With the development of artificial intelligence, machine learning (ML) is widely used to predict glass-forming ability (GFA). However, GFA experimental data usually exhibits a long-tailed distribution, and the similar...
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With the development of artificial intelligence, machine learning (ML) is widely used to predict glass-forming ability (GFA). However, GFA experimental data usually exhibits a long-tailed distribution, and the similarity between the enhanced dataset and the original dataset is unclear. In terms of modeling, although model fusion provides better prediction results than individual learners, it also faces the risk of overfitting. Therefore, two preprocessing methods designed for regression problems WEighted Relevance-based Combination Strategy (WERCS) and Synthetic Minority Over-sampling technique with Gaussian Noise (SMOGN) are employed. The best strategy is selected by Pairwise correlation difference (PCD). Based on the screening results, this paper further proposes a multi-layer stacking ensemble learning model (MLS) for predicting GFA. Considering model accuracy and diversity together, the base model and meta-model combinations are optimized by bayesian optimization algorithm (BOA). The results show that MLS achieves R2 = 0.79 in prediction accuracy, which is better than other models and criteria discussed in this paper. In addition, the generalization ability of the MLS model is verified in the Cu-Mg-Ca alloy system. To explain the MLS model, SHapley Additive exPlanation (SHAP) is introduced. With the help of MLS and SHAP methods, the formation law of bulk metallic glasses (BMGs) is revealed, and the BMGs of Zr-Cu-Al-Ag series alloys are successfully designed.
This paper presents a new evolutionary dynamic optimizationalgorithm, holographic memory-based bayesian optimization algorithm (HM-BOA), whose objective is to address the weaknesses of sequential memory-based dynamic...
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This paper presents a new evolutionary dynamic optimizationalgorithm, holographic memory-based bayesian optimization algorithm (HM-BOA), whose objective is to address the weaknesses of sequential memory-based dynamic optimization approaches. To this end, holographic associative neural memory is applied to one of the recent successful memory-based evolutionary methods, DBN-MBOA (memory-based BOA with dynamic bayesian networks). Holographic memory is appropriate for encoding environmental changes since its stimulus and response data are represented by a vector of complex numbers such that the phase and the magnitude denote the information and its confidence level, respectively. In the learning process in HM-BOA, holographic memory is trained by probabilistic models at every environmental change. Its weight matrix contains abstract information obtained from previous changes and is used for constructing a new probabilistic model when the environment changes. The unique features of HM-BOA are: 1) the stored information can be generalized, and 2) a small amount of memory is required for storing the probabilistic models. Experimental results adduce grounds for its effectiveness especially in random environments.
Hydraulic pump (HP) supplies the power for a hydraulic transmission system. It is critical for the fault diagnosis of HP to guarantee the healthy operation of systems. The rapid progress of artificial intelligence and...
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Hydraulic pump (HP) supplies the power for a hydraulic transmission system. It is critical for the fault diagnosis of HP to guarantee the healthy operation of systems. The rapid progress of artificial intelligence and measuring technique empowers data-driven methods. Diagnosis methods based on machine learning are limited in timeconsuming parameter adjustment. Moreover, current methods based on one measured signal achieve fault diagnosis only by using limited feature information. To address the two problems, this research proposes an intelligent fault diagnosis method for HP. First, original signals from multiple sources are obtained using multiple sensors. Due to the effective solution of frequency aliasing and the good robustness to the background noise of the signals, an intelligent method combining an improved deep model and synchrosqueezing wavelet transform is further established. The introduction of bayesianalgorithm completes the adaptive selection of main parameters and contributes to reduce the computing time. The optimal model is selected by updating hyperparameter groups and evaluating the performance. The optimized diagnostic model presents good convergence and stability. The diagnostic accuracies achieve 96.69 %, 97.58 %, and 99.89 % for three signals. The proposed diagnostic method presents the effectiveness in mining fault characteristic information and intelligent identification of common fault types.
Municipal wastewater generally contains high amounts of nitrogen (N), approximately 23-28 mg/L of total Kjeldahl Nitrogen (TKN), which causes eutrophication and pollution of groundwater. This article reports the gener...
