Measurement of exposure of radio frequency field (RF) radiation from global system for mobile communication (GSM) masts
May 2010
The objective of this study is to draw a conclusive position on the effect of radiofrequency (RF) radiation from GSM masts on human health. The measurement of the RF was conducted at 100 m and 200 m away from the masts of the major GSM operators in Nigeria; GLO, MTN and ZAIN. The data obtained were analyzed using correlation analysis to establish the fact that whether with time exposure to RF will have discernable...
An application of FDTD using quadratic extrapolation
May 2010
Finite difference time domain (FDTD) has been the most obvious choice of researchers to simulate an electromagnetic environment which is quite complex in nature. But the amount of time consumed in running the simulation has always been the limiting factor. In this work, a time efficient FDTD tool that is, Quadratic FDTD is developed and used for simulation of a rectangular cavity resonator. Traditional FDTD simulation...
Design and implementation of a model (ADS-3G) of a traffic light using automated solar power supply
May 2010
In this work, a model of an automated traffic light controller (ADS - 3G) had been designed, simulated, tested and implemented, using experimental techniques in electronic engineering, to manage the traffics at the busy four way junctions along Sahuda road in Mubi North Adamawa State, Nigeria. The designed was achieved with the help of 12V automated solar energy power supply, time base (555 timer), decade counter,...
Estimation of bifurcation point in multi-bus system using generator reactive power limit approach
March 2010
This paper proposes an approach for estimating bifurcation point in multi-bus systems. The approach assumes that the generators would violate their Q-limits before the bifurcation point is reached. The result of this assumption clearly raises the voltages along the PV curve which consequently yield an infinitesimal error. Therefore the final estimated point can be obtained after a number of load flow solutions depending...
Detection of acute hypotensive episodes via a trained adaptive network-based fuzzy inference system (ANFIS)
March 2010
The aim of this study is to detect acute hypotensive episodes (AHE) and mean arterial pressure dropping regimes (MAPDRs) using ECG signal and arterial blood pressure (ABP) waveforms. To meet this end, the QRS complexes and end-systolic end-diastolic pulses are first extracted using two innovative modified Hilbert transform-based algorithms namely as ECGMHT and BPMHT. The resulted systolic blood pressure (SBP) and...
Modified design of bootlace lens for multiple beam forming
February 2010
As of now, utility of microwave bootlace lens is well established. For broadband and wide scanning network, it is required to optimize and use features of this lens for better communication and scanning device. This paper presents the design of a compact bootlace lenses for multiple beam forming. Equations to design the lens have been given. The designed lenses has been fabricated and tested. The measured results are in...
Selection of optimum location of power system stabilizer in a multimachine power system
February 2010
In this paper an attempt has been made to propose a new technique for selection of optimum site of a power system stabilizer (PSS) to mitigate the small-signal stability problem in a multimachine power system. Study reveals that the PSS displaces the swing mode from its critical position to a more desirable position changing the response of the excitation system. Based on the change of the exciter transfer function with...
Implementation of DSP algorithms on reconfigurable embedded platform
November 2009
Field programmable PLD’s are becoming a standard in hardware technologies, as application demands have out placed the conventional processor's ability to deliver. The right combination of price, performance, ease-of use, along with significant power savings, can be achieved by using a Field Programmable Gate Array (FPGA). The versatility of these devices with the EDA tools such as Quartus, ISE,...
Transformer thermal and loss of life models
November 2009
In this paper, transformer thermal and loss of life models was studied. Based on the thermal model adopted by International Standards, small improvements to increase model accuracy are presented and a comparative study of resulted accuracy under different load and ambient temperature profiles was performed. Key words: Transformer thermal, loss of life models, estimate thermal parameters.
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