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- ItemDevelopment of an Operational Amplifier Virtual Laboratory based on iLab Architecture and NI ELVIS(American Society for Engineering Education, 2008) Osasona, OladipoWe have developed and deployed ‘OpAmp Lab’, a pedagogic operational amplifier virtual laboratory based on the MIT iLab architecture. The architecture is a three-tier architecture that abstracts the various parts of a remote laboratory system into different functional domains. This architecture makes the new virtual Lab experiments scalable and reduces the development and deployment time of new experiments through component reuse. OpAmp Lab uses the National Instrument ELVIS hardware platform for experimental set-up. Basic Op-amp circuits are realized through reconfigurable Dozen Impedance Op-amp configuration mounted on a multimode switch array. The front end or Client is implemented as a Winform Client, written in C# and uses connectible nodes as a metaphor for back-end hardware configuration. Strong emphasis is placed on the realism of the user interface, as we argue, the user interface is the most important determinant of the quality of a user’s educational experience. We discuss the various components of OpAmp Lab and the lessons learnt in the development of the system as well as the development of pedagogical experiments developed for it. OpAmp Lab has been in use at Obafemi Awolowo University, NIGERIA for the last two years. Faculty and students response has been strongly positive. We provide data showing that the Lab offers a viable means of augmenting the laboratory component of electrical engineering curricula in developing countries.
- ItemAdvanced Digital Laboratory: an FPGA-Based Remote Laboratory for Teaching Digital Electronics(American Society for Engineering Education, 2009, 2009-06) Osasona, OladipoThe experimentation component of most Science and Engineering curricula in Nigeria is inadequate. In Obafemi Awolowo University for example, undergraduate students typically carry out around five assignments related to digital electronics, and there is no treatment whatsoever of Field Programmable Gate Arrays(FPGAs). In the research work being reported, an attempt has been made to develop a remote laboratory though which the number of digital electronics experiments students carry out can be increased. The remote laboratory, called the Advanced Digital Lab (ADLab), allows students to synthesis digital systems on an FPGA with a hardware description language. To achieve this, a development board with an Altera Cyclone II FPGA is connected to a computer implementing the server tier of the iLab batched architecture. The client through which the remote student interacts with the ADLab is implemented with Java, which allows for a reasonable amount of platform independence. This paper discusses the software and hardware aspects of the ADLab architecture and gives some insight into some design decisions. The paper also reports that the system is being tested at Obafemi Awolowo University and that student feedback so far indicates high student satisfaction with the remote laboratory.
- ItemPolymer Optical Fibre in Communications and Environmental Monitoring(URSI Nigeria, 2010-12) Dairo, OluropoThis paper focuses on niche applications of polymer optical fibre (POF) in modern communication systems and other related areas. The electromagnetic isolation of POF and its relatively high sensitivity compared to conventional sensors has earned it a centre stage in sensing technology. The ability to detect and measure physical parameters such as temperature, humidity and wind speed makes POF suitable for real-time monitoring of environmental and climatic conditions. Other attractive features of POF include a lower cost compared with glass optical fibres, better fracture resistance and flexibility.
- ItemRemote Labs in Education. The Obafemi Awolowo University Experience(University of Deusto Bilbao, 2011) Osasona, Oladipo
- ItemImplementing Remote Laboratories with the ILAB Architecture: Three Case Studies from Obafemi Awolowo University, Nigeria(Computers in Education Journal, 2012-03) Osasona, OladipoA number of remote labs based on the iLabs Architecture have been developed and used for credit awarding courses in Obafemi Awolowo University (OAU), Nigeria. These include the Op-Amp iLab, Logic Design iLab, and Robotic Arm iLab. The Op-Amp Lab allows students to access a small operational amplifier circuit hosted in OAU, and with the aid of switching matrices, reconfigure the circuit, inject waveforms, and see the resulting output signals. The Logic Design Lab is built around a Field Programmable Gate Array (FPGA) chip that students can reprogram from afar using the VHDL, a hardware description language. The Robotic Arm iLab is a control engineering laboratory in which students can remotely control a robotic arm located in OAU. Video feedback through BroadCam Video Streaming Server and Livestream (www.livestream.com) allows users observe and measure the robotic arm’s response to their commands. In our paper, we describe the iLab Batched and Interactive architectures and describe three iLabs developed in OAU in detail. Emphasis is placed on technical details and design choices made in developing these labs. We also discuss other aspects of iLab development and use and dwell on issues that could hinder or accelerate the adoption of remote laboratories in developing countries.
