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Item Open Access A comprehensive review on the feasibility and challenges of millimeter wave in emerging 5G mobile communication(U.P, 2019) Agubor,Cosmas Kemdirim; Akwukwuegbu, Isdore; Olubiwe, Mathew; Nosiri, Chikezie Onyebuchi; Ehinomen, Atimati; Olukunle, Akande Akinyinka; Okozi, Samuel Okechukwu; Ezema, Longinus; Okeke, Benjamin ChukwujekwuThis article presents a comprehensive review on the feasibility and challenges of millimeter wave in emerging fifth generation (5G) mobile communication. 5G, a multigigabit wireless network is the next generation wireless communication network. The mmWave cellular system which operates in the 30-300 GHz band has been proposed for use as the propagation channel. Its large bandwidth potential makes it a candidate for the next-generation wireless communication system which is believed to support data rates of multiple Gb/s. High frequency bands such as mmWave have channel impairments. These impairments are challenges that are necessary to be properly understood. Employing mmWave as a propagation channel requires dealing with these challenges which this paper is aimed at reviewing. One aim of the work is to discuss these challenges in a more elaborate manner using simple mathematical equations and graphics to ensure clarity. To achieve this, current related works were studied. Challenges and solutions are identified and discussed. Suggested research directions for future work are also presented. One is developing suitable electronic such as fast analog-to-digital (ADC) and digital-to-analog (DAC) systems necessary for the transmitter/receiver (TX/RX) system.Item Open Access Performance improvement of a direction finding system antenna using method of moment (MOM)(U. P., 2020-01-15) Anaebo, Ogonna F.; Ezeh, Gloria N.; Nosiri, Onyebuchi C.; Agubor, Cosmas K.This paper focuses on the Performance Improvement of a Direction Finding System Antenna Using Method of Moment (MoM) Approach. The work is developed to provide an approximate current distribution for a direction finding system antenna by employing the use of Method of Moment on an array of Yagi-uda antenna. The parameters of the experimental antenna are derived and analyzed via Magnetic Vector Potential (MVP) operator. The accurate current flowing through the radiating elements of the direction finding system is analyzed using combination of Method of Moment technique and Magnetic Vector Potential (MVP) operator. This helps to avoid the detection of false alarms and inability of the system to detect remote targets. A typical direction finding system Yagi antenna is designed and operated at a frequency range of 0.6- 0.8 GHz. The antenna has a single reflector, an active (driven) element and three (3) parasitic directors. The antenna parameters are simulated using MatLab R2010a software tool. The average pointing vector of the designed Yagi antenna was obtained as 3.73watt per square metre, and Radiation Intensity value of about 9.400 coulomb per kilogram. The simulation results indicate an appreciable increase in directivity of 9.03dBi, an enhanced directive gain compared to that of the equivalent dipole antenna of 1.76dBi, signifying 7.27dBi enhancement.Item Open Access An evaluation of hand trajectory gesture controlled vehicular robot(Nigeria Consltants' Network (CN), 2021) Atimati, E. E.; Ezema, Longinus. S.; Okafor, K. C.; Achumba, I. E.; Ifediora, E. C.; Agubor, C. K.Vehicular robotics (VRs) is an emerging field in Mechatronics application that offers numerous benefits to assisted living systems, exploits in unsafe terrains, agricultural harvesting, and manufacturing automation, among others. The absence of gesture angular displacement to speed relationship remains unresolved in literature. Existing systems controlled by hand gesture uses Radio Frequency (RF) module as a medium of wireless communication. In this paper, a reengineered VR controlled by five palm gestures is implemented and evaluated. An accelerometer-powered transmitter circuitry for the palm glove is realized while integrating Bluetooth spectrum at the VR receiver for wireless signalling. C+ constructs are introduced for end-to-end control between the transmitter and receiver. Performance assessment carried out on actual speed, response time and a blind spot in both autonomous and semi autonomous modes provided satisfactory insights. It is observed that in semi-autonomous mode (gesture mode), under tilting palm angle ranged 0-40 degrees, a minimum speed of 0.55m/s was observed. A medium speed of 0.63m/s and a maximum speed of 0.91m/s are obtained at 40 to 60 degrees and 70 to 90 degrees respectively. Furthermore, the autonomous mode offered a speed of 0.97m/s.Item Open Access 5G network deployment in Nigeria: Key challenges and the way forward(U. P., 2021-03-17) Agubor, Cosmas Kemdirim; Chukwuchekwa, Nkwachukwu; Ezema, Longinus SundayMany countries are faced with different challenges in the deployment of 5G mobile wireless communication