Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

&nbsp;

IIT Palakkad

Isochromatic patterns in the vicinity of frictional contacts furnish vital clues for characterizing friction. Though friction effects are evident in a diametrally loaded circular disk, three-point loading provides better results towards highlighting friction. In this paper, a new method of characterizing friction at loading contacts using photoelastic isochromatics patterns is presented. Location of isotropic points (IPs) formed in three-point and four-point loadings of circular disk is used as a main tool to quantify the friction component using theoretical analysis. Bifurcation of isochromatic fringe loops near the distributed loads is explained by the presence of anti-symmetric Hertzian shear traction in addition to Hertzian normal traction. The classical solution by Flamant for point load at the edge of half plane is used to derive stresses in circular disk for all required loading configurations. A semicircualr ring under three-point loading is examined using photoelasticity to understand the isochromatics pattern theoretically by considering normal and shear traction components at loaded regions. © 2014 Society for Experimental Mechanics.

Department of Mechanical Engineering

World University root node

Experimental Mechanics

Characterizing Frictional Contact Loading via Isochromatics

Edge cracked specimens have been widely utilized for fracture testing. Edge cracked semicircular disk (ECSD) specimen has now been well characterized with regard to its form factor and weight function. This paper presents a modified semicircular ring version of this specimen to enhance the form factor in general while retaining other desirable features. The efficacy of the modified design is proved by combining theory of elasticity solutions with finite element results to arrive at the optimum design geometry. New insights emerging from this work are used to theoretically re-examine the arch-tension and the four-point bend specimens. © 2014 Elsevier Ltd.

Engineering Fracture Mechanics

Analysis of cracked and un-cracked semicircular rings under symmetric loading

Understanding user generated comments in response to news and blog posts is an important area of research. After ignoring irrelevant comments, one finds that a large fraction, approximately 50%, of the comments are very specific and can be further related to certain parts of the article instead of the entire story. For example, in a recent product review of Google Nexus 7 in ArsTechnica (a popular blog), the reviewer talks about the prospect of "Retina equipped iPad mini" in a few sentences. It is interesting that although the article is on Nexus 7, but a significant number of comments are focused on this specific point regarding "iPad". We pose the problem of detecting such comments as specific comments location (SCL) problem. SCL is an important open problem with no prior work. SCL can be posed as a correspondence problem between comments and the parts of the relevant article, and one could potentially use Corr-LDA type models. Unfortunately, such models do not give satisfactory performance as they are restricted to using a single topic vector per article-comments pair. In this paper we propose to go beyond the single topic vector assumption and propose a novel correspondence topic model, namely SCTM, which admits multiple topic vectors (MTV) per article-comments pair. The resulting inference problem is quite complicated because of MTV and has no off-the-shelf solution. One of the major contributions of this paper is to show that using stick-breaking process as a prior over MTV, one can derive a collapsed Gibbs sampling procedure, which empirically works well for SCL. SCTM is rigorously evaluated on three datasets, crawled from Yahoo! News (138,000 comments) and two blogs, ArsTechnica (AT) Science (90,000 comments) and AT-Gadget (160,000 comments). We observe that SCTM performs better than Corr-LDA, not only in terms of metrics like perplexity and topic coherence but also discovers more unique topics. We see that this immediately leads to an order of magnitude improvement in F1 score over Corr-LDA for SCL. © 2014 ACM.

Department of Data Science

WSDM 2014 - Proceedings of the 7th ACM International Conference on Web Search and Data Mining

Going beyond Corr-LDA for detecting specific comments on news &amp; blogs

Let n,r,k be positive integers such that 3≤k&lt;n and 2≤r≤k-1. Let m(n,r,k) denote the maximum number of edges an r-uniform hypergraph on n vertices can have under the condition that any collection of i edges spans at least i vertices for all 1≤i≤k. We are interested in the asymptotic nature of m(n,r,k) for fixed r and k as n→∞. This problem is related to the forbidden hypergraph problem introduced by Brown, Erdos, and Sós and very recently discussed in the context of combinatorial batch codes (CBCs). In this short paper we obtain the following results. Using a result due to Erdos we are able to show m(n,r,k)=o(nr) for 7≤k, and 3≤r≤k-1- ⌈logk⌉. This result is best possible with respect to the upper bound on r as we subsequently show through explicit construction that for 6≤k, and k-⌈logk⌉≤r≤k-1,m(n,r,k)=Θ(nr).This explicit construction improves on the non-constructive general lower bound obtained by Brown, Erdos, and Sós for the considered parameter values.For 2-uniform CBCs we obtain the following results. We provide exact value of m(n,2,5) for n≥5.Using a result of Lazebnik et al. regarding maximum size of graphs with large girth, we improve the existing lower bound on m(n,2,k) (Ω(n k+1/k-1)) for all k≥8 and infinitely many values of n.We show m(n,2,k)=O(n1 + 1/⌊k/4⌋) by using a result due to Bondy and Simonovits, and also show m(n,2,k)=Θ(n3/2) for k=6,7,8 by using a result of Kovári, Sós, and Turán. © 2013 Elsevier B.V. All rights reserved.

Department of Computer Science and Engineering

Discrete Applied Mathematics

On an extremal hypergraph problem related to combinatorial batch codes

A low cost optical fiber pH sensor has been proposed. The sensor is configured by coating a pH sensitive film of hydrogel synthesized by Poly (Vinyl Alcohol)/Poly (Acrylic Acid) blend coated on an etched single mode fiber. The pH response of the gel coated fiber is studied. © OSA 2014.