- ItemThe Impact of Cassava Wastewater from Starch Processing Industry on Surrounding Soil: A Case Study of Matna Foods Industry, Ogbese(FUOYE Journal of Engineering and Technology, 2016-09) Olayanju, OpeyemiThis study is aimed at determining the impacts of indiscriminate disposal of processed cassava wastewater into the environment by determining the physicochemical characteristics of the wastewater and soil characteristics within the vicinity of starch processing industry. The cassava wastewater quality was tested in accordance with the standard methods for the examination of water and wastewater while soil samples was analyzed using Atomic Absorption Spectrometer. The result of cassava wastewater shows that the effluent is acidic with pH of 3.8 and high conductivity of 6500μΩ. The cyanide content is also very high with 0.17mg/l as compared to 0.05mg/l recommended by WHO. The total solid, total dissolved solid and total suspended solid are also in high range of 20619, 17048 and 3571 mg/l respectively. Its hardness is 812mg/l, chloride 2516mg/l and nitrate 470mg/l. The dissolved oxygen was not detected while COD and BOD were also on the high side with values of 560 and 1410mg/l respectively. The results of soil analysis indicates that the cyanide concentration is high at the surface but reduces with depth. The pH is also in acidic range. However, Magnesium, Sodium, Sulphate, Zinc, Chromium, Vanadium, Europium and Rubidium were not detected in the soil samples. The percentage of calcium, potassium, copper, manganese and titanium were small and varying between 0.07 and 6.37ppm. Three unlined aerobic ponds provided for the treatment of cassava wastewater reduces the pollution strength of the wastewater but the untreated wastewater interfere with the surrounding soil during conveyance to the pond as well as pond environment. It is recommended that the wastewater conveyance and ponds should be well designed to prevent interference with the surrounding soil.
- ItemStatistical Analysis of Tropospheric Scintillation of Satellite Communication Signals using Karasawa and ITU-R Models(IEEE, 2017) Dairo, OluropoThe climatology of the tropics coupled with its deep convective evolution at the equatorial troposphere has continued to draw significant attention to the effects of scintillation on satellite communication signals. The dearth of signal degradation data perceived as scintillation fade depth is pronounced in the tropics. In particular, the effect of tropospheric scintillation on two major satellite providers, namely NigComSat-1R and Eutelsat, was considered. Karasawa and ITU-R statistical models were used. Twelve months of data were collected from the Tropospheric Data Acquisition Network stations with geo-spatial coverage representing Nigerian climatic zones. The variability is 9% for both models in the monsoon climate, and ~158%–180% in warm semi-arid climate for both ITU-R and Karasawa, respectively. Scintillation intensity was highest in the monsoon climate with values of 1.31dB, 1.51dB and 18.72 dB using ITU-R, and 0.88 dB, 1.06 dB and 27.05 dB using Karasawafor Eutelsat, NigComSat-1R and low elevation satellites.
- ItemHandover in Mobile Wireless Communication Network - A Review(International Journal of Advanced Engineering, Management and Science (IJAEMS), 2017-09) Orimogunje, AbidemiMobility is the characteristics of mobile communication that makes it irresistible by all and sundry. The whole world is now engaging in wireless communication as it provides users' ability to communicate on-the-go. This is achieved by transferring users from a radio network to another. This process is called handover. Handover occurs either by cell crossing or by deterioration in signal quality of the current channel. The continuation of an active call is a critical characteristic in cellular systems. Brief overview of handover, handover type, commonly used handover parameters, some methods employed in the literature and we present the convergent point for furtherance in the area of mobile wireless communication Handover
- ItemAdaptive Network Based Fuzzy Inference System Model for Minimizing Handover Failure in Mobile Networks(International Journal of Innovative Science and Research Technology, 2017-09) Orimogunje, AbidemiFor seamless connection between mobile users on the same and different mobile technologies there is need for the deployment of a more complex algorithm for a successful switching of mobile users. Signal to interference ratio, speed of the mobile users and traffic distance are the three input used in the Adaptive network based Fuzzy inference system (ANFIS) which is an hybrid of two techniques of artificial intelligence which make it suitable to handle complexities such as ping-pong effect and interference which impair on the quality of service (QoS) during call handover process as the mobile users move from one coverage area (cell) to another.