technology. These challenges have delayed the smooth rollout of this technology in these countries. Nigeria has its own issues that have hindered the implementation of this technology in the country. This paper discusses these challenges and suggestions made on what to do for the implementation of 5G technology. A survey was done by visiting and obtaining reports from two major players in the industry as well as understudying actions taken by other nations in tackling similar problems related to 5G network implementation. Based on the information gathered both from the industry and related literature some useful suggestions such as improved fiber infrastructure and relaxing regulatory barriers to encourage investors were made as a way forward for the full implementation and operation of the 5G technology in Nigeria.Item Open Access Transient configuration of a photovoltaic-deiesel energy sources for electric power production in Multi-Engineering Complex of Federal University of Technology, Owerri, Nigeria(U. P., 2021) Akwukwaegbu, Isdore Onyema; Anumaka, Michael Chukwukadibia; Agubor, Cosmas NkemmdirimThe work covers transient configuration of the grid connected photovoltaic-diesel power production in multiEngineering building complex of Federal University of Technology, Owerri (FUTO), Nigeria. The electric power shortage in Nigeria and the global drive towards exploring new energy sources have facilitated the consideration of the grid connected photovoltaic-diesel power generation, as a viable solution to poor energy supply system in multi-Engineering complex of FUTO, Nigeria. The work is achieved through estimation of complex’s daily average load profile in a consecutive number of ten hours, complex`s component selection and sizing of solar panels and solar PV modules, inverter without battery storage capacity, diesel generator capacity, transient configuration and modeling using Matlab/Simulink Sim scape Tool. The same tool is deployed for the transient configuration simulation of the developed system. The performance evaluation of the simulation results revealed that the active and reactive powers recorded permissible elongated transient duration period ranging from 0 to 3 seconds when the diesel generator is supplying the set load alone. However, when PV and diesel generator are connected to the building complex load without the grid, the transient optimum operation ranging from 0 to 2 seconds is recorded. The estimated load for the complex is approximated as 150kW, and this load operates at an average duration of 10 hours daily to produce approximately a total daily energy for the complex as 2,000KWh per day throughout the lifetime of the system design, which is shared among the PV-diesel power plant configuration at the ratio of 60%:40% daily. The PV system would supply 60% of the total daily power and energy demand of 89.616kW and 1,176.384KWh per day whereas, the diesel generator supplies 40% of the total daily power and energy demand of 59.744kW and 784.256KWh per day, so as to reduce the daily cost of fuel consumption.Item Open Access A study of the propagation characteristics of a 13 element yagi-uda antenna(International Association of Scientific Innovation and Research, 2017) Onwumere, Christogonus; Agubor, Cosmas KemdirimThis paper reports the propagation characteristics of a 13- element 640MHz Yagi antenna.The Yagi-Uda antenna is a highly directional antenna and in the transmit mode propagates electromagnetic energy in the direction running from the dipole or driven element toward the director and is sensitive to incoming electromagnetic energy in the receive direction. In this study, NBS 688 technical notes and antenna design curves were used and the resulting antenna estimate was modeled. The simulation and optimization was carried out using 4NEC2 antenna design software. Verification of the optimal design was achieved using EZNEC v.6.0 antenna modeler. The simulation result showed Antenna characteristics such as input impedance, radiated power, efficiency and far-field radiation pattern.Item Open Access Performance comparison of the designed microcontroller heartbeat monitor and clinical stethoscope medical insturments based on statistical approach(IAEME, 2021) Akwukwaegbu, Isdore Onyema; Ezugwu, Ernest Ozoemela; Agubor, Cosmas Nkemmdirim; Opara, Raymond Okechukwu; Olubiwe, Mattew; Obichere, Jude-Kennedy ChibuzoHeart related diseases are becoming more rampant, which if not properly checked and controlled, will continue to contribute a greater percentage of death rates among the younger generations. Controlling this deadly disease will be initiated by monitoring individual heartbeat rate regularly by a new low cost invented microcontroller based heartbeat medical measuring and monitoring instrument developed using electronic engineering techniques. The developed device uses electric microphone to detect the heartbeat and convert it to alternating current (ac) signal in millivolts, which is later amplified by a non inverting