In this study, the group method of data handling (GMDH)-based wavelet transform (WT) was developed to forecast significant wave height (SWH) in different lead times. The SWH dataset was collected from a buoy station located in the North Atlantic Ocean. For this purpose, the time series of SWH was decomposed into some subseries using WT and then decomposed time series were imported to the GMDH model to forecast the SWH. Performance of the wavelet group method of data handling (WGMDH) model was evaluated using an index of agreement (Ia), coefficient of efficiency and root mean square error. The analysis proved that the model accuracy is highly dependent on the decomposition levels. The results showed that the WGMDH model is able to forecast the SWH with a high reliability.
How do Photovoltaic Cells Actually Work?
Solar power is an abundant renewable source that could be the solution to our future energy needs, but just how does a solar array produce the electricity that powers our lives? The short answer is that, through a solar panel, photons (light particles) are able to knock electrons off atoms and this causes a flow of electricity. The long answer is a little more complex. A ‘Photovoltaic’ cell is the basic building block which converts sunlight to electric energy that we can utilize to power our homes...
On the Ground with Diesel Corrosion - Case Study
When the EPA revealed the results of its study in July on the increasing presence of substantial corrosion in diesel fuel tanks, it proved that the problem is much larger than anyone anticipated. The facts are staggering: 83%of the diesel tank systems exhibited moderate-to-severe corrosion. 75%of the owner/operators of those diesel tanks had no idea it was happening. The corrosion is developing in both steel and fiberglass tank systems. Even more staggering is the severity of the corrosion I have been...
Household greywater treatment methods using natural materials and their hybrid system
Discharge of household greywater into water bodies can lead to an increase in contamination levels in terms of the reduction in dissolved oxygen resources and rapid bacterial growth. Therefore, the quality of greywater has to be improved before the disposal process. The present review aimed to present a hybrid treatment system for the greywater generated from households. The hybrid system comprised a primary stage (a natural filtration unit) with a bioreactor system as the secondary treatment combined with...
Application of hybrid Kalman filter for improving water level forecast
Numerical modeling is one of the popular means to simulate and forecast the state of oceanographic systems. However, it still suffers from some limitations, e.g., parameter uncertainties, simplification of model assumptions, and absence of data for proper boundary and initial conditions. This paper proposes a hybrid data assimilation scheme, which combines the Kalman filter (KF) with a data-driven model (local linear model (LM)), to directly correct numerical model outputs at locations without measurements. Two...
Hybrid wavelet-support vector machine approach for modelling rainfall–runoff process
Because of the importance of water resources management, the need for accurate modeling of the rainfall–runoff process has rapidly grown in the past decades. Recently, the support vector machine (SVM) approach has been used by hydrologists for rainfall–runoff modeling and the other fields of hydrology. Similar to the other artificial intelligence models, such as artificial neural network (ANN) and adaptive neural fuzzy inference system, the SVM model is based on the autoregressive properties. In this paper, the...