- ItemRadio refractivity gradients in the lowest 100 m of the atmosphere over Lagos, Nigeria in the rainy-harmattan transition phase(Elsevier Ltd, 2018) Dairo, OluropoRadio engineers and researchers in conjunction with the International Telecommunication Union (ITU) have established the pivotal role of radio refractivity to the propagation of electromagnetic energy in the troposphere. In particular, the refractivity gradient statistics for the lowest 100m in the troposphere are used to determine the probability of occurrence of anomalous propagation conditions known as ducting. The major challenge to characterising the propagation condition over any environment is accessing the data of the lowest boundary layer of the atmosphere, which is highly dynamic and turbulent in evolution. High resolution radiosonde data from the Nigerian Meteorological Agency (NiMet) were used for a synoptic study of the rain-harmattan transition phase. The rain-harmattan transition phase marks the onset of the dry season due to the movement of the intertropical convergence zone interplay between (north-easterly and south-westerly) trade winds and monsoonal circulation. The lowest 100m data were analysed to determine the frequency of ducting per month. Progressive increase in the occurrence of ducting was observed during the rain-harmattan transition phase, which coincides with the West African Monsoon retreat. The results show significant divergence from previous studies, which reported that the tropospheric condition over Lagos (Geo. 6.5°N, 3.3°E), Nigeria, is predominantly super-refractive.
- ItemDevelopmentof a Propagation Model for IEEE 802.11 Wireless Networks: Case of GidanKwano Campus, FUT MINNA(Ahmadu Bello University Zaria Proceedings of the 1st National Communication Engineering Conference 2018, 2018-10-18) Ogunjide, SundayWireless propagation modeling is an essential task in planning wireless networks. In the last few decades, the use of Wireless Local Area Network (WLAN) popularly referred to as Wi-Fi(Wireless Fidelity) in communication system has been on the increase with the exponential usage of handheld cell phones, laptops, and palm-tops to mention but a few. Notwithstanding, WLAN faces a peculiar propagation issue which lies in its changing propagation environment and this affects the quality of service. Poor quality of service is experienced on WLAN of GidanKwano campus of Federal university of technology, Minna. This arises due to signal propagation impairment caused by the terrain and the structures within the campus. Received Signal Strength (RSS) measurements were conducted at different locations away from the selected Access Points (APs) both in Line of Sight (LOS) and Non- Line of Sight (NLOS) situations. The path loss exponent (n) and standard deviation (σ) were estimated for the environment. The obtained results were contrasted with the already published work to show the level of agreement. The empirical models were developed for LOS and NLOS situations and compared with the existing standard models.
- ItemPerformance Analysis of Temperature Models for Environmental Monitoring in Southwest Nigeria(LivingScience Foundation, 2019) Dairo, OluropoTemperature is a major meteorological parameter driving most of the atmospheric processes vis-a`-vis climate change. Therefore, a consistent model is necessary to achieve sustainable development goal 13 (SDG 13) known as climate action. Long-term monthly averages of surface temperature obtained from six southwest states in Nigeria were subjected to five mathematical models, namely the sum of two-Gaussians, the sum of two-Lorentzians, Fourier on four harmonics, Sine wave and Fourth-order polynomial functions. Statistical tools were used to examine the accuracy and fitness of the models. The evaluation showed that the Gaussian and Lorentzian models are good fits for the observed data. Furthermore, the performance indicators such as mean bias error (MBE), root mean square error (RMSE) and mean percentage error (MPE) recorded the lowest values for Fourier on the fourth harmonic model. Similarly, its correlation coefficient, R, was the highest ranging from 0.95 to 1. Consequently, the Fourier model presented the best correlation with the observed data and hence was recommended for predicting the temperature at the selected locations.
