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71.
This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz's portfolio selection theory and Sharpe's rule for investment decision. An analytical solution is presented to show how an institutional or individual investor can combine Markowitz's portfolio selection theory, generalized Sharpe's rule and Value-at-Risk(VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the generalized Markowitz's portfolio selection theory and generalized Sharpe's rule improve decision making for investment. 相似文献
72.
73.
James E. Bruno 《The Urban Review》1990,22(3):163-181
There are many subtle but extremely important differences between grouping students and tracking students for purposes of designing appropriate instructional interventions. Unfortunately, in many inner-city urban settings, the policy of grouping students eventually becomes a policy ofde facto tracking of students. While grouping students seems to be an educationally justifiable policy in many school situations, tracking students raises serious concerns with regard to its educational value, social desirability, and complicity with the legal notions of due process and equal protection. This study examines the use of a specific form ofshort-term grouping of students that is based on an information-referenced criterion for selection. Using a large sample of ninth- and eleventh-grade students, an information-referenced grouping procedure was designed for the areas of language arts and mathematics. The study finds that grouping selections, using an information-referenced criterion, are strongly associated with teachers perceptions of these students' actual educational and information needs. In addition, the information-referenced grouping design provides important specific educational feedback to both students and teachers to help low-attaining students move to mainstream classes. Finally, many of the due process concerns raised by educational researchers with regard to abuses and shortcomings of presently used ability or standardized test-driven grouping efforts are addressed. 相似文献
74.
Recent economic pressures have demanded higher education institutions respond with strong, authentic brand promises. This mixed method multi-case study explored the authenticity of common brand promises at three Universities in Canada through Twitter and Facebook postings from February to April 2016 using a cloud-based text and network analytic tool. Our study revealed the content shared on social media channels, while largely trustworthy, was fraught with shades of gray and revealed that sometimes brand promises were used against the university when they appeared disingenuous or threatened institutional norms around equity and social justice. Further, social media strategies are still largely limited to push notification suggesting universities are missing opportunities to strengthen their brand and counter negative messaging. For marketing managers it reinforces investments should be directed toward creating engaging and authentic content that can be expressed through multiple touch-points including social media and this can be monitored through low-cost analytic tools. 相似文献
75.
Anna E. Flynn James D. Klein 《Educational technology research and development : ETR & D》2001,49(3):71-86
The common practice of using discussion groups during case-based learning makes the role of discussion important in these
learning environments. However, little empirical research has been done to investigate the influence of discussion on performance
and motivation in case-based learning. The purpose of this article is to present the results of a study conducted to examine
the role of discussion groups in a case-based environment. College students completed two cases either individually or in
small discussion groups. Measures included two case analyses, an attitude survey, time on task, and document analysis. Results
revealed significant performance and time differences between instructional methods on the first case, but not on the second
case. In addition, results indicated significant differences in student attitudes between treatments. Overall, participants
who worked in groups liked their method significantly better than those who worked alone, felt they learned more working in
a group than they would have working alone, and expressed a preference for working in a group if they had to do the class
over again. Implications for implementing case-based learning and future research are discussed.
Anna E. Flynn is Vice President and NAPM Associate Professor with the National Association of Purchasing Management. 相似文献
76.
77.
The present study examined characteristics of students who took advantage of the opportunity to learn Algebra II from a highly skilled teacher. In particular, student information was gathered concerning: (a) the amount of mathematics students knew prior to the class, (b) their motivation for learning mathematics, (c) the number and types of interactions they had with the teacher during class, (d) degree of self-regulation, and (e) general aptitude. A model for achievement was used that suggests both opportunity and propensity are important (i.e., students must be willing and able to take advantage of opportunity). Support for the model was found. Propensity to take advantage of a highly favorable opportunity accounted for almost sixty percent of the variance in achievement. In particular, students who were self-regulated, had strong mathematics backgrounds, and had low levels of frustration benefited more from high-quality instruction. 相似文献
78.
Using Variables in School Mathematics: Do School Mathematics Curricula Provide Support for Teachers?
James Dogbey 《International Journal of Science and Mathematics Education》2016,14(6):1175-1196
This study employed content analysis to examine 3 popular middle-grades mathematics curricula in the USA on the support they provide for teachers to implement concepts associated with variables in school mathematics. The results indicate that each of the 3 curricula provides some type of support for teachers, but in a varied amount and quality. More specifically, whereas the University of Chicago School Mathematics Project (UCSMP) curriculum provides support for teachers on several aspects of using variables in school mathematics, the support found in the Connected Mathematics 2 and the Math Connects curricula focused mainly on one conception of variables—namely, the use of variables as quantity that varies in the Connected Mathematics 2 curriculum and the use of variables as specific unknowns in the Math Connects curriculum. Overall, the UCSMP curriculum provides the most support for teachers, followed by the Connected Mathematics 2 curriculum, with the Math Connects curriculum recording the least support for teachers to enact variable concepts. It is worth pointing out that, although the 3 curricula collectively provide guidance for teachers to implement variable ideas within meaningful real-world contexts, the supports identified in the respective curriculum were not sufficient in addressing all of the areas that are essential for teaching the many concepts associated with variables in school mathematics effectively. Recommendations for curriculum developers and for international researchers with interest in the roles of variables in school mathematics are provided. 相似文献
79.
The goals of this research were to describe the daily life of children and teachers in Chinese kindergarten programmes, to better understand how teacher–child interactions affect both teachers and children. The main assumption guiding this research was that teacher–child interaction is one of the most important processes in early childhood education. A clear understanding of typical teacher–child interactions may help to improve teachers’ support of children’s learning and development. In‐depth field observations of 12 Chinese teachers in six classrooms were conducted using a participant‐observer approach. Five hundred and eighty‐nine teacher–child interaction cases were observed and described. An inductive content analysis of the cases resulted in the creation of nine functional categories for teacher‐initiated interactive behaviours and nine functional categories for child‐initiated interactive behaviours. In this paper, we describe these functional interaction categories and report on their relative frequency in the Chinese kindergarten classrooms involved in this study. Teacher and child interactive behaviours are complementary, depending on the shared meaning of the interaction. Some differences were found in the interactive behaviours of older and younger children with their teachers. We discuss the results in the cultural context of China and conclude that careful and systematic observation and analysis of early childhood classroom interaction is essential for better understanding and improvement of teaching practices. 相似文献
80.
The purpose of this study was to examine: (a) the role of teacher talk in promoting peer interaction, (b) the adequacy of
social IEP objectives to reflect children’s social functioning and guide provision of teacher talk, and (c) differences in
children’s peer interaction and teacher talk in inclusive and segregated settings. Thirty children with disabilities and their
teachers participated. Overall, we observed low rates of teacher talk thought to support peer interaction; however, when teachers
verbally facilitated peer interaction, children were observed interacting more frequently with peers. Children’s social IEPs
accurately reflected their current level of social functioning. However, the social IEPs appeared to fail to influence teacher
intervention. Finally, children with disabilities in inclusive settings interacted with peers more than children in segregated
settings, even though there was no significant difference in amount of teacher talk in the two settings. 相似文献