A dynamic decision model for portfolio investment and assets management     

QIAN Edward Y.  FENG Ying  HIGGISION James 《浙江大学学报(A卷英文版)》2005,6(Z1)

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   

An Experiment In Empathy     

Marilyn Oden  James B. Meyer 《Counselor Education & Supervision》1970,9(4):292-294

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DIELECTRIC STUDIES OF UREASE AS A FUNCTION OF HYDRATION     

陆祖宏  Ronald Pethig  韦钰 《东南大学学报》1989,(2)

The steady-state electrical conductivity,as well as the dielectric propertiesbetween 2×10~(-4)Hz and 100 kHz,and at 1 GHz,are reported for urease compressed powdersamples of low hydration.The results show that the large,low frequency dielectricdispersion,known as α-dispersion,is due to the build-up of a space charge of protons atthe sample-electrode interfaces.A smaller dispersion,appearing at higher frequencies,isconcluded to be associated with hindered motions of the peptide residues in the molecularstructure of urease.The extent of these polypeptide backbone motions is shown to bestrongly depended on the extent of enzyme hydration.This work is contributed to the de-velopment of conductimetric biosensors.  相似文献   

Relationships of attitude toward classroom environment with attitude toward and achievement in science among tenth grade biology students     

E. Lynn Talton  Ronald D. Simpson 《科学教学研究杂志》1987,24(6):507-525

The purpose of the study was to examine the relationship of classroom environment to attitudes toward science and achievement in science among tenth grade biology students. An attitude instrument was administered at three times during the school year to measure student attitudes toward science and the classroom environment. The classroom environment measures examined six areas: emotional climate of the science classroom, science curriculum, physical environment of the science classroom, science teacher, other students in the science classroom, and friends attitudes toward science. Student achievement in science was measured by teacher reported semester grades. The results of the study indicated: (1) student attitudes toward the classroom environment predicted between 56 to 61% of the variance in attitudes toward science, (2) student attitudes toward the classroom environment predicted between 5 to 14% of the variance in achievement in science, (3) student attitudes toward science and attitudes toward the classroom environment predicted between 8 and 18% of the variance in achievement in science.  相似文献   

Design of technology-based information-referenced grouping systems for use in large urban schools     

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   

The university brand and social media: using data analytics to assess brand authenticity     

James Pringle  Samantha Fritz 《Journal of Marketing for HIGHER EDUCATION》2019,29(1):19-44

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   

The Roles of Parental Support and Family Stress in Adolescent Sleep          下载免费PDF全文

Kim M. Tsai  Ronald E. Dahl  Michael R. Irwin  Julienne E. Bower  Heather McCreath  Teresa E. Seeman  David M. Almeida  Andrew J. Fuligni 《Child development》2018,89(5):1577-1588

The current study examines the association between parental support and adolescent sleep under varying levels of family stress. Participants included 316 adolescents (M_age = 16.40 years, 43% male) and their parents (M_age = 45.67 years, 91% mothers) from diverse ethnic backgrounds. Both adolescents and parents completed questionnaires and adolescents wore wrist actigraphs and completed self‐reports on their sleep for 7 consecutive days. Results indicated that under contexts of family stress, more parental support was linked to longer sleep duration, less sleep variability, and less time spent awake during the night. Findings suggest that under contexts of family stress, cohesive family relationships may provide a sense of stability and security that is necessary for healthful sleep.  相似文献   

The influence of discussion groups in a case-based learning environment     

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   

The psychologist as wordsmith: a questionnaire study of the writing strategies of productive British psychologists     

James Hartley  Alan Branthwaite 《Higher Education》1989,18(4):423-452

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Characteristics of students who benefit from high-quality mathematics instruction     

Kristie K. Jones  James P. Byrnes 《Contemporary educational psychology》2006

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