- ItemRain Fade Analysis at C, Ka and Ku Bands in Nigeria(IISTE, 2019) Dairo, OluropoRain fade has continued to be a major concern to communication systems designers. The effect of these dynamic fluctuations of the received signal due to rain is very pronounced in the tropical region. This paper pertains to the analysis of rain fades at C, Ku and Ka bands at some selected stations covering the main geographical zones of Nigeria. The ITU-RP propagation model was used to calculate the fade depth at 6 GHz, 8 GHz, 12 GHz, 16 GHz, 20 GHz, 30 GHz and 40 GHz. The rain fade correlates with signal attenuation. Attenuation distributions for percentages of time for signal unavailability were also estimated. The results show that values of attenuation for vertically and circularly polarized signals are less than those of the horizontal polarization at all the frequencies. It is found that rain fade is less severe in the Northern part of the country and is most severe in the southern part of Nigeria, with Port Harcourt, Lagos and Nsukka experiencing the highest rain impairment.
- ItemSuitable Propagation Models for 2.4 GHz Wireless Networks: Case Study of Gidan Kwano Campus, FUT MINNA(3rd International Engineering Conference (IEC) Federal University of Technology Minna, 2019-09-25) Ogunjide, SundayIn the last few decades, the use of Wireless Local Area Network (WLAN) popularly referred to as Wi-Fi (Wireless Fidelity) in communication system has been on the increase with the exponential usage of handheld cell phones, laptops, and palm-tops to mention but a few. However, WLAN faces a peculiar propagation issue which lies in its changing propagation environment and this affects the quality of service. Poor quality of service is experienced on WLAN of Gidan Kwano campus of Federal University of Technology (FUT), Minna, due to signal propagation impairment caused by the terrain and the structures within the campus. In this work, Received Signal Strength (RSS) measurement was conducted at varying radial distances away from the selected Access Points (APs) both in Line of Sight (LOS) and Non- Line of Sight (NLOS) situations. The path loss exponent (n) and standard deviation (σ) were estimated for the environment. For LOS and NLOS scenarios, the obtained path loss exponents were 2.31 dB and 3.2 dB respectively. The developed models were contrasted with the existing standard models and found to perform better based on the quantitative measures taken in the study area. This shows that the developed models can be utilised for accurate access point deployment within the Gidan Kwano Campus, FUT Minna and other environments with similar features.
- Item1-Minute Rain Rate Distribution for Communication Link Design Based on Ground and Satellite Measurements in West Africa(Begell Journal, 2020) Dairo, OluropoWest Africa is in the tropical region and it is characterized by intense rainfall. Rain is a significant factor causing signal degradation on microwave links due to its variability; it causes scattering, absorption, and refraction of electromagnetic waves. Experimental studies have shown that rainfall intensities above 64 mm/h at 0.01% in this region result in noticeable digital television signal fading, squelching and complete outages. Hence the need for estimating rain rate distribution across West Africa. This paper analyzed the rain rate in six countries in West Africa, namely Benin, Cameroon, Cote d'Ivoire, Ghana, Nigeria, and Togo. Three locations were selected in each country. Rain data were obtained from the Tropical Rain Measuring Mission-Precipitation Radar (TRMM-PR) and the Global Precipitation Measurement (GPM) missions, and Tropospheric Data Acquisition Network (TRODAN) weather stations in Nigeria. This study used ITU-R and Moupfouma models for the conversion of the 5-minute rain rate to 1-minute integration time at a probability of exceedance ranging from 1% to 0.001%. The cumulative rain rate distribution from the measured rain rate is presented alongside the predictions of the models. ITU-R and Moupfouma predicted similar results at 0.1% probability of exceedance. ITU-R overestimates the rain rate above 0.01% probability of exceedance. On the other hand, the Moupfouma models prediction plots at 0.01% overlap for all locations, indicating that there will be a signal loss at 0.01% probability of exceedance across these locations. The result shows that the 5- minute conversion provides satisfactory performance and is suitable for estimating the 1-minute rain rate statistics required for propagation planning over West Africa.
