Analyzing an infinite buffer batch arrival and batch service queue under batch-size-dependent service policy

S. Pradhan,U.C. Gupta,S.K. Samanta 한국통계학회 2016 Journal of the Korean Statistical Society Vol.45 No.1

In this paper, we investigate an infinite-buffer queue with batch-arrival and batch-service wherein a single server operates under random serving capacity rule with service time dependent on the size of the batch under the service. First, we derive the probability generating function of state probabilities at service completion epoch, from which an entire spectrum regarding queue-length at various epochs is extracted. Using the departure epoch probabilities, we establish a stable relationship between departure and random epochs probabilities based on ‘rate in = rate out’ approach. Further, random epoch probabilities are used to obtain pre-arrival epoch probabilities. Finally, we illustrate our analytical results by means of numerical computation which includes the case of multiple roots.

Free vibration of functionally graded thin elliptic plates with various edge supports

K.K. Pradhan,S. Chakraverty 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.2

In this article, free vibration of functionally graded (FG) elliptic plates subjected to various classical boundary conditions has been investigated. Literature review reveals no study has been performed based on functionally graded elliptic plates till date. The mechanical kinematic relations are considered based on classical plate theory. Rayleigh-Ritz technique is used to obtain the generalized eigenvalue problem. The material properties of the FG plate are assumed to vary along thickness direction of the constituents according to power-law form. Trial functions denoting the displacement components are expressed in simple algebraic polynomial forms which can handle any edge support. The objective is to study the effect of geometric configurations and gradation of constituent volume fractions on the natural frequencies. New results for frequency parameters are incorporated after performing a test of convergence. A comparison study is carried out with existing literature for validation in special cases. Three-dimensional mode shapes for circular and elliptic FG plates are also presented with various boundary conditions at the edges.

Some Device Design Considerations to Enhance the Performance of DG-MOSFETs

S K Mohapatra,K P Pradhan,P K Sahu 한국전기전자재료학회 2013 Transactions on Electrical and Electronic Material Vol.14 No.6

When subjected to a change in dimensions, the device performance decreases. Multi-gate SOI devices, viz. the Double Gate MOSFET (DG-MOSFET), are expected to make inroads into integrated circuit applications previously dominated exclusively by planar MOSFETs. The primary focus of attention is how channel engineering (i.e. Graded Channel (GC))and gate engineering (i.e. Dual Insulator (DI)) as gate oxide) creates an effect on the device performance, specifically,leakage current (Ioff), on current (Ion), and DIBL. This study examines the performance of the devices, by virtue of a simulation analysis, in conjunction with N-channel DG-MOSFETs. The important parameters for improvement in circuit speed and power consumption are discussed. From the analysis, DG-DI MOSFET is the most suitable candidate for high speed switching application, simultaneously providing better performance as an amplifier.

3D finite element analysis of stress distributions and strain energy release rates for adhesive bonded flat composite lap shear joints having pre-existing delaminations

S. K. Parida,A. K. Pradhan 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.2

The rate of propagation of embedded delamination in the strap adherend of lap shear joint (LSJ) made of carbon/epoxy composites hasbeen evaluated employing three-dimensional non-linear finite elements. The delamination has been presumed to pre-exist in the thin resinlayer between the first and second plies of the strap adherend. The inter-laminar peel and shear stress distributions have been studied indetails and are seen to be predominantly three-dimensional in nature. The components of strain energy release rate (SERR) correspondingto the opening, sliding and cross sliding modes of delamination are significantly different at the two fronts of the embedded delamination. The sequential release of multi-point constraint (MPC) finite elements in the vicinity of the delamination fronts enables to simulatethe growth of the delamination at either ends. This simulation procedure can be utilized effectively for evaluation of the status of thestructural integrity of the bonded joints.

Free vibration of functionally graded thin elliptic plates with various edge supports

Pradhan, K.K.,Chakraverty, S. 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.2

In this article, free vibration of functionally graded (FG) elliptic plates subjected to various classical boundary conditions has been investigated. Literature review reveals no study has been performed based on functionally graded elliptic plates till date. The mechanical kinematic relations are considered based on classical plate theory. Rayleigh-Ritz technique is used to obtain the generalized eigenvalue problem. The material properties of the FG plate are assumed to vary along thickness direction of the constituents according to power-law form. Trial functions denoting the displacement components are expressed in simple algebraic polynomial forms which can handle any edge support. The objective is to study the effect of geometric configurations and gradation of constituent volume fractions on the natural frequencies. New results for frequency parameters are incorporated after performing a test of convergence. A comparison study is carried out with existing literature for validation in special cases. Three-dimensional mode shapes for circular and elliptic FG plates are also presented with various boundary conditions at the edges.

