With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impu...With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impurity-based artificial neural network structural optimizer(GIASO)is proposed to optimize the neural network structure,and the effects of five different initialization algorithms on the model performance and struc-ture optimization are investigated.Two physically guided models with additional resonant frequencies and sound transmission loss formula are achieved to further improve the prediction accuracy of the model.The results show that GIASO utilizing the gray wolf optimizer as the initialization method can significantly improve the prediction performance of the model.Simultaneously,the physical guidance model with additional resonant frequencies has the best performance and can better predict the edge data points.Eventually,the effect of each input parameter on the sound transmission loss is explained by combining sensitivity analysis and theoretical formulation.展开更多
Deterministic inversion based on deep learning has been widely utilized in model parameters estimation.Constrained by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learn...Deterministic inversion based on deep learning has been widely utilized in model parameters estimation.Constrained by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learning can establish nonlinear relationships between seismic data and model parameters.However,seismic data lacks low-frequency and contains noise,which increases the non-uniqueness of the solutions.The conventional inversion method based on deep learning can only establish the deterministic relationship between seismic data and parameters,and cannot quantify the uncertainty of inversion.In order to quickly quantify the uncertainty,a physics-guided deep mixture density network(PG-DMDN)is established by combining the mixture density network(MDN)with the deep neural network(DNN).Compared with Bayesian neural network(BNN)and network dropout,PG-DMDN has lower computing cost and shorter training time.A low-frequency model is introduced in the training process of the network to help the network learn the nonlinear relationship between narrowband seismic data and low-frequency impedance.In addition,the block constraints are added to the PG-DMDN framework to improve the horizontal continuity of the inversion results.To illustrate the benefits of proposed method,the PG-DMDN is compared with existing semi-supervised inversion method.Four synthetic data examples of Marmousi II model are utilized to quantify the influence of forward modeling part,low-frequency model,noise and the pseudo-wells number on inversion results,and prove the feasibility and stability of the proposed method.In addition,the robustness and generality of the proposed method are verified by the field seismic data.展开更多
Accurate energy consumption forecasting is essential for efficient resource management and sustainability in the building sector.Deep learning models are highly successful but struggle with limited historical data and...Accurate energy consumption forecasting is essential for efficient resource management and sustainability in the building sector.Deep learning models are highly successful but struggle with limited historical data and become unusable when historical data are unavailable,such as in newly constructed buildings.On the other hand,physics-based models,such as EnergyPlus,simulate energy consumption without relying on historical data but require extensive building parameter specifications and considerable time to model a building.This paper introduces a Physics-Guided Memory Network(PgMN),a neural network that integrates predictions from deep learning and physics-based models to address their limitations.PgMN comprises a Parallel Projection Layers to process incomplete inputs,a Memory Unit to account for persistent biases,and a Memory Experience Module to optimally extend forecasts beyond their input range and produce output.Theoretical evaluation shows that components of PgMN are mathematically valid for performing their respective tasks.The PgMN was evaluated on short-term energy forecasting at an hourly resolution,critical for operational decisionmaking in smart grid and smart building systems.Experimental validation shows accuracy and applicability of PgMN in diverse scenarios such as newly constructed buildings,missing data,sparse historical data,and dynamic infrastructure changes.This paper provides a promising solution for energy consumption forecasting in dynamic building environments,enhancing model applicability in scenarios where historical data are limited or unavailable or when physics-based models are inadequate.展开更多
Driven by increasing penetration of intermittent renewable energy generation,modern power systems are promoting the integration of energy storage(ES)and advocating highresolution dynamic security constrained optimal p...Driven by increasing penetration of intermittent renewable energy generation,modern power systems are promoting the integration of energy storage(ES)and advocating highresolution dynamic security constrained optimal power flow(DSCOPF)models to exploit ES time-shifting flexibility against contingencies and respond promptly to more frequent variations in the system operating status.While pioneering research works explore different methods to solve security constrained optimal power flow(SCOPF)problems at individual time steps,real-time implementation of DSCOPF still faces challenges associated with uncertainty adaptation,complex constraint satisfaction,and computational efficiency.This paper proposes a physics-guided safe policy learning method,featuring an analytical evaluation model to provide both accurate safety and cost-efficiency evaluations.A primal-dual-based learning procedure is developed to guide policy learning,fostering prompt convergence.A spatialtemporal graph neural network is constructed to enhance perception on the spatial-temporal uncertainties and leverage policy generalization.Case studies validate the effectiveness and scalability of the proposed method in safety,cost-efficiency,and computational performance and highlight the value of enhanced perception on IEEE 39-bus and 118-bus test systems.展开更多