amplifier. A Schmitt trigger (555 timer) coverts the amplified ac signal into a square wave (one pulse is represented by one square). These square waves are used to count the number of squares for 60 seconds and display the result on the liquid crystal display (LCD) screen. The developed device is packaged in a plastic casing with adequate spacing provided to accommodate all components. The mean and standard deviation measured heart beat results obtained using the developed device and conventional clinical stethoscope range from 70.63 to 82.37 beat per minute(bpm) and 69.65 to 81.63 beat per minute(bpm) respectively. The result obtained using the developed device when compared to those obtained from the manual test involving counting of heartbeat fall satisfactorily within the acceptable range of 60 to 120 beat per minute(bpm). This developed device is useful for families, hospitals, clinics, community medical centres and for other medical purposes.Item Open Access Comparative analysis of multiple and single antenna applications in mobile wireless communication(SAVAP International, 2014) Agubor, C. K.; Ndinechi, M. C.; Chukwudebe, G. A.; Opara, F. K.The performance of multiple-antenna and single antenna systems as applicable in mobile wireless communication are compared. The method applied involves matrix computation based on the system model. The expressions derived were used to evaluate the system performance with zero-forcing (ZF) equalizer at the receiver. MATLAB Toolbox version 7.0 was used to carry out error performance simulation for the different transmitting and receiving antenna configurations in a Raleigh fading environment. The result showed in terms of BER performance that multiple antenna technique is capable of combating multi-path effects due to the low error rate they exhibited. The diversity modes employed by the multiple antennas were also analysed by comparing their / (Energy per bit to noise power spectral density ratio). Transmit diversity technique with multiple antennas at the base station and a single antenna at the remote end was further shown to be a better candidate for the next generation of wireless communication than the single-input single-output system.Item Open Access Techniques in performance improvment of mobile wireless communication systems-A review(Progressive Academic Publishing, UK, 2015) Agubor, C. K.; Nosiri, O. C.; Ononiwu, G. C.; Atimati, E. E.; Onyishi, D. U.Mobile wireless communication providers are expected by their numerous subscribers to provide network that can allow higher data rates, and good voice quality. However, this may be restricted due to some technical problems such as limited availability of radio frequency spectrum, bandwidth, channel capacity, geographical areas and transmission problems caused by various factors like fading and multipath distortion. All these lead to overall system performance degradation. This has led to various studies on how improvement on the performance of wireless communication can be realized using different techniques. This paper is a review of some scholarly works on this subject. To achieve this some recent scholarly articles were accessed online and their findings were highlighted. It was observed that all the articles reviewed had results drawn only from theoretical analysis. Based on this, one of the recommendations is that theoretical analysis should be supported with data obtained from carrying out RF measurements in the field where possibleItem Open Access A survey on the availability of TV white spaces in Eastern Nigeria(U. P., 2015) Atimati, E. E.; Ezema, L. S.; Ezeh, G. N.; Iwuchukwu, U. C.; Agubor, C. K.Effective utilization of future wireless communication systems such as the TV White spaces depend largely on the availability of free unused spectrum within the 470 – 860MHz UHF band. The paper, analyses the effectiveness of TV White space for last mile delivery of broadband based on spectral availability. The survey was carried out on a spectral range of 470 – 870MHz within the study area, using a RF spectrum analyser and the readings were presented using graph plots through the aid of Touchstone PC spectrum analyser. Fixed measurement was adopted and two (2) sites were chosen to take measurement. The results revealed that, 64% of the 50 channels surveyed were dormant. The degree of occupancy was found to be very low, thus providing for unused spectra spaces within the UHF frequency band which can be used to provide broadband services in sparsely populated rural areas; where data rate could be compromised for range at zero or low cost for acquiring operating spectral licenseItem Open Access The design and construction of a shadow activated switching system for car park control(SAVAP International, 2013) Opara, R. O.; Ezeh, G. N.; Agubo, C. K.With the significant increase in the number of automobiles on our roads, adequate space management is very important both in commercial and residential areas. This research was necessitated by the urgent need to