Papers by Abubakar Abdulkarim
Healthcare workers’ attitudes and factors affecting sexual and reproductive health services to adolescents in refugee settlements, western Uganda
Introduction Adolescent sexual and reproductive health care needs are rising in both low and midd... more Introduction Adolescent sexual and reproductive health care needs are rising in both low and middle-income countries. This need is even higher in refugee settlements. This study aimed to assess the healthcare workers’ attitudes and the factors affecting adolescent sexual and reproductive health care in the Nakivale, Kyaka II, and Rwamwanja refugee settlements. Methods This was a cross-sectional quantitative study in which health workers from public and private health facilities from three randomly selected refugee communities in western Uganda responded to a questionnaire. The questionnaire collected information on services provided, the attitudes towards each of the services and the factors that hindered the provision of these services. Binary logistic regression was done to assess the baseline characteristics associated with provision of these services using SPSS version 26. Results Of the 386 medical professionals enrolled, 194(50.3%) were females with a mean age of 30.9 years (S...
Journal of Electrical Systems and Information Technology
Solar photovoltaic (PV) system is one of the most promising power systems based on renewable ener... more Solar photovoltaic (PV) system is one of the most promising power systems based on renewable energy sources, with several advantages compared to others. However, solar PV systems have a challenge of low conversion efficiency because most of the irradiances of the sun, which are channelled to the PV panels, are not fully utilized for power consumption. A more challenging situation of the system occurs when some of its panels are obstructed from full reception of the solar irradiance, a case referred to as partial shading conditions (PSC) in solar PV systems. This leads to the generation of multiple, unequal power peaks in the system, from which the one with the highest power must be tracked for optimum utilization of the system. To this regard, this work presents a modified firefly algorithm-based controller, tied operationally with a DC–DC boost converter. A model was developed and simulated on MATLAB, for tracking the maximum power point of the system, both at constant solar irradi...
Fudma Journal of Sciences, Apr 1, 2022
In this paper, we present an overview of both classical and fuzzy convexity, particularly, in con... more In this paper, we present an overview of both classical and fuzzy convexity, particularly, in conjunction with continuity 5 and some topological concepts, and provide proofs of some of their algebraic properties along with suitable illustrations. We have extended the work of (Ammar E. E., 1999) by proving that if μ and ν are two convex fuzzy sets, then μ + ν, μ − ν, μ * ν, and μ/ν are also convex fuzzy sets. We have also shown that the convexity of a fuzzy set implies semistrict quasi-convexity.
A Sensitivity Analysis on Power to Energy Ratios for Energy Storage Systems providing both Dynamic Firm and Dynamic Containment Frequency Response Services in the UK
This paper presents a sensitivity analysis on the power to energy ratio for Energy Storage System... more This paper presents a sensitivity analysis on the power to energy ratio for Energy Storage Systems (ESS) providing frequency response services on the Great Britain electricity network. Two services are considered; dynamic frequency response and dynamic containment, with the latter being a new service introduced in Oct 2020 by the Electricity System Operator. Each service proportionally responds in power to changes in grid frequency with each service differing in the response envelope. Whilst these services are based on power, for energy-limited assets such as ESS, the ratio of power to energy has an effect on its ability to deliver the service 100% of the time. In this paper, the availability, compliance against service terms and conditions, and equivalent cycles are considered showing that there is a significant difference between the two services. Currently, these services are delivered by battery ESS, however, it is demonstrated that the newer dynamic containment service can be effectively delivered by a higher power to energy ratio ESS and therefore offers opportunities for other technologies such as supercapacitors and flywheels.
