Fast periocular authentication in handheld devices with reduced phase intensive local pattern

To ensure highest security in handheld devices, biometric authentication has emerged as a reliable methodology. Deployment of mobile biometric authentication struggles due to computational complexity. For a fast response from a mobile biometric authentication method, it is desired that the feature extraction and matching should take least time. In this article, the periocular region captured through frontal camera of a mobile device is considered under investigation for its suitability to produce a reduced feature that takes least time for feature extraction and matching. A recently developed feature Phase Intensive Local Pattern (PILP) is subjected to reduction giving birth to a feature termed as Reduced PILP (R-PILP), which yields a matching time speed-up of 1.56 times while the vector is 20% reduced without much loss in authentication accuracy. The same is supported by experiment on four publicly available databases. The performance is also compared with one global feature: Phase Intensive Global Pattern, and three local features: Scale Invariant Feature Transform, Speeded-up Robust Features, and PILP. The amount of reduction can be varied with the requirement of the system. The amount of reduction and the performance of the system bears a trade-off. Proposed R-PILP attempts to make periocular suitable for mobile devices.     

CL-AGKA: certificateless authenticated group key agreement protocol for mobile networks

Wireless Networks - Wireless group communication has gained much popularity recently due to the increase in portable, lightweight devices. These devices are capable of performing group...     

Single image super resolution for texture images through neighbor embedding

This article proposes an improved learning based super resolution scheme using manifold learning for texture images. Pseudo Zernike moment (PZM) has been employed to extract features from the texture images. In order to efficiently retrieve similar patches from the training patches, feature similarity index matrix (FSIM) has been used. Subsequently, for reconstruction of the high resolution (HR) patch, a collaborative optimal weight is generated from the least square (LS) and non-negative matrix factorization (NMF) methods. The proposed method is tested on some color texture, gray texture, and some standard images. Results of the proposed method on texture images advocate its superior performance over established state-of-the-art methods.

     

Decoder side Wyner–Ziv frame estimation using Chebyshev polynomial-based FLANN technique for distributed video coding

Multidimensional Systems and Signal Processing - In this paper, a Chebyshev polynomial-based functional link artificial neural network (CFLANN) technique for Wyner–Ziv (WZ) frame estimation...     

A new modelling and identification scheme for time-delay systems with experimental investigation: a relay feedback approach

In this paper, the conventional relay feedback test has been modified for modelling and identification of a class of real-time dynamical systems in terms of linear transfer function models with time-delay. An ideal relay and unknown systems are connected through a negative feedback loop to bring the sustained oscillatory output around the non-zero setpoint. Thereafter, the obtained limit cycle information is substituted in the derived mathematical equations for accurate identification of unknown plants in terms of overdamped, underdamped, critically damped second-order plus dead time and stable first-order plus dead time transfer function models. Typical examples from the literature are included for the validation of the proposed identification scheme through computer simulations. Subsequently, the comparisons between estimated model and true system are drawn through integral absolute error criterion and frequency response plots. Finally, the obtained output responses through simulations are verified experimentally on real-time liquid level control system using Yokogawa Distributed Control System CENTUM CS3000 set up.     

Secrecy Capacity Analysis of MIMO System over Multiple Destinations and Multiple Eavesdroppers

Wireless Personal Communications - In this paper we address physical layer security of multiple input multiple output (MIMO) communication system in presence of multiple destinations and passive...     

PI/PID controller design based on IMC and percentage overshoot specification to controller setpoint change

In this work, the normalized Internal Model Control (IMC) filter time constant is designed to achieve a specified value of the maximum sensitivity for stable first and second order plus time delay process models, respectively. Since a particular value of the maximum sensitivity results in an almost constant percentage overshoot to controller setpoint change, an empirical relationship between the normalized IMC filter time constant and percentage overshoot is presented. The main advantage of the proposed method is that only a user-defined overshoot is required to design a PI/PID controller. Simulation examples are given to demonstrate the value of the proposed method.     

Electrical reliability aspects of HfO2 high-k gate dielectrics with TaN metal gate electrodes under constant voltage stress

The dielectric breakdown property of ultrathin 2.5 and 5.0 nm hafnium oxide (HfO₂) gate dielectric layers with metal nitride (TaN) gate electrodes for metal oxide semiconductor (MOS) structure has been investigated. Reliability studies were performed with constant voltage stressing to verify the processing condition effects (film thicknesses and post metal annealing temperatures) on times to breakdown. The leakage current characteristics are improved with post metal annealing temperatures (PMA) for both 2.5 and 5.0 nm HfO₂ physical thicknesses. However, it is more prominent (2 orders of magnitudes) for 2.5 nm HfO₂ film thickness. The values of oxide-trapped charge density and interface-state density are also improved for 2.5 nm HfO₂ film. The different stages of charge-trapping behaviors, i.e., stress-induced leakage current, soft and hard breakdown mechanisms have been detected. During constant voltage stress of the MOS capacitors, an increase in the time-dependent gate current is observed, followed by the occurrence of several fluctuations. The amplitude of the fluctuations is much larger in the 5.0 nm HfO₂ gate dielectric layer compared to the 2.5 nm HfO₂ layer. After the occurrence of such fluctuations, the current–voltage characteristics exhibited an increased in gate current compared to the fresh (unstressed) devices.     

Microstructural Analysis of Multi-phase Ultra-Thin Oxide Overgrowth on Al–Mg Alloy by High Resolution Transmission Electron Microscopy

High-resolution transmission electron microscopy analyses are carried out to understand the microstructure of the ultra-thin oxide-film grown on a (native) amorphous Al₂O₃-coated Al-0.8 at.% Mg alloy substrate at T = 600 K for t = 2 h and at pO₂ of 1 × 10^?2 Pa. This oxide-film is found to be non-uniformly thick with thicknesses varying from 1.50 to 4.60 nm. Occasionally, this oxide is found to diffuse into the Al–Mg alloy substrate, forming oxide thicknesses up to 10.5 nm. Overall, this oxide-film is found to consist of a mixed amorphous, (poly) crystalline and an intermediate amorphous-to-crystalline transition regions, with crystalline regions consisting mostly of MgO and the diffused oxide regions into the Al–Mg alloy substrate coated with γ-Al₂O₃. These observations are then compared with the experimental results obtained using angle-resolved X-ray Photoelectron Spectroscopy analysis and thermodynamic predictions for the growth of an ultra-thin oxide-film due to dry, thermal oxidation of Al–Mg alloy substrates.