Canonical variate analysis (CVA) is a widely used method for analyzing group structure in multivariate data. It is mathematically equivalent to a one-way multivariate analysis of variance and often goes by the name of canonical discriminant analysis. Change over time is a central feature of many phenomena of interest to researchers. This dissertation extends CVA to longitudinal data. It develops models whose purpose is to determine what is changing and what is not changing in the group structure. Three approaches are taken: a maximum likelihood approach, a least squares approach, and a covariance structure analysis approach. All methods have in common that they hypothesize canonical variates which are stable over time. The maximum likelihood approach models the positions of the group means in the subspace of the canonical variates. It also requires modeling the structure of the within-groups covariance matrix, which is assumed to be constant or proportional over time. In addition to hypothesizing stable variates over time, one can also hypothesize canonical variates that change over time. Hypothesis tests and confidence intervals are developed. The least squares methods are exploratory. They are based on three-mode PCA methods such as the Tucker2 and parallel factor analysis. Graphical methods are developed to display the relationships between the variables over time. Stable variates over time imply a particular structure for the between-groups covariance matrix. This structure is modeled using covariance structure analysis, which is available in the SAS package Proc Calis. Methods related to CVA are also discussed. First, the least squares methods are extended to canonical correlation analysis, redundancy analysis, Procrustes rotation and correspondence analysis with longitudinal data. These least squares methods lend themselves equally well to data from multiple datasets. Lastly, a least squares method for the common principal components model is developed. / Ph. D.

In adult populations, it is generally accepted there is an overall male advantage on spatial tasks and an overall female advantage on verbal tasks. These differences are inconsistent in children. The present study examined relations among age, sex, EEG hemispheric activation, and performance on spatial and verbal tasks. Thirty-two eight-year-olds (16 boys) and 32 college students (16 men) had EEG recorded at baseline and while performing a computerized 2-dimensional Gingerbread Man mental rotation task, a computerized 2-dimensional Alphanumeric mental rotation task, a computerized 3-dimensional Basketball Player mental rotation task, and a computerized Lexical Decision-Making task. Additionally, participants completed a paper-and-pencil Water Level task and an oral Verbal Fluency task. On the 2-dimensional Alphanumeric and 3-dimensional Basketball Player mental rotation tasks men performed better than boys, but the performance of women and girls did not differ. On the Lexical Decision-Making and Water level tasks, men performed better than women, while there was no difference between boys and girls. No sex differences were found on the 2-dimensional Gingerbread Man mental rotation task or Verbal Fluency task. Analyses of task-related data also indicate that computer familiarization or computer related task demands might contribute to sex differences on computerized tasks. EEG analyses indicated that, on the 2-dimensional Alphanumeric mental rotation task, men exhibited more left posterior temporal activation than women, while there were no differences between boys and girls. Additionally, there was evidence that simple, or 2-dimensional, mental rotation tasks are associated with left posterior brain activation, while 3-dimensional mental rotation tasks are associated with right posterior brain activation. On the 2-dimensional Gingerbread Man mental rotation task, males exhibited more activation of the left parietal area than females, while on the 2-dimensional Alphanumeric mental rotation task, men exhibited more activation of the left posterior temporal area than women. On the 3-dimensional Basketball player mental rotation task, all participants exhibited greater activation of the right parietal area than the left parietal area. / Ph. D.

An interesting stability property, as fascinating as that of spinning tops and gyroscopes, is observable in the motion of an unbalanced ring spinning on a rough horizontal surface. An analytical and numerical study is performed to investigate the general motion of an unbalanced ring modeled as a thin ring with a particle attached to its rim. The translational motion is represented by the rectangular coordinates of the ring geometric center. The rotational motion is represented by a 1-2-3 set of Euler angles. The kinetic motion equations are derived with the use of Newton's second law and Euler's rotational motion equations. The types of motion considered are the pure-rolling and rolling-with-slipping motions. Given favorable initial conditions, ring properties, and a sufficiently large constraint force in the form of friction, the ring undergoes a pure-rolling motion. For other conditions, however, limitations on the magnitude of the friction force render the pure the mathematical model to allow switching from pure-rolling to rolling-with-slipping motion and vice versa. The general motions of the unbalanced ring, obtained by numerically integrating the governing equations with the use of the seventh-eighth order Runge-Kutta method, are in very good qualitative agreement to those observed during an experiment performed with the use of a high-speed video camera. / Master of Science