manage parking spaces in banks, shopping malls and sports stadia which are areas identified as currently experiencing the worst parking problems. The aim of the study was to improve the parking arrangement of vehicles in an organized and accessible way, reduce stress and create aesthetics. In this research, shadow activated space management system (SASMS) was designed to address the challenges associated with car parking by combining the good qualities of the existing system and eliminating their setbacks. Modular robust methodology were adopted in the design and light dependent resistor (LDR) was used to construct a parking system. On testing, the five modules were found to be functioning effectively and the combined system also functioned as specified.Item Open Access An embedded voice activated automobile speed limiter: A design approach for cars(U. P., 2017-04) Nosiri, Onyebuchi Chikezie; Agbaka, Gloria Ezinne; Agubor, Cosmos Nkemdirim; Akande, Akinyinka OlukunleThe paper presents an improved design feature for conventional automobile speed limiters installed on cars used in Nigerian. The feature introduces an embedded voice activated prompt command system. The system was primarily designed to alert the Driver through a voice activated command when the speed of the car accelerates from 80km/hr to 95km/hr at an interval of 5km/hr. This became necessary to avoid abrupt jerking of the car at the maximum speed limit of 100km/hr and also functions as informative to the driver when attempts are made on unsafe movements such as inadequate/wrong calculated overtaking. Components such as resistors, diodes, transistors and relays were implemented in the design. Arduino UNO was used as the main controller of the system. Softwares such as Multisim and Proteus 8.5 professional were incorporated in the design with the use of C programming language for codes development. Algorithm was developed to enhance adequate system control. The simulated system demonstrated satisfactory performance based on the design specificationsItem Open Access Optimal design and fabrication of a wideband antenna for terrestrial DTV reception(U. P., 2016-10) Agubor, C. K.; Onwumere, C.Optimal design and fabrication of a wideband antenna for terrestrial digital TV (DTV) reception is presented in this paper. Reception of poor digital TV (DTV) signal using Yagi antennas supplied by cable providers in some suburban and rural areas in Nigeria has been a major concern to subscribers. This problem could be solved by the use of high gain antennas such as the one presented in this paper. In developing this antenna, NBS 688 technical notes and antenna design curves were applied and the resulting antenna estimate was modeled, simulated and optimized with 4NEC2 antenna design software. Optimal design verification was achieved using EZNEC v.6.0 antenna modeler. On testing after fabrication, received signal strength was 60dB compared to 45dB obtained with the service provider’s conventional Yagi antenna in position. A better picture clarity was observed owing to the15dB increase in signal level.Item Open Access Development of a new diversity scheme in 5G network at 28 GHz millimter-wave frequency for digital mobile system(Modern Education and Computer Science, 2021-02-08) Akande, Akinyinka Olukunle; Agubor, Cosmas Kemisdrin; Akinde, Olusola Kunle; Ezema, Longinus Sunday; Okozi, Samuel OkechukwuThis paper presents an improved hybrid Equal Gain Combiner-Maximal Ratio Combiner (EGC-MRC) diversity scheme in 5G millimeter wave (mm-wave) frequency. The term 5G mm-wave refers to the radio frequency spectrum between 24 𝐺𝐻𝑧 and 100 𝐺𝐻𝑧. The signal interference is a challenging task in 5G mm-wave frequency, and radio network suffer from co-channel and adjacent channel interference. 5G network deployment depends on large number of antennas, which resulted in signal interference. The conventional receiver’s diversity techniques have high hardware complexity and are characterized by low performance. A new hybrid EGC-MRC diversity scheme was proposed as an improvement on the performance of existing MRC scheme. In achieving this, Probability Density Function (PDF) of the hybrid model was derived using the instantaneous Signal-to- Noise Ratio (SNR) obtained from the output of MRC and EGC diversity schemes. The performance of the developed model was evaluated using Outage Probability (𝑃𝑜𝑢𝑡) and Processing time (𝑃𝑡) at different SNR with 𝐿 number of paths. Simulation of the MRC, EGC and hybrid EGC-MRC models were carried out using MATLAB 2018a and the results compared. The output results showed that hybrid EGC-MRC performed better than EGC and MRC by having a lower 𝑃𝑜𝑢𝑡 and 𝑃𝑡 . This new model has the potential to mitigate network interference, multipath propagation, and hardware complexity in 5G mm-wave frequency. Therefore, the developed model can be deployed by network operators to solve signal interference in 5G networkItem Open Access Efficient sideband noise cancellation for co-located networks using ANCT(Science