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.

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IIT Palakkad

The ε-pseudospectrum Λε (a) of an element a of an arbitrary Banach algebra A is studied. Its relationships with the spectrum and numerical range of a are given. Characterizations of scalar, Hermitian and Hermitian idempotent elements by means of their pseudospectra are given. The stability of the pseudospectrum is discussed. It is shown that the pseudospectrum has no isolated points, and has a finite number of components, each containing an element of the spectrum of a. Suppose for some ε &gt; 0 and a,b ∈ A, Λε (ax) = Λε (bx) ∀x ∈ A. It is shown that a = b if: (i) a is invertible. (ii) a is Hermitian idempotent. (iii) a is the product of a Hermitian idempotent and an invertible element. (iv) A is semisimple and a is the product of an idempotent and an invertible element. (v) A = B(X) for a Banach space X. (vi) A is a C∗ -algebra. (vii) A is a commutative semisimple Banach algebra. © ELEMENT, Zagreb.

World University root node

Department of Mathematics

Operators and Matrices

Pseudospectrum of an element of a Banach algebra

A stochastic version of the Barkai-Leibler model of chemotaxis receptors in Escherichia coli is studied here with the goal of elucidating the effects of intrinsic network noise in their conformational dynamics. The model was originally proposed to explain the robust and near-perfect adaptation of E. coli observed across a wide range of spatially uniform attractant/repellent (ligand) concentrations. In the model, a receptor is either active or inactive and can stochastically switch between the two states. The enzyme CheR methylates inactive receptors while CheB demethylates active receptors and the probability for a receptor to be active depends on its level of methylation and ligand occupation. In a simple version of the model with two methylation sites per receptor (M = 2), we show rigorously, under a quasi-steady state approximation, that the mean active fraction of receptors is an ultrasensitive function of [CheR]/[CheB] in the limit of saturating receptor concentration. Hence the model shows zeroorder ultrasensitivity (ZOU), similar to the classical two-state model of covalent modification studied by Goldbeter and Koshland (GK). We also find that in the limits of extremely small and extremely large ligand concentrations, the system reduces to two different two-state GK modules. A quantitative measure of the spontaneous fluctuations in activity is provided by the variance s2 a in the active fraction, which is estimated mathematically under linear noise approximation (LNA). It is found that s2 a peaks near the ZOU transition. The variance is a nonmonotonic, but weak function of ligand concentration and a decreasing function of receptor concentration. Gillespie simulations are also performed in models with M = 2, 3 and 4. For M = 2, simulations show excellent agreement with analytical results obtained under LNA. Numerical results for M = 3 and M = 4 are qualitatively similar to our mathematical results in M = 2; while all the models show ZOU in mean activity, the variance is found to be smaller for larger M. The magnitude of receptor noise deduced from available experimental data is consistent with our predictions. A simple analysis of the downstream signaling pathway shows that this noise is large enough to affect the motility of the organism, and may have a beneficial effect on it. The response of mean receptor activity to small time-dependent changes in the external ligand concentration is computed within linear response theory, and found to have a bilobe form, in agreement with earlier experimental observations. © 2017 Roy, Gopalakrishnan. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Department of Physics

Fulltext

PLoS ONE

Ultrasensitivity and fluctuations in the Barkai-Leibler model of chemotaxis receptors in Escherichia coli

Campaigners, advertisers, and activists are increasingly turning to social recommendation mechanisms, provided by social media, for promoting their products, services, brands, and even ideas. However, many a time, such social network-based campaigns perform poorly in practice, because the intensity of recommendations drastically reduces beyond a few hops from the source. A natural strategy for maintaining the intensity is to provide incentives. In this paper, we address the problem of minimizing the cost incurred by the campaigner for incentivizing a fraction of individuals in the social network, while ensuring that the campaign message reaches a given expected fraction of individuals. We also address the dual problem of maximizing the campaign penetration for a resource constrained campaigner. To help us understand and solve the above-mentioned problems, we use percolation theory to formally state them as optimization problems. These problems are not amenable to traditional approaches because of a fixed point equation that needs to be solved numerically. However, we use results from reliability theory to establish some key properties of the fixed point, which in turn enables us to solve these problems using algorithms that are linearithmic in maximum node degree. Furthermore, we evaluate the efficacy of the analytical solutions by performing simulations on real-world networks. © 2017 IEEE.