- ItemExploring the binding interactions of structurally diverse dichalcogenoimidodiphosphinate ligands with α-amylase: Spectroscopic approach coupled with molecular docking(Elsevier, 2020) Dairo, OluropoPostprandial hyperglycemia has orchestrated untimely death among diabetic patients over the decades and regulation of α-amylase activity is now becoming a promising management option for type 2 diabetes. The present study investigated the binding interactions of three structurally diverse dichalcogenoimidodiphosphinate ligands with α-amylase to ascertain the affinity of the ligands for α-amylase using spectroscopic and molecular docking methods. The ligands were characterized using 1H and 31P NMR spectroscopy and CHN analysis. Dis- elenoimidodiphosphinate ligand (DY300), dithioimidodiphosphinate ligand (DY301), and thio- selenoimidodiphosphinate ligand (DY302) quenched the intrinsic fluorescence intensity of α-amylase via a static quenching mechanism with bimolecular quenching constant (Kq) values in the order of x1011 M-1s-1, indicating formation of enzyme-ligand complexes. A binding stoichiometry of n≈1 was observed for α-amylase, with high binding constants (Ka). α-Amylase inhibition was as follow: Acarbose>DY301>DY300>DY302. Values of thermodynamic parameters obtained at temperatures investigated (298, 304 and 310 K) revealed spontaneous complex formation (ΔG<0) between the ligands and α-amylase; the main driving forces were hydrophobic in- teractions (with DY300, DY301, except DY302). UV–visible spectroscopy and Fo ̈rster resonance energy transfer (FRET) affirmed change in enzyme conformation and binding occurrence. Molecular docking revealed ligands interaction with α-amylase via some key catalytic site amino acid residues (Asp197, Glu233 and Asp300). DY301 perhaps showed highest α-amylase inhibition (IC50, 268.11 ± 0.74 μM) due to its moderately high affinity and composition of two sulphide bonds unlike the others. This study might provide theoretical basis for development of novel α-amylase inhibitors from dichalcogenoimidodiphosphinate ligands for management of postprandial hyperglycemia.
- ItemTropospheric Scintillation Effects on Satellite Links from X-band to Q-band over Nigerian Climatic Zones using Karasawa and ITU-R Models(Begell Journal, 2020) Dairo, OluropoThe tropospheric scintillation of satellite communication signals has continued to draw the attention of radio engineers. The effect and prevalent paucity of Earth-space tropospheric scintillation data in Africa are remarkable. The parameters of NigComSat-1R and Eutelsat-36B satellites were used for this modelling from X- to Q-band during the West African monsoon (WAM). The low error rates of Karasawa and ITU-R models reported for the tropical climates made them appropriate for this study. In situ data from the Tropospheric Data Acquisition Network stations spanning three climatic regions in Nigeria, namely Tropical Monsoon, Geo. 6.5o N, 3.5o E; Tropical Savanna, Geo. 8.99o N, 7.38o E; and the Sahel, Geo. 9.35o N, 12.5o E. The scintillation variability is lowest in the tropical monsoon climate and highest in the Sahel climate using both models. However, the ITU-R model recorded higher scintillation fade depths (SFDs) of 37.19 dB, 2.91 dB, and 2.52 dB, for low elevation, NigComSat-1R and Eutelsat-36B satellites respectively, over the tropical monsoon climatic zone, than Karasawa model, which recorded SFDs of 34.07 dB, 1.31 dB, and 1.09 dB for the respective satellites. The observed scintillation intensity increased with increasing carrier frequency, low elevation angle and small receiving antenna. High variability of the scintillation intensity characterizes the onset of WAM and post-monsoon months.
