Forecasting of global solar radiation using anfis and armax techniques

Procurement of measuring device, maintenance cost coupled with calibration of the instrument contributed to the difficulty in forecasting of global solar radiation in underdeveloped countries. Most of the available regressional and mathematical models do not capture well the behavior of the global solar radiation. This paper presents the comparison of Adaptive Neuro Fuzzy Inference System (ANFIS) and Autoregressive Moving Average with eXogenous term (ARMAX) in forecasting global solar radiation. Full-Scale (experimental) data of Nigerian metrological agency, Sultan Abubakar III international airport Sokoto was used to validate the models. The simulation results demonstrated that the ANFIS model having achieved MAPE of 5.34% outperformed the ARMAX model. The ANFIS could be a valuable tool for forecasting the global solar radiation

Mapping the Impacts of Anthropogenic Activities on Vegetation in the Area Councils of FCT using Remote Sensing

Globally, amongst all the factors threatening the existence of landcover in the biosphere, agriculture and urbanization plays the most potent role aside from the natural factor of climate. The study examines the effect of human factors on vegetal cover and identifies the drivers of the changes within the area councils of the FCT over a period of three decades. The need to conserve limited natural resources is threaten by the effect of increased population and their continuous anthropogenic activities on this limited resource, thus the vegetation cover which represents an important natural resource for both humans and other species is lost due to reckless and unsustainable usage. Using geospatial techniques, the magnitude of human activities of development is assessed as it affects vegetation cover. The results of the analysis show a tremendous impact of anthropogenic activities as the landcover continue to deplete from 1987 – 2016. Human impacts were identified as the major driver of vegetal cover change in all area councils as it increases from 11510.89km2 to 85563.01km2 in AMAC, 765.55km2 to 82820.74km2 in Gwagwalada, 1621.73km2 to 54267km2 in Kwali, 1259.49km2 to 4985.56km2 in Abaji, 6621.80km2 to 34295.20km2 in Kuje and 15678.82km2 to 24925.94km2 in Bwari.The study recommends that continuous inventory of human impacts should be carried out to check mate the unsustainable management practices of human induced activities in the study area. It concludes that anthropogenic activities are on the rise thus measures should be taken to mitigate its effects to ensure better environmental sustainability

Effect of HfO2and Al2O3 high -k dielectrics double layer thickness on the breakdown voltage of enhancement mode of iii-v metal insulator semiconductor-high electron mobility transistor

Dependence of Breakdown voltage (Vbr) on oxide thickness (TCH) for GaN-based Metal–Insulator Semiconductor High-Electron-Mobility Transistors (MIS-HEMTs) using HfO3 and Al2O3 as gate dielectric is studied in detail. Different (III-V) heterostructures (AlGaN/GaN and AlInN/GaN) with different dielectrics passivation layers were used and compared with HfAlOx double layer thickness for the simulation of these MIS devices. Interestingly, for all the sets of devices, anincrease in Vbr was observed initially with Al2O3, followed by another positive shift with HfAlOxof the same. A maximum of Vbr1500V was achieved. A comprehensive analytical model has been proposed to explain the variation of Vbr withAl2O2dielectrics and HfAlOx has been shown to match the experimental data for MIS-HEMTs fabricated on different heterostructures and with different values dielectrics. This model allows the extraction of different charge components in the oxide or at oxide/III-V interface. Normally OFF AlGaN/GaN MIS-HEMTs have been demonstrated with the optimized TCH of HfO2 and Al2O3. Index Terms—HfO2, Al2O3, AlGaN/GaN, MIS-HEMT, oxide thickness, threshold voltag