The main objective of this paper was to investigate the test method effect of two writing tests on the performances of sixty sophomore English majors from China University of Mining and Technology, who were divided ra...The main objective of this paper was to investigate the test method effect of two writing tests on the performances of sixty sophomore English majors from China University of Mining and Technology, who were divided randomly into two experiment groups and took a reading-integrated writing test and a timed impromptu essay test respectively. Their essays were rated anonymously by two independent raters using the same rating scale with categories that measured content, organization, accuracy and vocabulary. Besides examination of the reliability, Many-Faceted Rasch analysis was applied to probe into the influence of domain difficulty and rater severity. Results of the comparison revealed four important findings. First, both two tests were reliable to be fair measures for assessing writing abilities. Second, significant difference was found between two groups in content, organization, and vocabulary, but no difference was observed in accuracy. Third, the reading tasks facilitated participants in generating ideas, organizing essays and using vocabularies. Finally, compared with the participants in the reading-integrated writing test, participants in the timed impromptu essay test met difficulties in using their vocabularies in the writing process. Findings implicated that 1) a reading-integrated writing test could be an alternative to a timed impromptu essay test in academic contexts, and 2) much more investigation was still needed to probe into the writing process and read-to-write process.展开更多
This paper is devoted to a new error analysis of nonconforming finite element methods.Compared with the classic error analysis in literature,only weak continuity,the F-E-M-Test for nonconforming finite element spaces,...This paper is devoted to a new error analysis of nonconforming finite element methods.Compared with the classic error analysis in literature,only weak continuity,the F-E-M-Test for nonconforming finite element spaces,and basic Hm regularity for exact solutions of 2m-th order elliptic problems under consideration are assumed.The analysis is motivated by ideas from a posteriori error estimates and projection average operators.One main ingredient is a novel decomposition for some key average terms on(n.1)-dimensional faces by introducing a piecewise constant projection,which defines the generalization to more general nonconforming finite elements of the results in literature.The analysis and results herein are conjectured to apply for all nonconforming finite elements in literature.展开更多
This paper studies variational discretization for the optimal control problem governed by parabolic equations with control constraints. First of all, the authors derive a priori error estimates where｜｜｜u - Uh｜｜｜...This paper studies variational discretization for the optimal control problem governed by parabolic equations with control constraints. First of all, the authors derive a priori error estimates where｜｜｜u - Uh｜｜｜L∞（J;L2（Ω）） = O（h2 ＋ k）. It is much better than a priori error estimates of standard finite element and backward Euler method where ｜｜｜u- Uh｜｜｜L∞（J;L2（Ω）） = O（h ＋ k）. Secondly, the authors obtain a posteriori error estimates of residual type. Finally, the authors present some numerical algorithms for the optimal control problem and do some numerical experiments to illustrate their theoretical results.展开更多
文摘The main objective of this paper was to investigate the test method effect of two writing tests on the performances of sixty sophomore English majors from China University of Mining and Technology, who were divided randomly into two experiment groups and took a reading-integrated writing test and a timed impromptu essay test respectively. Their essays were rated anonymously by two independent raters using the same rating scale with categories that measured content, organization, accuracy and vocabulary. Besides examination of the reliability, Many-Faceted Rasch analysis was applied to probe into the influence of domain difficulty and rater severity. Results of the comparison revealed four important findings. First, both two tests were reliable to be fair measures for assessing writing abilities. Second, significant difference was found between two groups in content, organization, and vocabulary, but no difference was observed in accuracy. Third, the reading tasks facilitated participants in generating ideas, organizing essays and using vocabularies. Finally, compared with the participants in the reading-integrated writing test, participants in the timed impromptu essay test met difficulties in using their vocabularies in the writing process. Findings implicated that 1) a reading-integrated writing test could be an alternative to a timed impromptu essay test in academic contexts, and 2) much more investigation was still needed to probe into the writing process and read-to-write process.
基金supported by National Natural Science Foundation of China(Grant Nos.11031006 and 11271035)
文摘This paper is devoted to a new error analysis of nonconforming finite element methods.Compared with the classic error analysis in literature,only weak continuity,the F-E-M-Test for nonconforming finite element spaces,and basic Hm regularity for exact solutions of 2m-th order elliptic problems under consideration are assumed.The analysis is motivated by ideas from a posteriori error estimates and projection average operators.One main ingredient is a novel decomposition for some key average terms on(n.1)-dimensional faces by introducing a piecewise constant projection,which defines the generalization to more general nonconforming finite elements of the results in literature.The analysis and results herein are conjectured to apply for all nonconforming finite elements in literature.
基金supported by National Science Foundation of ChinaFoundation for Talent Introduction of Guangdong Provincial University+2 种基金Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2008)Specialized Research Fund for the Doctoral Program of Higher Education(20114407110009)Hunan Provincial Innovation Foundation for Postgraduate under Grant(1x2009B120)
文摘This paper studies variational discretization for the optimal control problem governed by parabolic equations with control constraints. First of all, the authors derive a priori error estimates where｜｜｜u - Uh｜｜｜L∞（J;L2（Ω）） = O（h2 ＋ k）. It is much better than a priori error estimates of standard finite element and backward Euler method where ｜｜｜u- Uh｜｜｜L∞（J;L2（Ω）） = O（h ＋ k）. Secondly, the authors obtain a posteriori error estimates of residual type. Finally, the authors present some numerical algorithms for the optimal control problem and do some numerical experiments to illustrate their theoretical results.
