A prototype portable system for EEG measurements

In this study, a prototype EEG recording and analysis module for biomedical research applications is designed. The design of the system consists of an analog and a digital part. The system has two signal channels, but it can be extended to six channels construction. The analog module involves the following units; an input instrumentation amplifier, gain adjustable amplifier, band-pass filter, and a driven-right-leg- (DRL) circuit. The digital board consists of A/D converter and RS232 communication unit. In order to test system, the circuit simulation and the real-time EEG measurements are implemented. The proposed EEG system can be used in our department’s biomedical laboratory.     

Denoising images corrupted by impulsive noise using projections onto the epigraph set of the total variation function (PES-TV)

In this article, a novel algorithm for denoising images corrupted by impulsive noise is presented. Impulsive noise generates pixels whose gray level values are not consistent with the neighboring pixels. The proposed denoising algorithm is a two-step procedure. In the first step, image denoising is formulated as a convex optimization problem, whose constraints are defined as limitations on local variations between neighboring pixels. We use Projections onto the Epigraph Set of the TV function (PES-TV) to solve this problem. Unlike other approaches in the literature, the PES-TV method does not require any prior information about the noise variance. It is only capable of utilizing local relations among pixels and does not fully take advantage of correlations between spatially distant areas of an image with similar appearance. In the second step, a Wiener filtering approach is cascaded to the PES-TV-based method to take advantage of global correlations in an image. In this step, the image is first divided into blocks and those with similar content are jointly denoised using a 3D Wiener filter. The denoising performance of the proposed two-step method was compared against three state-of-the-art denoising methods under various impulsive noise models.     

Computationally efficient bandwidth allocation and power control for OFDMA

The paper studies the problem of finding an optimal subcarrier and power allocation strategy for downlink communication to multiple users in an orthogonal-frequency-division multiplexing-based wireless system. The problem of minimizing total power consumption with constraints on bit-error rate and transmission rate for users requiring different classes of service is formulated and simple algorithms with good performance are derived. The problem of joint allocation is divided into two steps. In the first step, the number of subcarriers that each user gets is determined based on the users' average signal-to-noise ratio. The algorithm is shown to find the distribution of subcarriers that minimizes the total power required when every user experiences a flat-fading channel. In the second stage of the algorithm, it finds the best assignment of subcarriers to users. Two different approaches are presented, the rate-craving greedy algorithm and the amplitude-craving greedy algorithm. A single cell with one base station and many mobile stations is considered. Numerical results demonstrate that the proposed low complexity algorithms offer comparable performance with an existing iterative algorithm.     

Impact of energy efficiency upgrade retrofits on the residential energy consumption in Canada

The impact of various energy efficiency upgrade scenarios on the annual energy consumption of the Canadian housing stock is assessed using the Canadian Residential Energy End‐use Model (CREEM). The energy efficiency upgrade scenarios that are considered include major retrofits, such as the improvement of the house envelope by adding insulation, and the replacement of the existing heating system and appliances by higher efficiency units, as well as minor retrofits, such as lighting fixture, thermostat, showerhead and aerator upgrades that reduce energy consumption. The economic feasibility of each upgrade was assessed using the indicator ‘energy savings per dollar investment’. The results indicate that the energy savings potential of the retrofits is rather small, resulting in savings of 0–8 per cent of the total energy consumption of the Canadian housing stock. Copyright © 2001 John Wiley & Sons, Ltd.     

Memstor,memstance simulations via a versatile 4-port built with new adder and subtractor circuits

In this paper, novel voltage-mode (VM) n-channel metal-oxide semiconductor (NMOS) transistor-based analogue adder and subtractor circuits, which, respectively, perform V₁+V₂ and V₁?V₂ operations, are presented. The most important feature of the proposed circuits is their extremely simple structures containing only six NMOS transistors. Further, the presented adder and subtractor circuits have high input and low output impedances, resulting in easy cascadability. The post-layout simulations of the proposed circuits have been executed using TSMC 0.25 µm process parameters with ±1.25 V. The area of the suggested circuits is approximately 30 × 13 µm². Moreover, the topology of a generalised mutator, a versatile 4-port built with an adder and a subtractor, which acts as an ordinary mutator when properly reduced to a 2-port, is offered. A table for simulating lossless inductance, memristor, meminductor, memcapacitor and other elements under suitable termination of the 4-port is given, and three of these elements’ simulations with SPICE are also presented.     

