Compact printed multiband antenna with independent setting suitable for fixed and reconfigurable wireless communication systems

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This paper presents the design of a low-profile compact printed antenna for fixed frequency and reconfigurable frequency bands. The antenna consists of a main patch, four sub-patches, and a ground plane to generate five frequency bands, at 0.92, 1.73, 1.98, 2.4, and 2.9 GHz, for different wireless systems. For the fixed-frequency design, the five individual frequency bands can be adjusted and set independently over the wide ranges of 18.78%, 22.75%, 4.51%, 11%, and 8.21%, respectively, using just one parameter of the antenna. By putting a varactor (diode) at each of the sub-patch inputs, four of the frequency bands can be controlled independently over wide ranges and the antenna has a reconfigurable design. The tunability ranges for the four bands of 0.92, 1.73, 1.98, and 2.9 GHz are 23.5%, 10.30%, 13.5%, and 3%, respectively. The fixed and reconfigurable designs are studied using computer simulation. For verification of simulation results, the two designs are fabricated and the prototypes are measured. The results show a good agreement between simulated and measured results

Performance Analysis of MIMO-MRC in Double-Correlated Rayleigh Environments

We consider multiple-input multiple-output (MIMO) transmit beamforming systems with maximum ratio combining (MRC) receivers. The operating environment is Rayleigh-fading with both transmit and receive spatial correlation. We present exact expressions for the probability density function (p.d.f.) of the output signal-to-noise ratio (SNR), as well as the system outage probability. The results are based on explicit closed-form expressions which we derive for the p.d.f. and c.d.f. of the maximum eigenvalue of double-correlated complex Wishart matrices. For systems with two antennas at either the transmitter or the receiver, we also derive exact closed-form expressions for the symbol error rate (SER). The new expressions are used to prove that MIMO-MRC achieves the maximum available spatial diversity order, and to demonstrate the effect of spatial correlation. The analysis is validated through comparison with Monte-Carlo simulations.Comment: 25 pages. Submitted to the IEEE Transactions on Communication

Abnormal Myocardial Blood Flow Reserve Observed in Cardiac Amyloidosis

We performed real-time myocardial contrast echocardiography on a patient with cardiac amyloidosis and previous normal coronary angiography presenting with atypical chest pain to assess myocardial blood flow reserve (MBFR). Myocardial contrast echocardiography was performed and flash microbubble destruction and replenishment analysis was used to calculate myocardial blood flow. Dipyridamole was used to achieve hyperemia. MBFR was derived from the ratio of peak myocardial blood flow at hyperemia and rest. The results show a marked reduction in MBFR in our patient. Previous reports of luminal obstruction of intramyocardial rather than epicardial vessels by amyloid deposition may be causing microvascular dysfunction

Customizing kernel functions for SVM-based hyperspectral image classification

Previous research applying kernel methods such as support vector machines (SVMs) to hyperspectral image classification has achieved performance competitive with the best available algorithms. However, few efforts have been made to extend SVMs to cover the specific requirements of hyperspectral image classification, for example, by building tailor-made kernels. Observation of real-life spectral imagery from the AVIRIS hyperspectral sensor shows that the useful information for classification is not equally distributed across bands, which provides potential to enhance the SVM's performance through exploring different kernel functions. Spectrally weighted kernels are, therefore, proposed, and a set of particular weights is chosen by either optimizing an estimate of generalization error or evaluating each band's utility level. To assess the effectiveness of the proposed method, experiments are carried out on the publicly available 92AV3C dataset collected from the 220-dimensional AVIRIS hyperspectral sensor. Results indicate that the method is generally effective in improving performance: spectral weighting based on learning weights by gradient descent is found to be slightly better than an alternative method based on estimating ";relevance"; between band information and ground trut

The Brain in Business: The Case for Organisational Cognitive Neuroscience?

