gene expression programming (GEP) is used in this research to develop an empirical model that predicts the bond strength between the concrete surface and carbon fiber reinforced polymer (CFRP) sheets under direct pull...
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gene expression programming (GEP) is used in this research to develop an empirical model that predicts the bond strength between the concrete surface and carbon fiber reinforced polymer (CFRP) sheets under direct pull out. Therefore, a large and reliable database containing 770 test specimens is collected from the literature. The gene expression programming model is developed using eight parameters that predominantly control the bond strength. These parameters are concrete compressive strength, maximum aggregate size, fiber reinforced polymer (FRP) tensile strength, FRP thickness, FRP modulus of elasticity, adhesive tensile strength, FRP length, and FRP width. The model is validated using the experimental results and a statistical assessment is implemented to evaluate the performance of the proposed GEP model. Furthermore, the predicted bond results, obtained using the GEP model, are compared to the results obtained from several analytical models available in the literature and a parametric study is conducted to further ensure the consistency of the model by checking the trends between the input parameters and the predicted bond strength. The proposed model can reasonably predict the bond strength that is most fitting to the experimental database compared to the analytical models and the trends of the GEP model are in agreement with the overall trends of the analytical models and experimental tests.
New empirical models were developed to predict the soil deformation moduli using gene expression programming (GEP). The principal soil deformation parameters formulated were secant (E-s) and reloading (E-r) moduli. Th...
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New empirical models were developed to predict the soil deformation moduli using gene expression programming (GEP). The principal soil deformation parameters formulated were secant (E-s) and reloading (E-r) moduli. The proposed models relate E-s and E-r obtained from plate load-settlement curves to the basic soil physical properties. The best GEP models were selected after developing and controlling several models with different combinations of the influencing parameters. The experimental database used for developing the models was established upon a series of plate load tests conducted on different soil types at depths of 1-24 m. To verify the applicability of the derived models, they were employed to estimate the soil moduli of a part of test results that were not included in the analysis. The external validation of the models was further verified using several statistical criteria recommended by researchers. A sensitivity analysis was carried out to determine the contributions of the parameters affecting E-s and E-r. The proposed models give precise estimates of the soil deformation moduli. The E-s prediction model provides considerably better results in comparison with the model developed for E-r. The simplified formulation for E-s significantly outperforms the empirical equations found in the literature. The derived models can reliably be employed for pre-design purposes. (C) 2010 Elsevier Ltd. All rights reserved.
Evaporation of water from free water surfaces or from land surfaces is one of the main components of the hydrological cycle, and its occurrence is governed by various meteorological and physical factors. There is a mu...
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Evaporation of water from free water surfaces or from land surfaces is one of the main components of the hydrological cycle, and its occurrence is governed by various meteorological and physical factors. There is a multitude of models developed for estimating daily evaporation values by using weather data. This paper evaluates a gene expression programming (GEP) model for estimating evaporation through spatial and temporal data scanning techniques. It is by using leave-one-out' procedures, a complete scan of the possible train and test set configurations is carried out according to temporal and spatial criteria. Comparison of the GEP model with empirical-physical models shows that daily evaporation values computed by the GEP model are more accurate. Further, local calibration of the GEP model may not be needed, if enough climatic data are available at other stations. The performance of the GEP model fluctuates throughout the period of study and between stations. A suitable assessment of the model should consider a complete temporal and/or spatial scan of the data set used. Copyright (c) 2012 John Wiley & Sons, Ltd.
In this paper, two new approaches are proposed for extracting composite priority rules for scheduling problems. The suggested approaches use simulation and gene expression programming and are able to evolve specific p...
