Constrained multi-objective optimization problems(CMOPs)generally contain multiple constraints,which not only form multiple discrete feasible regions but also reduce the size of optimal feasible regions,thus they prop...Constrained multi-objective optimization problems(CMOPs)generally contain multiple constraints,which not only form multiple discrete feasible regions but also reduce the size of optimal feasible regions,thus they propose serious challenges for solvers.Among all constraints,some constraints are highly correlated with optimal feasible regions;thus they can provide effective help to find feasible Pareto front.However,most of the existing constrained multi-objective evolutionary algorithms tackle constraints by regarding all constraints as a whole or directly ignoring all constraints,and do not consider judging the relations among constraints and do not utilize the information from promising single constraints.Therefore,this paper attempts to identify promising single constraints and utilize them to help solve CMOPs.To be specific,a CMOP is transformed into a multitasking optimization problem,where multiple auxiliary tasks are created to search for the Pareto fronts that only consider a single constraint respectively.Besides,an auxiliary task priority method is designed to identify and retain some high-related auxiliary tasks according to the information of relative positions and dominance relationships.Moreover,an improved tentative method is designed to find and transfer useful knowledge among tasks.Experimental results on three benchmark test suites and 11 realworld problems with different numbers of constraints show better or competitive performance of the proposed method when compared with eight state-of-the-art peer methods.展开更多
In multimodal multiobjective optimization problems(MMOPs),there are several Pareto optimal solutions corre-sponding to the identical objective vector.This paper proposes a new differential evolution algorithm to solve...In multimodal multiobjective optimization problems(MMOPs),there are several Pareto optimal solutions corre-sponding to the identical objective vector.This paper proposes a new differential evolution algorithm to solve MMOPs with higher-dimensional decision variables.Due to the increase in the dimensions of decision variables in real-world MMOPs,it is diffi-cult for current multimodal multiobjective optimization evolu-tionary algorithms(MMOEAs)to find multiple Pareto optimal solutions.The proposed algorithm adopts a dual-population framework and an improved environmental selection method.It utilizes a convergence archive to help the first population improve the quality of solutions.The improved environmental selection method enables the other population to search the remaining decision space and reserve more Pareto optimal solutions through the information of the first population.The combination of these two strategies helps to effectively balance and enhance conver-gence and diversity performance.In addition,to study the per-formance of the proposed algorithm,a novel set of multimodal multiobjective optimization test functions with extensible decision variables is designed.The proposed MMOEA is certified to be effective through comparison with six state-of-the-art MMOEAs on the test functions.展开更多
Molecular dynamics(MD)has served as a powerful tool for designing materials with reduced reliance on laboratory testing.However,the use of MD directly to treat the deformation and failure of materials at the mesoscale...Molecular dynamics(MD)has served as a powerful tool for designing materials with reduced reliance on laboratory testing.However,the use of MD directly to treat the deformation and failure of materials at the mesoscale is still largely beyond reach.In this work,we propose a learning framework to extract a peridynamics model as a mesoscale continuum surrogate from MD simulated material fracture data sets.Firstly,we develop a novel coarse-graining method,to automatically handle the material fracture and its corresponding discontinuities in the MD displacement data sets.Inspired by the weighted essentially non-oscillatory(WENO)scheme,the key idea lies at an adaptive procedure to automatically choose the locally smoothest stencil,then reconstruct the coarse-grained material displacement field as the piecewise smooth solutions containing discontinuities.Then,based on the coarse-grained MD data,a two-phase optimizationbased learning approach is proposed to infer the optimal peridynamics model with damage criterion.In the first phase,we identify the optimal nonlocal kernel function from the data sets without material damage to capture the material stiffness properties.Then,in the second phase,the material damage criterion is learnt as a smoothed step function from the data with fractures.As a result,a peridynamics surrogate is obtained.As a continuum model,our peridynamics surrogate model can be employed in further prediction tasks with different grid resolutions from training,and hence allows for substantial reductions in computational cost compared with MD.We illustrate the efficacy of the proposed approach with several numerical tests for the dynamic crack propagation problem in a single-layer graphene.Our tests show that the proposed data-driven model is robust and generalizable,in the sense that it is capable of modeling the initialization and growth of fractures under discretization and loading settings that are different from the ones used during training.展开更多