Energy Informatics, Mar 13, 2023
Demand-side management, a new development in smart grid technology, has enabled communication bet... more Demand-side management, a new development in smart grid technology, has enabled communication between energy suppliers and consumers. Demand side energy management (DSM) reduces the cost of energy acquisition and the associated penalties by continuously monitoring energy use and managing appliance schedules. Demand response (DR), distributed energy resources (DER), and energy efficiency (EE) are three categories of DSM activities that are growing in popularity as a result of technological advancements in smart grids. During the last century, the energy demand has grown significantly in tandem with the increase in the global population. This is related to the expansion of business, industry, agriculture, and the increasing use of electric vehicles. Because of the sharp increase in global energy consumption, it is currently extremely difficult to manage problems such as the characterization of home appliances, integration of intermittent renewable energy sources, load categorization, various constraints, dynamic pricing, and consumer categorization. To address these issues, it is critical to examine demand-side management (DSM), which has the potential to be a practical solution in all energy demand sectors, including residential, commercial, industrial, and agricultural. This paper has provided a detailed analysis of the different challenges associated with DSM, including technical, economic, and regulatory challenges, and has proposed a range of potential solutions to overcome these challenges. The PRISMA reviewing methodology is adopted based on relevant literature to focus on the issues identified as barriers to improving DSM functioning. The optimization techniques used in the literature to address the problem of energy management were discussed, and the hybrid techniques have shown a better performance due to their faster convergence speed. Gaps in future research and prospective paths have been briefly discussed to provide a comprehensive understanding of the current DSM implementation and the potential benefits it can offer for an energy management system. This comprehensive review of DSM will assist all researchers in this field in improving energy management strategies and reducing the effects of system uncertainties, variances, and restrictions.
Maximizing energy availability for a Dynamic Regulation Frequency Response Service for Battery Energy Storage Systems
IECON 2022 – 48th Annual Conference of the IEEE Industrial Electronics Society, Oct 17, 2022
Journal of emerging technologies and innovative research, Feb 1, 2021
Exposure human to high doses of radon-222 through ingestion in water or inhalation as gas can lea... more Exposure human to high doses of radon-222 through ingestion in water or inhalation as gas can lead to stomach or lung cancer. In this research, the concentrations of Radon-222 (222 Rn) were investigated from eleven (11) water samples collected at different locations within Geidam town, Geidam Local Government Area of Yobe state, using liquid vacuum degasification process and RD-35 device. From the results obtained, the minimum value of radon concentration is found in the main borehole of Low-Cost near Friday mosques to be 0.57 pCi/L, while the maximum value measured which was related to a water tank in the general hospital quarters recoded 1.89 pCi/L. The overall average radon concentration for all water samples is found to be (0.99 ± 0.14) pCi/L. According to the achieved results, the radon concentration from all the water samples was lower than the maximum allowable concentration set by EPA and WHO guidelines.
Economies of scale in electricity generation in the United Kingdom
International Journal of Energy Research, 1977
The investment programme of the Central Electricity Generating Board (CEGB) since the late ninete... more The investment programme of the Central Electricity Generating Board (CEGB) since the late nineteen fifties has been predicated in principle on economies of scale and has been largely based in practice on 500 MW(e) turbine generator sets. This paper compares the strategy adopted by the CEGB with alternative hypothetical strategies based on smaller units of plant. Simulation of the supply system over ten years suggests that the economies of scale in very large plant have not been sufficient to offset the attendant disadvantages. Allowance is made for the variation with capacity of the capital cost, thermal efficiency, construction time, planning margin and availability. It is concluded that better results might have been obtained with sets between 200 MW(e) and 300 MW(e). It is acknowledged that this post hoc analysis has only an indirect connection with the decisions that now face the CEGB. the potential economics of scale in nuclear stations are not of the same form as those in fossil fuelled stations. There are also unsatisfactory aspects of the analysis which leave some uncertainty about the validity of the conclusions. But what the analysis does show is that there are conditions where economies of scale are outweighed by other factors, that these conditions are not especially remarkable, that they seem to have been satisfied by the CEGB system and that supply utilities in developing countries, where comparable decisions have now to be taken and where the disadvantages of scale are more pronounced, should examine carefully the case for large generating units in local circumstances.