Forest management strategies directly affect landowner welfare, and factors ranging from natural disturbances to institutional environments play important roles in influencing the outcomes for both landowners and society. This dissertation, consisting of three essays, delves into the forest sectors in both developed and developing countries with an aim of uncovering the impacts of various factors in forest management, as well as resulting welfare changes felt by landowners and society. The first essay extends previous literature on natural disturbances and forest management, where a single disturbance and immediate clearcut after it are always assumed, through the introduction of multiple disturbances and flexible harvest timing. A Faustmann-type rotation model is developed and used to guide simulations of loblolly pine management in the southern United States. We show that failure to consider the possibility of multiple disturbances and the oversimplification of harvest rules after a single disturbance leads to suboptimal harvest decisions. The second essay further extends the natural disturbance literature by considering the amenity value of unharvested forests in addition to timber value. As before, multiple types of disturbances as well as flexible harvest timing are incorporated into a Hartmann-type framework. Alternative amenity functions are employed in the simulations in which socially optimal harvest strategies are derived. We further examine the discrepancies between optimal harvest decisions of the landowner and those of the social planner, and compute social costs of ignoring amenity value. Our results show that ignoring amenity value can generate social costs and render harvest decisions socially suboptimal. Forest production in developing countries also suffers from institutional weaknesses that distorts household decision making. The third essay therefore investigates impacts of village democracy on rural household welfare in China through changes in production efficiency in forestry and agriculture sectors using data collected from a household survey. A theoretical framework is first established, and based upon that framework stochastic production frontier models are estimated where democracy is incorporated as a potential factor affecting the variation of technical efficiency. We find that higher levels of village democracy significantly increase production efficiency. A first study on how village democracy affects rural household welfare, we provide policy lessons for other developing countries undergoing democratization. / Ph. D.

An experimental investigation was conducted to study the inelastic rotation capability of flush end-plate moment connections. Seven specimens representing two-bolt and four-bolt flush end-plate configurations were tested under cyclic loading. "Quasi-static" or "slow-cyclic" loading histories suggested by SAC and the Applied Technology Council were used to load the specimens. Experimental results for maximum moment resisted by the connections were compared with analytical predictions. Moment strengths of the connections were calculated using yield-line theory to predict end-plate yielding and maximum bolt force calculations including prying action. Experimental results were also compared to previous research with regards to strength and stiffness. The inelastic rotation of connections was calculated and conclusions were drawn on the compliance of these connections with current AISC specifications. / Master of Science

The area of cognitive research that has produced the most consistent sex differences is the area of spatial ability. Particularly, males usually perform better on mental rotation tasks than do females. One argument for these differences is that experience with spatial activity drives these differences, such that traditionally more masculine activities require more practice of spatial abilities. Another argument is biological in nature, such that there is either 1) a critical period of development that leads to differential lateralization of the brain, or 2) differential activation of the brain by circulating hormones. Performance on mental rotation tasks has been associated with right parietal activation levels, both during task performance and prior to performance during baseline recordings. The present study examined the relations among sex, age, EEG hemispheric activation (at the 10.5-13.5Hz. frequency band), and 2-dimensional mental rotation task ability. Nineteen eight-year-olds (10 boys) and 20 college students (10 men), had EEG recorded at baseline and while performing a mental rotation task. Men performed better on the mental rotation task than women, while there were no differences between boys and girls. After covarying for baseline EEG high alpha power values, EEG results during the mental rotation task indicated an interaction, with men exhibiting more activation (lower EEG power values at 10.5-13.5Hz) than women in the parietal and posterior temporal regions, while boys' and girls' power values 10.5-13.5Hz did not differ in the parietal or posterior temporal regions. Furthermore, during the baseline condition, men generally exhibited more activation (lower EEG power values at 10.5-13.5Hz) throughout all regions of the scalp. Results support the hypothesis that hormones, or hormonal influence, may result in a biological change which affects both brain activation and performance on mental rotation tasks. / Master of Science

The Current project investigated whether a drawing based training regiment will improve performance on a mental rotation test involving the same figures drawn during the training. There were two experimental groups: drawing and non-drawing. The participants' responses were measured using reaction time and accuracy. The main . effects found were for angle of rotation and whether the shape was familiar or not. Shapes were considered familiar if they were drawn in the drawing training. Contrary to the research hypothesis the drawing training did not have an effect upon the participant's performance on the mental rotation task. Further research is needed to fully examine the relationship between a training using drawing and its effect on mental rotation. The results from this study are discussed with implications for fields such as architecture baggage screening and dentistry.

