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

In this paper, we investigate streaming codes over a three-node relay network. Source node transmits a sequence of message packets to the destination via a relay. Source-to-relay and relay-to-destination links are unreliable and introduce at most N1 and N2 packet erasures, respectively. Destination needs to recover each message packet with a strict decoding delay constraint of T time slots. We propose streaming codes under this setting for all feasible parameters N1, N_2, T. Relay naturally observes erasure patterns occurring in the source-to-relay link. In our code construction, we employ a channel-state-dependent relaying strategy, which rely on these observations. In a recent work, Fong et al. provide streaming codes featuring channel-state-independent relaying strategies, for all feasible parameters N1, N_2, T. Our schemes offer a strict rate improvement over the schemes proposed by Fong et al., whenever N_1< N_2. © 2021 IEEE.

Department of Data Science

World University root node

2021 IEEE Information Theory Workshop, ITW 2021 - Proceedings

High Rate Streaming Codes over the Three-Node Relay Network

In the conventional cascaded H-bridge-based split-battery energy storage (CHB-SBES) system, the dc-bus voltages are measured for state-of-charge (SoC) balancing and charge/discharge control of battery packs, and multilevel voltages are sensed for open-circuit (OC) fault detection in the submodules. In this paper, a new control approach is proposed where the multilevel voltage measurement of the CHB-SBES system alone is utilized for control (i.e., SoC balancing and charge/discharge control) as well as fault detection. The dc-bus voltage of each submodule is estimated from the measured multilevel voltages, gating signals and grid currents for control purposes. Further, to localize OC faults within a fundamental line cycle, a simplified fault detection method is proposed using the estimated dc-bus voltages. The proposed method eliminates n dc-bus voltage sensors per phase and the associated sensor power supplies in CHB-SBES system, where n is the number of submodules per phase. Results from MATLAB-Simulink model are presented to validate the proposed method.

Department of Electrical Engineering

Operation of Cascaded H-bridge-Based Split-Battery Energy Storage System With Reduced Sensors

Streaming codes are a class of packet-level erasure codes that ensure packet recovery over a sliding window channel which allows either a burst erasure of size b or a random erasures within any window of size (\tau+1) time units, under a strict decoding-delay constraint \tau. The field size over which streaming codes are constructed is an important factor determining the complexity of implementation. The best known explicit rate-optimal streaming code requires a field size of q^{2} where q\geq\tau+b-a is a prime power. In this work, we present an explicit rate-optimal streaming code, for all possible \{a, b,\tau\} parameters, over a field of size q^{2} for prime power q\geq \tau. This is the smallest-known field size of a general explicit rate-optimal construction that covers all \{a, b, \tau\} parameter sets. We achieve this by modifying the non-explicit code construction due to Krishnan et al. to make it explicit, without change in field size. © 2021 IEEE.

IEEE International Symposium on Information Theory - Proceedings

Explicit Rate-Optimal Streaming Codes with Smaller Field Size

DC microgrids with photovoltaic (PV) systems often incorporate a battery energy storage system (BESS) to regulate the dc bus voltage fluctuations due to the intermittent irradiance changes and load transients. Traditional control schemes do not consider the battery charging rate, leading to high current stress and shortening the battery lifetime. In this paper, a coordinated control for a PV system and the BESS is proposed, which implements a deterministic rule-based control strategy that regulates the battery charging rate depending on the available PV power reserve and the battery state-of-charge. Furthermore, the proposed control considers the PV system as the primary dc voltage regulator and treats the BESS as a secondary voltage regulating resource. The performance of the proposed control is investigated via simulation results. © 2021 IEEE.

