The main objective of this study is to evaluate the comparative performance of three artificial neural network techniques (radial basis functions “RBF”, multilayer perceptron “MLP”, and group method of data handling “GMDH”) based approach with the Penman–Monteith “PM” method for determining the group reference evapotranspiration “ET0” on monthly basis in Basrah City, south of Iraq. Climate information extends over 22 years (1991- 2012), monthly records of maximum temperature (Tmax), mean temperature (Tmean), minimum temperature (Tmin), wind speed (U) and relative humidity (RH) are used in this research. The architecture of artificial neural network models is performed during the process of training. The efficiency of trained model is checked by using the testing data, which is not used in the process of training. The evaluating of the artificial neural model performance is carried out by using cross-validation, a set of rows for each validation fold is determined randomly after stratification on the target variable “ET0”. Various set of climate inputs variables are used for creating nine artificial neural network models. The efficiency of artificial neural network models with two predictor variables (Tmean & U) for simulating ET0 is highly efficient according to the evaluation criteria. There is a significant improvement in the results of all artificial neural network models when using three input combination variables (Tmean, U, & RH) compared with the models that have only two-climate variables. Artificial neural network models especially (RBF, MLP, and GMDH) are efficient and powerful techniques for simulating ET0.
The maintenance operation of complexes and the direction of it is management is considered the most important activities which must be given much more efforts and seriousness because of it is considered the national resource and is to save the best ways of living equally all social classes in addition to it considered one of modern and civilized appearances. The paper deals with field study of the town with (2800) housing units with various and complete service units through shedding the light on the real work of the organization runs maintenance in the technical and administrative fields as well as appointing the weak point and finding the best way to handle by developing the existing maintenance order . The proposed development focusing on the following: •The periodic maintenance with some general terms (checking and evaluation) the best means to control defects.•The administrative operation elements in the organization especially the regulation and planning. •Saving the necessary financial resources to carry out the activities of various maintenance. •The importance of limiting the priorities in the work. •Trying to practices new subject in dealing with employees in simple and polite way and create anther image of collection management. Therefor, we draw conclusion of the beneficiary of these systems actively to develop the complexes maintenance system in all over the country by making the suitable amendment for every case.
This work study the effect of partial replacement of cement by hydrated cement on some properties of cement paste and cement mortar such as normal consistency, initial and final setting time, compressive strength, and length change. The results show that pastes containing hydrated cement require more water than reference paste to give normal consistency. The results also show that the replacement by hydrated cement delay the initial and final setting time of cement paste. The delay in setting time increased with increasing the partial replacement by hydrated cement. Compressive strength test was carried out on (54) cubes of (50) mm side dimensions of mortars containing (5, 10, 15, 20, and 25%) of hydrated cement at (3, 7, and 28) days. They were then compared with reference mortar. The compressive strength results show that the compressive strength decreases with increasing the replacement percentage by hydrated cement at all ages. The decreases in compressive strength reached (23.05 %) when (25%) of cement was replaced by hydrated cement in (28) days. The results also show that the replacement of cement by hydrated cement increases the length change of mortars compared with reference mortar.