2022 |
Afolayan, A O; Akinola, N A CELL SELECTION TECHNIQUE FOR INTERFERENCE MITIGATION IN HETEROGENEOUS NETWORKS Journal Article International Journal of Applied Geophysics and Computational Fluid Mechanics, 1 (2), pp. 1 - 5, 2022, ISSN: 2550-7222. @article{IJAGCFM-22-001, title = {CELL SELECTION TECHNIQUE FOR INTERFERENCE MITIGATION IN HETEROGENEOUS NETWORKS}, author = {Afolayan, A. O. and Akinola, N. A.}, editor = {Dr. Akinola Johnson OLAREWAJU}, url = {http://perfectengineeringassociates.com/wp-content/uploads/2023/09/IJAGCFM-22-001.pdf}, issn = {2550-7222}, year = {2022}, date = {2022-12-01}, journal = {International Journal of Applied Geophysics and Computational Fluid Mechanics}, volume = {1}, number = {2}, pages = {1 - 5}, abstract = {The significant advances in cellular networks and mobile devices have led to a rapidly growing demand for high speed multimedia applications. The co-existence of macro eNodeBs and the additional low power nodes (LPNs) could lead to higher interference in LTE-Advanced Heterogeneous Networks (HetNets). Due to high transmission power emitted by macro cell, very few users will be off-loaded to nearby pico cell which leads to underutilization of pico cells in HetNets. Hence, in practical HetNets scenario, Range Extension (RE) is a promising scheme to utilize the low power node (LPN) resources more effectively and improve the cell edge performance. With the help of CRE, user equipment (UE) will add a bias value to actual signal strength received from pico cell and thereby offload their traffic from macro cell to pico cell. However, if the bias value is not properly set in a way to capture the users’ distribution and network density, it may introduce more interference. In this paper, a solution of Intelligent Pico Cell Range Expansion which calculates the optimal and effective bias value for each mobile station independently is been proposed. Simulation results demonstrate that the proposed scheme can reduce the number of outage and increase the number of offloaded UE in HetNet. Keywords: Cell Association, Cell Range Expansion, Heterogeneous, Networks, Inter-Cell Interference, Pico Cell}, keywords = {}, pubstate = {published}, tppubtype = {article} } The significant advances in cellular networks and mobile devices have led to a rapidly growing demand for high speed multimedia applications. The co-existence of macro eNodeBs and the additional low power nodes (LPNs) could lead to higher interference in LTE-Advanced Heterogeneous Networks (HetNets). Due to high transmission power emitted by macro cell, very few users will be off-loaded to nearby pico cell which leads to underutilization of pico cells in HetNets. Hence, in practical HetNets scenario, Range Extension (RE) is a promising scheme to utilize the low power node (LPN) resources more effectively and improve the cell edge performance. With the help of CRE, user equipment (UE) will add a bias value to actual signal strength received from pico cell and thereby offload their traffic from macro cell to pico cell. However, if the bias value is not properly set in a way to capture the users’ distribution and network density, it may introduce more interference. In this paper, a solution of Intelligent Pico Cell Range Expansion which calculates the optimal and effective bias value for each mobile station independently is been proposed. Simulation results demonstrate that the proposed scheme can reduce the number of outage and increase the number of offloaded UE in HetNet. Keywords: Cell Association, Cell Range Expansion, Heterogeneous, Networks, Inter-Cell Interference, Pico Cell |
2019 |
Nigeria, Akinola Johnson OLAREWAJU Effects of Loading Wave Velocity on Various Behaviors of Underground Structures Journal Article International Journal of Applied Geophysics and Computational Fluid Mechanics, 1 (1), pp. 1-6, 2019, ISSN: ISSN: 2550-7222. @article{IJAGCFM-19-01-001, title = {Effects of Loading Wave Velocity on Various Behaviors of Underground Structures}, author = {Nigeria, Akinola Johnson OLAREWAJU}, editor = {Dr. Akinola Johnson OLAREWAJU}, url = {http://perfectengineeringassociates.com/wp-content/uploads/2020/02/IJAGCFM-19-01-001.pdf}, issn = {ISSN: 2550-7222}, year = {2019}, date = {2019-11-10}, journal = {International Journal of Applied Geophysics and Computational Fluid Mechanics}, volume = {1}, number = {1}, pages = {1-6}, abstract = {Behavior of underground pipes due to underground accidental explosion was studied using finite element based numerical code, ABAQUS. Using numerical method, the values of the loading wave velocities, Cp (m/s) were estimated and the ground movement parameters were used to study the behaviors of modeled steel and concrete pipes buried in loose sand, dense sand and undrained clay. The boundary condition of the model is either fixed or roller. Raleigh damping is meant to reflect physical damping in the actual material. Contrary to our usual engineering intuition, introducing damping to the solution reduces the stable time increment. A small amount of numerical damping is introduced in the form of bulk viscosity to control high frequency oscillations. For the elastic, homogeneous and isotropic materials considered, the values of Young’s modulus, E, Poisson’s ratio, υ and densities of steel, concrete, loose sand, dense sand and undrained clay as revealed by several researchers and pipe manufacturers were used to observed the behavior of underground pipes due to loads from underground accidental explosion and parameters varied. Time integration technique of finite difference and finite element in ABAQUS/Explicit numerical code was used to solve the governing dynamic equation of motion. From the results,, for a given loading wave velocity, displacement in pipes is almost constant at all embedment ratios considered irrespective of the material properties. Irrespective of the ground media, as the seismic velocity increases, displacement increases linearly and for low stiffness pipes buried at low depth of burial, especially in undrained clay soil, there is need for