As a result of crisis and scandals, a lot of criticism has been emphasized against an auditor’sindependence and profession. In order to re-establish confidence in financial statements, theEuropean Commission introduced a Green Paper that above all included a proposal of mandatoryaudit firm rotation aiming to enhance an auditor's independence. The aim of this thesis istherefore to describe whether an auditor’s independence may be affected by the new lawregarding Mandatory Audit Firm Rotation, by contributing with more information regarding auditfirm rotation based on Swedish companies from the Swedish market. The study is based on a quantitative approach using a multivariate logistic regression in order tocompile and analyze the results. Six hypotheses have been tested in order to determine whetherchosen variables may affect an auditor's independence and their statements. Based on our results,we accepted four hypotheses, showing that four variables have an influence on qualified opinion,with rotation as a reference variable. The four variables are leverage, size, specialist and losswhich showed a statistically significance using a 5% significance level. The results imply thataudit firm rotation may enhance an auditor's independence.

Abstract Background: Golf is a sport with a growing focus on the physical aspect of the game and its relationship to performance. Studies have determined a correlation between club head speed and performance in golf. Rotational power has proven to be an important factor for the club head speed. By examining the relationship between club head speed and rotational power, researchers has found that rotation power on the golfers dominant side have a moderate to high correlation with club head speed. Previous research has mostly investigated the peak rotational power on the dominant side. Furthermore, additional research is needed to examine the bilateral strength and its relationship to club head speed. Aim: The aim of this study was to examine the correlation between peak trunk rotational power and club head speed in elite golfers, and also to study the impact of bilateral rotational strength on club head speed. Methods: The study included 27 elite golf players (21 males, 6 females) age 19±2 years. The subjects attended two sessions where the first session included a club head speed test and the second session a rotation power test in the Quantum machine. The rotational peak power ratio (dominant/non-dominant side) were ranged from 1-27 (the closer to 1, the higher order) to study a linier relationship with club head speed. Spearman’s nonparametric rank correlations coefficient (rs) was used since the data was not normally distributed. Results: There was a moderate correlation between peak trunk rotational power on the dominant side and club head speed ( rs=0.58, p=0.01). The correlation between the peak trunk rotational powers on the dominant and non- dominant side was high, rs=0.82 (p=0.01). There were no significant correlation found between the ranged rotational peak power ratio and club head speed (rs=0.30, p=0.1). Conclusion: The current study found a slightly lower correlation between peak trunk rotational power and club head speed than found in earlier studies. The golfers in this study had symmetric strength in the trunk, other studies have shown that the rotational strength in golfer´s dominant side were higher than of the non- dominant side. The result of this study indicates that balance between the sides not necessarily has a relationship with how high the golfer’s club head speed is. Future research is needed to analyze the quadratic correlation between ratio and club head speed on a more advanced level. The results of this study can, if validated, be used for further researching and understanding of club head speed and golf performance.

