强对称矩阵及其性质

在对称矩阵定义的基础上给出了强对称矩阵的概念,利用对称矩阵的研究方法,推出了强对称矩阵的若干性质,讨论了强对称矩阵和强正交矩阵之间的关系,得出了一些新的结果.     

(Re)conceptualisation of ELT professionals: academic high school English teachers’ professional identity in Korea

This study investigates Korean English teachers’ responses to the current English Language Teaching (ELT) policies and reveals the attributes of their professional identity from their responses. Data collected from different narratives demonstrate that the teachers value the principles of communicative language teaching, but are not supportive of teaching English in English and do not regard oral competence as a prerequisite for ELT professionals, both of which are the main concern of the current policies. The teachers emphasise human education, having practical knowledge and willingness to learn something new, and using different methods or materials depending on the students’ needs and levels. These understandings of the meaning systems of their professional identity provide some implications for the establishment of professional standards and desirable pedagogies, as well as the reform of the English curriculum. First, broader attributes of the teachers’ qualities need to be reflected into professional standards. Second, the state needs to form a partnership with the teachers that leads to producing a more feasible and coherent curriculum. Third, to be accredited as professionals, English teachers’ active reflection on their own teaching is indispensable.     

Implementation of approach to compute the Lyapunov characteristic exponents for continuous dynamical systems to higher dimensions

A general method for accurately computing the Lyapunov characteristic exponents (LCEs) of continuous dynamical systems has been developed in [10]. In this paper, this method is extended to implementations on systems of arbitrary dimensions. An accurate implementation of the extension of the method to compute LCEs that uses available numerical techniques is presented for systems of arbitrary dimensions. Previously in [10], the original approach had only been implemented for general systems of up to dimension three. Closed form expressions for the exponential of skew symmetric matrices of order 4 and 5 will be presented. These formulas are used to obtain an accurate and efficient implementation of the method for dynamical systems of dimensions 4 and 5. Numerical examples illustrating the accuracy of the implementations are presented.