The application of cognitive neuroscientific techniques to understanding social behaviour has resulted in many discoveries. Yet advocates of the ‘social cognitive neuroscience’ approach maintain that it suffers from a number of limitations. The most notable of these is its distance from any form of real-world applicability. One solution to this limitation is ‘Organisational Cognitive Neuroscience’ – the study of the cognitive neuroscience of human behaviour in, and in response to, organizations. Given that all of us will spend most of our lives in some sort of work related organisation, organisational cognitive neuroscience allows us to examine the cognitive underpinnings of social behaviour that occurs in what may be our most natural ecology. Here we provide a brief overview of this approach, a definition and also some possible questions that the new approach would be best suited to address

Ash Vaporization and Condensation During Combustion of a Suspended Coal Particle

The results of a theoretical study of the formation and growth of the submicron flyash aerosol around a single burning coal particle are presented. The vaporization of ash and subsequent aerosol formation near the coal particle are studied because the local combustion environment influences these processes strongly. A mathematical model is developed that describes the transport of ash vapor and and the growth of the aerosol. The ash aerosol calculation is superimposed on an existing solution to the combustion problem. Included in the model are the effects of convective transport and of both homogeneous and heterogeneous condensation of the ash vapor. The results of the calculations show that refractory compounds with low surface tension, like silica, nucleate very near the coal particle's surface and produce a substantial mass loading of aerosol. The presence of the aerosol does not greatly affect the ash vaporization rate, which is primarily a function of combustion conditions. The size and amount of the submicron ash aerosol are determined by both the local combustion conditions and the ash's physical properties

Robust Spectrum Sharing via Worst Case Approach

This paper considers non-cooperative and fully-distributed power-allocation for secondary-users (SUs) in spectrum-sharing environments when normalized-interference to each secondary-user is uncertain. We model each uncertain parameter by the sum of its nominal (estimated) value and a bounded additive error in a convex set, and show that the allocated power always converges to its equilibrium, called robust Nash equilibrium (RNE). In the case of a bounded and symmetric uncertainty set, we show that the power allocation problem for each SU is simplified, and can be solved in a distributed manner. We derive the conditions for RNE's uniqueness and for convergence of the distributed algorithm; and show that the total throughput (social utility) is less than that at NE when RNE is unique. We also show that for multiple RNEs, the the social utility may be higher at a RNE as compared to that at the corresponding NE, and demonstrate that this is caused by SUs' orthogonal utilization of bandwidth for increasing the social utility. Simulations confirm our analysis

Prevalence and risk factors of sarcopenia among adults living in nursing homes

Objectives: Sarcopenia is a progressive loss of skeletal muscle and muscle function, with significant healthand disability consequences for older adults. We aimed to evaluate the prevalence and risk factors ofsarcopenia among older residential aged care adults using the European Working Group on Sarcopeniain Older People (EWGSOP) criteria.Study design: A cross-sectional study design that assessed older people (n = 102, mean age 84.5 ± 8.2 years)residing in 11 long-term nursing homes in Australia.Main outcome measurements: Sarcopenia was diagnosed from assessments of skeletal mass index bybioelectrical impedance analysis, muscle strength by handheld dynamometer, and physical performanceby the 2.4 m habitual walking speed test. Secondary variables where collected to inform a risk factoranalysis.Results: Forty one (40.2%) participants were diagnosed as sarcopenic, 38 (95%) of whom were categorizedas having severe sarcopenia. Univariate logistic regression found that body mass index (BMI) (Oddsratio (OR) = 0.86; 95% confidence interval (CI) 0.78–0.94), low physical performance (OR = 0.83; 95% CI0.69–1.00), nutritional status (OR = 0.19; 95% CI 0.05–0.68) and sitting time (OR = 1.18; 95% CI 1.00–1.39)were predictive of sarcopenia. With multivariate logistic regression, only low BMI (OR = 0.80; 95% CI0.65–0.97) remained predictive.Conclusions: The prevalence of sarcopenia among older residential aged care adults is very high. Inaddition, low BMI is a predictive of sarcopenia