Accurate origin–destination(OD)demand prediction is crucial for the efficient operation and management of urban rail transit(URT)systems,particularly during a pandemic.However,this task faces several limitations,incl...Accurate origin–destination(OD)demand prediction is crucial for the efficient operation and management of urban rail transit(URT)systems,particularly during a pandemic.However,this task faces several limitations,including real-time availability,sparsity,and high-dimensionality issues,and the impact of the pandemic.Consequently,this study proposes a unified framework called the physics-guided adaptive graph spatial–temporal attention network(PAG-STAN)for metro OD demand prediction under pandemic conditions.Specifically,PAG-STAN introduces a real-time OD estimation module to estimate real-time complete OD demand matrices.Subsequently,a novel dynamic OD demand matrix compression module is proposed to generate dense real-time OD demand matrices.Thereafter,PAG-STAN leverages various heterogeneous data to learn the evolutionary trend of future OD ridership during the pandemic.Finally,a masked physics-guided loss function(MPG-loss function)incorporates the physical quantity information between the OD demand and inbound flow into the loss function to enhance model interpretability.PAG-STAN demonstrated favorable performance on two real-world metro OD demand datasets under the pandemic and conventional scenarios,highlighting its robustness and sensitivity for metro OD demand prediction.A series of ablation studies were conducted to verify the indispensability of each module in PAG-STAN.展开更多
This paper develops a physics-guided graph network to enhance the robustness of distribution system state estimation(DSSE)against anomalous real-time measurements,as well as a deep auto-encoder(DAE)-based detector and...This paper develops a physics-guided graph network to enhance the robustness of distribution system state estimation(DSSE)against anomalous real-time measurements,as well as a deep auto-encoder(DAE)-based detector and a Gaussian process-aided residual learning(GARL)to deal with challenges arising from topology changes.A global-scanning jumping knowledge network(GSJKN)is first designed to establish the regression rule between the measurement data and state variables.The structural information of distribution system(DS)and a global-scanning module are incorporated to guide the propagation of scarce measurements in the graph topology,contributing to valid estimation precision in sparsely measured DSs.To monitor the topology changes of the network,a DAE network is employed to learn an efficient representation of the measurements of the system under a certain topology,which can achieve online monitoring of the network structure by observing the variation tendency of the reconstruction error.When the topology change occurs,a Gaussian process with a composite kernel is applied to the modeling of the pre-trained GSJKN residual to adapt to the new topology.The embedding of the physical structural knowledge enables the proposed GSJKN method to restore the missing/noisy values utilizing the adjacent measurements,which enhances the robustness to typical data acquisition errors.The adopted DAE network and special GARL-based transfer method further allow the DSSE method to rapidly detect and adapt to the topology change,as well as achieve effective quantification of the estimation uncertainties.Comparative tests on balanced and unbalanced systems demonstrate the accuracy,robustness,and adaptability of the proposed DSSE method.展开更多
This paper investigates a novel engineering problem,i.e.,security-constrained multi-period operation of micro energywater nexuses.This problem is computationally challenging because of its high nonlinearity,nonconvexi...This paper investigates a novel engineering problem,i.e.,security-constrained multi-period operation of micro energywater nexuses.This problem is computationally challenging because of its high nonlinearity,nonconvexity,and large dimension.We propose a two-stage iterative algorithm employing a hybrid physics and data-driven contingency filtering(CF)method and convexification to solve it.The convexified master problem is solved in the first stage by considering the base case operation and binding contingencies set(BCS).The second stage updates BCS using physics-based data-driven methods,which include dynamic and filtered data sets.This method is faster than existing CF methods because it relies on offline optimization problems and contains a limited number of online optimization problems.We validate effectiveness of the proposed method using two different case studies:the IEEE 13-bus power system with the EPANET 8-node water system and the IEEE 33-bus power system with the Otsfeld 13-node water system.展开更多
基金the Science and Technology Commission of Shanghai Municipality(No.19030501100)the Technical Service Platform for Vibration and Noise Testing and Control of New Energy Vehicles(No.18DZ2295900)。
文摘With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impurity-based artificial neural network structural optimizer(GIASO)is proposed to optimize the neural network structure,and the effects of five different initialization algorithms on the model performance and struc-ture optimization are investigated.Two physically guided models with additional resonant frequencies and sound transmission loss formula are achieved to further improve the prediction accuracy of the model.The results show that GIASO utilizing the gray wolf optimizer as the initialization method can significantly improve the prediction performance of the model.Simultaneously,the physical guidance model with additional resonant frequencies has the best performance and can better predict the edge data points.Eventually,the effect of each input parameter on the sound transmission loss is explained by combining sensitivity analysis and theoretical formulation.
