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Stability and Time-Scale Analysis of Malaria Transmission in Human-Mosquito Population
Kodwo Annan,
Cedrick Dizala Mukinay
Issue:
Volume 2, Issue 1, January 2017
Pages:
1-9
Received:
9 September 2016
Accepted:
4 November 2016
Published:
2 December 2016
Abstract: More realistic human-mosquito mathematical model in which re-infected asymptomatic humans are considered is presented. The Next Generation Matrix technique is used to construct epidemiological threshold known as the reproduction number. Locally and globally asymptotically stable disease-free equilibrium conditions for the model are established. Possible time-scale of events for model transition from non-endemic to endemic is analyzed. Results show that the buildup of the latent asymptomatic humans at steady state is the main dynamics of malaria in the endemic region.
Abstract: More realistic human-mosquito mathematical model in which re-infected asymptomatic humans are considered is presented. The Next Generation Matrix technique is used to construct epidemiological threshold known as the reproduction number. Locally and globally asymptotically stable disease-free equilibrium conditions for the model are established. Pos...
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Geo-cosmic Universal X-structure of Solar System Planets and Satellites in Applying to Exoplanet Systems
Issue:
Volume 2, Issue 1, January 2017
Pages:
10-24
Received:
13 October 2016
Accepted:
22 December 2016
Published:
18 January 2017
Abstract: Given a new unique method of calculating satellite systems approved at all, without exception, 185 satellites of the Solar system. The base of the Geo-cosmic Universal X-structure of Solar system planets and satellites represents a discrete-continuous distribution of satellite and longest rings in axes the density/orbital radius (semi-major axis of the orbit), converted to the scale of the central body. Previously, it was found that in all cases, the maximum radius of the rings is the same as the triple radius of the central body for the border zones of destructive tidal actions with 12% spread. For Pluto's radius 1184 km radius of rings on X-structure may range from 4000 to 7000 km. It was far enough away from 12000 km radius of passage of spacecraft "New horizons". The success of the application of the method of the X-structure is shown here. For some exoplanets within 50 light-years (15pc) of the Earth by a method of the Geo-cosmic universal X-structure it is studied questions of the definition of the exoplanets parameters: density-diameter etc. Given also the Universal Geo-cosmic X-structure theoretical Levels of the similarity of natural satellites of the Solar system planets. Comparative characteristics between the method of the X-structure on the one hand and the modification of the Lunar systems Titius-Bode law оn the other hand given in Appendix A. From the theory, in particularly, follows the mystery similarity between the Mercury and the Earth’s Moon. Study of this layer of the undoubted new reality held in Appendix B. On pictures of the surface of Pluto and Charon the crust thickness was determined. Crust of Pluto from pole 21 km. The ice crust Charon thickness at pole is 18 km.
Abstract: Given a new unique method of calculating satellite systems approved at all, without exception, 185 satellites of the Solar system. The base of the Geo-cosmic Universal X-structure of Solar system planets and satellites represents a discrete-continuous distribution of satellite and longest rings in axes the density/orbital radius (semi-major axis of...
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Improved Arc Interruption of High Voltage SF6 Circuit Breakers Using Modified Mayr’s Differential Equation
Okpura Nseobong. I.,
Udoakah Y. N.,
Umoren M. A.
Issue:
Volume 2, Issue 1, January 2017
Pages:
25-29
Received:
16 October 2016
Accepted:
29 December 2016
Published:
19 January 2017
Abstract: The study of arc interruption is very essential in high voltage circuit breakers since arc extinction must be achieved in the shortest possible time for effective protection of the power system. This paper presents some conventional arc models used in the research of interaction between switching arc and circuit during the interruption process of high voltage circuit breakers. It goes ahead to develop a model that is current dependent with a constant time parameter that helps to improve the process of arc interruption in high voltage SF6 circuit breaker. The simulation results show that the model has the capability of reducing the arc interruption time by completely extinguishing the arc current almost instantaneously.
Abstract: The study of arc interruption is very essential in high voltage circuit breakers since arc extinction must be achieved in the shortest possible time for effective protection of the power system. This paper presents some conventional arc models used in the research of interaction between switching arc and circuit during the interruption process of h...
