Higher education institutions are becoming increasingly concerned with the retention of their students.This work is motivated by the interest in predicting and reducing student dropout,and consequently in reducing the...Higher education institutions are becoming increasingly concerned with the retention of their students.This work is motivated by the interest in predicting and reducing student dropout,and consequently in reducing the financial losses of said institutions.Based on the characterization of the dropout problem and the application of a knowledge discovery process,an ensemble model is proposed to improve dropout prediction.The ensemble model combines the results of three models:logistic regression,neural networks,and decision tree.As a result,the model can correctly classify 89%of the students as enrolled or dropped and accurately identify 98.1%of dropouts.When compared with the Random Forest ensemble method,the proposed model demonstrates desirable characteristics to assist management in proposing actions to retain students.展开更多
To protect user privacy and data security,the integration of Federated Learning(FL)and blockchain has become an emerging research hotspot.However,the limited throughput and high communication complexity of traditional...To protect user privacy and data security,the integration of Federated Learning(FL)and blockchain has become an emerging research hotspot.However,the limited throughput and high communication complexity of traditional blockchains limit their application in large-scale FL tasks,and the synchronous traditional FL will also reduce the training efficiency.To address these issues,in this paper,we propose a Directed Acyclic Graph(DAG)blockchain-enabled generalized Federated Dropout(FD)learning strategy,which could improve the efficiency of FL while ensuring the model generalization.Specifically,the DAG maintained by multiple edge servers will guarantee the security and traceability of the data,and the Reputation-based Tips Selection Algorithm(RTSA)is proposed to reduce the blockchain consensus delay.Second,the semi-asynchronous training among Intelligent Devices(IDs)is adopted to improve the training efficiency,and a reputation-based FD technology is proposed to prevent overfitting of the model.In addition,a Hybrid Optimal Resource Allocation(HORA)algorithm is introduced to minimize the network delay.Finally,simulation results demonstrate the effectiveness and superiority of the proposed algorithms.展开更多
基金the National Council for Scientific and Technological Development of Brazil(CNPQ)the Coordination for the Improvement of Higher Education Personnel-Brazil(CAPES)(Grant PROAP 88887.842889/2023-00-PUC/MG,Grant PDPG 88887.708960/2022-00-PUC/MG-INFORMATICA and Finance Code 001)Minas Gerais State Research Support Foundation(FAPEMIG)under Grant No.:APQ-01929-22,and the Pontifical Catholic University of Minas Gerais,Brazil.
文摘Higher education institutions are becoming increasingly concerned with the retention of their students.This work is motivated by the interest in predicting and reducing student dropout,and consequently in reducing the financial losses of said institutions.Based on the characterization of the dropout problem and the application of a knowledge discovery process,an ensemble model is proposed to improve dropout prediction.The ensemble model combines the results of three models:logistic regression,neural networks,and decision tree.As a result,the model can correctly classify 89%of the students as enrolled or dropped and accurately identify 98.1%of dropouts.When compared with the Random Forest ensemble method,the proposed model demonstrates desirable characteristics to assist management in proposing actions to retain students.
基金supported in part by the National Key R&D Program of China under Grant 2021YFB1714100in part by the National Natural Science Foundation of China(NSFC)under Grant 62371082 and 62001076in part by the Natural Science Foundation of Chongqing under Grant CSTB2023NSCQ-MSX0726 and cstc2020jcyjmsxmX0878.
文摘To protect user privacy and data security,the integration of Federated Learning(FL)and blockchain has become an emerging research hotspot.However,the limited throughput and high communication complexity of traditional blockchains limit their application in large-scale FL tasks,and the synchronous traditional FL will also reduce the training efficiency.To address these issues,in this paper,we propose a Directed Acyclic Graph(DAG)blockchain-enabled generalized Federated Dropout(FD)learning strategy,which could improve the efficiency of FL while ensuring the model generalization.Specifically,the DAG maintained by multiple edge servers will guarantee the security and traceability of the data,and the Reputation-based Tips Selection Algorithm(RTSA)is proposed to reduce the blockchain consensus delay.Second,the semi-asynchronous training among Intelligent Devices(IDs)is adopted to improve the training efficiency,and a reputation-based FD technology is proposed to prevent overfitting of the model.In addition,a Hybrid Optimal Resource Allocation(HORA)algorithm is introduced to minimize the network delay.Finally,simulation results demonstrate the effectiveness and superiority of the proposed algorithms.
