Comparative study on Radio Refractivity Gradient in the troposphere using Chaotic Quantifiers

Ojo, J. S.; Adelakun, A. O.; Edward, O.V.

doi:10.1016/j.heliyon.2019.e02083

Cited by 15 publications

(9 citation statements)

References 29 publications

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“…Therefore, the similarities are based on the fact that their measurements are based on the diagonal lines of RP which are clearly stated in equations (22), (23) and (24).…”

Section: Resultsmentioning

confidence: 99%

Chaotic Signatures and Global Solar Radiation model estimate over Nigeria, a Tropical region

Adelakun

2020

Preprint

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Abstract. In a tropical region like Nigeria, accurate estimation and chaotic signatures of global solar radiation (Rs) are essential to the design of solar energy utilization systems in PV technology companies and one of the plant growth determinants in Agriculture. The Rs model is a function of solar declination angle, temperature difference, and relative humidity. In this paper, the daily re-analyzed atmospheric data obtained from the archive of ERA-Interim was used to estimate the nonlinear Global Solar radiation model and investigated chaotic signatures across the tropical climatic regions of Nigeria. The well-known statistical tools were used to analyze the chosen meteorological parameters and the correlation was found to be perfect, close with low values of RMSE across the selected regions over Nigeria. For proper modeling and prediction of the underlying dynamics, the extensive chaotic measures of phase space reconstruction using recurrence plots and recurrence quantification analyses are also presented, analyzed and discussed with the appropriate choice of embedded dimension, m, and time delay τ. The radiant energy from the sun is one of the most available and renewable resources across the season in a tropical region like Nigeria. The information, therefore, suggests how vital the solar irradiance can be useful in Agriculture and Photovoltaic technology companies. Based on the scarcely gauged of global solar radiation (GSR) at meteorological stations in developing countries. This demand necessitates a better understanding of the underlying dynamics for better prediction mostly by the nonlinear Global Solar radiation model estimate and chaotic signature measurement. The optimum usage of meteorological parameters such as solar radiation, relative humidity and temperature difference needs further studies, using RPs and RQA measures. However, several data such as rainfall data, geomagnetic data, ionospheric data, wind speed data etc obtained from different parts of the world have been estimated with several models and applied to RQA measures for better prediction and modeling. Using RPs and RQA, features due to external effects such as harmattan and intertropical discontinuity (ITD) on solar radiation data in this tropical region were uniquely identified. Meanwhile, the inverse characteristic behavior of solar radiation and relative humidity were vividly maintained. The results show a very low value of RMSE while the value of R2 is very closed to 1, which depicts a good prediction for all locations. However, the highest values of both SSE and RMSE, as well as the lowest value of R2 were observed in kano station, which indicates high solar irradiance location. The RPs reviewed the observed clusters points around the parallel diagonal lines with short segments, which implies the presence of chaos. Additional complex measure, the RQA also shows that the solar radiation during the dry season of the months has lower values of Lmax, determinism and entropy, and higher values during the wet season of the months.

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“…Therefore, the similarities are based on the fact that their measurements are based on the diagonal lines of RP which are clearly stated in equations (22), (23) and (24).…”

Section: Resultsmentioning

confidence: 99%

Chaotic Signatures and Global Solar Radiation model estimate over Nigeria, a Tropical region

Adelakun

2020

Preprint

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“…High rising buildings with congested terrestrial features might have prevented the reception of the direct transmitted signal from the base station by both antennae leading to multipath fading. Multipath fading occurs as a result of signal encountering an obstacle leading to different paths before getting to the receiver (Ojo et al, 2019). The signal received by both antennae might primarily be the reflected or scattered signal as line of sight could not be established between transmitting and receiving antennae.…”

Section: Propagation Curves Over Study Areasmentioning

confidence: 99%

Propagation curves and coverage areas of digital terrestrial television base stations in the tropical zone

Akinbolati¹,

Ajewole

Adediji

et al. 2020

Heliyon

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This study investigated the propagation curves and coverage areas of some Digital Terrestrial Television Broadcast Stations (DTTBS) over four climatic zones of coastal (Lagos), tropical rain forest (Akure), Sudan Savannah (Kaduna) and Sahel Savannah (Katsina) cities of Nigeria. Measurement of the Received Signal Strength (RSS) was carried out along different routes with each of the DTTBS as reference points. Measurements of RSS were carried out using two specified antenna receiver heights of 1.5 and 3.0 m for each data point. The GPS receiver was used to measure the geographic coordinates, elevation and Line of Sight (LOS) of data points along the routes in a drive test. Measurement was done during dry and wet season months at 1 km interval up to about 20 km in each of the selected routes covering a period of three years (2016)(2017)(2018). Mean data were obtained and used to generate the propagation curves and the coverage areas over the study locations. Generally, results revealed that RSS undulates with LOS separation distance from DTTBS in all routes irrespective of seasons and routes. Particularly, RSS reduces to about half of its base station's value at about 8 and 12 km LOS from the DTTBS in Akure and Katsina respectively while, it reduces to about half of its base station's value at about 6 km from the DTTBS in Lagos and Kaduna. The implication of this is that higher coverage areas were obtained in suburban compared to urban cities. In addition, radial maps showing coverage areas and their grades useful for networking purposes were generated. Television White Spaces (TVWS) for secondary users were also proposed. For networking purposes and spatial arrangements of DTTBS that will ensure optimum coverage over the study locations, DTTBS can be sited at 8.0 and 13.5 km (LOS) interval from each other in urban and sub urban cities respectively. The overall results will enable system engineers to know the appropriate distance(s) and locations to site additional DTTBS for networking purposes and prepare power budget for optimum coverage area and good quality of services for terrestrial digital channels.

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“…In addition, a chaotic system can also occur if one of the Lyapunov exponent is positive and hyperchaotic if two of the Lyapunov exponents is positive. The largest Lyapunov exponent λ1 can be used to determine the rate of divergence [18][19][20] as:…”

Section: Chaotic Dynamics Analysismentioning

confidence: 99%

Chaotic assessment of the key performance indicators for a GSM Network congestion in an election period in Nigeria

Adelakun¹,

Lawal²,

Adekoya³

et al. 2020

njpap

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This paper investigates the chaos-based assessment of the Key performance Indicators (KPIs) for the Cellular network congestion during and after 2011 People Democratic Party (PDP) presidential primary election in Eagle Square within Abuja and its environs. Chaotic quantifiers such as average mutual information, Lyapunov exponents and specific attenuation were employed to study the congestion rate or dynamical state of the network. The chaotic assessment of the Wideband Code Division Multiplexing Access (WCDMA) data services provided by MTN network using KPIs are reported. The data retrieved from the three Base Transceiver Stations (BTSs) were used to analyse the performance of the network. The results revealed the state of dynamical behaviour of the congestion during the study period. Keywords: Key performance Indicators (KPIs); Wideband Code Division Multiplexing Access (WCDMA); Global System of Mobile communication (GSM); Base Transceiver Station (BTS); Chaotic Quantifiers

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Comparative study on Radio Refractivity Gradient in the troposphere using Chaotic Quantifiers

Cited by 15 publications

References 29 publications

Chaotic Signatures and Global Solar Radiation model estimate over Nigeria, a Tropical region

Chaotic Signatures and Global Solar Radiation model estimate over Nigeria, a Tropical region

Propagation curves and coverage areas of digital terrestrial television base stations in the tropical zone

Chaotic assessment of the key performance indicators for a GSM Network congestion in an election period in Nigeria

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