The rapid progression of the Internet of Things(IoT)technology enables its application across various sectors.However,IoT devices typically acquire inadequate computing power and user interfaces,making them susceptibl...The rapid progression of the Internet of Things(IoT)technology enables its application across various sectors.However,IoT devices typically acquire inadequate computing power and user interfaces,making them susceptible to security threats.One significant risk to cloud networks is Distributed Denial-of-Service(DoS)attacks,where attackers aim to overcome a target system with excessive data and requests.Among these,low-rate DoS(LR-DoS)attacks present a particular challenge to detection.By sending bursts of attacks at irregular intervals,LR-DoS significantly degrades the targeted system’s Quality of Service(QoS).The low-rate nature of these attacks confuses their detection,as they frequently trigger congestion control mechanisms,leading to significant instability in IoT systems.Therefore,to detect the LR-DoS attack,an innovative deep-learning model has been developed for this research work.The standard dataset is utilized to collect the required data.Further,the deep feature extraction process is executed using the Residual Autoencoder with Sparse Attention(ResAE-SA),which helps derive the significant feature required for detection.Ultimately,the Adaptive Dense Recurrent Neural Network(ADRNN)is implemented to detect LR-DoS effectively.To enhance the detection process,the parameters present in the ADRNN are optimized using the Renovated Random Attribute-based Fennec Fox Optimization(RRA-FFA).The proposed optimization reduces the False Discovery Rate and False Positive Rate,maximizing the Matthews Correlation Coefficient from 23,70.8,76.2,84.28 in Dataset 1 and 70.28,73.8,74.1,82.6 in Dataset 2 on EPC-ADRNN,DPO-ADRNN,GTO-ADRNN,FFA-ADRNN respectively to 95.8 on Dataset 1 and 91.7 on Dataset 2 in proposed model.At batch size 4,the accuracy of the designed RRA-FFA-ADRNN model progressed by 9.2%to GTO-ADRNN,11.6%to EFC-ADRNN,10.9%to DPO-ADRNN,and 4%to FFA-ADRNN for Dataset 1.The accuracy of the proposed RRA-FFA-ADRNN is boosted by 12.9%,9.09%,11.6%,and 10.9%over FFCNN,SVM,RNN,and DRNN,using Dataset 2,showing a better improvement in accuracy with that of the proposed RRA-FFA-ADRNN model with 95.7%using Dataset 1 and 94.1%with Dataset 2,which is better than the existing baseline models.展开更多
As the global economy develops and people's awareness of environmental protection increases,the efficient scheduling of production lines in workshops has received more and more attention.However,there is very litt...As the global economy develops and people's awareness of environmental protection increases,the efficient scheduling of production lines in workshops has received more and more attention.However,there is very little research focusing on distributed scheduling for heterogeneous factories.This study addresses a multi-objective distributed heterogeneous permutation flow shop scheduling problem with sequence-dependent setup times(DHPFSP-SDST).The objective is to optimize the trade-off between the maximum completion time(Makespan)and total energy consumption.First,to describe the concerned problems,we establish a mathematical model.Second,we use the artificial bee colony(ABC)algorithm to optimize the two objectives,incorporating five local search strategies tailored to the problem characteristics to enhance the algorithm's performance.Third,to improve the convergence speed of the algorithm,a Q-learning based strategy is designed to select the appropriated local search operator during iterations.Finally,based on experiments conducted on 72 instances,statistical analysis and discussions show that the Q-learning based ABC algorithm can effectively solve the problems better than its peers.展开更多
The atomic cluster expansion is a general polynomial expansion of the atomic energy in multi-atom basis functions.Here we implement the atomic cluster expansion in the performant C++code PACE that is suitable for use ...The atomic cluster expansion is a general polynomial expansion of the atomic energy in multi-atom basis functions.Here we implement the atomic cluster expansion in the performant C++code PACE that is suitable for use in large-scale atomistic simulations.We briefly review the atomic cluster expansion and give detailed expressions for energies and forces as well as efficient algorithms for their evaluation.We demonstrate that the atomic cluster expansion as implemented in PACE shifts a previously established Pareto front for machine learning interatomic potentials toward faster and more accurate calculations.Moreover,general purpose parameterizations are presented for copper and silicon and evaluated in detail.We show that the Cu and Si potentials significantly improve on the best available potentials for highly accurate large-scale atomistic simulations.展开更多