Department of Chemistry

International Conference on Fibre Optics and Photonics, 2014

Study on polymer coated etched optical fiber for pH sensing

This study proposes a robust controller in conjunction with the dynamic modeling of an existing three degrees of freedom planar parallel manipulator which can perform effectually in the presence of parameter uncertainties and external disturbances. The planar manipulator discussed here has three legs each with a prismatic-prismatic-revolute (3-PPR) joint configuration and located on the same plane connecting the moving platform which is in the form of an equilateral triangle. Each leg consists of an active prismatic joint, a passive prismatic joint and a passive rotary joint. The dynamic model has been obtained using the Euler-Lagrangian formulation method which is based on the kinetic and potential energies of the system. The proposed controller is based on a sliding mode control scheme with a nonlinear disturbance observer incorporated which aids in eliminating disturbances present in the system which is a result of both disturbances (internal and external disturbances) and parameter uncertainties which might arise due to un-modeled dynamics. Computer based numerical simulations are performed to demonstrate the effectiveness of the proposed control and results confirming the same in the presence of disturbances. © 2014 IEEE.

SCES 2014: Inspiring Engineering and Systems for Global Sustainability

Robust disturbance observer based sliding mode control of a planar parallel (3-PPR) manipulator

Increased use of fibre reinforced concrete (FRC) in India has resulted in the urgent need to standardise testing and characterisation. The current paper addresses the different available techniques and gives pre-normative suggestions for toughness characterisation. The use of an unnotched beam test is advocated here considering the dearth of laboratories for performing more sophisticated tests and the use of FRC being by-and-large restricted to slabs-on-grade and other non-structural applications. In this study, different types of steel fibres were incorporated in a typical M35 concrete used in India in flooring applications. Flexural tests were conducted to obtain the load-deflection curves and determine various toughness parameters, viz., flexural strength, equivalent flexural strength, equivalent flexural strength ratio and residual strength. The load-deflection curves of FRC with undulated fibres differed significantly from those with straight hookedended fibres in that the concrete failure often occurred with significant crack branching and spalling. The tests indicate no significant change in compressive strength due to addition of fibres while the flexural strength of FRC is slightly higher than that of plain concrete emphasising the need for determining the flexural strength by testing rather than using values from empirical equations or from tests of plain concrete. Specifically, the results illustrate that hooked-ended fibres do not influence the behaviour until after the peak and are more efficient in improving toughness, especially at larger deflections resulting in higher equivalent flexural strengths, in comparison with the undulated fibres. As expected, the higher aspect ratio and higher dosage of steel fibres impart more toughness to the concrete. It is shown that different combinations of fibre type and dosage can yield similar equivalent flexural strength ratios (Re,n) and different fibres at same dosage can have different Re,n values. It was observed, in general, that the variability of flexural strength is much higher than that of the compressive strength and that the variation of results is lower for straight hooked-ended fibres. The scatter in the residual strengths is much higher than that in the equivalent flexural strength, which results in a relatively lower characteristic value for the former in comparison to the latter at similar deflections. Based on the study, recommendations have been made for consideration in an Indian test standard.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

Indian Concrete Journal

Characterisation of the toughness of fibre reinforced concrete - Revisited in the Indian context

Given a connected outerplanar graph G of pathwidth p, we give an algorithm to add edges to G to get a supergraph of G, which is 2-vertex-connected, outerplanar and of pathwidth O(p). This settles an open problem raised by Biedl [1], in the context of computing minimum height planar straight line drawings of outerplanar graphs, with their vertices placed on a two-dimensional grid. In conjunction with the result of this paper, the constant factor approximation algorithm for this problem obtained by Biedl [1] for 2-vertex-connected outerplanar graphs will work for all outer planar graphs. © 2014 Elsevier B.V.

Theoretical Computer Science

2-Connecting outerplanar graphs without blowing up the pathwidth

In recent years, materials with unique metallurgical properties such as Inconel-718 have been developed to meet the demands of extreme applications. In this paper an experimental investigation has been carried out to study the influence of various parameters like peak current, pulse-on time and dielectric flushing pressure on EDM deep-hole drilling of Inconel-718. Copper tube of external diameter 2.5 mm and internal diameter 1 mm was selected as the tool electrode which provides flow of dielectric through the electrode, thereby making the process of flushing less critical. Moreover, the performance of machining is evaluated in terms of material removal rate (MRR), electrode wear ratio (EWR) and overcut. Optical microscope was used to judge the quality at the rim of the drilled holes. Peak current, pulse-on time and flushing pressure were found to be the most critical parameters in EDM deep-hole drilling of Inconel-718.

Conference Proceedings - 14th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2014

EDM drilling of Inconel-718 using copper tube electrode

Post-grouting of deep foundations following installation is a proven technique for enhancing axial resistance. The grouting is performed either below the tip of the foundation only (e.g., post-tip-grouted drilled shafts) or at both the side and the tip (e.g., jetted, side, and tipgrouted precast piles). The interaction of such foundations in group placement is currently unknown. This research focused on the group behavior of post-tip-grouted drilled shafts and jetted, side, and tip-grouted piles at a center-to-center spacing of three times the pile/shaft diameter. The study revealed that the post-tip-grouted drilled shafts acted independently within the group (i.e., negligible group interaction), whereas jetted, side, and tip-grouted piles behaved as a block under axial loading. It was determined that side grouting of a foundation prior to tip grouting significantly increases the grout pressure developed during tip grouting and helps in the formation of a tip grout bulb via a spherical cavity expansion process. Thus, the side and tip grouting of adjacent foundations within a group increases the confining stress and relative density of the soil mass within the group, resulting in block behavior under top-down loading. In contrast, tip-only grouted foundations showed little if any increase in radial stress and radial soil displacement, resulting in minimal improvement of the soil stiffness between shafts; as a result there was no block behavior and a negligible group effect at the tip. Copyright © 2014 by ASTM Int'l (all rights reserved); Mon Jul 14 01:15:34 EDT.