基金the sponsorship of Shandong Province Foundation for Laoshan National Laboratory of Science and Technology Foundation(LSKJ202203400)National Natural Science Foundation of China(42174139,42030103)Science Foundation from Innovation and Technology Support Program for Young Scientists in Colleges of Shandong Province and Ministry of Science and Technology of China(2019RA2136)。
文摘Deterministic inversion based on deep learning has been widely utilized in model parameters estimation.Constrained by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learning can establish nonlinear relationships between seismic data and model parameters.However,seismic data lacks low-frequency and contains noise,which increases the non-uniqueness of the solutions.The conventional inversion method based on deep learning can only establish the deterministic relationship between seismic data and parameters,and cannot quantify the uncertainty of inversion.In order to quickly quantify the uncertainty,a physics-guided deep mixture density network(PG-DMDN)is established by combining the mixture density network(MDN)with the deep neural network(DNN).Compared with Bayesian neural network(BNN)and network dropout,PG-DMDN has lower computing cost and shorter training time.A low-frequency model is introduced in the training process of the network to help the network learn the nonlinear relationship between narrowband seismic data and low-frequency impedance.In addition,the block constraints are added to the PG-DMDN framework to improve the horizontal continuity of the inversion results.To illustrate the benefits of proposed method,the PG-DMDN is compared with existing semi-supervised inversion method.Four synthetic data examples of Marmousi II model are utilized to quantify the influence of forward modeling part,low-frequency model,noise and the pseudo-wells number on inversion results,and prove the feasibility and stability of the proposed method.In addition,the robustness and generality of the proposed method are verified by the field seismic data.
基金supported in part by the Climate Action and Awareness Fund[EDF-CA-2021i018,Environnement Canada,K.Siddiqui and K.Grolinger]in part by the Canada Research Chairs Program[CRC-2022-00078,K.Grolinger].
文摘Accurate energy consumption forecasting is essential for efficient resource management and sustainability in the building sector.Deep learning models are highly successful but struggle with limited historical data and become unusable when historical data are unavailable,such as in newly constructed buildings.On the other hand,physics-based models,such as EnergyPlus,simulate energy consumption without relying on historical data but require extensive building parameter specifications and considerable time to model a building.This paper introduces a Physics-Guided Memory Network(PgMN),a neural network that integrates predictions from deep learning and physics-based models to address their limitations.PgMN comprises a Parallel Projection Layers to process incomplete inputs,a Memory Unit to account for persistent biases,and a Memory Experience Module to optimally extend forecasts beyond their input range and produce output.Theoretical evaluation shows that components of PgMN are mathematically valid for performing their respective tasks.The PgMN was evaluated on short-term energy forecasting at an hourly resolution,critical for operational decisionmaking in smart grid and smart building systems.Experimental validation shows accuracy and applicability of PgMN in diverse scenarios such as newly constructed buildings,missing data,sparse historical data,and dynamic infrastructure changes.This paper provides a promising solution for energy consumption forecasting in dynamic building environments,enhancing model applicability in scenarios where historical data are limited or unavailable or when physics-based models are inadequate.
