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Error-detecting abilities of binary nonlinear constant weight codes

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Chinese Science Bulletin 1997年第4期42卷 347-350页

作者： Fu, fw Xia, ST Department of Mathematics Nankai University Tianjin China

CONSTANT weight codes are very important in coding theory for its application to communication. In refs. [1—5], the undetected error probabilities (UEP)of binary nonlinear constant weight codes (BNCW) were studied, and Wang et al. showed that when n>8, BNCW codes (n, 2, ω) were not proper, Wang proposed a conjecture that when n>4δ and δ> 1, BNCW codes (n, 2δ, ω) are not proper. in this note, the error-detecting abilities

关键词： nonlinear constant weight code optimum constant weight code.

Period distribution of generalized B-J codes and constructions of cyclically permutable (CP ) codes

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Chinese Science Bulletin 1997年第14期42卷 1222-1227页

作者： Xia, ST Fu, fw Yang, YX Department of Mathematics Nankai University Tianjin China Department of Information Engineering Beijing University of Posts and Telecommunication Beijing China

NGUYEN et al. give a method for constructing binary CP constant-weight (CPC) codes,then they construct protocol sequences with good performance by using the codes. To makethe minimum distance of the CP codes large enough, Nguyen et al. select two classes of maxi-mum distance separable(MDS) codes which are q-ary Reed-Solomon (R-S) codes and q-arygeneralized Berlekamp-Justesen(B-J) codes. The generalized B-J codes are more

关键词： cyclically permutable codes generalized CP codes period distribution generalized PD generalized B-J codes.

Course Evaluation Based on Deep Learning and SSA Hyperparameters Optimization

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Computers, Materials & Continua 2022年第4期71卷 941-959页

作者： Alaa A.El-Demerdash Sherif E.Hussein John fw Zaki Department of Computer and Systems Faculty of EngineeringMansoura UniversityMansoura35516Egypt

Sentiment analysis attracts the attention of Egyptian Decisionmakers in the education *** offers a viable method to assess education quality services based on the students’feedback as well as that provides an understanding of their *** machine learning techniques offer automated strategies to process big data derived from social media and other digital channels,this research uses a dataset for tweets’sentiments to assess a few machine learning *** dataset preprocessing to remove symbols,necessary stemming and lemmatization is performed for features *** is followed by several machine learning techniques and a proposed Long Short-Term Memory(LSTM)classifier optimized by the Salp Swarm Algorithm(SSA)and measured the corresponding ***,the validity and accuracy of commonly used classifiers,such as Support Vector Machine,Logistic Regression Classifier,and Naive Bayes classifier,were ***,LSTM based on the SSA classification model was compared with Support Vector Machine(SVM),Logistic Regression(LR),and Naive Bayes(NB).Finally,as LSTM based SSA achieved the highest accuracy,it was applied to predict the sentiments of students’feedback and evaluate their association with the course outcome evaluations for education quality purposes.

关键词： Sentiment analysis course evaluation deep learning Bi-LSTM opinion mining students feedback natural language processing machine learning tweets analysis SSA

STUDY　ON　FINITE　ELEMENT　METHOD　APPLIED　TO　HARTREE－FOCK－SLATER　CALCULATIONS　FOR　LINEAR　MOLECULES

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维普期刊数据库

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Chinese Chemical Letters 1995年第5期6卷 407-410页

作者： Chen, fw Chen, ZD Li, LM Liu, ZP Liang, ZX Beijing Univ Dept Chem Beijing 100871 Peoples R China State Key Lab Struct Chem Fuzhou 35002 Fujian Peoples R China Chinese Acad Sci Computat Ctr Beijing 100870 Peoples R China

In efficient finite element method with a new type of trial function applied to Hartree-Fock-Slater calculations for molecular system is presented. The advantage of using new trial functions is that they are able to describe the cusplike behavior of molecular orbitals near location of atomic nuclei. The results calculated on the H2+ and H2systems show that our approach is more practical and efficient than the traditional finite element method.

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The mechanisms of cracks formation of silver-based contact materials under arc and making pressure

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Journal of Coal Science & Engineering(China) 2004年第1期10卷 73-77页

作者：郭凤仪陈忠华张玲玲张继华 fw Leuschner Department of Electrical Engineering Liaoning Technical University Fuxin 123000 China Department of Electrical Electronics and Computer Engineering University of Pretoria South Africa

The arc erosion experiments on five kinds of silver-based contact materials, AgZnO (10), AgSnO2 (8.5) In2O3 (4), AgCdO (12), AgNi(10), AgWC(12)C(3) were carried out according to different breaking times, breaking currents, and making pressures. Then based on the theoretical analysis and the photographs taken by scanning electronic mi-croscope with EDAX analyzer, the crack morphology was studied scientifically. Three types of cracks, which are cavity cracks, grain boundaries (or phase boundaries) slipping cracks, and thermal stress cracks, were put forward under arc and making pressure through establishing their physical models and discussing their formation mechanisms.

关键词： contact materials cracks mechanisms