Sarang, India
Sarang, India

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Deshpande R.,RITM | Kumar B.,BPIT | Jain S.B.,IGIT
IET Communications | Year: 2010

Design of finite impulse response (FIR) notch filters (NFs) with highly narrow rejection bandwidth (RBW) is suggested. RBW is the distance between 3 dB points on the response. Reduction in the RBW is achieved progressively in three stages. In the first stage, an FIR NF is designed from a second order infinite impulse response (IIR) prototype filter. For a given length L of the NF, the authors choose maximum permissible value of 'r' (the pole length of IIR prototype filter) to achieve very narrow RBW of the FIR filter. In the next stage, by using an amplitude change function (ACF): H(z)(2 - H(z)), the designed filter is sharpened. Consequently, the RBW of the resulting NF is reduced to almost half of the earlier value. This reduction of bandwidth makes the resulting NF of length 2L. In the next stage, RBW can be further reduced by the repeated sharpening of the filter by the same ACF. © 2010 The Institution of Engineering and Technology.


Deshpande R.,RITM | Kumar B.,BPIT | Jain S.B.,IGIT
International Journal of Circuit Theory and Applications | Year: 2012

A methodology for designing FIR multi notch filters (NFs) derived from second-order prototype IIR NFs is suggested. Rejection bandwidth for the designed filter can be controlled by suitable choice of 'r', the pole radius of the IIR prototype NFs. The suggested multi NF can also be adapted to eliminate second-, third- and fourth-order harmonics of periodic noise besides the fundamental noise frequency component. A special case when two notch frequencies ω 1 and ω 2 are such that [(cosω 1)(cosω 2) = - 1/2] has also been discussed. The IIR multi NF design for this special case results in reduction of the number of multipliers without affecting the response of the desired NF. For the aforereferred condition, the required coefficients of impulse response of FIR multi notch filter get reduced to almost half in number resulting in reduced computations. The number of zero coefficients further reduces with increase in 'r' value. In addition, the frequency response becomes better, with reduced ripples in the pass bands, when 'r' is increased and length 'L' of the FIR NF is chosen appropriately. Copyright © 2010 John Wiley & Sons, Ltd.


Kumar A.,University of Delhi | Maheshwari S.,Netaji Subhas Institute of Technology | Sharma C.,IGIT | Beri N.,University of Delhi
Materials and Manufacturing Processes | Year: 2010

Electrical discharge machining (EDM) is a well-established modern machining process used to manufacture geometrically complex shapes, process hard materials that are extremely difficult to machine by conventional machining processes. This noncontact machining technique is continuously emerging from a mere tool and dies making process to a microscale machining applications. In recent years, researches have emphasized on increasing machining performance coupled with deliberate surface treatments. Additive mixed electrical discharge machining (AEDM) is a novel innovation for enhancing the capabilities of electrical discharge machining process in this direction. This article presents comprehensive history, mechanism of AEDM process, and reviews research literature in this area. The last part of this article outlines trends for future AEDM research directions. Copyright © Taylor & Francis Group, LLC.


Sahoo A.K.,KIIT University | Sahoo B.,IGIT
International Journal of Industrial Engineering Computations | Year: 2013

Turning hardened component with PCBN and ceramic inserts have been extensively used recently and replaces traditional grinding operation. The use of inexpensive multilayer coated carbide insert in hard turning is lacking and hence there is a need to investigate the potential and applicability of such tools in turning hardened steels. An attempt has been made in this paper to have a study on turning hardened AISI 4340 steel (47 ± 1 HRC) using coated carbide inserts (TiN/TiCN/Al2O3/ZrCN) under dry environment. The aim is to assess the tool life of inserts and evolution of flank wear with successive machining time. From experimental investigations, the gradual growth of flank wear for multilayer coated insert indicates steady machining without any premature tool failure by chipping or fracturing. Abrasion is found to be the dominant wear mechanisms in hard turning. Tool life of multilayer coated carbide inserts has been found to be 31 minute and machining cost per part is Rs.3.64 only under parametric conditions chosen i.e. v = 90 m/min, f = 0.05 mm/rev and d = 0.5 mm. The mathematical model shows high determination coefficient, R2 (99%) and fits the actual data well. The predicted flank wear has been found to lie very close to the experimental value at 95% confidence level. This shows the potential and effectiveness of multilayer coated carbide insert used in hard turning applications. © 2013 Growing Science Ltd. All rights reserved.


Sahoo A.K.,KIIT University | Sahoo B.,IGIT
International Journal of Industrial Engineering Computations | Year: 2011

This paper presents the experimental study, development of mathematical model and parametric optimization for surface roughness in turning D2 steel using TiN coated carbide insert using Taguchi parameter design and response surface methodology. The experimental plan and analysis was based on the Taguchi L27 orthogonal array taking cutting speed (v), feed (f) and depth of cut (d) as important cutting parameters. The influence of the machining parameters on the surface finish has also been investigated and the optimum cutting condition for minimizing the surface roughness is evaluated. The optimal parametric combination for TiN coated cutting insert is found to be v3-f1-d3. The ANOVA result shows that feed the most significant process parameter on surface roughness followed by depth of cut. The cutting speed is found to be insignificant from the study. The RSM model shows good accuracy between predicted values and experimental values with 95% confidence intervals and adequate. It is concluded that the developed RSM model can be effectively utilized to predict the surface roughness in turning D2 steel. © 2011 Growing Science Ltd. All rights reserved.