基金funded by Science and Technology Program of State Grid“Research of Iteractive Control between Distributed Energy Resources and Mega-City Grids under Multi-constraints”(No.5700-202311602A-3-2-ZN)。
文摘Driven by increasing penetration of intermittent renewable energy generation,modern power systems are promoting the integration of energy storage(ES)and advocating highresolution dynamic security constrained optimal power flow(DSCOPF)models to exploit ES time-shifting flexibility against contingencies and respond promptly to more frequent variations in the system operating status.While pioneering research works explore different methods to solve security constrained optimal power flow(SCOPF)problems at individual time steps,real-time implementation of DSCOPF still faces challenges associated with uncertainty adaptation,complex constraint satisfaction,and computational efficiency.This paper proposes a physics-guided safe policy learning method,featuring an analytical evaluation model to provide both accurate safety and cost-efficiency evaluations.A primal-dual-based learning procedure is developed to guide policy learning,fostering prompt convergence.A spatialtemporal graph neural network is constructed to enhance perception on the spatial-temporal uncertainties and leverage policy generalization.Case studies validate the effectiveness and scalability of the proposed method in safety,cost-efficiency,and computational performance and highlight the value of enhanced perception on IEEE 39-bus and 118-bus test systems.
基金supported by the National Natural Science Foundation of China(72288101,72201029,and 72322022).
文摘Accurate origin–destination(OD)demand prediction is crucial for the efficient operation and management of urban rail transit(URT)systems,particularly during a pandemic.However,this task faces several limitations,including real-time availability,sparsity,and high-dimensionality issues,and the impact of the pandemic.Consequently,this study proposes a unified framework called the physics-guided adaptive graph spatial–temporal attention network(PAG-STAN)for metro OD demand prediction under pandemic conditions.Specifically,PAG-STAN introduces a real-time OD estimation module to estimate real-time complete OD demand matrices.Subsequently,a novel dynamic OD demand matrix compression module is proposed to generate dense real-time OD demand matrices.Thereafter,PAG-STAN leverages various heterogeneous data to learn the evolutionary trend of future OD ridership during the pandemic.Finally,a masked physics-guided loss function(MPG-loss function)incorporates the physical quantity information between the OD demand and inbound flow into the loss function to enhance model interpretability.PAG-STAN demonstrated favorable performance on two real-world metro OD demand datasets under the pandemic and conventional scenarios,highlighting its robustness and sensitivity for metro OD demand prediction.A series of ablation studies were conducted to verify the indispensability of each module in PAG-STAN.
基金supported in part by Fundamental Research Funds for the Central Universities(No.ZYGX2024J014)in part by the National Natural Science Foundation of China(No.52277083).
文摘This paper develops a physics-guided graph network to enhance the robustness of distribution system state estimation(DSSE)against anomalous real-time measurements,as well as a deep auto-encoder(DAE)-based detector and a Gaussian process-aided residual learning(GARL)to deal with challenges arising from topology changes.A global-scanning jumping knowledge network(GSJKN)is first designed to establish the regression rule between the measurement data and state variables.The structural information of distribution system(DS)and a global-scanning module are incorporated to guide the propagation of scarce measurements in the graph topology,contributing to valid estimation precision in sparsely measured DSs.To monitor the topology changes of the network,a DAE network is employed to learn an efficient representation of the measurements of the system under a certain topology,which can achieve online monitoring of the network structure by observing the variation tendency of the reconstruction error.When the topology change occurs,a Gaussian process with a composite kernel is applied to the modeling of the pre-trained GSJKN residual to adapt to the new topology.The embedding of the physical structural knowledge enables the proposed GSJKN method to restore the missing/noisy values utilizing the adjacent measurements,which enhances the robustness to typical data acquisition errors.The adopted DAE network and special GARL-based transfer method further allow the DSSE method to rapidly detect and adapt to the topology change,as well as achieve effective quantification of the estimation uncertainties.Comparative tests on balanced and unbalanced systems demonstrate the accuracy,robustness,and adaptability of the proposed DSSE method.
基金supported by U.S.National Science Foundation under Award no.2124849.
文摘This paper investigates a novel engineering problem,i.e.,security-constrained multi-period operation of micro energywater nexuses.This problem is computationally challenging because of its high nonlinearity,nonconvexity,and large dimension.We propose a two-stage iterative algorithm employing a hybrid physics and data-driven contingency filtering(CF)method and convexification to solve it.The convexified master problem is solved in the first stage by considering the base case operation and binding contingencies set(BCS).The second stage updates BCS using physics-based data-driven methods,which include dynamic and filtered data sets.This method is faster than existing CF methods because it relies on offline optimization problems and contains a limited number of online optimization problems.We validate effectiveness of the proposed method using two different case studies:the IEEE 13-bus power system with the EPANET 8-node water system and the IEEE 33-bus power system with the Otsfeld 13-node water system.
