Emmanuel Ubom
A PhD holder in Communication Engineering with strong electrical, electronic and computer engineering background. Highly enthusiastic, with 20+ years of experience in the full cycle of design, planning, implementation, operations, testing, commissioning and management of fixed and mobile telecommunication networks, enterprise services, systems Integration and training. Expertise includes telecommunication projects management and supervision, process/procedures development, change management, fault identification, isolation and recovery planning, Data center operations, core and transmission networks and network operations management. A self-starter, able to work independently or as a valued, resourceful, committed and dependable team member.
Phone: +234(803)2978581
Address: Department of Electrical and Electronics Engineering, Faulty of Engineering, Akwa Ibom State University, Ikot Akpaden, Mkpat Enin, Akwa Ibom State
Phone: +234(803)2978581
Address: Department of Electrical and Electronics Engineering, Faulty of Engineering, Akwa Ibom State University, Ikot Akpaden, Mkpat Enin, Akwa Ibom State
less
InterestsView All (8)
Uploads
Papers by Emmanuel Ubom
Similarly, the no-talk-zone in kilometers was characterized as a function of the transmit power of the secondary user device in dBm for co-channel usage to be d_((r_n-r_(p)) )=antilog[(P_s-89.76)/(17.96)] modeled as a function of the secondary user transmit power P_s. The separation distance in kilometers from the TV station to the possible secondary user transmitter beyond which no interference exist was computed to have a relationship equal to antilog⟦(P_t+P_s-57.11)/(17.96)⟧.
power plants. The reason is because the photovoltaic panels produce more electric energy when their surfaces are
perpendicular to the sun's rays. Researchers have developed models for estimating the optimal tilt angle for any given
location across the globe. In this paper, a site specific model is developed for more accurate estimation of the optimal tilt
angle for fixed-tilt angle PV installations at the Ibom E-Library in Uyo metropolis, Akwa state of Nigeria. The solar
radiation data used for the study was obtained from the National Aeronautics and Space Administration Surface
meteorology and Solar Energy (NASA SSE) website. PVsyst simulation software was used to perform the transposition of
the global radiation on horizontal plane to tilted plane. For the location with latitude of 5.123° the existing model estimated
the optimal tilt angle as 7.16035° whereas, the site-specific model estimated 11.5° for the optimal tilt angle. The model has
prediction accuracy of 99.77% and root mean square error of 0.002567. The optimal tilt angle model can be employed for
fixed tilted plane PV installations in the nearby locations.
watt-hour energy demand of the electrical appliances in the health centre. The estimated daily load demand is 35 kWh/day with
peak load of 7.735 kW. The sea ambient temperature is about 8% lower than that obtainable on land while the wind speed on sea
is about 67% higher than the wind speed on land. The cumulative effect of the lower offshore temperature and higher offshore
wind speed is offshore PV cell temperature that is about 18% lower than the PV cell temperature on land. The system is designed
with 3 days of autonomy and the resultant load demand will be satisfied by 11.41 kW PV modules and 4765.8Ah battery capacity
which amounts to 64 units of the selected PV panels and 24 units of the selected battery.
HOMER (Hybrid Optimization of Multiple Energy Resources) software cell temperature, Ross cell temperature model and Davis
and Rauschenbach cell temperature model. Noticeably, unlike PVSysts software, the three models do not include the effect of
wind speed. Three models are analyzed using the meteorological data of a site in Ibeno, Akwa Ibom state, Nigeria. The results
showed that among the three NOCT-based cell temperature models, the Ross model has the highest cell temperature for any
given ambient temperature and solar irradiance. The HOMER Davis and Rauschenbach models have almost the same cell
temperature values but in all the occasions, the HOMER model gives the lowest cell temperature among the three models.
Equally, Ross model has the lowest annual energy yield and the highest thermal loss whereas the HOMER model has the highest
annual energy yield and the lowest thermal loss.
derived from experimental data collected in Port Harcourt in
South-South region of Nigeria from 10 existing microcells
operating at 876 MHz. The results of the measurements were
used to develop path loss models for the urban (Category A) and
the suburban (Category B) areas of Port Harcourt. The
measurement results showed that the Pathloss increases by
35.5dB and 25.7dB per decade in the urban (Category A) and
suburban (Category B) areas respectively. Variations in path
loss between the measured and the predicted values from the
Okumura-Hata model were calculated by finding the mean
square errors (MSE) to be 10.7dB and 13.4dB for the urban and
suburban terrains respectively. These variations (errors) were
used to modify the Okumura-Hata models for the two terrain
categories. Comparing the modified Hata model with the
measured values for the two categories showed a better result.