Finding alloys with specific design properties is challenging due to the large number of possible compositions and the complex interactions between elements.This study introduces a multiobjective Bayesian optimization...Finding alloys with specific design properties is challenging due to the large number of possible compositions and the complex interactions between elements.This study introduces a multiobjective Bayesian optimization approach guiding molecular dynamics simulations for discovering high-performance refractory alloys with both targeted intrinsic static thermomechanical properties and also deformation mechanisms occurring during dynamic loading.The objective functions are aiming for excellent thermomechanical stability via a high bulk modulus,a low thermal expansion,a high heat capacity,and for a resilient deformation mechanism maximizing the retention of the BCC phase after shock loading.Contrasting two optimization procedures,we show that the Pareto-optimal solutions are confined to a small performance space when the property objectives display a cooperative relationship.Conversely,the Pareto front is much broader in the performance space when these properties have antagonistic relationships.Density functional theory simulations validate these findings and unveil underlying atomic-bond changes driving property improvements.展开更多
The properties of electrons in matter are of fundamental importance.They give rise to virtually all material properties and determine the physics at play in objects ranging from semiconductor devices to the interior o...The properties of electrons in matter are of fundamental importance.They give rise to virtually all material properties and determine the physics at play in objects ranging from semiconductor devices to the interior of giant gas planets.Modeling and simulation of such diverse applications rely primarily on density functional theory(DFT),which has become the principal method for predicting the electronic structure of matter.While DFT calculations have proven to be very useful,their computational scaling limits them to small systems.We have developed a machine learning framework for predicting the electronic structure on any length scale.It shows up to three orders of magnitude speedup on systems where DFT is tractable and,more importantly,enables predictions on scales where DFT calculations are infeasible.Our work demonstrates how machine learning circumvents a long-standing computational bottleneck and advances materials science to frontiers intractable with any current solutions.展开更多
We present and analyze an unsupervised method for Word Sense Disambiguation（WSD）.Our work is based on the method presented by McCarthy et al.in 2004 for finding the predominant sense of each word in the entire corpu...We present and analyze an unsupervised method for Word Sense Disambiguation（WSD）.Our work is based on the method presented by McCarthy et al.in 2004 for finding the predominant sense of each word in the entire corpus.Their maximization algorithm allows weighted terms（similar words） from a distributional thesaurus to accumulate a score for each ambiguous word sense,i.e.,the sense with the highest score is chosen based on votes from a weighted list of terms related to the ambiguous word.This list is obtained using the distributional similarity method proposed by Lin Dekang to obtain a thesaurus.In the method of McCarthy et al.,every occurrence of the ambiguous word uses the same thesaurus,regardless of the context where the ambiguous word occurs.Our method accounts for the context of a word when determining the sense of an ambiguous word by building the list of distributed similar words based on the syntactic context of the ambiguous word.We obtain a top precision of 77.54%of accuracy versus 67.10%of the original method tested on SemCor.We also analyze the effect of the number of weighted terms in the tasks of finding the Most Precuent Sense（MFS） and WSD,and experiment with several corpora for building the Word Space Model.展开更多
Real-time time-dependent density functional theory(TDDFT)is presently the most accurate available method for computing electronic stopping powers from first principles.However,obtaining application-relevant results of...Real-time time-dependent density functional theory(TDDFT)is presently the most accurate available method for computing electronic stopping powers from first principles.However,obtaining application-relevant results often involves either costly averages over multiple calculations or ad hoc selection of a representative ion trajectory.We consider a broadly applicable,quantitative metric for evaluating and optimizing trajectories in this context.This methodology enables rigorous analysis of the failure modes of various common trajectory choices in crystalline materials.Although randomly selecting trajectories is common practice in stopping power calculations in solids,we show that nearly 30%of random trajectories in an FCC aluminum crystal will not representatively sample the material over the time and length scales feasibly simulated with TDDFT,and unrepresentative choices incur errors of up to 60%.We also show that finite-size effects depend on ion trajectory via“ouroboros”effects beyond the prevailing plasmon-based interpretation,and we propose a cost-reducing scheme to obtain converged results even when expensive core-electron contributions preclude large supercells.This work helps to mitigate poorly controlled approximations in first-principles stopping power calculations,allowing 1–2 order of magnitude cost reductions for obtaining representatively averaged and converged results.展开更多
