The Implementation of Machine Learning and Deep Learning Algorithms for Crop Yield Prediction in Agriculture
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AGRI ARTIC 2nd Rahimov
Bulletin of TUIT: Management and Communication Technologies
Nodir Rahimov, Dilmurod Khasanov 2023.Vol-2(4) values of the dependent variable and the actual values of the dependent variable. In multivariate regression, the number of independent variables can vary, and the number of dependent variables can be more than one. In cases where there are multiple dependent variables, the regression equation takes the form: Y 1 = β 01 + β 11 X 1 + β 12 X 2 + β 13 X 3 + ... + ε 1 Y 2 = β 02 + β 21 X 1 + β 22 X 2 + β 23 X 3 + ... + ε 2 Y 3 = β 03 + β 31 X 1 + β 32 X 2 + β 33 X 3 + ... + ε 3 ... Y n = β 0n + β n1 X 1 + β n2 X 2 + β n3 X 3 + ... + ε n where Y 1 , Y 2 , Y 3 , ..., Y n are the n dependent variables, X 1 , X 2 , X 3 , ... are the independent variables, β 01 , β 11 , β 12 , β 13 , ..., β n1 , β n2 , β n3 , ... are the coefficients or regression weights, and ε 1 , ε 2 , ε 3 , ..., ε n are the error terms. Overall, the structure of multivariate regression involves fitting a linear equation to the data to model the relationship between multiple independent variables and a single or multiple dependent variables, and estimating the coefficients using the OLS regression method. 2.2. Multiple Linear Regression (MLR) Multiple linear regression (MLR), also referred to as multiple regression, is a statistical approach that employs several explanatory variables to forecast the outcome of a response variable. The objective of MLR is to establish a linear relationship between the independent or explanatory variables and dependent or response variables. Essentially, multiple regression is an extension of ordinary least-squares (OLS) regression, as it involves more than one explanatory variable [8]. In the context of publishing an article, MLR can be a powerful tool for analyzing data and drawing conclusions that are supported by statistical evidence. For example, MLR can be used to investigate the relationship between various demographic factors and a specific health outcome, or to analyze the relationship between different types of marketing strategies and sales outcomes. To use MLR effectively, researchers must carefully choose their independent and dependent variables and ensure that they are measuring each variable accurately and consistently. They must also ensure that they have a sufficient sample size to achieve statistically significant results. Once the data is collected, researchers can use MLR to determine the strength and direction of the relationships between the independent variables and the dependent variable. They can also use MLR to create predictive models that can be used to estimate the value of the dependent variable based on specific values of the independent variables [8]. Multiple linear regression is a statistical method that aims to model the relationship between a dependent variable and multiple independent variables. The structure of a multiple linear regression model can be represented as follows: Y = β 0 + β 1 X 1 + β 2 X 2 + ... + β n X n + ε Where: Y is the dependent variable; X 1 , X 2 , ..., X n are the independent variables; β 0 is the intercept or constant term; β 1 , β 2 , ..., β n are the regression coefficients, which represent the expected change in Y for a one-unit change in X 1 , X 2 , ..., X n , while holding all other independent variables constant; ε is the error term, which represents the unexplained variability in Y that is not accounted for by the independent variables; The multiple linear regression model aims to estimate the values of the regression coefficients that best fit the data, in order to make predictions about the dependent variable based on the independent variables. The quality of the model fit can be assessed using measures such as the R-squared value, which indicates the proportion of variance in the dependent variable that is explained by the independent variables [8]. In practice, multiple linear regression models can be complex and may involve interactions or nonlinear relationships between the independent variables and the dependent variable. However, the basic structure remains the same, with the aim of modeling and predicting the relationship between a Bulletin of TUIT: Management and Communication Technologies Nodir Rahimov, Dilmurod Khasanov 2023.Vol-2(4) dependent variable and multiple independent variables. 2.3. Deep Neural Network (DNN) A deep neural network (DNN) is a particular type of artificial neural network (ANN) that includes multiple hidden layers situated between the input and output layers, as depicted in Figure 1. The process of learning in DNNs involves a repetitive error backpropagation procedure, which modifies weights to minimize the loss function's value through optimization functions such as pure propagation and stochastic gradient descent [1]. Nonetheless, increasing the depth of a neural network can lead to gradient vanishing or exploding, while increasing the number of neurons may lead to overfitting. To tackle the issue of gradient vanishing or exploding, an appropriate weight initialization technique that is based on the type of activation function can be employed. Additionally, overfitting can be reduced by utilizing techniques such as dropout and batch normalization. Furthermore, advancements in hardware, such as improved graphics processing units (GPUs), have significantly reduced the computation time of complex matrices in deep learning. DNNs that address these challenges can perform complex nonlinear modeling. Therefore, these techniques are highly effective in developing highly accurate machine learning models capable of handling complex, high-dimensional data. In conclusion, DNNs are a powerful tool for addressing complex machine learning problems, and their ability to learn complex non-linear mappings from high-dimensional data makes them highly effective in various fields [1]. Figure 1. Construction of the deep neural network (DNN) model [9]. 2.4.Gradient Boosting Regressor Tree (GBRT) Boosting is a type of ensemble machine learning technique that combines multiple weak learners to create a strong learner, as demonstrated in Figure 2. Gradient boosting is one of the most popular and commonly utilized boosting algorithms, which focuses on improving the accuracy of the model by enhancing the predictions made by prior models [1]. Figure 2. The typical structure of GBRT model [16]. To start the gradient boosting algorithm, the first model calculates the average prediction value of the Bulletin of TUIT: Management and Communication Technologies Nodir Rahimov, Dilmurod Khasanov 2023.Vol-2(4) target variables across the entire dataset and computes the residual. This residual is then utilized to train multiple decision trees that create a stronger model. The process of enhancing the model iteratively continues by obtaining the gradient of the residual and using it to reduce the residual even further in the next model. Gradient boosting has been found to be highly effective in improving the accuracy of machine learning models [15-17]. It can be applied to a broad range of data types and has been extensively utilized to address regression problems. Therefore, gradient boosting is a robust and powerful ensemble technique that can significantly enhance the prediction accuracy of machine learning models. Download 0.67 Mb. Do'stlaringiz bilan baham: |
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