Signal Detection for QPSK Based Cognitive Radio Systems using Support Vector Machines

Cognitive radio based network enables opportunistic dynamic spectrum access by sensing, adopting and utilizing the unused portion of licensed spectrum bands. Cognitive radio is intelligent enough to adapt the communication parameters of the unused licensed spectrum. Spectrum sensing is one of the most important tasks of the cognitive radio cycle. In this paper, the auto-correlation function kernel based Support Vector Machine (SVM) classifier along with Welch's Periodogram detector is successfully implemented for the detection of four QPSK (Quadrature Phase Shift Keying) based signals propagating through an AWGN (Additive White Gaussian Noise) channel. It is shown that the combination of statistical signal processing and machine learning concepts improve the spectrum sensing process and spectrum sensing is possible even at low Signal to Noise Ratio (SNR) values up to -50 dB

Design and Focused Ion Beam Fabrication of Single Crystal Diamond Nanobeam Cavities

We present the design and fabrication of nanobeam photonic crystal cavities in single crystal diamond for applications in cavity quantum electrodynamics. First, we describe three-dimensional finite-difference time-domain simulations of a high quality factor (Q ~ 10^6) and small mode volume (V ~ 0.5 ({\lambda}/n)^3) device whose cavity resonance corresponds to the zero-phonon transition (637nm) of the Nitrogen-Vacancy (NV) color center in diamond. This high Q/V structure, which would allow for strong light-matter interaction, is achieved by gradually tapering the size of the photonic crystal holes between the defect center and mirror regions of the nanobeam. Next, we demonstrate two different focused ion beam (FIB) fabrication strategies to generate thin diamond membranes and nanobeam photonic crystal resonators from a bulk crystal. These approaches include a diamond crystal "side-milling" procedure as well as an application of the "lift-off" technique used in TEM sample preparation. Finally, we discuss certain aspects of the FIB fabrication routine that are a challenge to the realization of the high-Q/V designs

Biological activities of aerial parts of Paeonia emodi wall

The ethanolic extract derived from the aerial parts of Paeonia emodi was screened for various in vitro biological activities including antifungal, antibacterial, insecticidal, phytotoxic and haemagglutination activities. General toxicity (brine shrimp lethality assay) of this extract has also been assessed. The extract was found to possess excellent phytotoxicity against Lemna minor L., moderate heamagglutination activity against human erythrocytes and reasonable insecticidal activity against Bruchus pisorum. The crude extract did not display any antifungal or antibacterial activity against the fungi and bacteria used in this study. No significant general toxicity was observed with the extract at tested concentrations

Sensitive Coverage Saves Lives: Improving media portrayal of suicidal behaviour

The report outlines the results of consultations with journalists, suicide prevention agencies and mental health groups conducted by the journalism ethics charity MediaWise. It makes recommendations for action by media organisations and suicide prevention agencies

Chiral symmetry and the axial nucleon to Delta(1232) transition form factors

We study the momentum and the quark mass dependence of the axial nucleon to Delta(1232) transition form factors in the framework of non-relativistic chiral effective field theory to leading-one-loop order. The outcome of our analysis provides a theoretical guidance for chiral extrapolations of lattice QCD results with dynamical fermions.Comment: 18 pages, 3 figure

Chiral Perturbation Theory and Finite Size Effects on the Nucleon Mass in unquenched QCD

We calculate finite size effects on nucleon masses in chiral perturbation theory. We confront the theoretical predictions with N_f=2 lattice results and discuss chiral extrapolation formulae.Comment: talk at Lattice 03 (spectrum), 3 pages latex, 3 figures. Assignment of 2 data points to incorrect data sets in plot 1 and of 1 data point in plot 2 corrected. 1 fm lattice result updated. Conclusions unchange

Correlates of socioeconomic status and the health of older people in the United Kingdom: a review

This paper reviews the existing literature on the association between the socio-economic status (SES) and the health of the ageing population in the United Kingdom (UK). It has been noted that socio-economic differentials are more marked across the UK than they are in other developed countries. Social class gradients are significant in health for working age people (up to age 65), whereas studies on older populations have so far been limited so as to draw any robust conclusions. In this paper, we examine the inequalities through selected SES indicators in order to tease out the effects on health outcomes of the older population. We critically review the physical and mental health indicators of older people in the UK with regard to their SES differentials. The findings reveal that older people with lower SES are more likely to experience poorer health outcomes (for example, long-standing illness or increased disability) and have shorter life expectancy compared to those of higher SES. We illustrate how education remains the single most important determinant of health inequality in later life. We suggest that educational level or occupational class allied with material deprivation offer the best combined indicators of SES for studying health inequalities among older people. The findings of this paper has profound implications for prioritising policies to improve the health and wellbeing of elderly people with lower SES and go offer an evidence base of how to understand and to develop interventions that minimise the inequalities in health in later life in the UK