Lack of rigorous reproducibility and validation are significant hurdles for scientific development across many fields.Materials science,in particular,encompasses a variety of experimental and theoretical approaches th...Lack of rigorous reproducibility and validation are significant hurdles for scientific development across many fields.Materials science,in particular,encompasses a variety of experimental and theoretical approaches that require careful benchmarking.Leaderboard efforts have been developed previously to mitigate these issues.However,a comprehensive comparison and benchmarking on an integrated platform with multiple data modalities with perfect and defect materials data is still lacking.This work introduces JARVIS-Leaderboard,an open-source and community-driven platform that facilitates benchmarking and enhances reproducibility.The platform allows users to set up benchmarks with customtasks and enables contributions in the form of dataset,code,and meta-data submissions.We cover the following materials design categories:Artificial Intelligence(AI),Electronic Structure(ES).展开更多
基金supported in part by the National Key Research and Development Program of China(2022YFD2001200)the National Natural Science Foundation of China(62176238,61976237,62206251,62106230)+3 种基金China Postdoctoral Science Foundation(2021T140616,2021M692920)the Natural Science Foundation of Henan Province(222300420088)the Program for Science&Technology Innovation Talents in Universities of Henan Province(23HASTIT023)the Program for Science&Technology Innovation Teams in Universities of Henan Province(23IRTSTHN010).
文摘Constrained multi-objective optimization problems(CMOPs)generally contain multiple constraints,which not only form multiple discrete feasible regions but also reduce the size of optimal feasible regions,thus they propose serious challenges for solvers.Among all constraints,some constraints are highly correlated with optimal feasible regions;thus they can provide effective help to find feasible Pareto front.However,most of the existing constrained multi-objective evolutionary algorithms tackle constraints by regarding all constraints as a whole or directly ignoring all constraints,and do not consider judging the relations among constraints and do not utilize the information from promising single constraints.Therefore,this paper attempts to identify promising single constraints and utilize them to help solve CMOPs.To be specific,a CMOP is transformed into a multitasking optimization problem,where multiple auxiliary tasks are created to search for the Pareto fronts that only consider a single constraint respectively.Besides,an auxiliary task priority method is designed to identify and retain some high-related auxiliary tasks according to the information of relative positions and dominance relationships.Moreover,an improved tentative method is designed to find and transfer useful knowledge among tasks.Experimental results on three benchmark test suites and 11 realworld problems with different numbers of constraints show better or competitive performance of the proposed method when compared with eight state-of-the-art peer methods.
基金supported in part by National Natural Science Foundation of China(62106230,U23A20340,62376253,62176238)China Postdoctoral Science Foundation(2023M743185)Key Laboratory of Big Data Intelligent Computing,Chongqing University of Posts and Telecommunications Open Fundation(BDIC-2023-A-007)。
文摘In multimodal multiobjective optimization problems(MMOPs),there are several Pareto optimal solutions corre-sponding to the identical objective vector.This paper proposes a new differential evolution algorithm to solve MMOPs with higher-dimensional decision variables.Due to the increase in the dimensions of decision variables in real-world MMOPs,it is diffi-cult for current multimodal multiobjective optimization evolu-tionary algorithms(MMOEAs)to find multiple Pareto optimal solutions.The proposed algorithm adopts a dual-population framework and an improved environmental selection method.It utilizes a convergence archive to help the first population improve the quality of solutions.The improved environmental selection method enables the other population to search the remaining decision space and reserve more Pareto optimal solutions through the information of the first population.The combination of these two strategies helps to effectively balance and enhance conver-gence and diversity performance.In addition,to study the per-formance of the proposed algorithm,a novel set of multimodal multiobjective optimization test functions with extensible decision variables is designed.The proposed MMOEA is certified to be effective through comparison with six state-of-the-art MMOEAs on the test functions.
