Genetic Algorithms and Investment Strategies: A Global Perspective

The profitability of momentum portfolios in the equity markets is derived from the continuation of stock returns over medium time horizons. The empirical evidence of momentum, however, is significantly different across markets around the world. The purpose of this dissertation is to: 1) help global investors determine the optimal selection and holding periods for momentum portfolios, 2) evaluate the profitability of the optimized momentum portfolios in different time periods and market states, 3) assess the investment strategy profits after considering transaction costs, and 4) interpret momentum returns within the framework of prior studies on investors’ behavior. Improving on the traditional practice of selecting arbitrary selection and holding periods, a genetic algorithm (GA) is employed. The GA performs a thorough and structured search to capture the return continuations and reversals patterns of momentum portfolios. Three portfolio formation methods are used: price momentum, earnings momentum, and earnings and price momentum and a non-linear optimization procedure (GA). The focus is on common equity of the U.S. and a select number of countries, including Australia, France, Germany, Japan, the Netherlands, Sweden, Switzerland and the United Kingdom. The findings suggest that the evolutionary algorithm increases the annualized profits of the U.S. momentum portfolios. However, the difference in mean returns is statistically significant only in certain cases. In addition, after considering transaction costs, both price and earnings and price momentum portfolios do not appear to generate abnormal returns. Positive risk-adjusted returns net of trading costs are documented solely during “up” markets for a portfolio long in prior winners only. The results on the international momentum effects indicate that the GA improves the momentum returns by 2 to 5% on an annual basis. In addition, the relation between momentum returns and exchange rate appreciation/depreciation is examined. The currency appreciation does not appear to influence significantly momentum profits. Further, the influence of the market state on momentum returns is not uniform across the countries considered. The implications of the above findings are discussed with a focus on the practical aspects of momentum investing, both in the U.S. and globally.

The effects of required/sequenced preparatory courses on academic success and retention at a community college

This dissertation had two purposes: first, to analyze how required sequenced college preparatory courses in mathematics, reading, and writing affect students' academic success and, second, to add to a theoretical model for predicting student retention at a community college. Grade point average, number of degree credits earned, and reenrollment rate were measured as determinants of academic success. The treatment group had a significantly higher grade point average than the control group. There was no significant difference in the number of degree credits earned or re-enrollment rate for the groups. A series of logistic regressions used the independent variables E-ASSET scores in math, reading, and writing; number of college prep areas required; credits earned; grade point average; students' status; academic restrictions/required course sequencing; sex; race; and socio-economic status to determine the predictor variables for retention. The academic variable that showed the greatest potential as a predictor for retention was grade point average. Overall, receiving financial aid was the greatest predictor for reenrollment. For a financial aid recipient the odds of reenrollment were 2.70 times more likely than if no financial aid was received.

Physical therapy recruitment and retention strategies of hospitals in the US

Hospitals are seeing a reduction of physical therapy (PT) staff due to increased opportunities and competition. Planning effective recruitment and retention strategies for PTs in hospital settings may play an important role in reducing the problem. The primary purpose of this descriptive research was to compile information on recruitment and retention strategies used for physical therapists working in hospital settings. Four hundred surveys were mailed nationwide to hospital-based physical therapy managers. Strategies most commonly used were: attractive benefit package, interdisciplinary teams, competitive salaries, and student employment. The least used strategies used were: sign-on bonus, incentive pay programs, recruitment and retention committee and temporary staffing. It was concluded that hospital administrators need to analyze current strategies used and future recruitment and retention staffing trends, in order to institute successful strategies appropriate to their departments to effectively recruit and retain their staff.

What are the effects of the 6 +1 Writing Traits on the Attitudes and Writing Skills of Fifth Grade ELLs?

In the Bahamas, ELLs consist mainly of Haitian descent students. Unfortunately, this demographic of students continuously score below their Bahamian counterparts in Creative Writing. This research examined the affects the 6 + 1 Writing Traits assessment had on the attitudes and writing abilities of fifteen, fifth grade, Haitian descent students.