Thesis (MScAgric)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Sustainability issues and the structural over-supply of wheat in the Western Cape since the middle 1990‟s have caused the introduction of alternative crop rotation systems in the Middle Swartland, a dry-land winter cereal production area of the Western Cape. Crop rotation systems typically consist of cereals and oilseed crops and pastures. Alternative crop rotations systems are currently scientifically evaluated at the Langgewens Experimental farm. Currently more than half the cultivated area in the Swartland is still under wheat production, a third of which is wheat monoculture. An issue regarding the adoption of such a crop rotation system is the cash flow and affordability of implementing such an alternative system. The goal of this study is to determine the cash-flow implications of a shift from wheat monoculture to a crop rotation system. Typical strategies available to producers to support such a shift are investigated. The complexity of farm systems as well as the interrelationships between crops within such a crop rotation system necessitates the implementation of a systems approach. A multi-period, whole-farm budget model was constructed to capture the interrelationships of the farm system and to express the financial performance thereof in standard profitability criteria. The farm model is based on a typical farm for the Middle Swartland. The model was used to determine the expected profitability of various crop rotation systems and to evaluate alternative strategies to accommodate the shift to alternative systems. The Langgewens crop rotation trial results are used to determine expected profitability of various crop rotation systems. A wheat-monoculture system serves as basis for the shift to alternative systems with the focus on the practical implications of such as shift. The profitability calculations show that various crop rotation systems are expected to be more profitable than wheat monoculture. The most profitable system is one year canola followed by three years of wheat, followed by a wheat/medic system with Dohne Merino sheep on the medic pastures. The shift from wheat monoculture is simulated by four scenarios. The first evaluated the financial implications of a shift form monoculture to the three year wheat and one year canola system. The second simulates a shift from monoculture to a wheat/medic system within two years and using own funds. The third scenario simulate the same shift with own funding, but over a ten year period. The fourth is similar to the second, but borrowed money is used to fund the shift.Lower input costs and consistently higher yields results in higher expected gross margins for the crop rotation systems, especially with nitrogen fixing plants. The inclusion of medic and medic/clover pastures and alternative cash crops such as canola and lupins show a higher yield on investment than wheat monoculture. Insight into the factors that producers should consider was also generated by this study, concerning changes to crop rotation systems. These factors include; time period over which a shift is planned and the availability of financing options. It seems that a quicker shift, using borrowed funds, is more profitable over the longer term. / AFRIKAANSE OPSOMMING: Volhoubaarheidskwessies, en die strukturele ooraanbod van koring in die Wes-Kaap, het sedert die middel 1990‟s, gelei tot alternatiewe gewasproduksiestelsels in die Swartland, ʼn droëland wintergraanproduserende area van die Wes-Kaap. Gewasproduksiestelsels bestaan tipies uit graan- en oliesaad- en weidings gewasse. Alternatiewe gewas-wisselboustelsels word wetenskaplik gevalueer op die Langgewens proefplaas. Tans is meer as die helfte van die area in die Swartland steeds onder koring produksie, ʼn derde daarvan is koring monokultuur. ʼn Bekommernis rakende die aanneem van wisselboustelsels is die kontantvloei en bekostigbaarheid van die implementering van so ʼn alternatiewe stelsel. Die doel van hierdie studie is om te bepaal wat die kontantvloei implikasies van ʼn skuif van ʼn koringmonokultuurstelsel na ʼn wisselboustelsel is. Tipiese strategieë beskikbaar aan produsente om so skuif te finansier is ook ondersoek. Die kompleksiteit van boerderystelsels en die interverwantskap tussen gewasse in ʼn wisselboustelsel noodsaak die insluiting van ʼn stelselsbenadering. ʼn Multi-periode, geheelplaasbegrotingsmodel is ontwikkel om die interverwantskap van die boerdery te verenig en finansiële prestasie uit te druk in erkende winsgewendheid kriteria. Die boerderymodel is gebaseer op ʼn tipiese plaas vir die Middel-Swartland. Die model is gebruik om die winsgewendheid van verskillende wisselboustelsels te bepaal en om verskillende strategieë te assesseer wat die oorgang van wisselboustelsel kan akkommodeer. Die Langgewens wisselbouproefdata is gebruik om die winsgewendheid van verskillende wisselboustelsels te bepaal. „n Koringmonokultuurstelsel dien as basis vir die oorskakeling na alternatiewe wisselboustelsels, met die fokus op die praktiese implikasies van so ʼn skuif. Die winsgewendheid bepaling wys dat verskeie wisselboustelsels meer winsgewend is as koring monokultuur. Die mees belowende stelsels is een jaar canola gevolg deur drie jaar koring en ʼn koring/medic stelsel met Dohne Merino skape op die medic weidings. Die oorskakeling vanaf koring monokultuur is gesimuleer deur vier scenario‟s. Die eerste scenario evalueer die finansiële implikasie van ʼn skuif van koringmonokultuur na ʼn wisselboustelsel met een jaar canola. Die tweede scenario evalueer ʼn skuif na ʼn koring medic stelsel binne twee jaar met eie fondse. Die derde scenario simuleer dieselfde skuif maar oor ʼn tien jaar tydperk, met eie fondse. Die vierde scenario simuleer dieselfde skuif na koring/medics maar oor ʼn twee jaar periode met geleende fondse. Laer insetkoste en konstante hoër opbrengste lewer hoër brutomarges vir die wisselboustelsels, veral die met stikstofbindende weidingsgewasse. Die insluiting van medic en medic/klawer weidings en alternatiewe kontantgewasse soos canola en lupiene wys ʼn beter opbrengs op kapitaal investering in vergelyking met koringmonokultuur. Bykomende daartoe verskaf die resultate van die studie insig in die faktore wat graanprodusente behoort te oorweeg wanneer ʼn oorskakeling na alternatiewe wisselboustelsels oorweeg word. Die faktore sluit in, die tydperk waaroor die oorskakeling beoog word en die beskikbare finansieringsopsies. Dit blyk dat ʼn vinniger oorskakeling, selfs teen die koste van finansiering, oor die langtermyn meer winsgewend is.