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 study vector codes with all-symbol locality, where the local code is either a Minimum Bandwidth Regenerating (MBR) code or a Minimum Storage Regenerating (MSR) code. In the first part, we present vector codes with all-symbol MBR locality, for all parameters, that have both optimal minimum-distance and optimal rate. These codes combine ideas from two popular codes in the distributed storage literature; Product-Matrix codes and Tamo-Barg codes. In the second part which deals with codes having all-symbol MSR locality, we follow a Pairwise Coupling Transform-based approach to arrive at optimal minimum-distance and optimal rate, for a range of parameters. All the code constructions presented in this paper have a low field-size that grows linearly with the code-length n. © 2018 IEEE.

Department of Data Science

World University root node

IEEE International Symposium on Information Theory - Proceedings

Codes with Combined Locality and Regeneration Having Optimal Rate, dmin and Linear Field Size

Recovery of data packets from packet erasures in a timely manner is critical for many streaming applications. An early paper by Martinian and Sundberg introduced a framework for streaming codes and designed rate-optimal codes that permit delay-constrained recovery from an erasure burst of length up to B. A recent work by Badr et al. extended this result and introduced a sliding-window channel model C(N, B, W). Under this model, in a sliding-window of width W, one of the following erasure patterns are possible (i) a burst of length at most B or (ii) at most N (possibly non-contiguous) arbitrary erasures. Badr et al. obtained a rate upper bound for streaming codes that can recover with a time delay T, from any erasure patterns permissible under the C(N, B, W) model. However, constructions matching the bound were absent, except for a few parameter sets. In this paper, we present a family of codes that achieves the rate upper bound for all feasible parameters N, B, W and T. © 2018 IEEE.

Rate-Optimal Streaming Codes for Channels with Burst and Isolated Erasures

Among the materials, composites have unique properties due to less weight and high strength thus meeting the specific requirements for given applications with greater advantages. However, functionally graded materials (FGMs) are a special class of composites. FGMs gained more importance because they have diversified and potential applications in various areas such as automotive, marine, aerospace, medical, etc. FGMs have good mechanical properties and can retain the properties even at high temperatures if design and process is proper. The development of FGMs offers freedom to develop the components with specific properties along different directions with various ratios. The FGMs are fabricated by various methods with various sizes. Hence, in this work, a review of various processing methods for surface coatings and bulk FGMs, FGM applications, and recent research activities on FGMs with more emphasis on additive manufacturing (AM) processes have been done. © 2018 Elsevier Ltd. All rights reserved.

Department of Mechanical Engineering

Materials Today: Proceedings

Functionally graded materials and processing techniques: An art of review

We use a combination of confocal microscopy, rheology, and molecular dynamics simulations to investigate jammed emulsions under shear, by analyzing the 3D droplets rearrangements in the shear frame. Our quantitative analysis of local dynamics reveals elementary nonaffine rearrangements that underlie the onset of the flow at small strains. We find that the mechanism of unjamming and the upturn in the material flow curve are associated to a qualitative change in spatiotemporal correlations of such rearrangements with the applied shear rate. At high shear rates, droplet clusters follow coordinated, stringlike motion. Conversely, at low shear rates, the elementary nonaffine rearrangements exhibit longer-ranged correlations, with complex spatiotemporal patterns. The 3D microscopic details provide novel insights into the specific features of the material flow curve, common to a large class of technologically relevant soft disordered solids and new fundamental ingredients for constitutive models. © 2018 American Physical Society.