- ItemEstimation of Rain Fade Durations on Communication Links at Ka Band in Equatorial and Tropical Regions(Begell Journal, 2020) Dairo, OluropoDuration of rain fade events is a major parameter to be considered when designing a communication link. Fading is a phenomenon responsible for intermittent fluctuations of radio signals observed in the tropical region. The prevalence of rain in the tropics accounts for the frequency of fading observed in this region. Despite, the efforts of researchers to help systems designers give due consideration to fade mitigation techniques in other parts of the world, there is still a dearth of fade duration data from the African equatorial and tropical regions. Hence, this study estimates the number of fade events per fade duration interval exceeding attenuation thresholds ranging from 1 dB to 18 dB at ka-Band (26.5 GHz−40 GHz), leading to nonavailability of satellite systems during raining events in the African equatorial regions. The range of fade durations is from 10 s to 5000 s. The International Telecommunication Union (ITU-RP) propagation model and data from the Tropospheric Data Acquisition Network (TRODAN) were used for the analysis. The eight TRODAN observatories, under the Centre for Atmospheric Research (CAR), cover the major climatic regions in the sub-Saharan region, namely equatorial, humid tropical and tropical zones (Geo. 4.82єN to 9.58єN). Fade duration decreases latitudinally as the attenuation threshold increases from low to higher latitudes. The equatorial region suffers the highest frequency of fade events while the tropical zones recorded the lowest. In addition, the 10 s fade duration recorded the highest occurrence of fade events. The implication is that heavy rains, causing higher attenuation, occur for a shorter time duration. Similarly, higher attenuation depends on raindrops' size and rain intensity. Consequently, the number of fade events exceeding 1 dB threshold is higher than other thresholds with respect to the fade duration.
- ItemInfluence of Eigenvector on Selected Facial Biometric Identification Strategies(World Journal of Engineering Research and Technology, 2020-02-16) Jooda, JanetFace identification strategies are becoming more popular among biometric-based strategies as it measures an individual‟s natural data to authenticate and identify individuals by analyzing their physical characteristics. For face identification system to be efficient and robust to serve it purpose of security, there is need to use the best strategy out of the many strategies that have been proposed in literatures for face identification. Amidst the most popularly used face identification strategies, Principal Component Analysis PCA, Binary Principal Component Analysis BPCA, and Principal Component Analysis – Artificial Neural Network PCA-ANN were selected for performance evaluation. The research was experimented by varying the eigenvector of the training images for each strategy to compare the performance using Recognition Rate RR and Total Recognition Time TR as performance metrics. Results showed that PCA – ANN strategy gave the best recognition rate of 94% with a trade-off in recognition time. Also, the recognition rates of PCA and B-PCA increased with decreasing number of eigenvectors but PCA-ANN recognition rate was negligible. Hence PCA-ANN outperforms the other face identification strategies.
- ItemSuitable Propagation Models for 2.4 GHz Wireless Networks: Case Study of Gidan Kwano Campus, FUT MINNA(ABUAD Journal of Engineering Research and Development (AJERD), 2020-06-30) Ogunjide, SundayIn the last few decades, the use of Wireless Local Area Network (WLAN) popularly referred to as Wi-Fi (Wireless Fidelity) in communication system has been on the increase with the exponential usage of handheld cell phones, laptops, and palm-tops to mention but a few. However, WLAN faces a peculiar propagation issue which lies in its changing propagation environment and this affects the quality of service. Poor quality of service is experienced on WLAN of Gidan Kwano campus of Federal University of Technology (FUT), Minna, due to signal propagation impairment caused by the terrain and the structures within the campus. In this work, Received Signal Strength (RSS) measurement was conducted at varying radial distances away from the selected Access Points (APs) both in Line of Sight (LOS) and Non- Line of Sight (NLOS) situations. The path loss exponent (n) and standard deviation (σ) were estimated for the environment. For LOS and NLOS scenarios, the obtained path loss exponents were 2.31 dB and 3.2 dB respectively. The developed models were contrasted with the existing standard models and found to perform better based on the quantitative measures taken in the study area. This shows that the developed models can be utilised for accurate access point deployment within the Gidan Kwano Campus, FUT Minna and other environments with similar features.