A dynamic decision model for portfolio investment and assets management

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.     

Florida and Puerto Rico Secondary Science Teachers’ Knowledge and Teaching of Climate Change Science

Misconceptions about climate change science are pervasive among the US public. This study investigated the possibility that these misconceptions may be reflective of science teachers’ knowledge and teaching of climate change science. Florida and Puerto Rico secondary science teachers who claim to teach extensively about climate change were surveyed in regard to their conceptions of climate change science and the climate change-related topics they teach. Results show that many teachers hold naïve views about climate change (e.g. that ozone layer depletion is a primary cause of climate change) and climate change science (e.g. that it must be based on controlled experiments for it to be valid). In addition, teachers in both groups neglect crucial topics such as how evidence for climate change is developed and the social, political, and economic dimensions of climate change. Our results suggest the need for teachers to understand how to teach climate change and the nature of climate change science using authentic contexts that promote effective socioscientific decision-making and climate change mitigation.     

Breaking the tyranny of office hours: Overcoming professor avoidance

ABSTRACT

Studies have found that Faculty–Student Interaction (FSI) has many positive benefits for students including academic support, professional development, mentoring, and career planning. Research-intensive universities exhibit the lowest levels of faculty–student interaction within higher education. This article utilises qualitative methods to explore faculty, student, and staff perceptions of faculty–student interactions, particularly those that take place out of the classroom, at a research-intensive public U.S. university. We identify social distance between faculty and students based on unequal status within a rigid, hierarchically-organised culture as a key barrier to FSI. We then discuss methods that some of the faculty in our study used to mitigate their social distance with students in an effort to increase FSI.     

A comparison of the dimensions used by Iranian and American students in rating instruction

This study investigated the dimensions of teacher behavior and classroom characteristics used by Iranian high school students (N=880) in evaluating their classroom experience. Secondly, it compared these dimensions to those used by American high school students (N=599). During January, 1978, both groups of students completed the Classroom Behavior Survey (CBS). Principal components analysis with varimax rotation yielded a 12 factor solution for Iranian data and 14 for the American data. Comparison of the factors suggest that the dimensions on which Iranian and American students evaluate their teachers are substantially different, though the dimensions they use to evaluate characteristics of the course and content are similar.

---

Zusammenfassung Diese Studie untersucht die Dimensionen von Lehrerverhalten und Unterrichtsweisen, die iranische Studenten zur Evaluation ihrer Klassenerfahrungen angewandt haben. Ferner vergleicht sie diese Dimensionen mit den von amerikanischen Sekundarschülern benutzten. Beide Schülergruppen beendeten ihre Untersuchungen über Unterrichtsverhalten im Januar 1978. Eine Analyse der Hauptkomponenten, mit Varimax Rotation, ergab eine 12-Faktorenlösung für die iranischen Daten gegenüber 14 Faktoren für die amerikanischen. Ein Vergleich dieser Faktoren deutet darauf hin, daß die Dimensionen, aufgrund derer die iranischen und amerikanischen Schüler ihre Lehrer bewerten, stark voneinander abweichen, während sich die für die Beurteilung der Kurse und Inhalte gebrauchten gleichen.

---

Résumé Cette étude porte sur les cotes du comportement de l'enseignant et des caractéristiques de la classe utilisées par les élèves iraniens de l'enseignement secondaire. (N=880) dans leur évaluation de leur expérience scolaire. Elle compare ensuite ces cotes à celles utilisées par les élèves américains du secondaire. Les deux groupes d'élèves ont terminé leur enquête sur le comportement de la classe (CBS ECC) en janvier 1978. L'analyse des principales composantes avec rotation varimax a donné une solution à 12 facteurs pour les données iraniennes et à 14 facteurs pour les données américaines. La comparaison des facteurs suggère que les cotes selon lesquelles les élèves iraniens et américains évaluent leurs enseignants sont notablement différentes, bien que celles qu'ils utilisent pour évaluer les caractéristiques du cours et de son contenu soient similaires.

     

Interference and auditory short-term memory in the bottlenosed dolphin

Interference in auditory short-term memory in the bottlenosed dolphin,Tursiops truncatus (Montagu), was studied using a delayed matching-to-sample task. At each trial, one of two sample sounds, chosen randomly, was projected underwater for 4 sec and then, after a variable delay interval, both sounds were presented. A response to the sound matching the initial sample was reinforced. Correct matching was significantly reduced following short intervals between trials in combination with long delays after the sample (proactive interference), or when a near continuous irrelevant sound was inserted into the delay interval (retroactive interference). There was rapid habituation to interference if the irrelevant sound was short in duration relative to the delay interval. For both proactive and retroactive interference, the errors were predominantly responses to the sample sound appropriate to the prior trial rather than to the current trial, indicating that memory for the relative recency of events (temporal memory) was degraded by interference. When interference was deleted or minimized, temporal memory remained nearly perfect over 30-sec delay intervals, the longest tested. The importance of distinguishing between temporal memory and nontemporal, or event, memory in different forms of the delayed matching task was emphasized.     

Developmental issues in cognitive mapping: the selection and utilization of environmental landmarks

2 studies were conducted to investigate developmental differences in the ability to select and use environmental landmarks for cognitively organizing distance information from a walk. In experiment 1, second-grade, fifth-grade, and college subjects viewed a simulated walk and selected scenes that were high in potential landmark value. In experiment 2, children from the same grade levels first viewed the walk and then ranked distances among either the test scenes most frequently selected by their peers or those selected most frequently by adults. Results indicated that (a) adults and children may not spontaneously select the same features as real-world landmarks; (b) children are less capable than adults in judging the value of potential landmarks as distance cues; and (c) the ability to use environmental landmarks as cues for distance information developmentally precedes the ability to assess this potential information value.