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In this paper, two new approaches are proposed for extracting composite priority rules for scheduling problems. The suggested approaches use simulation and gene expression programming and are able to evolve specific priority rules for all dynamic scheduling problems in accordance with their features. The methods are based on the idea that both the proper design of the function and terminal sets and the structure of the gene expression programming approach significantly affect the results. In the first proposed approach, modified and operational features of the scheduling environment are added to the terminal set, and a multigenic system is used, whereas in the second approach, priority rules are used as automatically defined functions, which are combined with the cellular system for gene expression programming. A comparison shows that the second approach generates better results than the first;however, all of the extracted rules yield better results than the rules from the literature, especially for the defined multi-objective function consisting of makespan, mean lateness and mean flow time. The presented methods and the generated priority rules are robust and can be applied to all real and large-scale dynamic scheduling problems.
Sand media filters are specially used to avoid emitter clogging when water with large amount of organic pollutants like effluents are used in micro-irrigation systems. Estimation of water quality parameters such as di...
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Sand media filters are specially used to avoid emitter clogging when water with large amount of organic pollutants like effluents are used in micro-irrigation systems. Estimation of water quality parameters such as dissolved oxygen at sand filter outlet (DOo) is of great interest for irrigation engineers. Artificial neural networks (ANN), gene expression programming (GEP) and Multi Linear Regression (MLR) based models were trained for estimating DOo using data from 769 experimental filtration cycles. Instead of considering a single configuration of the training and test data sets, which is the usual procedure for those applications in agricultural studies, the performance of those models was assessed through k-fold testing, ensuring a complete performance evaluation. In general, the GEP model tended to provide the most accurate estimations, followed by ANN and, lastly, by MLR models. After the evaluation of the models, the GEP approach was used to provide a new equation to estimate DOo based on the complete data set. This procedure revealed that only inlet DO, pH, electrical conductivity and filter head loss were necessary to feed the models. Furthermore, the consideration of leave one out or, at least, k-fold assessment should be advisable to perform a suitable evaluation of the model performance. Otherwise, conclusions drawn might be only partially valid. (C) 2013 Elsevier B.V. All rights reserved.
Attempts to predict metal recovery accurately have been hindered by the complexity of the solvent extraction process, nonlinear effects, and the multitude of influencing factors. Conventional computing algorithms must...
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Attempts to predict metal recovery accurately have been hindered by the complexity of the solvent extraction process, nonlinear effects, and the multitude of influencing factors. Conventional computing algorithms must be improved for solving practical problems due to insufficient or noisy data and complex multidimensional scenarios. In this study, a gene expression programming (GEP) model was developed to predict zinc extraction (ZE) from the bioleaching process utilizing the most influential parameters such as stirring speed (0-800 rpm), temperature (25-45 degrees C), pH (1-2.5), Di-(2-ethylhexyl) phosphoric acid (D2EHPA) concentration (5-20%), phase ratio (1:5-10:1), saponification degree (0-40%), and contact time (0-900 s) as the input parameters. Under optimal conditions of 20% D2EHPA, 15% saponification degree, 650 rpm stirring speed, pH2, and an A:O ratio of 1:1, zinc extraction reached 98.4%. The main motivation for constructing the GEP model is to present a rational mathematical model with more accurate results than statistical models. Furthermore, a model should be applicable for future usages to predict the value of metal recovery using independent variables accurately. The developed GEP model outperformed multiple linear regression and multiple nonlinear regression models with the adjusted R2 of 0.9551 and 0.9453, RMSE of 5.5100 and 7.2727, MAE of 0.0758 and 2.8308, MARE of 0.0260 and 0.0334, and VAF of 92.3069 and 87.9199 for the respective training and testing parts. Besides, the sensitivity analysis was performed using the cosine amplitude (CA) technique, and the stirring speed and D2EHPA concentration have the highest (rij = 0.931) and lowest (rij = 0.581) impact on the predicted ZE, respectively. The conducted study proves the appropriateness of the developed GEP model for ZE prediction.
In this study, a new variant of genetic programming, namely gene expression programming (GEP) is utilized to predict the shear strength of reinforced concrete (RC) beams with stirrups. The derived model relates the sh...