基金the projects support by the National Science Foundation(No.DMS-1753031)the Air Force Office of Scientific Research(No.FA9550-22-1-0197)+3 种基金partially supported by the National Science Foundation(No.2019035)the support of the Sandia National Laboratories(SNL)Laboratory-directed Research and Development Programthe U.S.Department of Energy(DOE)Office of Advanced Scientific Computing Research(ASCR)under the Collaboratory on Mathematics and Physics-Informed Learning Machines for Multiscale and Multiphysics Problems(PhILMs)project。
文摘Molecular dynamics(MD)has served as a powerful tool for designing materials with reduced reliance on laboratory testing.However,the use of MD directly to treat the deformation and failure of materials at the mesoscale is still largely beyond reach.In this work,we propose a learning framework to extract a peridynamics model as a mesoscale continuum surrogate from MD simulated material fracture data sets.Firstly,we develop a novel coarse-graining method,to automatically handle the material fracture and its corresponding discontinuities in the MD displacement data sets.Inspired by the weighted essentially non-oscillatory(WENO)scheme,the key idea lies at an adaptive procedure to automatically choose the locally smoothest stencil,then reconstruct the coarse-grained material displacement field as the piecewise smooth solutions containing discontinuities.Then,based on the coarse-grained MD data,a two-phase optimizationbased learning approach is proposed to infer the optimal peridynamics model with damage criterion.In the first phase,we identify the optimal nonlocal kernel function from the data sets without material damage to capture the material stiffness properties.Then,in the second phase,the material damage criterion is learnt as a smoothed step function from the data with fractures.As a result,a peridynamics surrogate is obtained.As a continuum model,our peridynamics surrogate model can be employed in further prediction tasks with different grid resolutions from training,and hence allows for substantial reductions in computational cost compared with MD.We illustrate the efficacy of the proposed approach with several numerical tests for the dynamic crack propagation problem in a single-layer graphene.Our tests show that the proposed data-driven model is robust and generalizable,in the sense that it is capable of modeling the initialization and growth of fractures under discretization and loading settings that are different from the ones used during training.
基金funded by the Ministry of Higher Education Malaysia,Fundamental Research Grant Scheme(FRGS),FRGS/1/2024/ICT07/UPNM/02/1.
文摘The rapid progression of the Internet of Things(IoT)technology enables its application across various sectors.However,IoT devices typically acquire inadequate computing power and user interfaces,making them susceptible to security threats.One significant risk to cloud networks is Distributed Denial-of-Service(DoS)attacks,where attackers aim to overcome a target system with excessive data and requests.Among these,low-rate DoS(LR-DoS)attacks present a particular challenge to detection.By sending bursts of attacks at irregular intervals,LR-DoS significantly degrades the targeted system’s Quality of Service(QoS).The low-rate nature of these attacks confuses their detection,as they frequently trigger congestion control mechanisms,leading to significant instability in IoT systems.Therefore,to detect the LR-DoS attack,an innovative deep-learning model has been developed for this research work.The standard dataset is utilized to collect the required data.Further,the deep feature extraction process is executed using the Residual Autoencoder with Sparse Attention(ResAE-SA),which helps derive the significant feature required for detection.Ultimately,the Adaptive Dense Recurrent Neural Network(ADRNN)is implemented to detect LR-DoS effectively.To enhance the detection process,the parameters present in the ADRNN are optimized using the Renovated Random Attribute-based Fennec Fox Optimization(RRA-FFA).The proposed optimization reduces the False Discovery Rate and False Positive Rate,maximizing the Matthews Correlation Coefficient from 23,70.8,76.2,84.28 in Dataset 1 and 70.28,73.8,74.1,82.6 in Dataset 2 on EPC-ADRNN,DPO-ADRNN,GTO-ADRNN,FFA-ADRNN respectively to 95.8 on Dataset 1 and 91.7 on Dataset 2 in proposed model.At batch size 4,the accuracy of the designed RRA-FFA-ADRNN model progressed by 9.2%to GTO-ADRNN,11.6%to EFC-ADRNN,10.9%to DPO-ADRNN,and 4%to FFA-ADRNN for Dataset 1.The accuracy of the proposed RRA-FFA-ADRNN is boosted by 12.9%,9.09%,11.6%,and 10.9%over FFCNN,SVM,RNN,and DRNN,using Dataset 2,showing a better improvement in accuracy with that of the proposed RRA-FFA-ADRNN model with 95.7%using Dataset 1 and 94.1%with Dataset 2,which is better than the existing baseline models.