Development and Verification of Control and Protection Strategies in Hybrid AC/DC Power Systems for Smart Grid Applications

Modern power networks incorporate communications and information technology infrastructure into the electrical power system to create a smart grid in terms of control and operation. The smart grid enables real-time communication and control between consumers and utility companies allowing suppliers to optimize energy usage based on price preference and system technical issues. The smart grid design aims to provide overall power system monitoring, create protection and control strategies to maintain system performance, stability and security. This dissertation contributed to the development of a unique and novel smart grid test-bed laboratory with integrated monitoring, protection and control systems. This test-bed was used as a platform to test the smart grid operational ideas developed here. The implementation of this system in the real-time software creates an environment for studying, implementing and verifying novel control and protection schemes developed in this dissertation. Phasor measurement techniques were developed using the available Data Acquisition (DAQ) devices in order to monitor all points in the power system in real time. This provides a practical view of system parameter changes, system abnormal conditions and its stability and security information system. These developments provide valuable measurements for technical power system operators in the energy control centers. Phasor Measurement technology is an excellent solution for improving system planning, operation and energy trading in addition to enabling advanced applications in Wide Area Monitoring, Protection and Control (WAMPAC). Moreover, a virtual protection system was developed and implemented in the smart grid laboratory with integrated functionality for wide area applications. Experiments and procedures were developed in the system in order to detect the system abnormal conditions and apply proper remedies to heal the system. A design for DC microgrid was developed to integrate it to the AC system with appropriate control capability. This system represents realistic hybrid AC/DC microgrids connectivity to the AC side to study the use of such architecture in system operation to help remedy system abnormal conditions. In addition, this dissertation explored the challenges and feasibility of the implementation of real-time system analysis features in order to monitor the system security and stability measures. These indices are measured experimentally during the operation of the developed hybrid AC/DC microgrids. Furthermore, a real-time optimal power flow system was implemented to optimally manage the power sharing between AC generators and DC side resources. A study relating to real-time energy management algorithm in hybrid microgrids was performed to evaluate the effects of using energy storage resources and their use in mitigating heavy load impacts on system stability and operational security.

Effects of a modified English listening comprehension curriculum on students' achievement in English listening comprehension at Tamsui Oxford University College in Taiwan

Due to increased international trade, English as a foreign language is important to Taiwan. However, ESL teaching and learning in Taiwan emphasizes reading and writing skills only. ESL teaching in Taiwan causes students to lack competence in complete communication. Improving students' listening and speaking is a vital issue in Taiwan. ^ The purposes of this study are to determine the effects of a modified curriculum for the English listening comprehension course, to investigate whether the modified curriculum results in a significant improvement in student's listening comprehension, and to determine whether students were motivated to increase listening comprehension ability as a result of the new listening activities. An experimental and a control group, randomly assigned, received either the modified or the traditional curriculum at Tamsui Oxford University College (TOUC) in Taiwan over a fourteen week period of time. ^ A Michigan Listening Comprehension posttest was used to determine the difference in achievement between the two groups. A final examination was conducted to compare the two groups' achievement and to determine whether the goal of increasing listening comprehension achievement by using a modified curriculum was met. Subjects completed two questionnaires, one common form prior to class and another unique form for each group at the end of instruction. ^ Frequency distribution, chi-square, t-test for independent samples and analysis of covariance were used to analyze the data. The findings indicated that there were no significant differences in students' attitude and interest in English listening comprehension between those who were taught with an English listening modified curriculum compared with those students who were taught with a traditional curriculum. The findings also indicated that there was a difference in the final examination with the control group taught using the traditional curriculum scoring higher than the experimental group taught using the modified curriculum for performance in English listening comprehension, but there was no difference in scores on the Michigan Listening Comprehension Test (posttest). In addition, it was found that learning attitude and motivation influence students' learning. ^

The effects of writing process instruction on the writing and reading performance of students with learning disabilities

