Privacy-Preserving iVector-Based Speaker Verification

This paper introduces an efficient algorithm to develop a privacy-preserving voice verification based on iVector and linear discriminant analysis techniques. This research considers a scenario in which users enrol their voice biometric to access different services (i.e., banking). Once enrolment is completed, users can verify themselves using their voice print instead of alphanumeric passwords. Since a voice print is unique for everyone, storing it with a third-party server raises several privacy concerns. To address this challenge, this paper proposes a novel technique based on randomization to carry out voice authentication, which allows the user to enrol and verify their voice in the randomized domain. To achieve this, the iVector-based voice verification technique has been redesigned to work on the randomized domain. The proposed algorithm is validated using a well-known speech dataset. The proposed algorithm neither compromises the authentication accuracy nor adds additional complexity due to the randomization operations

The role of flow geometry in influencing the stability criteria for low angular momentum axisymmetric black hole accretion

Using mathematical formalism borrowed from dynamical systems theory, a complete analytical investigation of the critical behaviour of the stationary flow configuration for the low angular momentum axisymmetric black hole accretion provides valuable insights about the nature of the phase trajectories corresponding to the transonic accretion in the steady state, without taking recourse to the explicit numerical solution commonly performed in the literature to study the multi-transonic black hole accretion disc and related astrophysical phenomena. Investigation of the accretion flow around a non rotating black hole under the influence of various pseudo-Schwarzschild potentials and forming different geometric configurations of the flow structure manifests that the general profile of the parameter space divisions describing the multi-critical accretion is roughly equivalent for various flow geometries. However, a mere variation of the polytropic index of the flow cannot map a critical solution from one flow geometry to the another, since the numerical domain of the parameter space responsible to produce multi-critical accretion does not undergo a continuous transformation in multi-dimensional parameter space. The stationary configuration used to demonstrate the aforementioned findings is shown to be stable under linear perturbation for all kind of flow geometries, black hole potentials, and the corresponding equations of state used to obtain the critical transonic solutions. Finally, the structure of the acoustic metric corresponding to the propagation of the linear perturbation studied are discussed for various flow geometries used.Comment: 13 pages. 5 figure

Near infrared spectroscopy of benzoic acid adsorbed on montmorillonite

The adsorption of benzoic acid on both sodium and calcium montmorillonites has been studied by near infrared spectroscopy complimented with infrared spectroscopy. Upon adsorption of benzoic acid additional near infrared bands are observed at 8665 cm-1 and assigned to an interaction of benzoic acid with the water of hydration. Upon adsorption of the benzoic acid on Na-Mt, the NIR bands are now observed at 5877, 5951, 6028 and 6128 cm-1 and are assigned to the overtone and combination bands of the CH fundamentals. Additional bands at 4074, 4205, 4654 and 4678 cm-1 are attributed to CH combination bands resulting from the adsorption of the benzoic acid. Benzoic acid is used as a model molecule for adsorption studies. The application of near infrared spectroscopy to the study of adsorption has the potential for the removal of acids from polluted aqueous systems

Hysteresis effects and diagnostics of the shock formation in low angular momentum axisymmetric accretion in the Kerr metric

The secular evolution of the purely general relativistic low angular momentum accretion flow around a spinning black hole is shown to exhibit hysteresis effects. This confirms that a stationary shock is an integral part of such an accretion disc in the Kerr metric. The equations describing the space gradient of the dynamical flow velocity of the accreting matter have been shown to be equivalent to a first order autonomous dynamical systems. Fixed point analysis ensures that such flow must be multi-transonic for certain astrophysically relevant initial boundary conditions. Contrary to the existing consensus in the literature, the critical points and the sonic points are proved not to be isomorphic in general. Homoclinic orbits for the flow flow possessing multiple critical points select the critical point with the higher entropy accretion rate, confirming that the entropy accretion rate is the degeneracy removing agent in the system. However, heteroclinic orbits are also observed for some special situation, where both the saddle type critical points of the flow configuration possesses identical entropy accretion rate. Topologies with heteroclinic orbits are thus the only allowed non removable degenerate solutions for accretion flow with multiple critical points, and are shown to be structurally unstable. Depending on suitable initial boundary conditions, a homoclinic trajectory can be combined with a standard non homoclinic orbit through an energy preserving Rankine-Hugoniot type of stationary shock. An effective Lyapunov index has been proposed to analytically confirm why certain class of transonic flow can not accommodate shock solutions even if it produces multiple critical points. (Abridged)Comment: mn2e.cls format. 24 pages. 4 figure

ACQ-treated veneer based composite VBC hardwood hollow utility poles from mid-rotation plantation thinned trees: Life cycle GHG emissions

Hardwood plantations are slow to mature with low financial returns in the early stage. Veneer Based Composite (VBC) products from mid-rotation plantation thinned trees are currently being developed at Griffith University in partnership with the Salisbury Research Centre, Queensland Government, which may offer an opportunity to improve the industry’s profitability and win new markets. Due to shortage in utility solid hardwood poles, VBC poles are proposed as a potential alternative. In this study, greenhouse gas emissions of alkaline copper quaternary (ACQ) preservative-treated VBC pole was assessed using ‘cradle to grave’ life cycle assessment methodology. ACQ preservative was used to extend the service life of wood poles due to wood products are commonly to be degraded in wet environments subject to microbial or insect attack. The manufacturing process considered in this study is based on the current technologies in Salisbury Research Centre. Two (2) end-of-life scenarios were considered: landfilling and incineration with energy recovery. The function unit was a 1-metrelength pole with 115mm internal-diameter and 15mm wall-thickness. Global warming potential (GWP100) was calculated using the IPCC 2007 method. Results indicated disposal stage contributed the most impact. Incineration with energy recovery had the lowest GWP impact (0.337kg-CO2-Eq) followed by landfilling. Transportation distance was identified as a significant parameter affecting the result. Sensitivity analysis indicated that increasing the transportation distance by 100 km would increase the GWP100 by 21% in the incineration option

Television as an Instrument for Bridging Cultures: A Study of Television's Effects on Taiwanese Students in the United States

This study tested American television effects on Taiwanese Students in uncertainty reduction and stereotype forming. The study consisted of a questionnaire analysis and a focus group discussion. Fifty-five subjects responded to the questionnaires and twenty of them joined two group discussions

Important Issues in Implementing Global networks

Global communication networks are used by multinational companies for instant access to information and communications. Many advantages can be obtained from implementing a global network; however, many challenges exist in designing and implementing a network that encompasses different countries. This article presents some key issues for the design and implementation of a global network

Understanding ourselves and the environment in which we live

This paper calls for a new methodological paradigm for understanding the adaptive human–nature relationship to achieve a sustainable global environment. It proposes three future research directions: theoretically framing societal processes in natural resources management; establishing a new methodological paradigm for understanding co-evolving human–nature systems; and developing system-scale experimental research