Department of Computer Science and Engineering

IEEE/ACM Transactions on Networking

Incentivized campaigning in social networks

In this paper, we present a generic controller that ensures fair and efficient operation of IEEE 802.11 infrastructure wireless local area networks (WLANs) with multiple co-channel access points. Our controller addresses performance issues of long-lived TCP transfers in multi-AP WLANs, by overlaying a coarse time-slicing scheduler on top of a cascaded fair queuing scheduler. The time slices and queue weights, used in our controller, are obtained from the solution of a constrained utility optimization formulation. A study of the impact of coarse time-slicing on TCP is also presented in this paper. We also present a methodology to improve the performance of co-existing short-lived and interactive TCP flows. Finally, we report the results of experiments performed on a real testbed, demonstrating the efficacy of our controller. © 2017 Elsevier Ltd

Journal of Network and Computer Applications

A generic controller for managing TCP transfers in IEEE 802.11 infrastructure WLANs

In this paper, we introduce the first method that (1) can complete kernel matrices with completely missing rows and columns as opposed to individual missing kernel values, with help of information from other incomplete kernel matrices. Moreover, (2) the method does not require any of the kernels to be complete a priori, and (3) can tackle non-linear kernels. The kernel completion is done by finding, from the set of available incomplete kernels, an appropriate set of related kernels for each missing entry. These aspects are necessary in practical applications such as integrating legacy data sets, learning under sensor failures and learning when measurements are costly for some of the views. The proposed approach predicts missing rows by modelling both within-view and between-view relationships among kernel values. For within-view learning, we propose a new kernel approximation that generalizes and improves Nyström approximation. We show, both on simulated data and real case studies, that the proposed method outperforms existing techniques in the settings where they are available, and extends applicability to new settings. © 2016, The Author(s).

Department of Data Science

Machine Learning

Multi-view kernel completion

In order to enable the adoption of fibre reinforced concrete (FRC) in applications such as slabs-on-grade, it is imperative to develop comprehensive guidelines that address different facets of the slab behavior. The current study aims at providing a design methodology for FRC slabs-on-grade and pavements, which incorporates suitable material parameters and considers various failure conditions. The approach is based on inelastic analysis since the presence of fibres imparts sufficient rotation capacity to the slabs. The equivalent flexural strength, fiflα150fifl is used to incorporate the crack resisting potential in the design. The required expressions are developed based on yield line analysis for different types of loads and lead to performance requirements in terms of the equivalent flexural strength, for a minimum thickness and chosen grade of concrete, by using appropriate limiting moment equations. The methodology also accounts for stresses due to temperature variations and restraint to shrinkage. A detailed calculation is also given to illustrate the use of the design procedure.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

Indian Concrete Journal

Design methodology for fibre reinforced concrete slabs-on-grade based on inelastic analysis

Comprehensive modelling of urban freight operations remains a challenge in transportation research. This is partly due to the diversity of commodities transported, shipment units, vehicle types used, stakeholders' objectives (e.g. suppliers, carriers, receivers), and to the limited availability of data. Thus, existing modelling efforts require several assumptions yet have limited behavioral foundations and minimal interaction between agents. This paper proposes a new agent-based modelling framework, which considers the heterogeneity of urban freight agents and their interactions. Agents include establishments (suppliers, carriers, and receivers) and freight vehicle drivers. Agents' decisions are structured in three temporal resolutions: strategic, tactical, and operational. A single set of agents is represented throughout all modelling levels ensuring a consistent and sequential flow of information. At the strategic level, establishments' characteristics and strategic decisions are modelled. These include location choices, fleet constitution, annual production/consumption of commodities, and establishment-to-establishment commodity flows. At the tactical level, shipments are assigned to carriers, who in turn plan their operations in terms of vehicle-driver-route assignments. Finally, at the operational level, the interactions between daily operational demands and transportation network supply are simulated. The supply representation has two different resolution levels (micro or meso) allowing for either detailed or computational efficient simulation. The simulation platform is distinct from previous works, as it explicitly considers planning horizons, replicates agent decision makings/interactions and involves a structure that allows for the propagation of influences bottom-up (e.g., prior simulation travel times on future route choice). The paper describes the simulation platform, constituent models, and illustrates its capabilities using an application of the modelling framework to the city of Singapore. © 2017 The Authors. Published by Elsevier B.V.