基金supported by the Science and Technology Development Fund(FDCT),Macao SAR(No.0019/2021/A)National Natural Science Foundation of China(No.62173356)+2 种基金Zhuhai Industry-University-Research Project with Hongkong and Macao(No.ZH22017002210014PWC)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011531)Key Technologies for Scheduling and Optimization of Complex Distributed Manufacturing Systems(No.22JR10KA007).
文摘As the global economy develops and people's awareness of environmental protection increases,the efficient scheduling of production lines in workshops has received more and more attention.However,there is very little research focusing on distributed scheduling for heterogeneous factories.This study addresses a multi-objective distributed heterogeneous permutation flow shop scheduling problem with sequence-dependent setup times(DHPFSP-SDST).The objective is to optimize the trade-off between the maximum completion time(Makespan)and total energy consumption.First,to describe the concerned problems,we establish a mathematical model.Second,we use the artificial bee colony(ABC)algorithm to optimize the two objectives,incorporating five local search strategies tailored to the problem characteristics to enhance the algorithm's performance.Third,to improve the convergence speed of the algorithm,a Q-learning based strategy is designed to select the appropriated local search operator during iterations.Finally,based on experiments conducted on 72 instances,statistical analysis and discussions show that the Q-learning based ABC algorithm can effectively solve the problems better than its peers.
基金The authors acknowledge helpful discussions with Marc Cawkwell.R.D.acknowledges funding through the German Science Foundation(DFG),project number 405621217Sandia National Laboratories is a multimission laboratory managed and operated by National Technology&Engineering Solutions of Sandia,LLC,a wholly owned subsidiary of Honeywell International Inc.,for the U.S.Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
文摘The atomic cluster expansion is a general polynomial expansion of the atomic energy in multi-atom basis functions.Here we implement the atomic cluster expansion in the performant C++code PACE that is suitable for use in large-scale atomistic simulations.We briefly review the atomic cluster expansion and give detailed expressions for energies and forces as well as efficient algorithms for their evaluation.We demonstrate that the atomic cluster expansion as implemented in PACE shifts a previously established Pareto front for machine learning interatomic potentials toward faster and more accurate calculations.Moreover,general purpose parameterizations are presented for copper and silicon and evaluated in detail.We show that the Cu and Si potentials significantly improve on the best available potentials for highly accurate large-scale atomistic simulations.
文摘Finding alloys with specific design properties is challenging due to the large number of possible compositions and the complex interactions between elements.This study introduces a multiobjective Bayesian optimization approach guiding molecular dynamics simulations for discovering high-performance refractory alloys with both targeted intrinsic static thermomechanical properties and also deformation mechanisms occurring during dynamic loading.The objective functions are aiming for excellent thermomechanical stability via a high bulk modulus,a low thermal expansion,a high heat capacity,and for a resilient deformation mechanism maximizing the retention of the BCC phase after shock loading.Contrasting two optimization procedures,we show that the Pareto-optimal solutions are confined to a small performance space when the property objectives display a cooperative relationship.Conversely,the Pareto front is much broader in the performance space when these properties have antagonistic relationships.Density functional theory simulations validate these findings and unveil underlying atomic-bond changes driving property improvements.
基金This work was in part supported by the Center for Advanced Systems Understanding(CASUS)which is financed by Germany’s Federal Ministry of Education and Research(BMBF)and by the Saxon state government out of the State budget approved by the Saxon State Parliament.
文摘The properties of electrons in matter are of fundamental importance.They give rise to virtually all material properties and determine the physics at play in objects ranging from semiconductor devices to the interior of giant gas planets.Modeling and simulation of such diverse applications rely primarily on density functional theory(DFT),which has become the principal method for predicting the electronic structure of matter.While DFT calculations have proven to be very useful,their computational scaling limits them to small systems.We have developed a machine learning framework for predicting the electronic structure on any length scale.It shows up to three orders of magnitude speedup on systems where DFT is tractable and,more importantly,enables predictions on scales where DFT calculations are infeasible.Our work demonstrates how machine learning circumvents a long-standing computational bottleneck and advances materials science to frontiers intractable with any current solutions.
基金Supported by the Mexican Government(SNI,SIP-IPN,COFAA-IPN,and PIFI-IPN),CONACYT and the Japanese Government.
