Nowadays, federated learning emerges as a new technique to preserve data privacy in distributed machine learning by limiting local data to the client and only aggregating model parameters from multiple parties on the server side. However, it also faces consequent threats from malicious clients, and some methods have been proposed without sufficient defense capability and efficient aggregation. To address these problems, we propose a novel aggregation algorithm, which incorporates PCA operation and clustering to select the excellent client in each round; and brings in a momentum-accelerated historical quality gradient-based approach to increase the weight when the performances of the global model are consistently degraded, which can achieve faster convergence on the basis of ensuring that the update direction of the global model is not manipulated by malicious nodes. Experimental results on the MNIST datasets show that our algorithm is only 0.93% lower than FedAvg under a no-attack scenario, and exhibits faster convergence compared to Krum, Multi-Krum, and Trimmed Mean Aggregation, and the accuracy improves 10.68%,35.83%,19.65% under Black-Box Edge Attack, Sign Flipping Attack, and Same Value Attack.
High school is the key period of the formation of student information literacy, reasonable and scientific evaluation of learners' information literacy is essential. According to the evaluation index system of domestic information literacy is not perfect, the phenomenon of more traditional evaluation methods, through literature research, expert consultation and practice research, the study developed the index assessment of information literacy of high school students, designed and developed the system of information literacy assessment in senior high school students to realize the data acquisition online and the results of visualization. Also, the system can show the different views of the index and score ranking from the dimensions of county, school, grade, class and gender. The practice result showed that the system could meet the requirements of the information literacy assessment, make positive effects on the students' information literacy level, and provide effective decision-making support for the department of education.
An empirical analysis was made on 36 research and development teams through questionnaire investigation and the results showed that the research and development,innovation performance of virtual research and development teams were affected by the above three factors.Through flexible management of these three factors,the virtual research and development teams could enhance the research and development,innovation performance.
We analysed the quantity, subjects, characteristics, existing problems in the theses about sports research in university, middle school, and primary school in Guangxi through the method of observing, investigating and summarizing experience in the past two years, and put forward corresponding suggestion to discussing the current situation of sports scientific research in schools in Guangxi.
Along with the broad and deep advancement of the reformation of fundamental education courses, the integration of the information technology and geography courses appears in the current general outline of geography teaching,the integration is also emphasized in the newly-issued courses standards. The writer makes a primary study of the meaning and theoretical foundation and principle and several modes of the integration in order to promote the geography teaching with the aid of modern information technology.
Perceiving that it is important to foster and enhance students' perceived self-efficacy in autonomous learning,the writer introduces some models and features of learner automony and self-efficacy and advocate the establishment of students' perceived self-efficacy in autonomous learning will constitute a breakthrough and a win-win strategy in our English teaching reform.
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