A Tight Lower Bound on the Sub-Packetization Level of Optimal-Access MSR and MDS Codes

The first focus of the present paper, is on lower bounds on the sub-packetization level $\alpha$ of an MSR code that is capable of carrying out repair in help-by-transfer fashion (also called optimal-access property). We prove here a lower bound on $\alpha$ which is shown to be tight for the case $d=(n-1)$ by comparing with recent code constructions in the literature. We also extend our results to an $[n,k]$ MDS code over the vector alphabet. Our objective even here, is on lower bounds on the sub-packetization level $\alpha$ of an MDS code that can carry out repair of any node in a subset of $w$ nodes, $1 \leq w \leq (n-1)$ where each node is repaired (linear repair) by help-by-transfer with minimum repair bandwidth. We prove a lower bound on $\alpha$ for the case of $d=(n-1)$. This bound holds for any $w (\leq n-1)$ and is shown to be tight, again by comparing with recent code constructions in the literature. Also provided, are bounds for the case $d<(n-1)$. We study the form of a vector MDS code having the property that we can repair failed nodes belonging to a fixed set of $Q$ nodes with minimum repair bandwidth and in optimal-access fashion, and which achieve our lower bound on sub-packetization level $\alpha$. It turns out interestingly, that such a code must necessarily have a coupled-layer structure, similar to that of the Ye-Barg code.Comment: Revised for ISIT 2018 submissio

An Integrative Review of Web 3.0 in Academic Libraries

Purpose – The aim of this paper is to present an integrated literature review exploring the nature of responsive, semantic and interactive Web 3.0 technologies applicable for academic libraries. Design/methodology/approach – We conducted an integrated review of the literature combining a strategy of automated and keywords search. The main source for identifying the studies are Emerald Library Studies and Information & Knowledge Management eJournals, Web of Knowledge, and Library, Information Science & Technology Abstracts (EBSCO) databases. To this end, a sample of (n= 140) studies were analyzed to characterize the Web 3.0 trends and its applications based on theme, years and document types. Findings – A review of literature reveals that Web 3. needs evaluation as to what extent they are integrated, deployed and mainstreamed into library services and in information management practices. It is important to develop a conceptual framework that explores the linkages of Web 3.0 technologies and their applications in academic libraries. Originality/value –This review shows how Web 3.0 technologies enhance library services in its holistic conceptualization and how academic libraries are moving into a more robust, inclusive and adaptable phase in their service values and innovation

Thermal modeling of lithium ion batteries for temperature rise predictions in hybrid vehicle application

In order to develop a hybrid vehicle with lithium ion battery packs, it is necessary to understand the thermal behaviour of the lithium ion batteries used. This paper focuses on predicting the temperature rise of lithium ion batteries during a drive cycle in hybrid two wheeler applications. To predict the rise in temperature, a model is developed in Simulink, parameterized using the empirical parameters. The model is based on the Joule heating effect and heat capacity equation while considering the variation of internal resistance with respect to ambient temperature of operation, state of charge and C rate of operation. The internal resistance is measured by parameter evaluation testing through the pulse power characterisation method. To validate the Simulink model, the lithium ion batteries are tested on standard drive cycles and constant current discharges, and the rise in temperature is measured. The accuracy of the Simulink model was found to be ± 2.2°C, which is acceptable for this study and comparable to the other available models in the literature

Brauer group of moduli spaces of pairs

We show that the Brauer group of any moduli space of stable pairs with fixed determinant over a curve is zero.Comment: 12 pages. Final version, accepted in Communications in Algebr