文摘We present and analyze an unsupervised method for Word Sense Disambiguation（WSD）.Our work is based on the method presented by McCarthy et al.in 2004 for finding the predominant sense of each word in the entire corpus.Their maximization algorithm allows weighted terms（similar words） from a distributional thesaurus to accumulate a score for each ambiguous word sense,i.e.,the sense with the highest score is chosen based on votes from a weighted list of terms related to the ambiguous word.This list is obtained using the distributional similarity method proposed by Lin Dekang to obtain a thesaurus.In the method of McCarthy et al.,every occurrence of the ambiguous word uses the same thesaurus,regardless of the context where the ambiguous word occurs.Our method accounts for the context of a word when determining the sense of an ambiguous word by building the list of distributed similar words based on the syntactic context of the ambiguous word.We obtain a top precision of 77.54%of accuracy versus 67.10%of the original method tested on SemCor.We also analyze the effect of the number of weighted terms in the tasks of finding the Most Precuent Sense（MFS） and WSD,and experiment with several corpora for building the Word Space Model.
基金AK,ADB,and SBH were partially supported by the US Department of Energy Science Campaign 1.SBH and TWH were partially supported by the US Department of Energy,Office of Science Early Career Research Program,Office of Fusion Energy Sciences under Grant No.FWP-14-017426All authors were partially supported by Sandia National Laboratories’Laboratory Directed Research and Development(LDRD)Project No.218456.
文摘Real-time time-dependent density functional theory(TDDFT)is presently the most accurate available method for computing electronic stopping powers from first principles.However,obtaining application-relevant results often involves either costly averages over multiple calculations or ad hoc selection of a representative ion trajectory.We consider a broadly applicable,quantitative metric for evaluating and optimizing trajectories in this context.This methodology enables rigorous analysis of the failure modes of various common trajectory choices in crystalline materials.Although randomly selecting trajectories is common practice in stopping power calculations in solids,we show that nearly 30%of random trajectories in an FCC aluminum crystal will not representatively sample the material over the time and length scales feasibly simulated with TDDFT,and unrepresentative choices incur errors of up to 60%.We also show that finite-size effects depend on ion trajectory via“ouroboros”effects beyond the prevailing plasmon-based interpretation,and we propose a cost-reducing scheme to obtain converged results even when expensive core-electron contributions preclude large supercells.This work helps to mitigate poorly controlled approximations in first-principles stopping power calculations,allowing 1–2 order of magnitude cost reductions for obtaining representatively averaged and converged results.
基金supported by the financial assistance award 70NANB19H117 from the U.S.Department of Commerce,National Institute of Standards and Technologysupported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences and Engineering Division,as part of the Computational Materials Sciences Program and Center for Predictive Simulation of Functional Materials+5 种基金supported by the Center for Nanophase Materials Sciences,which is a US Department of Energy,Office of Science User Facility at Oak Ridge National LaboratoryAHR thanks the Supercomputer Center and San Diego Supercomputer Center through allocation DMR140031 from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)program,which is supported by National Science Foundation grants#2138259,#2138286,#2138307,#2137603,and#2138296supported by NIST award 70NANB19H005 and NSF award CMMI-2053929S.H.W.especially thanks to the NSF Non-Academic Research Internships for Graduate Students(INTERN)program(CBET-1845531)for supporting part of the work in NIST under the guidance of K.CA.M.K.acknowledges support from the School of Materials Engineering at Purdue University under startup account F.10023800.05.002support by the Federal Ministry of Education and Research(BMBF)under Grant No.01DM21001B(German-Canadian Materials Acceleration Center).
文摘Lack of rigorous reproducibility and validation are significant hurdles for scientific development across many fields.Materials science,in particular,encompasses a variety of experimental and theoretical approaches that require careful benchmarking.Leaderboard efforts have been developed previously to mitigate these issues.However,a comprehensive comparison and benchmarking on an integrated platform with multiple data modalities with perfect and defect materials data is still lacking.This work introduces JARVIS-Leaderboard,an open-source and community-driven platform that facilitates benchmarking and enhances reproducibility.The platform allows users to set up benchmarks with customtasks and enables contributions in the form of dataset,code,and meta-data submissions.We cover the following materials design categories:Artificial Intelligence(AI),Electronic Structure(ES).