The purpose of this study was to determine the efficacy of a writing process approach for the instruction of language arts with learning disabled elementary students. A nonequivalent control group design was used. The sample included 24 students with learning disabilities who were in second and third grade. All students were instructed in resource room settings for ninety minutes per day in language arts. The students in the treatment group received instruction using the writing process steps to create complete meaningful compositions on self-chosen topics. A literature-based reading program accompanied instruction in writing to provide examples of good writing and to provide a basis for topic selection. The students in the control group received instruction through the use of the county-adopted textbooks and accompanying worksheets. The teacher followed basic textbook and curriculum guide suggestions which consisted mainly of fill in the blank and matching type exercises. The treatment group consisted of 12 students: five second-graders and seven third-graders. The control group consisted of 12 students: four second-graders and eight third-graders. All students were pretested and posttested using the Woodcock-Johnson Tests of Achievement-Revised (WJ-R ACH) for writing samples and the Woodcock Reading Mastery Test (WRMT) for reading achievement. T-tests were also done to investigate the gain from pre to post for each reading or writing variable for each group separately. The results showed a highly significant difference from pretest to posttest for all writing and reading variables for both groups. Analysis of Covariance showed that the population mean posttest achievement scores for all variables adjusted for the pretest were higher for the treatment group than those for the control group.

Narrative comprehension: Semantic and syntactic summary production

The purpose of this research was to examine from a syntactic and narrative structure perspective two narrative summary types: a summary with a length constraint and an unconstrained summary. In addition, this research served to develop a multidimensional theory of narrative comprehension.^ College freshmen read two short stories written by written by Sake and were asked to write a constrained summary for one text and an unconstrained summary for the other text. Following this the subjects completed a metacognitive questionnaire. The summaries were analyzed to examine transitivity features and narrative structure features. The metacognitive questionnaires were examined to extract information about plot structure, differences between one and two episode stories, and to gain insight into the strategies used by subjects in producing both summary types.^ A Paired t-test conducted on the data found that there was a significant transitivity feature mean difference between a constrained summary and an unconstrained summary indicating that the number of transitivity features produced from each summary type were task dependent.^ Chi-square tests conducted on the data found that there were proportional differences in usage between plot features and thematic abstract units in an unconstrained summary and a constrained summary indicating that plot features and thematic abstract units produced from each summary type were task dependent.^ Qualitative analyses indicated that setting, goal, and resolution are typical within plot organization, there are summary production differences between one and two episode narratives, and subjects do not seem to be aware of summary production strategies.^ The results of this research have implications for comprehension and writing instruction. ^

The Effect of Authentic Literacy Experiences as Book Buddies with Hispanic Fourth Graders on Preservice Teachers’ Literacy Content Knowledge and Reading Maturity

From a sociocultural perspective, individuals learn best from contextualized experiences. In preservice teacher education, contextualized experiences include authentic literacy experiences, which include a real reader and writer and replicate real life communication. To be prepared to teach well, preservice teachers need to gain literacy content knowledge and possess reading maturity. The purpose of this study was to examine the effect of authentic literacy experiences as Book Buddies with Hispanic fourth graders on preservice teachers’ literacy content knowledge and reading maturity. The study was a pretest/posttest design conducted over 12 weeks. Preservice teacher participants, the focus of the study, were elementary education majors taking the third of four required reading courses in non-probabilistic convenience groups, 43 (n = 33 experimental, n = 10 comparison) Elementary Education majors. The Survey of Preservice Teachers’ Knowledge of Teaching and Technology (SPTKTT), specifically designed for preservice teachers majoring in elementary or early childhood education and the Reading Maturity Survey (RMS) were used in this study. Preservice teachers chose either the experimental or comparison group based on the opportunity to earn extra credit points (experimental = 30 points, comparison = 15). After exchanging introductory letters preservice teachers and Hispanic fourth graders each read four books. After reading each book preservice teachers wrote letters to their student asking higher order thinking questions. Preservice teachers received scanned copies of their student’s unedited letters via email which enabled them to see their student’s authentic answers and writing levels. A series of analyses of covariance were used to determine whether there were significant differences in the dependent variables between the experimental and comparison groups. This quasi-experimental study tested two hypotheses. Using the appropriate pretest scores as covariates for adjusting the posttest means of the subcategory Literacy Content Knowledge (LCK), of the SPTKTT and the RMS, the mean adjusted posttest scores from the experimental group and comparison group were compared. No significant differences were found on the LCK dependent variable using the .05 level of significance, which may be due to Type II error caused by the small sample size. Significant differences were found on RMS using the .05 level of significance.