A Survey of Occurrence and Risk Assessment of Pharmaceutical Substances in the Great Lakes Basin

The present study is an overview of the literature on the occurrence and potential risks of pharmaceutical substances in the wastewater treatment plants (WWTP), natural waters and drinking water treatment plants served by the Great Lakes Basin (Canada and the USA) between the years of 2007–2012. Large number of pharmaceutical substances, including anti-inflammatories, lipid regulators, antidepressants, antibiotics, beta blockers, anti-epileptics, anti-hypertensions and stimulants, in high ng/L concentrations, has been reported in the WWTP influents. Most of these compounds have also been detected in the WWTP effluents at comparable concentrations with the exception of caffeine, cotinine and salicylic acid suggesting the inefficiency of conventional treatment processes in the degradation of pharmaceutical compounds. Decreasing surface water concentrations have been observed with the distance downstream of the discharge point due to the dilution effect. Surface waters located around septic systems and agricultural areas have also been found to be contaminated with pharmaceutical substances. Carbamazepine, caffeine, its metabolite paraxanthine, ibuprofen, gemfibrozil and sulfamethoxazole have been frequently detected in the surface waters. The number of occurrences of carbamazepine, ibuprofen, naproxen, gemfibrozil, bezafibrate, sulfamethoxazole and macrolide antibiotics in drinking water sources, at ng/L concentration ranges, has been quite high. Although the detection frequencies in treated drinking waters were relatively low, the concentrations of the above mentioned pharmaceutical substances were at the same range as the source water concentrations.

Six of the detected pharmaceutical substances, namely, fluoxetine, sulfamethoxazole, clarithromycin, erythromycin, carbamazepine and esterone exhibit a high environmental risk in Great Lakes WWTP effluents and surface waters, while none of the pharmaceutical substances seem to pose a risk for human health at their highest reported concentrations in the drinking water sources from the Great Lakes.     

Application of fuzzy logic controller to active power filters

In this paper, the way to use one of the most powerful problem-solving methodologies, fuzzy logic, to enhance the quality of the power system is described. To prove the power of fuzzy logic for the modeling of nonlinear systems, the modeling of active power filters with a fuzzy logic based control strategy is presented as a case study and its capability to reject reactive power eliminate current harmonic components is simulated by MATLAB. The advantages in using fuzzy logic as emphasized in the case study are its simple application to various types of systems, high performance, lower cost, and higher productivity.     

Secondary transitions and thermodynamic interaction parameters of poly (phenyl sulfone) by gas chromatography

Summary Trace amount of solvents such as n-octane, n-nonane, n-decane, isopropyl acetate, tert-butyl acetate and isoamyl acetate were passed through the column of a gas chromatograph, which stationary phase is poly (phenyl sulfone) trademarked as Radel^®R. The retention diagrams were obtained by plotting the logarithm of the specific retention volumes of the solvents against reciprocal of the absolute column temperature between 50 and 280 °C. The slope changes on the diagram were assigned as secondary transitions. Three secondary transition temperatures were established at 140, 110 and 80 °C below glass transition temperature, 210 °C. Weight fraction activity coefficients of the solvents at infinite dilution, ₁ - and hard-core polymer solvent interaction parameters _t , were given for the studied solvents at 250 °C. The values of the parameters ₁ - and _t suggest that n-alkanes are very poor whereas esters studied are moderately poor solvents for poly (phenyl sulfone) at 250 °C.     

A novel circularly polarized reader antenna design for UHF RFID applications

Wireless Networks - In this article, a novel ultra-high frequency radio frequency identification (UHF RFID) reader antenna is proposed and experimentally investigated. The proposed RFID antenna...