Fock state atom interaction,when frequency modulation with a non zero phase is *** study done with squeezed field has shown the same behavior of the population inversion.

关键词： Jaynes-Cummings model two level atom squeezed field

Application of Response Surface Methodolody to Prediction of Dilution in Plasma Transferred Arc Hardfacing of Stainless Steel on Carbon Steel

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Journal of Iron and Steel Research International 2009年第1期16卷 44-53页

作者： V Balasubramanian A k Lakshminarayanan R Varahamoorthy S babu Centre for Materials Joining and Research (CEMAJOR) Department of Manufacturing EngineeringAnnamalai UniversityAnnamalai Nagar 608002Tamil NaduIndia

The application of response surface methodology was highlighted to predict and optimize the percentage of dilution of iron-based hardfaced surface produced by the PTA （plasma tratisferred arc welding） process. The experiments were conducted based on five-factor five-level central composite rotatable design with full replication technique and a mathematical model was developed using response surface methodology. Furthermore, the response surface methodology was also used to optimize the process parameters that yielded the lowest percentage of dilution.

关键词： plasma transferred arc hardfacing dilution response surface methodology

Software Operational Profile Based Test Case Allocation Using Fuzzy Logic

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International Journal of Automation and computing 2007年第4期4卷 388-395页

作者： k.Saravana kumar Ravindra babu Misra Reliability Engineering Center Indian Institute of TechnologyKharagpur 721302India

Software operational profile （SOP） is used in software reliability prediction, software quality assessment, performance analysis of software, test case allocation, determination of ＂when to stop testing,＂ etc. Due to the limited data resources and large efforts required to collect and convert the gathered data into point estimates, reluctance is observed by the software professionals to develop the SOP. A framework is proposed to develop SOP using fuzzy logic, which requires usage data in the form of linguistics. The resulting profile is named fuzzy software operational profile （FSOP）. Based on this work, this paper proposes a generalized approach for the allocation of test cases, in which occurrence probability of operations obtained from FSOP are combined with the criticality of the operations using fuzzy inference system （FIS）. Traditional methods for the allocation of test cases do not consider the application in which software operates. This is intuitively incorrect. To solve this problem, allocation of test cases with respect to software application using the FIS model is also proposed in this paper.

关键词： Software reliability software operational profile criticality fuzzy logic test case allocation.

Photon condensation： A new paradigm for Bose-Einstein condensation

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Frontiers of physics 2016年第5期11卷 103-110页

作者： Renju Rajan P. Ramesh babu k. Senthilnathan Department of Physics School of Advanced Sciences VIT University Vellore Tamil Nadu 632015 India

Bose-Einstein condensation is a state of matter known to be responsible for peculiar properties exhibited by superfluid Helium-4 and superconductors. Bose-Einstein condensate （BEC） in its pure form is realizable with alkali atoms under ultra-cold temperatures. In this paper, we review the experimental scheme that demonstrates the atomic Bose-Einstein condensate. We also elaborate on the theoretical framework for atomic Bose-Einstein condensation, which includes statistical mechan- ics and the Gross-Pitaevskii equation. As an extension, we discuss Bose-Einstein condensation of photons realized in a fluorescent dye filled optical microcavity. We analyze this phenomenon based on the generalized Planck＇s law in statistical mechanics. Further, a comparison is made between photon condensateand laser. We describe how photon condensate may be a possible alternative for lasers since it does not require an energy consuming population inversion process.