2021 IEEE Energy Conversion Congress and Exposition, ECCE 2021 - Proceedings

Control Strategy for Effective Battery Utilization in a Stand-Alone DC Microgrid with Solar Energy

We study the kinetics of crystallization in deeply supercooled liquid silicon employing computer simulations and the Stillinger-Weber three-body potential. The free energy barriers to crystallization are computed using umbrella sampling Monte Carlo simulations and from unconstrained molecular dynamics simulations using a mean first passage time formulation. We focus on state points that have been described in earlier work [S. Sastry and C. A. Angell, Nat. Mater. 2, 739 (2003)] as straddling a liquid-liquid phase transition (LLPT) between two metastable liquid states. It was argued subsequently [Ricci et al., Mol. Phys. 117, 3254 (2019)] that the apparent transition is due to the loss of metastability of the liquid state with respect to the crystalline state. The presence of a barrier to crystallization for these state points is therefore of importance to ascertain, which we investigate, with due attention to ambiguities that may arise from the choice of order parameters. We find a well-defined free energy barrier to crystallization and demonstrate that both umbrella sampling and mean first passage time methods yield results that agree quantitatively. Our results thus provide strong evidence against the possibility that the liquids at state points close to the reported LLPT exhibit slow, spontaneous crystallization, but they do not address the existence of a LLPT (or lack thereof). We also compute the free energy barriers to crystallization at other state points over a broad range of temperatures and pressures and discuss the effect of changes in the microscopic structure of the metastable liquid on the free energy barrier heights. © 2021 Author(s).

Department of Physics

Fulltext

Journal of Chemical Physics

Thermodynamics and kinetics of crystallization in deeply supercooled Stillinger-Weber silicon

We consider the problem (Formula presented.) where (Formula presented.), n>2, λ is a positive parameter, (Formula presented.) belongs to a class of continuous functions which satisfy certain decay assumptions, and (Formula presented.) belongs to a class of continuous functions which are superlinear at ∞ with (Formula presented.). Recently, several authors have studied positive radial solutions to this problem assuming that the weight function is radial. We allow non-radial weights and study the existence and non-existence of positive solutions. We prove the existence of a positive solution for small values of λ using variational methods. A non-existence result is established for large values of λ. © 2021 Informa UK Limited, trading as Taylor & Francis Group.

Department of Mathematics

Complex Variables and Elliptic Equations

Positive solutions to superlinear semipositone problems on the exterior of a ball

This study presents a novel digital control algorithm with state estimator technique for semi-active control of structures with magneto-rheological (MR) damper. The proposed control strategy is based on servomechanism (popularly known as command-following or tracking system), where the measured output of a system pursues the command of reference input. This is achieved through a hybrid proportional–integral (PI) controller, different from the conventional output or state-based feedback design, where the control force is proportional to the feedback of internal state (i.e., displacement and velocity) as well as the integral state (i.e., integral of output error signal) of the system. In this approach, optimal observer technique through Kalman filter is modified to estimate the full state and integral state vector of the system for feedback from the measured absolute acceleration output. Optimal gains of the proposed regulator (i.e., both proportional and integrator gains) and estimator are formulated by minimizing a desired performance index in discrete time. In addition, the present study proposes a direct algorithm, where the applied voltage to the MR damper varies continuously between the maximum and minimum range instead of being restricted to only maximum and minimum values. The adequacy of the proposed strategy is studied in terms of reduction in the following: (a) structural responses, (b) optimal control force, (c) sensor noise and process noise covariance of the filter output, and (d) applied voltage (as compared to clipped on–off case). Finally, it has been demonstrated that the proposed control algorithm provides superior performance and stability in comparison to the conventional proportional (state)-based techniques. © 2021 John Wiley & Sons, Ltd.