Temperature and Frequency Dependent Multiferroic Features of Gadolinium Doped BiFeO3 -PbTiO3 Electronic System

S. K. Pradhan,S. N. Das,S. Bhuyan,Seshadev Sahoo,R. N. P. Choudhary 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.2

Multiferroic gadolinium (Gd) doped BiFeO 3 (BFO) and PbTiO 3 (PT) samples [(Pb 1−x Bi 0.5x Gd 0.5x )(Fe x Ti 1−x )O 3 ] with x = 0.1, 0.3, 0.5 and 0.7 are formulated by adopting the solid state reaction process. The impact of gadolinium substitution in the crystal structure, morphological behavior and electrical properties has been studied. By altering the Gd concentration in the solid solution a change in the structure is observed that is from tetragonal to rhombohedral. The size of the grain in the compounds reduces as a result of enrich in gadolinium content of the furnished sample. The subsidence of lead minimizes the toxic behavior of the material with significant improvements in dielectric response of gadolinium modifi ed BiFeO3 – PbTiO 3synthesized system. From the impedance study, the material presents negative temperature coefficient of resistance characteristics and the impedance is due to the presence of grain and grain boundary eff ect inside the materials. It is realized that the remnant polarization decreases and frequency dependent ac conductivity increases with the concentration of gadolinium in the electronic system. From conductivity study, the equipped electronic materials show non-exponential type of conductivity relaxation.

SUMS OF BALANCING-LIKE SEQUENCES WITH BINOMIAL COEFFICIENTS

S. S. Pradhan,G. K. Panda 장전수학회 2020 Proceedings of the Jangjeon mathematical society Vol.23 No.3

For a, b ∈ R we study some binomial sums of the form where {xn}, {yn}, {zn} and {wn} are the balancing-like, lucas balancing-like, cobalancing-like and lucas-cobalancing-like sequences respectively. Moreover, we express these sums in a dierent combinatorial way and also provide some closed form solutions of many forms of these sums.

Structural, Morphological, Electrical and Impedance Spectroscopy Investigation of Pb 1/2 Ba 1/2 Ni 1/2 W 1/2 O 3 Electronic Material

S. Kalingani,Satyaprakash Narayan Das,S. K. Pradhan,S. Bhuyan,R. N. P. Choudhary 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.1

In this present study the (Pb 1/2 Ba 1/2 )(Ni 1/2 W 1/2 )O 3 , [PBNW] perovskite compound has been formulated and synthesized by adopting a solid-state reaction technique. The detailed structural, morphological, and electrical characterization has been carried out to explore its characteristics for further application in the field of electronic devices and sensors. With the help of x-ray diff raction analysis orthorhombic structure has been recognized. Dielectric, impedance spectroscopy, and a.c. conductivity analysis has been carried out through a wide range of temperatures as well as frequency (temperature range 25–500 °C, frequency range 1 kHz to 1 MHz). Presence of a single semi-circular arc from Nyquist analysis points toward the grain contribution of the sample. An equivalent circuit model has been developed to explore its electrical behavior. The activation energy, as well as the charge carrier mobility, has been estimated. Methodical studies for dielectric properties at high temperatures are accomplished for analysing electrical inhomogeneity allied with surfaces, grain boundaries, or grains, which are imperative for fundamental characterization and device fabrication.

A Study of SCEs and Analog FOMs in GS-DGMOSFET with Lateral Asymmetric Channel Doping

P. K Sahu,S. K. Mohapatra,K. P. Pradhan 대한전자공학회 2013 Journal of semiconductor technology and science Vol.13 No.6

The design and analysis of analog circuit application on CMOS technology are a challenge in deep sub-micrometer process. This paper is a study on the performance value of Double Gate (DG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET) with Gate Stack and the channel engineering Single Halo (SH), Double Halo (DH). Four different structures have been analysed keeping channel length constant. The short channel parameters and different sub-threshold analog figures of merit (FOMs) are analysed. This work extensively provides the device structures which may be applicable for high speed switching and low power consumption application.

Thermoelastic effect on inter-laminar embedded delamination characteristics in Spar Wingskin Joints made with laminated FRP composites

P.K. Mishra,A.K. Pradhan,M.K. Pandit,S.K. Panda 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.3

This paper presents two sets of full three-dimensional thermoelastic finite element analyses of superimposed thermo-mechanically loaded Spar Wingskin Joints made with laminated Graphite Fiber Reinforced Plastic composites. The study emphasizes the influence of residual thermal stresses and material anisotropy on the inter-laminar delamination behavior of the joint structure. The delamination has been pre-embedded at the most likely location, i.e., in resin layer between the top and next ply of the fiber reinforced plastic laminated wingskin and near the spar overlap end. Multi-Point Constraint finite elements have been made use of at the vicinity of the delamination fronts. This helps in simulating the growth of the embedded delamination at both ends. The inter-laminar thermoelastic peel and shear stresses responsible for causing delamination damage due to a combined thermal and a static loading have been evaluated. Strain energy release rate components corresponding to the Mode I (opening), Mode II (sliding) and Mode III (tearing) of delamination are determined using the principle of Virtual Crack Closure Technique. These are seen to be different and non-self-similar at the two fronts of the embedded delamination. Residual stresses developed due to the thermoelastic anisotropy of the laminae are found to strongly influence the delamination onset and propagation characteristics, which have been reflected by the asymmetries in the nature of energy release rate plots and their significant variation along the delamination front.