Department of Physics

Physical Review Letters

Rate Dependence of Elementary Rearrangements and Spatiotemporal Correlations in the 3D Flow of Soft Solids

We develop a new method, Stars' Galactic Origin (StarGO), to identify the galactic origins of halo stars using their kinematics. Our method is based on a self-organizing map (SOM), which is one of the most popular unsupervised learning algorithms. StarGO combines SOM with a novel adaptive group identification algorithm with essentially no free parameters. To evaluate our model, we build a synthetic stellar halo from mergers of nine satellites in the Milky Way. We construct the mock catalog by extracting a heliocentric volume of 10 kpc from our simulations and assigning expected observational uncertainties corresponding to bright stars from Gaia DR2 and LAMOST DR5. We compare the results from StarGO against those from a friends-of-friends-based method in the space of orbital energy and angular momentum. We show that StarGO is able to systematically identify more satellites and achieve higher number fraction of identified stars for most of the satellites within the extracted heliocentric volume. When applied to data from Gaia DR2, StarGO will enable us to reveal the origins of the inner stellar halo in unprecedented detail. © 2018. The American Astronomical Society. All rights reserved.

Astrophysical Journal

StarGO: A New Method to Identify the Galactic Origins of Halo Stars

Stay cable systems are used extensively for the construction of long-span bridges owing to their inherent advantages. In most cable-stayed bridges the steel strands within the main tension elements (MTEs) are grouted to provide a corrosion protection system. However, there could be segregated grout, voids, and water accumulation/infiltration within these voids in the ducts due to poor quality of the grouting material and grouting techniques. These locations may act as initiators for the corrosion of steel strands within the ducts, which can have serious implications on the load carrying capacity and safety of cable-stayed bridges. In this investigation, several nondestructive evaluation (NDE) techniques are evaluated to determine their ability to detect grout defects within the anchorage regions, end caps, and MTEs of the stay cable system. Four stay cable specimen mock-ups with known grout defects and voids were fabricated. NDE methods that were part of this investigation included ground penetrating radar, infrared thermography, electrical capacitance tomography, impact echo, sounding, ultrasonic tomography, ultrasonic pulse velocity, low frequency ultrasound, visual testing, and borescope. While a few NDE methods could identify voids and water infiltration defects within the high-density polyethylene (HDPE) MTEs, it is evident that there is still a need for a method that is effective in detecting grout defects within the metal ducts embedded in the anchorage region and metal MTEs. Although visual testing and borescope methods are effective in identifying the defects, prior information about the location of the defects is generally required. © National Academy of Sciences: Transportation Research Board 2018.

Department of Civil Engineering

Transportation Research Record

Nondestructive Evaluation of Non-Strand Defects in Stay Cable Specimens

For a family of graphs F, an n-vertex graph G, and a positive integer k, the F-Deletion problem asks whether we can delete at most k vertices from G to obtain a graph in F. F-Deletion generalizes many classical graph problems such as Vertex Cover, Feedback Vertex Set, and Odd Cycle Transversal. A (multi) graph G = (V, ?ai=1Ei), where the edge set of G is partitioned into a color classes, is called an a-edge-colored graph. A natural extension of the F-Deletion problem to edge-colored graphs is the Simultaneous (F1, . . ., Fa)-Deletion problem. In the latter problem, we are given an a-edge-colored graph G and the goal is to find a set S of at most k vertices such that each graph Gi - S, where Gi = (V, Ei) and 1 = i = a, is in Fi. Recently, a subset of the authors considered the aforementioned problem with F1 = . . . = Fa being the family of all forests. They showed that the problem is fixed-parameter tractable when parameterized by k and a and can be solved in O(2O(ak)) time1. In this work, we initiate the investigation of the complexity of Simultaneous (F1, . . ., Fa)-Deletion with di erent families of graphs. In the process, we obtain a complete characterization of the parameterized complexity of this problem when one or more of the Fis is the class of bipartite graphs and the rest (if any) are forests. We show that if F1 is the family of all bipartite graphs and each of F2 = F3 = . . . = Fa is the family of all forests then the problem is fixed-parameter tractable parameterized by k and a. However, even when F1 and F2 are both the family of all bipartite graphs, then the Simultaneous (F1, F2)-Deletion problem itself is already W[1]-hard. © Akanksha Agrawal, R. Krithika, Daniel Lokshtanov, Amer E. Mouawad, and M. S. Ramanujan.