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Municipal wastewater generally contains high amounts of nitrogen (N), approximately 23-28 mg/L of total Kjeldahl Nitrogen (TKN), which causes eutrophication and pollution of groundwater. This article reports the generation of empirical models for estimating the nitrogen removal efficacy of two outputs (NH4-N 4-N and NO3-N) 3-N) from the anoxic riser of a highly efficient municipal wastewater treatment system involving a gas-liquid-solid circulating fluidized bed (GLSCFB) bioreactor. To identify the important variables and discard irrelevant ones, the ReliefF algorithm is applied initially. Out of 10 independent variables, this method indicates that only three, such as flow rate, total Kjeldahl Nitrogen (TKN), and downer effluent of NO3-N, are meaningful for anoxic nitrogen removal. Then, a hybrid bayesian optimization algorithm and Support Vector Regression (BOA-SVR) is implemented, considering only the essential variables. In this regard, real-life laboratory data are utilized to develop the models. The BOA approach and k-fold cross-validation technique are explicitly applied to optimize the model's hyperparameters and avoid overfitting. The established models provided sufficiently accurate predictions via their comparisons to the experimental observations. Besides, the BOA-SVR model outperforms the classical multiple linear regression (MLR). The BOA-SVR models' forecasted results for both the predicted amount of NH4-N 4-N and NO3-N 3-N are favorably compared with the laboratory trials (R2> 2 > 99 %). A comprehensive evaluation is further conducted to validate the performance of this model by calculating the root mean square error, mean absolute percentage error, fractional bias, and computational efficiency. Gaussian white noise is used to add three distinct noise levels (20 %, 40 %, and 60 %) to the testing data to evaluate the model's robustness. Moreover, the plots of relative deviations and residuals were dispersed across the zero-reference line with moderate
A rolling bearing fault diagnosis technique is proposed based on Recurrence Quantification Analysis (abbreviated as RQA) and bayesian optimized Support Vector Machine (abbreviated as RQA-Bayes-SVM). Firstly, analyzing...
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A rolling bearing fault diagnosis technique is proposed based on Recurrence Quantification Analysis (abbreviated as RQA) and bayesian optimized Support Vector Machine (abbreviated as RQA-Bayes-SVM). Firstly, analyzing the vibration signal with recurrence plot and the nonlinear feature parameters are extracted with RQA, constructing a feature matrix describing the fault mode and fault degree comprehensively. Finally, bayesian optimization algorithm is introduced for searching the best penalty factor C and kernel function parameter g of SVM and establishing an optimal Bayes-SVM model. Bearing datasets from CWRU is imported for diagnosis on fault mode and fault degree. The results show that the technique presents a good performance on fault mode diagnosis as well as fault degree distinction. Compared with common k-Nearest Neighbor (abbreviated as KNN) and Random Forest (abbreviated as RF) diagnosis models, Bayes-SVM has the best accuracy and stability, which indicates a potential value for engineering applications.
In this paper, a new evolutionary algorithm termed DBN-MBOA (Memory based BOA with Dynamic bayesian Networks) is proposed for the dynamic optimization. In DBN-MBOA, the knowledge obtained from previously solved proble...
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In this paper, a new evolutionary algorithm termed DBN-MBOA (Memory based BOA with Dynamic bayesian Networks) is proposed for the dynamic optimization. In DBN-MBOA, the knowledge obtained from previously solved problems is encoded in some structures called network translators. The network translators defined on non-stationary Dynamic bayesian Networks (nsDBNs) describe the correlation between conditional dependencies of candidate solution variables before and after environmental changes. The network translators constructed for the changes are stored in memory. When any change occurs in the environment, a relevant network translator is retrieved from the memory and is used for modifying the dependencies of the current bayesian network. In the retrieve stage, unlike existing memory-based methods, the relevant network translator is selected based on the characteristic of the change itself, not that of the new environmental state. Experimental results show that DBN-MBOA achieves better performance in random environments as well as cyclic environments.
To address the limitation of many conventional grey forecasting methods that prioritize temporal dynamics analysis while often overlooking the essential spatial characteristics, we developed a multi-output discrete gr...
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To address the limitation of many conventional grey forecasting methods that prioritize temporal dynamics analysis while often overlooking the essential spatial characteristics, we developed a multi-output discrete grey model tailored for forecasting electricity consumption in China's Yangtze River Delta, incorporating spatial effects. Specifically, we design a dynamic spatial interaction matrix to precisely capture the spatial correlations among neighboring areas, and integrate multiple sets of fixed-effect parameters to adeptly address spatial heterogeneity. Additionally, we implement regularization technique to prevent overfitting and utilize the bayesian optimization algorithm for hyper-parameter adjustment, considerably enhancing the model's stability of parameter estimation and its resilience to noise. Finally, a comprehensive case study, benchmarked against seven other models, highlights our model's outstanding multi-step predictive accuracy and robustness against input data uncertainty, exceeding the performance of existing methods.