关键词： Bose-Einstein condensation photon condensation magneto-optical trap Gross-Pitaevskii equation Planck's radiation law

Damage and geological assessment of the 18 September 2011 M_w 6.9 earthquake in Sikkim,India using very high resolution satellite data

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Geoscience Frontiers 2015年第6期6卷 793-805页

作者： Tapas R.Martha k.babu Govindharaj k.Vinod kumar National Remote Sensing Centre(NRSC) Indian Space Research Organisation(ISRO)

Post-disaster very high resolution（VHR） satellite data are potential sources to provide detailed information on damage and geological changes for a large area in a short *** this paper,we studied landslides triggered by the M_w 6.9 earthquake in Sikkim,India which occurred on 18 September 2011 using VHR data from Cartosat-1,GeoEye-1,QuickBird-2 and WorldView-2 *** the earthquake-affected area is located in mostly inaccessible Himalayan terrain,VHR data from these satellites provided a unique opportunity for quick and synoptic assessment of the *** visual change analysis technique through comparison of pre- and post-earthquake images,we assessed the damage caused by the event.A total of 123 images acquired from eight satellites,covering an area of4105 km2 were analysed and 1196 new landslides triggered by the earthquake were *** blockages and severely affected villages were also *** assessment of the terrain highlighted linear disposition of landslides along existing fault scarps,suggesting a reactivation of *** landslide inventory map prepared from VHR images also showed a good correlation with the earthquake shake *** showed that several parts of north Sikkim,particularly Mangan and Chungthang,which are close to the epicentre,were severely affected by the earthquake,and that the event-based landslide inventory map can be used in future earthquake-triggered landslide susceptibility assessment studies.

关键词： International Charter Damage Landslide Fault VHR Disaster

Continuous segregation of binary heterogeneous solids in fluidized beds

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Particuology 2017年第6期15卷 93-100页

作者： M. Prasad babu P.S.T. Sai k. krishnaiah Department of Chemical Engineering Indian Institute of Technology Madras Chennai 600 036 India

Continuous segregation of a binary mixture of heterogeneous （different density） solids is carried out in a gas-solid fluidized bed. We investigate how gas velocity, solids feed rate, flotsam feed composition, bottom discharge pipe diameter, and minimum fluidization velocity ratio of the flotsam to jetsam parti- cles influence the solids holdup, separation factor, and product quality （flotsam purity at the top outlet）. The results are interpreted in terms of solids holdup information. The results indicate that the separation factor decreases when the gas velocity, bottom discharge pipe diameter, flotsam feed composition, or the minimum fluidization velocity ratio increase, while the separation factor increases as the solids feed rate increases. The product quality decreases when the gas velocity, solids feed rate, or minimum fluidization velocity ratio increase, while the product quality increases as the bottom discharge pipe diameter or flot- sam feed composition increase. Correlations for predicting the separation factor and product quality are proposed using a logistic model for individual flotsam feed compositions, which satisfactorily compares with the present experimental data.

关键词： Normal fluidized bed Continuous segregation Heterogeneous particles Separation factorHoldup

Continuous segregation of binary heterogeneous solids in a fast-fluidized bed

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Particuology 2017年第6期15卷 101-107页

作者： M. Prasad babu P.S.T. Sai k. krishnaiah Department of Chemical Engineering Indian Institute of Technology Madras Chennai 600 036 India

Continuous segregation of binary heterogeneous solids （different density mixtures） is carried out in a gas-solid fluidized bed to study the effects of gas velocity, solids feed rate, feed composition and density difference of solids on the separation factor （recovery of flotsam at top outlet） and the quality of the product （purity of flotsam at top outlet） in a continuous fast-fluidized bed. The holdup of the bed material is obtained in each experimental run. It is observed that the separation factor decreases with increase in solids feed rate or density difference of solids, and increases with gas velocity or proportion of flotsam in the feed. The quality of the product decreases with increase in gas velocity or solids flow rate, and increases with feed composition or density difference of solids. The experimental results show that the separation factor and the quality of the product are more sensitive to gas velocity than to other operating parameters, Empirical correlations for predicting the separation factor and quality of the product are proposed based on the Richards model for individual flotsam mass fraction in the feed, and the predictions agree satisfactorily with the present exlgerimental data,

关键词： Fast-fluidized bed Gas-solid Continuous segregation Heterogeneous solids Solids holdup