A review of dust-induced electromagnetic waves scattering theories and models for 5G and beyond wireless communication systems
Scientific African
Tikrit Journal For Political Science
American dominance made an important objective in American political thought by virtue of the ter... more American dominance made an important objective in American political thought by virtue of the terms of reference that have shaped the mentality of the external decision-maker from using of all means in order to achieve this goal. Its came to rationalize the successive American administrations in the best use of the components of American power in order to perpetuate this domination. the most important contributions to this area was the intellectual theory of Joseph Nye and Zbigniew Brzezinski، who were to have an important role in the sharp debate about American hegemony and its future، by highlighting America's strengths compared with competitors hinted Lin، who can threaten American dominance in this century.
Sustainability
The rapid increase in data traffic caused by the proliferation of smart devices has spurred the d... more The rapid increase in data traffic caused by the proliferation of smart devices has spurred the demand for extremely large-capacity wireless networks. Thus, faster data transmission rates and greater spectral efficiency have become critical requirements in modern-day networks. The ubiquitous 5G is an end-to-end network capable of accommodating billions of linked devices and offering high-performance broadcast services due to its several enabling technologies. However, the existing review works on 5G wireless systems examined only a subset of these enabling technologies by providing a limited coverage of the system model, performance analysis, technology advancements, and critical design issues, thus requiring further research directions. In order to fill this gap and fully grasp the potential of 5G, this study comprehensively examines various aspects of 5G technology. Specifically, a systematic and all-encompassing evaluation of the candidate 5G enabling technologies was conducted. ...
Large scale survey for radio propagation in developing machine learning model for path losses in communication systems
Scientific African
Physical layer security using boundary technique for emerging wireless communication systems
SECURITY AND PRIVACY
Journal of Ambient Intelligence and Humanized Computing
The success of deep learning over the traditional machine learning techniques in handling artific... more The success of deep learning over the traditional machine learning techniques in handling artificial intelligence application tasks such as image processing, computer vision, object detection, speech recognition, medical imaging and so on, has made deep learning the buzz word that dominates Artificial Intelligence applications. From the last decade, the applications of deep learning in physiological signals such as electrocardiogram (ECG) have attracted a good number of research. However, previous surveys have not been able to provide a systematic comprehensive review including biometric ECG based systems of the applications of deep learning in ECG with respect to domain of applications. To address this gap, we conducted a systematic literature review on the applications of deep learning in ECG including biometric ECG based systems. The study analyzed systematically, 150 primary studies with evidence of the application of deep learning in ECG. The study shows that the applications of deep learning in ECG have been applied in different domains. We presented a new taxonomy of the domains of application of the deep learning in ECG. The paper also presented discussions on biometric ECG based systems and meta-data analysis of the studies based on the domain, area, task, deep learning models, dataset sources and preprocessing methods. Challenges and potential research opportunities were highlighted to enable novel research. We believe that this study will be useful to both new researchers and expert researchers who are seeking to add knowledge to the already existing body of knowledge in ECG signal processing using deep learning algorithm.
Journal of Engineering Science and Technology Review, 2019
Thermistors are widely used in temperature measurement due to their fast response, high accuracy,... more Thermistors are widely used in temperature measurement due to their fast response, high accuracy, and low cost. However, due to the nonlinear resistance-temperature relationship, there is a need for linearisation in order to design a signal conditioning circuit for accurate temperature measurement. Thus, this paper presents the design of a thermistor signal conditioning circuit based on Wheatstone Bridge. An experiment was conducted on an NTC thermistor to acquire the resistance response to temperature change between 25 ºC to 65º C which was in turn used for the model linearization. The obtained parameters from the linearized model are used to design the Wheatstone bridge signal conditioning circuit. The designed measurement system performance evaluation demonstrated a high degree of accuracy with only 1.1 % non-linearity within the specified temperature range.
International Journal of Signal and Imaging Systems Engineering, 2018
This paper considers the effect of an end-user assisted jamming scheme to achieve a secure transm... more This paper considers the effect of an end-user assisted jamming scheme to achieve a secure transmission of information over Nakagami-m fading channel in wireless broadcast system. In this work, full duplex (FD) antenna at the legitimate receiver (LR) was introduced in a way that the LR will contribute additional noise to the system to degrade the eavesdropper's channel. The approach achieves secured transmission with improved secrecy when compared to the conventional method that artificial noise (AN) scheme is transmitted from the transmitter only. Numerical analysis and simulation results show an improvement in the secrecy performance metrics.