Department of Civil Engineering

Structural Control and Health Monitoring

A novel servomechanism based proportional–integral controller with Kalman filter estimator for seismic response control of structures using magneto-rheological dampers

A collection of linear orders on X, say L, is said to realize a partially ordered set (or poset) P= (X, ≼) if, for any two distinct x,y ∈ X, x ≼ y if and only if x ≺Ly, ∀ L∈ L. We call L a realizer of P. The dimension of P, denoted by dim(P) , is the minimum cardinality of a realizer of P. A containment modelMP of a poset P= (X, ≼) maps every x ∈ X to a set Mx such that, for every distinct x,y ∈ X, x ≼ y if and only if Mx⫋ My. We shall be using the collection (Mx)x∈X to identify the containment model MP. A poset P= (X, ≼) is a Containment order of Paths in a Tree (CPT poset), if it admits a containment model MP=(Px)x∈X where every Px is a path of a tree T, which is called the host tree of the model. We show that if a poset P admits a CPT model in a host tree T of maximum degree Δ and radius r, then dim(P)≤lglgΔ+(12+o(1))lglglgΔ+lgr+12lglgr+12lgπ+3. This bound is asymptotically tight up to an additive factor of min(12lglglgΔ,12lglgr). Further, let P(1 , 2 ; n) be the poset consisting of all the 1-element and 2-element subsets of [n] under ‘containment’ relation and let dim(1,2;n) denote its dimension. The proof of our main theorem gives a simple algorithm to construct a realizer for P(1 , 2 ; n) whose cardinality is only an additive factor of at most 32 away from the optimum. © 2020, Springer Nature B.V.

Department of Computer Science and Engineering

Order

Dimension of CPT Posets

Let G be a graph with no isolated vertices. A k-coupon coloring of G is an assignment of k colors to the vertices of G such that every vertex contains vertices of all k colors in its neighborhood. The coupon chromatic number of G, denoted χc(G), is the maximum k for which a k-coupon coloring exists. In this paper, we present an upper bound for the coupon chromatic number of Cartesian product of graphs G and H in terms of |V(G)| and |V(H)|. Further, we prove that if G and H are bipartite graphs then G□ H has a coupon coloring with 2 min { χc(G), χc(H) } colors. As consequences, for any positive integer n, we obtain the coupon chromatic number and total domination number of n-dimensional torus □i=1nCki with some suitable conditions to each ki, which turns out to be a generalization of the result due to S. Gravier [Total domination number of grid graphs, Discrete Appl. Math. 121 (2002) 119–128]. Finally, for any r≥ 0, d≥ 2, we obtain the coupon coloring for the Hamming graph Kd□ Kd□ ⋯ □ Kd (2r times). © 2021, Springer Nature Switzerland AG.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

On Coupon Coloring of Cartesian Product of Some Graphs

(1) Background: Chorea-acanthocytosis and McLeod syndrome are the core diseases among the group of rare neurodegenerative disorders called neuroacanthocytosis syndromes (NASs). NAS patients have a variable number of irregularly spiky erythrocytes, so-called acanthocytes. Their detection is a crucial but error-prone parameter in the diagnosis of NASs, often leading to misdiagnoses. (2) Methods: We measured the standard Westergren erythrocyte sedimentation rate (ESR) of various blood samples from NAS patients and healthy controls. Furthermore, we manipulated the ESR by swapping the erythrocytes and plasma of different individuals, as well as replacing plasma with dextran. These measurements were complemented by clinical laboratory data and single-cell adhesion force measurements. Additionally, we followed theoretical modeling approaches. (3) Results: We show that the acanthocyte sedimentation rate (ASR) with a two-hour read-out is significantly prolonged in chorea-acanthocytosis and McLeod syndrome without overlap compared to the ESR of the controls. Mechanistically, through modern colloidal physics, we show that acanthocyte aggregation and plasma fibrinogen levels slow down the sedimentation. Moreover, the inverse of ASR correlates with the number of acanthocytes (R2 = 0.61, p = 0.004). (4) Conclusions: The ASR/ESR is a clear, robust and easily obtainable diagnostic marker. Independently of NASs, we also regard this study as a hallmark of the physical view of erythrocyte sedimentation by describing anticoagulated blood in stasis as a percolating gel, allowing the application of colloidal physics theory. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.