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Comparative Study of RMSE and Functional Composition of Residual - Based Tuning of Hata Pathloss Model in the Suburban Area
Wali Samuel,
Nwiido Friday,
Udoka Uduak Etim
Issue:
Volume 2, Issue 1, January 2017
Pages:
30-35
Received:
16 October 2016
Accepted:
4 January 2017
Published:
29 January 2017
Abstract: In this paper, RMSE and functional composition of residual are used as correction factors for tuning Hata model in the suburban area and 800-900MHz GSM frequency band. The study is based on empirical measurements conducted at Abak town, a suburban area in Akwa Ibom state, Nigeria. The tuned model is obtained by adding the correction factor to the original Hata pathloss model for the suburban area. The results showed that the functional composition of residual - based tuning approach has better prediction performance when compared with the RMSE-based tuning approach. Particularly, when the functional composition tuning approach is employed Hata model has the lowest RMSE value of 4.47, the highest prediction accuracy of 97.19% and the highest competitive success rate of 64.29%. On the other hand, the RMSE-tuned Hata model has a higher RMSE value of 7.03, lower prediction accuracy of 96.19% and the lower competitive success rate of 35.71%.
Abstract: In this paper, RMSE and functional composition of residual are used as correction factors for tuning Hata model in the suburban area and 800-900MHz GSM frequency band. The study is based on empirical measurements conducted at Abak town, a suburban area in Akwa Ibom state, Nigeria. The tuned model is obtained by adding the correction factor to the o...
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Mathematical Model and Algorithm for Determination of Minimum Antenna Mast Height for Terrestrial Line of Sight Microwave Link with Zero Path Inclination
Wali Samuel,
Steve Worgu,
Elsie Chidinma Anderson
Issue:
Volume 2, Issue 1, January 2017
Pages:
36-41
Received:
31 October 2016
Accepted:
4 January 2017
Published:
31 January 2017
Abstract: In this paper, mathematical model and algorithm for determination of minimum antenna mast height for terrestrial line of sight microwave link with zero path inclination is presented. The mathematical expressions developed are used for computing relevant link parameters while the algorithm gives the procedure for using the mathematical expressions for computing the minimum antenna mast heights. Sample 40km 10GHz Ku-band microwave link is used to demonstrate the application of the model and algorithm; in this case, the transmitter is located at longitude 7.711747 and latitude 5.178536 and the receiver is located at longitude 8.039903and latitude 5.055223. The link is required to make a minimum of 100% clearance with respect to the Fresnel zone 1. The results show that the transmitter and receiver antenna are at the same line of sight height of 158.7 m whereas the transmitter antenna mast height is 68.8 m while the receiver antenna mast height is 109.7m. Also, the maximum obstruction height of 128.58m occurred at a distance of 14306.98m from the transmitter with percentage clearance of 100% in respect of Fresnel zone 1. The result shows that the model can be used to ensure that the specified percentage clearance is achieved through the application of the models presented in this paper.
Abstract: In this paper, mathematical model and algorithm for determination of minimum antenna mast height for terrestrial line of sight microwave link with zero path inclination is presented. The mathematical expressions developed are used for computing relevant link parameters while the algorithm gives the procedure for using the mathematical expressions f...
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Comparative Evaluation of the Pathloss Prediction Performance Hata-Okumura Pathloss Model for Urban, Suburban and Rural Areas
Steve Worgu,
Samuel Godwin Ajumo,
Njumoke N. Odu
Issue:
Volume 2, Issue 1, January 2017
Pages:
42-50
Received:
31 October 2016
Accepted:
5 January 2017
Published:
23 February 2017
Abstract: In this paper, comparative evaluation of the pathloss prediction performance of the popular Hata-Okumura model for urban, suburban and rural areas is carried out. The study is based on empirical measurements conducted at Imo state university campus for 800 MHz GSM network. The prediction performance of the three categories of the Hata-Okumura model is analyzed and compared in terms of Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Prediction Accuracy (PA). The results showed that the Hata-Okumura model for the Urban area has the best prediction accuracy when not optimised but it has the lowest optimised prediction accuracy. On the other hand the Hata-Okumura model for the rural/open area has the least prediction accuracy when not optimised but it has the highest prediction accuracy when it is optimised. The results show that adoption of a model because it has the highest prediction accuracy is not the best approach to the selection of pathloss models. Rather the models should be optimised and the best optimised model should be adopted.
Abstract: In this paper, comparative evaluation of the pathloss prediction performance of the popular Hata-Okumura model for urban, suburban and rural areas is carried out. The study is based on empirical measurements conducted at Imo state university campus for 800 MHz GSM network. The prediction performance of the three categories of the Hata-Okumura model...
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