Computer Engineering and Applications Journal, 2019
The growing evidence of the global warning phenomena and the rapid depletion of fossil fuels have... more The growing evidence of the global warning phenomena and the rapid depletion of fossil fuels have drawn the world attention to the exploitation of renewable energy sources (RES). However standalone RES have been proven to be very expensive and unreliable in nature owing to the stochastic nature of the energy sources. Hybrid energy system is an excellent solution for electrification of areas where the grid extension is difficult and not economical. One of the main attribute of hybridising is to be able to optimally size each RES including storages with the aim of minimizing operation costs while efficiently and reliably responding to load demand. Hybrid RES emerges as a trend born out of the need to fully utilize and solve problems associated with the reliability of RES. This paper present a review of techniques used in recent optimal sizing of hybrid RES. It discusses several methodologies and criteria for optimization of hybrid RES. The recent trend in optimization in the field of ...
International journal of paediatric dentistry / the British Paedodontic Society [and] the International Association of Dentistry for Children, 2011
To undertake a child-centred evaluation of treatment provision for visible enamel defects. Postal... more To undertake a child-centred evaluation of treatment provision for visible enamel defects. Postal questionnaires, developed with children, were sent to 88 patients, aged 7-16 years, with visible enamel defects of permanent incisors and who had received microabrasion, with/without additional composite restoration at Sheffield Dental Hospital, UK. The questionnaires sought children's perceptions about their teeth before and after the intervention, as well as their evaluation of how they had been treated. Anonymised responses were graded using a 10 cm visual analogue scale (VAS) where a score of 10 indicated the most negative response, and zero the most positive response. Sixty three questionnaires were returned (72% response). Prior to treatment, children reported high levels of worry (VAS=6.8), embarrassment (VAS=6.9) and a perception that their teeth looked yellow and discoloured (VAS=7.3). Following treatment, children thought their teeth looked much better (VAS=1.6), felt happ...
IEEE Transactions on Industrial Electronics, 1995
This paper introduces, analyzes, and experimentally verifies a novel dddc converter called the cu... more This paper introduces, analyzes, and experimentally verifies a novel dddc converter called the current-source parallelresonant converter. The converter consists of a large choke inductor, two switches, and a parallel-resonant circuit. Each switch consists of a MOSFET in series with a diode. It has a nonpulsating input current with a very low ac ripple. The MOSFET's are driven with respect to ground and, therefore, have a simple gate-drive circuit. The analysis of the converter is carried out in the frequency domain using Fourier series techniques. Analytical expressions are derived for performance parameters of the converter. A prototype of the converter circuit was designed, built, and tested. The theoretical results were in good agreement with the experimental results.
Genetic Epidemiology, 2008
As part of the Genetic Epidemiology Network of Arteriopathy study, hypertensive non‐Hispanic Whit... more As part of the Genetic Epidemiology Network of Arteriopathy study, hypertensive non‐Hispanic White sibships were screened using 471 single nucleotide polymorphisms (SNPs) to identify genes influencing coronary artery calcification (CAC) measured by computed tomography. Individuals with detectable CAC and CAC quantity ≥70th age‐ and sex‐specific percentile were classified as having a high CAC burden and compared to individuals with CAC quantity <70th percentile. Two sibs from each sibship were randomly chosen and divided into two data sets, each with 360 unrelated individuals. Within each data set, we applied two machine learning algorithms, Random Forests and RuleFit, to identify the best predictors of having high CAC burden among 17 risk factors and 471 SNPs. Using five‐fold cross‐validation, both methods had ∼70% sensitivity and ∼60% specificity. Prediction accuracies were significantly different from random predictions (P‐value<0.001) based on 1,000 permutation tests. Predi...
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Papers by Abubakar Abdulkarim