Publishing Group, 2015) Nosiri, Onyebuchi Chikezie; Ezeh, Gloria Nwabugo; Agubor, Cosmos Kemdirim; Nkwachukwu, ChukwuchekwaAn efficient noise cancellation technique for a co-located network was realized using Adaptive Noise Cancellation Technique (ANCT). The technique was developed as improved feature to the classical application of passive filters. The paper focused on achieving a theoretical perfect cancellation considering three essential parameters: the amplitude, phase and delay characteristics of the signal and noise at both the primary path and the reference path of the co-located system. An experimental test-bed of the ANC Architecture was developed using Matlab-Simulink block design which demonstrated the error signals before and after cancellation.Item Open Access Modelling of sand drying process in a sheet/hallow glass plant(U. P., 2020) Uzondu, F .N.; Osoka, E. C.The sand drying process in a sheet/hallow glass plant has been modelled under steady state and unsteady state conditions. A model equation was developed for a differential length of the cylindrical drum dryer based on reasonable theoretical assumptions and solved under steady state and unsteady state conditions subject to the applicable boundary conditions. The model predicted the actual length of the drum dryer to an accuracy of 98.7% (1.3% deviation) and the diameter of the drum dryer to an accuracy of 98.3% (1.7% deviation). This model can be used for design, simulation and control of drum dryers for sand drying in a sheet/hallow glass plantItem Open Access An economic evaluation of investment in Mucuna solannie production(2016) Uwaezuoke, N.; Obah, Boniface; Onwukwe, Stanley I.; Igwilo, Kevin C.Mucuna solannie, a perennial crop, is a Fabaceae found in the South East of Nigeria and in some African and Asian countries. It exhibits interesting properties as a food additive, where it serves as viscosifier. It has, hence, been tested and used to formulate a drilling mud. The drilling mud formulated from it compares quite fine with other muds; with excellent rheological properties. It is suitable for top hole sections. The purpose of Mucuna solannie farming, as a cash crop, is to maintain adequate supply for continued application in the drilling industry; hence, it is a business venture. Also, a comprehensive list of processing equipment has been provided. The study gives the first pass assessments of the requirements for production and processing, necessary for sustained supply. A suitable farm location has been found in South-East Nigeria. Square planting pattern, on 10 hectares area of land, based on one plant per hill, with no filler crops, has been shown to yield 63.9 metric tonnes per year. An initial minimum investment of about $820,920 is required for seeds, land rent, equipment costs and other contingencies; with projected minimum revenue of $283,500 per year, at 22% DCF ROR, if the venture must remain profitable.Item Open Access Determining the optimum concentration of multiwalled carbon nanotubes as filtrate loss additive in field‑applicable mud systems(Springer, 2019) Okoro, Emeka E.; Zuokumor, Anita A.; Okafor, Ikechukwu S.; Igwilo, K, C.; Orodu, Kale B.In a bid to combat fluid loss in muds where the effects of high downhole temperatures have pronounced effects on conventional fluid loss additives, several materials have over time been evaluated. One of such materials is the multiwalled carbon nanotubes (MWCNTs). Most studies in the literature limit the scope of their investigation to how the MWCNT affects mud rheology when added in minute concentrations (0.01–1 ppb). In this study, however, the performance of high concentrations (0.5–3 ppb) of multiwall carbon nanotubes as fluid loss control additives in field-applicable mud systems was put to the test. The essence was to establish an optimal concentration useful for field applications. The degree to which the introduction of varying concentrations of the MWCNT altered the muds capacity to control filter loss was the cardinal areas evaluated. The following are the major outcomes of the experimental study: The plastic viscosity, the yield point and the gel strengths showed a progressive increase as the concentration of the MWCNT in the mud increased for both the water- and oil-based muds. However, an optimum concentration of 2 ppb was observed for the water-based mud. For the filter loss tests on the oil-based mud, the results indicate that low concentrations (0.5 ppb) of the MWCNT led to high filter loss volumes (15 ml), but an increase up to 2.5 ppb reduced the margin of the filter loss volume by 52% (7 ml) from the initial value and a 50% decrease for the standard case. In the case of the water-based mud, equivalent amounts of MWCNT recorded less fluid loss than the standard. A moderately hard and firm cake was reported for all concentrations of the standard and MWCNT for the water- and oil-based muds; however, their cake thickness values were 2 mm and 1 mm for the water- and the oil-based muds, respectively