Department of Computer Science and Engineering

Leibniz International Proceedings in Informatics, LIPIcs

On the parameterized complexity of simultaneous deletion problems

Cryptographic primitives need high-speed implementations that are also resistant to side channel attacks. The absolute control over instructions and registers that such implementations demand makes assembly language programming a necessity. In this article, we describe Verse, a typed low-level language embedded in Coq designed specifically to generate assembly language programs for cryptographic primitives. Despite being a low-level language, the programming experience is markedly high-level: • The type system of Verse is rich enough to even prevent errors in array indexing and endian conversion. • Being embedded in Coq, we have at our disposal Gallina, the underlying functional programming language, as a macro assembler for code generation, and Ltac, the tactic language, as an automation tool for proof obligations inherent to our type system. We also provide a generic framework to formulate semantic aspects of Verse. This framework has value beyond providing an interpretation of Verse in Coq. We demonstrate this versatility by using it to localise uninitialised/clobbered variable use, and arithmetic overflows. © 2018 Association for Computing Machinery.

ACM International Conference Proceeding Series

Verse: An EDSL for cryptographic primitives

Let σ be some positive integer and (formula presented). The theory behind finding a lower bound on the number of distinct blocks P 1 , …, P σ ∈ {0, 1} n satisfying a set of linear equations {P i ⊕ P j = c i,j : (i, j) ∈ C} for some c i,j ∈ {0, 1} n , is called mirror theory. Patarin introduced the mirror theory and provided a proof for this. However, the proof, even for a special class of equations, is complex and contains several non-trivial gaps. As an application of mirror theory, XORP[w] (known as XOR construction) returning (w − 1) block output, is a pseudorandom function (PRF) for some parameter w, called width. The XOR construction can be seen as a basic structure of some encryption algorithms, e.g., the CENC encryption and the CHM authenticated encryption, proposed by Iwata in 2006. Due to potential application of XORP[w] and the nontrivial gaps in the proof of mirror theory, an alternative simpler analysis of PRF-security of XORP[w] would be much desired. Recently (in Crypto 2017) Dai et al. introduced a tool, called the χ 2 method, for analyzing PRF-security. Using this tool, the authors have provided a proof of PRF-security of XORP[2] without relying on the mirror theory. In this paper, we resolve the general case; we apply the χ 2 method to obtain a simpler security proof of XORP[w] for any w ≥ 2. For w = 2, we obtain a tighter bound for a wider range of parameters than that of Dai et al.. Moreover, we consider variable width construction XORP[∗] (in which the widths are chosen by adversaries adaptively), and also provide variable output length pseudorandom function (VOLPRF) security analysis for it. As an application of VOLPRF, we propose an authenticated encryption which is a simple variant of CHM or AES-GCM and provides much higher security than those at the cost of one extra blockcipher call for every message. © 2018, Ruhr-Universitat Bochum. All rights reserved.

IACR Transactions on Symmetric Cryptology

Revisiting variable output length XOR pseudorandom function

Very recently (in CRYPTO 2017) Dai, Hoang, and Tessaro have introduced the Chi-square method (χ2 method) which can be applied to obtain an upper bound on the statistical distance between two joint probability distributions. The authors have applied this method to prove the pseudorandom function security (PRF-security) of sum of two random permutations. In this work, we revisit their proof and find a non-trivial gap in the proof. We plug this gap for two specific cases and state the general case as an assumption whose proof is essential for the completeness of the proof by Dai et al. A complete, correct, and transparent proof of the full security of the sum of two random permutations construction is much desirable, especially due to its importance and two decades old legacy. The proposed χ2 method seems to have potential for application to similar problems, where a similar gap may creep into a proof. These considerations motivate us to communicate our observation in a formal way. On the positive side, we provide a very simple proof of the PRF-security of the truncated random permutation construction (a method to construct PRF from a random permutation) using the χ2 method. We note that a proof of the PRF-security due to Stam is already known for this construction in a purely statistical context. However, the use of the χ2 method makes the proof much simpler. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.