The classification of various building roof types within point clouds has become a significant research topic, as it constitutes a crucial step for numerous applications, including the automatic detection and extracti...
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The classification of various building roof types within point clouds has become a significant research topic, as it constitutes a crucial step for numerous applications, including the automatic detection and extraction of buildings, urban area mapping, and energy potential analysis. This study aims to develop a novel deep learning architecture that uses point clouds as input data to classify different types of building roofs. For this purpose, the proposed architecture, whose hyperparameters are optimized using the bayesian optimization algorithm, is trained and tested on the RoofN3D dataset. This architecture classified three different types of roof on the test data with an overall classification accuracy of 95%. In addition, the classification performance of the proposed architecture is compared with the well-known PointNet architecture. The outputs indicate that the classification performance of the two architectures is almost identical, with only a small difference due to the fact that the original design of the proposed architecture has fewer layers and thus a shorter training time. Therefore, the proposed architecture is an important method for automatically classifying different building roof types from point cloud data.
Geothermal heat flow (GHF) comprises comprehensive data on geothermal temperature gradients, rock thermal conductivity, and crustal/mantle heat flow, which is crucial for evaluating regional geothermal resources and c...
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Geothermal heat flow (GHF) comprises comprehensive data on geothermal temperature gradients, rock thermal conductivity, and crustal/mantle heat flow, which is crucial for evaluating regional geothermal resources and conducting other studies. However, the traditional hyperparameter tuning methods such as grid search and bayesianoptimization (BO) are computationally intensive and susceptible to local optima, thereby complicating the accurate prediction of GHF. Moreover, the risk of overfitting poses a significant challenge in developing robust predictive models of GHF. To address these challenges, this study employed a genetic algorithm (GA) to tune the hyperparameters of the gradient boosted regression tree (GBRT) model. This research integrated the GBRT model with GA to establish a GA-GBRT hybrid model for predicting GHF more accurately. The GA-GBRT hybrid model incorporates 17 geological and geophysical features from Henan Province and its surroundings for sample data training. It is demonstrated that the GA-GBRT model improves the generalization performance of the test dataset and increases the R2 by 11.75% compared with the GBRT model after BO. Through prediction performance analysis, the GA-GBRT model outperformed the existing optimized random forest (RF), deep neural network (DNN), and traditional interpolation methods in all of the studied cases. Based on the GA-GBRT model, a new GHF map was created and it demonstrated a more rational representation of the GHF distribution within the area of interest compared to traditional interpolation outcomes. The superiority of the GA-GBRT model to predict GHF was validated by the geological background, geodynamics, geophysical information, and high-temperature hot springs data from Henan Province.
作者:
Chen, GuangxuTian, HailongXiao, TingXu, TianfuLei, HongwuJilin Univ
Key Lab Groundwater Resources & Environm Minist Educ Changchun 130021 Peoples R China Jilin Univ
Jilin Prov Key Lab Water Resources & Environm Changchun 130021 Peoples R China Univ Utah
Dept Civil & Environm Engn Salt Lake City UT USA Univ Utah
Energy & Geosci Inst Salt Lake City UT 84108 USA Chinese Acad Sci
Inst Rock & Soil Mech State Key Lab Geomech & Geotech Engn Wuhan 430071 Peoples R China Jilin Univ
Key Lab Groundwater Resources & Environm Minist Educ Changchun 130021 Peoples R China
An accurate prediction of oil production is critical for the oilfield development, and many deep learning models have been widely employed for this purpose. However, those methods show insufficiencies in extracting co...
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An accurate prediction of oil production is critical for the oilfield development, and many deep learning models have been widely employed for this purpose. However, those methods show insufficiencies in extracting complex features from multivariable time series datasets, which leaves the prediction of oil production still challenging. In this study, a novel CNN-GRU model combining Convolutional Neural Networks (CNN) and Gate Recurrent Unit (GRU) neural network was proposed to accurately predict oil production for Enhanced Oil Recovery (EOR) performance. The CNN layer can extract the features from variables affecting oil production, and the GRU layer models temporal information using the transmitted features for prediction. The bayesian optimization algorithm (BO) was employed to design the optimal hyper-parameters of CNN-GRU. For evaluation purpose, two case studies were carried out with the production data from a CO2-EOR project and a waterflooding project. The prediction performance of the proposed approach was compared with typical deep learning methods and a hybrid (statistical and machine learning) method. The results of experiments and comparisons indicate that the proposed CNN-GRU model outperforms other prediction approaches. The CNN-GRU model provides future oil production of wells, enabling engineers to make informed decisions in development plan of reservoirs.
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