Improved source localization with LIGO India

A global network of advanced gravitational wave interferometric detectors is under construction. These detectors will offer an order of magnitude improvement in sensitivity over the initial detectors and will usher in the era of gravitational wave astronomy. In this paper, we evaluate the benefits of relocating one of the advanced LIGO detectors to India.Comment: 7 pages, 3 figures, accepted for publication in proceedings of ICGC2011 conference. Localization figures update

Investigating the impact of combining handwritten signature and keyboard keystroke dynamics for gender prediction

© 2019 IEEE. The use of soft-biometric data as an auxiliary tool on user identification is already well known. Gender, handorientation and emotional state are some examples which can be called soft-biometrics. These soft-biometric data can be predicted directly from the biometric templates. It is very common to find researches using physiological modalities for soft-biometric prediction, but behavioural biometric is often not well explored for this context. Among the behavioural biometric modalities, keystroke dynamics and handwriting signature have been widely explored for user identification, including some soft-biometric predictions. However, in these modalities, the soft-biometric prediction is usually done in an individual way. In order to fill this space, this study aims to investigate whether the combination of those two biometric modalities can impact the performance of a soft-biometric data, gender prediction. The main aim is to assess the impact of combining data from two different biometric sources in gender prediction. Our findings indicated gains in terms of performance for gender prediction when combining these two biometric modalities, when compared to the individual ones

A cross-layer architecture for satellite network security: CL-IPsec

Cross-layer architectures (CLAs) are proposed to improve performance in networks where physical layer impairments are unpredictable and provision of security services may be challenging, as in satellite networks. This paper proposes an extension to the IPsec protocol, named Cross-Layer IPsec (CL-IPsec), able to provide authentication and integrity services through a cross-layer architecture when the adopted protocol is UDP-Lite. This is suitable for multicast applications that are cost-effectively provided by satellite systems. A satellite emulation platform has been used to validate the CL-IPsec implementation and to evaluate the performance improvement derived from the proposed CLA. © 2008 IEEE

Network layer security: Design for a cross layer architecture

Traditional modular layering schemes have served a major part in the development of a variety of protocols. However, as the physical layer impairments become more unpredictable, a cross layer design (CLD) which is dynamic in nature provides better performance. CLD introduces new challenges in protocol design as well as in the area of security. Using numerical analysis, we show that a link layer design employing header compression and cross layer signalling to protect protocol headers can limit packet discarding. This paper also reviews the IPsec protocol and describes how IPsec can be modified for cross layer architecture. © 2007 IEEE

Nebular Line Emission During the Epoch of Reionization

Nebular emission lines associated with galactic HII regions carry information about both physical properties of the ionised gas and the source of ionising photons as well as providing the opportunity of measuring accurate redshifts and thus distances once a cosmological model is assumed. While nebular line emission has been extensively studied at lower redshift there are currently only few constraints within the epoch of reionisation (EoR, $z>6$), chiefly due to the lack of sensitive near-IR spectrographs. However, this will soon change with the arrival of the Webb Telescope providing sensitive near-IR spectroscopy covering the rest-frame UV and optical emission of galaxies in the EoR. In anticipation of Webb we combine the large cosmological hydrodynamical simulation Bluetides with photoionisation modelling to predict the nebular emission line properties of galaxies at $z=8\to 13$. We find good agreement with the, albeit limited, existing direct and indirect observational constraints on equivalent widths though poorer agreement with luminosity function constraints.Comment: 17 pages, accepted to MNRAS, significant modification from v1.0 data available at https://stephenmwilkins.github.io/BluetidesEmissionLines_Public

A universal constraint between charge and rotation rate for degenerate black holes surrounded by matter

We consider stationary, axially and equatorially symmetric systems consisting of a central rotating and charged degenerate black hole and surrounding matter. We show that $a^2+Q^2=M^2$ always holds provided that a continuous sequence of spacetimes can be identified, leading from the Kerr-Newman solution in electrovacuum to the solution in question. The quantity $a=J/M$ is the black hole's intrinsic angular momentum per unit mass, $Q$ its electric charge and $M$ the well known black hole mass parameter introduced by Christodoulou and Ruffini.Comment: 19 pages, 2 figures, replaced with published versio

Evaluating the impact of transport mechanisms on web performance for effective web access

Peer reviewedPostprin

A critical reflection of current trends in discourse analytical research on leadership across disciplines. A call for a more engaging dialogue

This paper takes the frequently lamented state of current leadership research in business and organisational sciences as a starting point and argues for a more open and engaging dialogue with leadership researchers in applied linguistics and pragmatics. Focusing on current debates around terminological issues and methodological questions that are particularly prominent in critical leadership studies, we show that research in applied linguistics and pragmatics has the potential to make important contributions by providing the analytical tools and processes to support critical leadership researchers in their quest to challenge hegemonic notions of leadership by moving beyond simplistic and often problematic leader-follower dichotomies and by providing empirical evidence to capture leadership in situ thereby feeding into current theorisations of leadership

Loop Quantum Geometry: A primer

This is the written version of a lecture given at the ``VI Mexican School of Gravitation and Mathematical Physics" (Nov 21-27, 2004, Playa del Carmen, Mexico), introducing the basics of Loop Quantum Geometry. The purpose of the written contribution is to provide a Primer version, that is, a first entry into Loop Quantum Gravity and to present at the same time a friendly guide to the existing pedagogical literature on the subject. This account is geared towards graduate students and non-experts interested in learning the basics of the subject.Comment: 25 pages. Contribution for the Proceedings of the VI Mexican School of Gravitation and Mathematical Physics. Corrected typo

Horizon energy and angular momentum from a Hamiltonian perspective

Classical black holes and event horizons are highly non-local objects, defined in terms of the causal past of future null infinity. Alternative, (quasi)local definitions are often used in mathematical, quantum, and numerical relativity. These include apparent, trapping, isolated, and dynamical horizons, all of which are closely associated to two-surfaces of zero outward null expansion. In this paper we show that three-surfaces which can be foliated with such two-surfaces are suitable boundaries in both a quasilocal action and a phase space formulation of general relativity. The resulting formalism provides expressions for the quasilocal energy and angular momentum associated with the horizon. The values of the energy and angular momentum are in agreement with those derived from the isolated and dynamical horizon frameworks.Comment: 39 pages, 3 figures, Final Version : content essentially unchanged but many small improvements made in response to referees, a few references adde