Department of Civil Engineering

Transportation Research Procedia

A multi-scale agent-based modelling framework for urban freight distribution

We study the relationship between postulation and reduction vectors of admissible multigraded filtrations F = [[[[F(n)]]]]n∈Zs of ideals in Cohen-Macaulay local rings of dimension at most two. This is enabled by a suitable generalization of the Kirby-Mehran complex. An analysis of its homology leads to an analogue of Huneke's fundamental lemma which plays a crucial role in our investigations. We also clarify the relationship between the Cohen-Macaulay property of the multigraded Rees algebra of F and reduction vectors with respect to complete reductions of F. © 2017 Rocky Mountain Mathematics Consortium.

Journal of Commutative Algebra

Postulation and reduction vectors of multigraded filtrations of ideals

We study the Wu metric for the non-convex domains of the form E2m = (z ∈ ℂn: |z1|2m + |z2|2 + · · · + |zn-1|2 + |zn|2 &lt; 1), where 0 &lt; m &lt; 1/2. We give explicit expressions for the Kobayashi metric and the Wu metric on such pseudoeggs E2m. We verify that the Wu metric is a continuous Hermitian metric on E2m, real analytic everywhere except along the complex hypersurface Z = ((0, z2, . . . , zn) ∈ E2m). We also show that the holomorphic curvature of the Wu metric for this noncompact family of pseudoconvex domains is bounded above in the sense of currents by a negative constant independent of m. This verifies a conjecture of S. Kobayashi and H. Wu for such E2m. © Indian Academy of Sciences.

Proceedings of the Indian Academy of Sciences: Mathematical Sciences

Analysing the Wu metric on a class of eggs in ℂn - II

The focus of this research was to evaluate and improve Florida Department of Transportation (FDOT) FB-Deep software prediction of nominal resistance of H-piles, prestressed concrete piles in limestone, large diameter (&gt; 36”) open steel and concrete piles, as well as estimation of unit side friction on permanent steel casing for drilled shafts in Florida limestone. To accomplish this the following data was collected, (1) 642 dynamic load tests (DLT) and 33 static load tests on H-piles, (2) 100 DLT tests for prestressed concrete piles in Florida limestone, (3) 50 open-ended steel and concrete piles (22 piles larger than 36-in) from coastal areas in the U.S. and Asia, and (4) 17 cased drilled shafts embedded in Florida limestone. Evaluation of the H-piles revealed that generally, the piles undergo both setup and plugging after driving that is lost after a few restrikes; in addition, long piles undergo skin friction unloading. Recommendations to improve FBDeep H-pile prediction include averaging Standard Penetration Test (SPT) N values only beneath the pile tip and increasing the limiting N values to 100 for strong limestone layers. In the case of prestressed concrete piles embedded in limestone, (1) weak limestone which for the purposes of this report was classified as N &lt; 45 blows per foot, exhibit unit skin friction values more representative of soil than rock/shelly sand, (2) for competent limestone (N&gt;45) the limiting SPT N value for estimating side and tip resistance should be increased to 100, and (3) the nominal tip resistance should be estimated by averaging the SPT N values within four diameters (or pile width) “B” below the pile tip. For all limestone (weak and competent), a revised unit tip resistance for 4B SPT N averaging is recommended. For all open-ended steel and concrete cylinder piles, it was found that many piles behaved plugged per the static load test results. It was established for both FB-Deep (2015) program and American Petroleum Institute (API - 2011) method that the end bearing was the minimum of inside side friction or unit end bearing acting over the bottom soil plug; in addition, the limiting N value should be increased to 100. Finally, for a permanent cased drilled shaft, the unit skin friction in load tested shafts was found to increase with rock strength to a limiting value of 1.2 tsf; an equation of nominal resistance as well as mobilized resistance as a function of displacement is presented. The contribution of casing in drilled shafts that derive most of their side resistance from the rock socket interface should not be implemented in design, due to strain incompatibility between the cased and uncased portions of the embedded length.