Kumar A.,University of Delhi | Maheshwari S.,Netaji Subhas Institute of Technology | Sharma C.,IGIT | Beri N.,University of Delhi
Materials and Manufacturing Processes | Year: 2012

The present experimental investigations have been carried to evaluate machining efficiency with additive powder mixed in dielectric fluid of electrical discharge machining on Inconel 718 with copper and cryogenically treated copper electrodes. Experiments have been conducted to study the effect of input parameters viz. polarity, type of electrode, peak current, pulse on time, duty cycle, gap voltage, retract distance, and concentration of fine graphite powder on machining efficiency. Machining efficiency is evaluated in terms of tool wear rate (TWR) and wear ratio (WR). The optimum factor/level combination of process parameters has been determined by Taguchi's approach treating performance measure as single objective response. Analysis of variance (ANOVA) is employed to indicate the level of significance of machining parameters for TWR and WR. The recommended optimal process input conditions have been verified by conducting confirmation experiments and significant improvement in TWR and WR is observed. © 2012 Copyright Taylor and Francis Group, LLC.


Beri N.,University of Delhi | Maheshwari S.,Netaji Subhas Institute of Technology | Sharma C.,IGIT | Kumar A.,University of Delhi
Materials and Manufacturing Processes | Year: 2010

Electrical discharge machining (EDM) is a well-established machining option for processing hard materials with complex geometrical shapes which are extremely difficult-to-machine by conventional machining processes. These hard materials find applications where lower surface cracks, wear resistance, corrosion resistance, etc. are desirable surface properties. In recent years, research has been carried out to determine the possibility of employing electrode as feed stock material in an effort to produce significant surface alloying. These electrodes are generally produced through powder metallurgy (PM) technique in order to achieve necessary combination of operating characteristics. This paper reports state of art related to the usefulness of PM-processed electrodes in imparting desirable surface properties and modification of the machined surface. The final part of the paper outlines the trends for future EDM research using PM-processed electrodes. Copyright © Taylor & Francis Group, LLC.


Samantaray S.R.,Indian Institute of Technology Bhubaneswar | Tripathy L.N.,IGIT | Dash P.K.,Siksha ‘O’ Anusandhan University
International Journal of Electrical Power and Energy Systems | Year: 2012

The paper presents a differential energy based protection scheme for transmission line including Thyristor Controlled Series Compensator (TCSC) using time-frequency transform such as S-transform. Initially the current at sending and receiving ends are retrieved and processed through the time-frequency transform such as S-transform to generate the time-frequency patterns (frequency contours). Spectral energy content of the frequency contours of both current signals are calculated and differential energy is computed to register the fault patterns in the transmission line. The tripping signal can be issued based on a set threshold, within two cycles from the fault inception, meeting the speed criteria of the digital relay. The results indicate that the differential energy based protection scheme can reliably detect the fault patterns in TCSC line including wide variations in operating conditions of the faulted power network. © 2012 Elsevier Ltd. All rights reserved.


Sethi S.,IGIT | Udgata S.K.,University of Hyderabad
ICWET 2010 - International Conference and Workshop on Emerging Trends in Technology 2010, Conference Proceedings | Year: 2010

Many networking applications such as video-on-demand services, video conferencing, and distributed database replications require multicast communications. Providing scalable and reliable multicast are basic requirements to develop a better routing protocols which is used for disaster management, emergency relief, mobile conferencing among many other applications. As mobile host changes its access point over a time interval, multicast routes have to be updated frequently. This poses several challenges to provide an efficient multicast routing. In this paper, we propose a Scalable Reliable Multicast Ad hoc On Demand Distance Vector (SRMAODV) protocol based on Ad hoc On Demand Distance Vector (AODV) and Multicast AODV (MAODV) protocol to support scalability and reliability for online routing of delivery-guaranteed multicasts. Exhaustive simulation experiments reveal that Packet Delivery Ratio (PDR) which is an important measure of reliability for SRMAODV is much better together with improved end-to-end delay. Copyright 2010 ACM.


Sahu S.,I.G.I.T | Choudhury B.B.,I.G.I.T
Materials Today: Proceedings | Year: 2015

Coated tools are used to improve the performance in machining applications, such as high-speed machining and machining of hard materials. Surface roughness and tool wear prediction plays a significant role in machining for proper planning and control of machining parameters and optimization of cutting conditions. The present work studies the performance of multi-layer TiN coated tool in machining of hardened steel (AISI 4340 steel) under high speed turning,which has also been compared with that of uncoated tool. The influence of cutting parameters(speed, feed, and depth of cut)on surface roughness have been analyzed using Taguchi methodology. Finally, scanning electron microscopy (SEM) images are used to observe the surface morphology and to predict the tool wear. It has been found that the machining of hard materials at higher speeds and lower feeds is improved by using coated tools. © 2015 Elsevier Ltd.

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