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In this study, a new variant of genetic programming, namely gene expression programming (GEP) is utilized to predict the shear strength of reinforced concrete (RC) beams with stirrups. The derived model relates the shear strength to mechanical and geometrical properties. The model is developed using a database containing 466 experimental test results gathered from the literature. Sensitivity and parametric analyses are performed for further verification of the model. The comparative study proves the superior performance of the GEP model compared to the expressions developed in several codes of practice. (C) 2016 Elsevier Ltd. All rights reserved.
The flanged, barbell, and rectangular squat reinforced concrete (RC) walls are broadly used in low-rise commercial and highway under and overpasses. The shear strength of squat walls is the major design consideration ...
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The flanged, barbell, and rectangular squat reinforced concrete (RC) walls are broadly used in low-rise commercial and highway under and overpasses. The shear strength of squat walls is the major design consideration because of their smaller aspect ratio. Most of the current design codes or available published literature provide separate sets of shear capacity equations for flanged, barbell, and rectangular walls. Also, a substantial scatter exists in the predicted shear capacity due to a large discrepancy in the test data. Thus, this study aims to develop a single gene expression programming (GEP) expression that can be used for predicting the shear strength of these three cross-sectional shapes based on a dataset of 646 experiments. A total of thirteen influencing parameters are identified to contrive this efficient empirical compared to several shear capacity equations. Owing to the larger database, the proposed model shows better performance based on the database analysis results and compared with 9 available empirical models.
Surface incoming solar radiation is a key variable for many agricultural, meteorological and solar energy conversion related applications. In absence of the required meteorological sensors for the detection of global ...
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Surface incoming solar radiation is a key variable for many agricultural, meteorological and solar energy conversion related applications. In absence of the required meteorological sensors for the detection of global solar radiation it is necessary to estimate this variable. Temperature based modeling procedures are reported in this study for estimating daily incoming solar radiation by using gene expression programming (GEP) for the first time, and other artificial intelligence models such as Artificial Neural Networks (ANNs), and Adaptive Neuro-Fuzzy Inference System (ANFIS). A comparison was also made among these techniques and traditional temperature based global solar radiation estimation equations. Root mean square error (RMSE), mean absolute error (MAE) RMSE-based skill score (SSRMSE). MAE-based skill score (SSMAE) and r(2) criterion of Nash and Sutcliffe criteria were used to assess the models' performances. An ANN (a four-input multilayer perceptron with 10 neurons in the hidden layer) presented the best performance among the studied models (2.93 MJ m(-2) d(-1) of RMSE). The ability of GEP approach to model global solar radiation based on daily atmospheric variables was found to be satisfactory. (C) 2012 Elsevier Ltd. All rights reserved.
The Penman-Monteith FAO-56 equation requires the complete climatic records for estimating reference evapotranspiration (ET0). The present study is aimed at developing and evaluating a gene expression programming (GEP)...
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The Penman-Monteith FAO-56 equation requires the complete climatic records for estimating reference evapotranspiration (ET0). The present study is aimed at developing and evaluating a gene expression programming (GEP) model for estimating mean monthly ET0 by using minimal amount of climatic data. The data used in the analysis are collected from 32 weather stations in Egypt through the CLIMWAT database. The results showed that the accuracy of the GEP model significantly improved when either mean relative humidity (RH) or wind speed at 2-m height (u(2)) was used as additional input variables. The GEP model with the inputs as maximum and minimum air temperature, RH, and u(2) showed the lowest root mean square error (0.426 mm d(-1) and 0.430 mm d(-1)) and, the highest coefficient of determination, (0.963 and 0.962) overall index of model performance (0.960 and 0.960), and index of agreement (0.991 and 0.990) for training and testing sets, respectively. Comparing the results of GEP models with other empirical models showed that the GEP technique are more accurate and can be employed successfully in modelling ET0. (C) 2017 Elsevier B.V. All rights reserved.
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