explosion resistance evaluation}, keywords = {}, pubstate = {published}, tppubtype = {article} } Behavior of underground pipes due to underground accidental explosion was studied using finite element based numerical code, ABAQUS. Using numerical method, the values of the loading wave velocities, Cp (m/s) were estimated and the ground movement parameters were used to study the behaviors of modeled steel and concrete pipes buried in loose sand, dense sand and undrained clay. The boundary condition of the model is either fixed or roller. Raleigh damping is meant to reflect physical damping in the actual material. Contrary to our usual engineering intuition, introducing damping to the solution reduces the stable time increment. A small amount of numerical damping is introduced in the form of bulk viscosity to control high frequency oscillations. For the elastic, homogeneous and isotropic materials considered, the values of Young’s modulus, E, Poisson’s ratio, υ and densities of steel, concrete, loose sand, dense sand and undrained clay as revealed by several researchers and pipe manufacturers were used to observed the behavior of underground pipes due to loads from underground accidental explosion and parameters varied. Time integration technique of finite difference and finite element in ABAQUS/Explicit numerical code was used to solve the governing dynamic equation of motion. From the results,, for a given loading wave velocity, displacement in pipes is almost constant at all embedment ratios considered irrespective of the material properties. Irrespective of the ground media, as the seismic velocity increases, displacement increases linearly and for low stiffness pipes buried at low depth of burial, especially in undrained clay soil, there is need for explosion resistance evaluation |
2019 |
Nigeria, Akinola Johnson OLAREWAJU Effects of Loading Wave Velocity on Various Behaviors of Underground Structures Journal Article International Journal of Applied Geophysics and Computational Fluid Mechanics, 1 (1), pp. 1-6, 2019, ISSN: ISSN: 2550-7222. @article{IJAGCFM-19-01-001, title = {Effects of Loading Wave Velocity on Various Behaviors of Underground Structures}, author = {Nigeria, Akinola Johnson OLAREWAJU}, editor = {Dr. Akinola Johnson OLAREWAJU}, url = {http://perfectengineeringassociates.com/wp-content/uploads/2020/02/IJAGCFM-19-01-001.pdf}, issn = {ISSN: 2550-7222}, year = {2019}, date = {2019-11-10}, journal = {International Journal of Applied Geophysics and Computational Fluid Mechanics}, volume = {1}, number = {1}, pages = {1-6}, abstract = {Behavior of underground pipes due to underground accidental explosion was studied using finite element based numerical code, ABAQUS. Using numerical method, the values of the loading wave velocities, Cp (m/s) were estimated and the ground movement parameters were used to study the behaviors of modeled steel and concrete pipes buried in loose sand, dense sand and undrained clay. The boundary condition of the model is either fixed or roller. Raleigh damping is meant to reflect physical damping in the actual material. Contrary to our usual engineering intuition, introducing damping to the solution reduces the stable time increment. A small amount of numerical damping is introduced in the form of bulk viscosity to control high frequency oscillations. For the elastic, homogeneous and isotropic materials considered, the values of Young’s modulus, E, Poisson’s ratio, υ and densities of steel, concrete, loose sand, dense sand and undrained clay as revealed by several researchers and pipe manufacturers were used to observed the behavior of underground pipes due to loads from underground accidental explosion and parameters varied. Time integration technique of finite difference and finite element in ABAQUS/Explicit numerical code was used to solve the governing dynamic equation of motion. From the results,, for a given loading wave velocity, displacement in pipes is almost constant at all embedment ratios considered irrespective of the material properties. Irrespective of the ground media, as the seismic velocity increases, displacement increases linearly and for low stiffness pipes buried at low depth of burial, especially in undrained clay soil, there is need for explosion resistance evaluation}, keywords = {}, pubstate = {published}, tppubtype = {article} } Behavior of underground pipes due to underground accidental explosion was studied using finite element based numerical code, ABAQUS. Using numerical method, the values of the loading wave velocities, Cp (m/s) were estimated and the ground movement parameters were used to study the behaviors of modeled steel and concrete pipes buried in loose sand, dense sand and undrained clay. The boundary condition of the model is either fixed or roller. Raleigh damping is meant to reflect physical damping in the actual material. Contrary to our usual engineering intuition, introducing damping to the solution reduces the stable time increment. A small amount of numerical damping is introduced in the form of bulk viscosity to control high frequency oscillations. For the elastic, homogeneous and isotropic materials considered, the values of Young’s modulus, E, Poisson’s ratio, υ and densities of steel, concrete, loose sand, dense sand and undrained clay as revealed by several researchers and pipe manufacturers were used to observed the behavior of underground pipes due to loads from underground accidental explosion and parameters varied. Time integration technique of finite difference and finite element in ABAQUS/Explicit numerical code was used to solve the governing dynamic equation of motion. From the results,, for a given loading wave velocity, displacement in pipes is almost constant at all embedment ratios considered irrespective of the material properties. Irrespective of the ground media, as the seismic velocity increases, displacement increases linearly and for low stiffness pipes buried at low depth of burial, especially in undrained clay soil, there is need for explosion resistance evaluation |