The developed statistical Pathloss models or the modified Hata
models can be used in the urban and suburban areas of
South-South Nigeria.
Similarly, the no-talk-zone in kilometers was characterized as a function of the transmit power of the secondary user device in dBm for co-channel usage to be d_((r_n-r_(p)) )=antilog[(P_s-89.76)/(17.96)] modeled as a function of the secondary user transmit power P_s. The separation distance in kilometers from the TV station to the possible secondary user transmitter beyond which no interference exist was computed to have a relationship equal to antilog⟦(P_t+P_s-57.11)/(17.96)⟧.
power plants. The reason is because the photovoltaic panels produce more electric energy when their surfaces are
perpendicular to the sun's rays. Researchers have developed models for estimating the optimal tilt angle for any given
location across the globe. In this paper, a site specific model is developed for more accurate estimation of the optimal tilt
angle for fixed-tilt angle PV installations at the Ibom E-Library in Uyo metropolis, Akwa state of Nigeria. The solar
radiation data used for the study was obtained from the National Aeronautics and Space Administration Surface
meteorology and Solar Energy (NASA SSE) website. PVsyst simulation software was used to perform the transposition of
the global radiation on horizontal plane to tilted plane. For the location with latitude of 5.123° the existing model estimated
the optimal tilt angle as 7.16035° whereas, the site-specific model estimated 11.5° for the optimal tilt angle. The model has
prediction accuracy of 99.77% and root mean square error of 0.002567. The optimal tilt angle model can be employed for
fixed tilted plane PV installations in the nearby locations.
watt-hour energy demand of the electrical appliances in the health centre. The estimated daily load demand is 35 kWh/day with
peak load of 7.735 kW. The sea ambient temperature is about 8% lower than that obtainable on land while the wind speed on sea
is about 67% higher than the wind speed on land. The cumulative effect of the lower offshore temperature and higher offshore
wind speed is offshore PV cell temperature that is about 18% lower than the PV cell temperature on land. The system is designed
with 3 days of autonomy and the resultant load demand will be satisfied by 11.41 kW PV modules and 4765.8Ah battery capacity
which amounts to 64 units of the selected PV panels and 24 units of the selected battery.
HOMER (Hybrid Optimization of Multiple Energy Resources) software cell temperature, Ross cell temperature model and Davis
and Rauschenbach cell temperature model. Noticeably, unlike PVSysts software, the three models do not include the effect of
wind speed. Three models are analyzed using the meteorological data of a site in Ibeno, Akwa Ibom state, Nigeria. The results
showed that among the three NOCT-based cell temperature models, the Ross model has the highest cell temperature for any
given ambient temperature and solar irradiance. The HOMER Davis and Rauschenbach models have almost the same cell
temperature values but in all the occasions, the HOMER model gives the lowest cell temperature among the three models.
Equally, Ross model has the lowest annual energy yield and the highest thermal loss whereas the HOMER model has the highest
annual energy yield and the lowest thermal loss.
derived from experimental data collected in Port Harcourt in
South-South region of Nigeria from 10 existing microcells
operating at 876 MHz. The results of the measurements were
used to develop path loss models for the urban (Category A) and
the suburban (Category B) areas of Port Harcourt. The
measurement results showed that the Pathloss increases by
35.5dB and 25.7dB per decade in the urban (Category A) and
suburban (Category B) areas respectively. Variations in path
loss between the measured and the predicted values from the
Okumura-Hata model were calculated by finding the mean
square errors (MSE) to be 10.7dB and 13.4dB for the urban and
suburban terrains respectively. These variations (errors) were
used to modify the Okumura-Hata models for the two terrain
categories. Comparing the modified Hata model with the
measured values for the two categories showed a better result.
The developed statistical Pathloss models or the modified Hata
models can be used in the urban and suburban areas of
South-South Nigeria.