Investigation of Electromagnetic Radiations by GSM Base Stations in Nigeria for Compliance Testing

Thousands of base station antennas (BSA) have been installed in Nigeria to support the development of mobile telephony. At the same time there is a public concern about the electromagnetic fields induced by these antennas, particularly there is a great fear by those living in the vicinity of these antennas, of being exposed to the harmful effects of this radiation. This fear has created the need to investigate and establish the level and also to determine whether this level is harmful or not based on the International Committee for Non-Ionization Radio Protection (ICNIRP) Standards. In this study, field measurement approach was used to investigate the impact and compare the result with the safety standard as given by ICNIRP. The analysis of the result provided information on the radiation level in the university of Nigeria environment. The results showed that Odim location recorded the maximum power density of 0.1879 mW/m2, while PG recorded the minimum power density of 0.0158 mW/m2.  The maximum power density value obtained occurred at 200m away from the foot of base station antenna. When this power density level was compared with the international safety level standard of about 4.5W/m2, the result showed low radiation, 0.004 percent of the safety level. Keywords: EMR, Base Station, Radiation, Measurement, Environment, Power Densit

Leveraging RSS Data For An Improved Radiolocation Estimation Algorithm Realization In LoRaWAN Using A Two-Tier Normalization

An attempt to further enhance the accuracy and reliability of M-iWMLR localization algorithm using a new weight matrix that was formulated with two-tier RSS data normalization is presented. The two-tier normalization: data clipping and z-score normalization were applied to form a new weight matrix in this work. Data clipping was first applied to reduce significantly the effects of outliers on the RSS data while z-score normalization provides data consistency. The new localization algorithm herein, referred to as Ext.M-iWMLR algorithm is carefully evaluated by the use of location accuracy (location error), root mean square error (RMSE), range of error, and R2 score metrics. This algorithm is validated with the Modified Improved Weighted Multiple Linear Regression (M-iWMLR). The simulation results generated with MATLAB show that the Ext.M-iWMLR algorithm, at 95 percentile reduced the mean location error by 19.45%. The range of error and RMSE are reduced by 11.08% and 17.95%, respectively. Furthermore, the respective R2 scores were increased by 5.71% and 17.17% for the latitude and longitude coordinates. It was established that the new weight matrix formulated through two-step normalization enhanced all the considered metrics

Pectoral Muscle Removal in Digital Mammograms Using Region Based Standard Otsu Technique

Mammography is usually the first preference of imaging diagnostic modalities used for detection of breast cancer in the early stage. Two projections Cranio Caudal (CC) and Medio-Lateral Oblique (MLO) which depict different degrees for visualizing the breast are used during digital mammogram acquisition and the MLO view shows more breast tissue and Pectoral Muscle (PM) area when compared to CC view. Although, the PM is a criterion used to show proper positioning, it can result in biased results of mammographic analysis like: cancer detection and breast tissue density estimation, because the PM area has similar or even higher intensity than breast tissue and breast lesions if present. This paper proposed a Region Based Standard Otsu thresholding method for the elimination of PM area present in MLO mammograms. The proposed algorithm was implemented using 322 digital mammograms from the Mammographic Image Analysis Society (MIAS) database, and the difference between the PM detected and the manually drawn PM region by an expert was evaluated. The results showed an average: Jaccard Similarity Index, False Positive Rate (FPR) and False Negative Rate (FNR) of 93.2%, 3.54% and 5.68% respectively and also an acceptable rate of 95.65