Thesis (MA)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The primary aim of the present study was to examine whether the culture of a society influences the way in which people justify certain aggressive behaviours in certain situations. A total of 756 students from Spain, Japan and South Africa participated in completing the CAMA, a measure of justification of aggression. The results showed that there were significant differences within the countries. There were differences in the levels of acceptance of certain acts between these countries. Further fmdings also indicated that there was a difference between the males of the countries and between the females of these countries. It was found that cultural influences and the norms within these countries bring about differences in justification of aggression in different situations. There were also some general trends of acceptance, with direct and indirect verbal acts e.g. sarcasm, hindering and shouting being more acceptable than physical acts such as hitting, killing and torture. It is hoped that the present findings of this research will make members of society more aware of their responsibility to help reduce aggressive acts by teaching and reinforcing norms against it. It is also hoped that the international community will gain better insight into the fact that South-Africa faces unique challenges because of the political and social changes in the country. / AFRIKAANSE OPSOMMING: Die primêre doel van die huidige studie was om vas te stelof 'n samelewing se kultuur 'n rol speel by die regverdiging van sekere aggressiewe gedrag in bepaalde omstandighede. 'n Totaal van 756 studente van Spanje, Japan en Suid Afrika het die CAMA vraelys voltooi. Die vraelys meet die regverdiging van aggressie in sekere omstandighede. Betekenisvolle verskille is tussen die lande gevind. Daar is ook betekenisvolle verskille tussen die mans van die drie lande asook tussen die vrouens van die drie lande gevind. Daar is gevind dat kulturele verskille en die norme binne 'n samelewing meebring dat daar verskille is in die mate waarin samelewings sekere aggressiewe gedrag aanvaarbaar vind in sekere situasies. Daar was ook 'n groter algemene aanvaarbaarheid van verbale aggressie bv. sarkasme, verhindering en skreeu as fisiese aggressie soos slaan, om dood te maak en marteling. Hopelik maak hierdie navorsing mense meer bewus van elkeen in die samelewing se verantwoordelikheid om die norme teen geweld te versterk asook om die norme aan hulle nageslagte oor te dra. Verder sal die internasionale gemeenskap hopelik beter insig kry oor die unieke uitdagings wat Suid-Afrika bied as gevolg van die politieke en sosiale veranderinge in die land.

This study introduces a new analytical procedure based on the chi-square (x²) statistic to evaluate tree- ring weather relationships. An iterative x² method, developed previously for relating annual crop production to daily values of meteorological measurements, is applied to tree-ring data and compared to results obtained from correlation and bootstrapped response function analyses. All three analytical procedures use a southern Arizona chronology (Pinus arizonica Engelm.) and the latter two use monthly average meteorological data. The x² analysis revealed most of the relationships exhibited by the correlation and response function analyses as well as new linear and nonlinear associations. In addition, cardinal values were obtained that define daily thresholds of the meteorological variables at which the limitation to growth becomes significant. Some of the associations are plausible from the physical system but require more study to confirm or refute a real cause and effect. A few associations appear to be too late in the season or too early in the previous year to affect ring width. We recommend that this x² technique be added to the existing dendroclimatic procedures because it reveals many more possible cause and effect relationships.

This study was designed to determine whether chis-quared based tests for independence give reliable estimates (as compared to the exact values provided by Fisher's exact probabilities test) of the probability of a relationship between the variables in 3 X 3, 3 X 4 , and 3 X 5 contingency tables when the sample size is 10, 20, or 30. In addition to the classical (uncorrected) chi-squared test, four methods for continuity correction were compared to Fisher's exact probabilities test. The four methods were Yates' correction, two corrections attributed to Cochran, and Mantel's correction. The study was modeled after a similar comparison conducted on 2 X 2 contingency tables and published by Michael Haber.

GIS (Geographic Information Systems) and remote sensing techniques were used to predict relationships between bald eagle nest presences and land type, distance to land type and impervious surface cover area. Data plots revealed bald eagle nest presence decreases in response to an increase in area of bareland; increases with an increase in area of forested land; decreases with an increase in distance (m) to shoreline, and decreases in response to an increase in area of impervious surfaces. Logistic regression models identified impervious surfaces as an indicator for bald eagle nest presence (P 24% as unsuitable. Unsuitable area covered 17.82% of the total study area, impacted area covered 13.40%, and, sensitive area covered 68.77%. The projected increase in population in the state of Virginia and subsequent increase in impervious surfaces presents a challenge to the future viability of the Virginia Chesapeake Bay bald eagle population. The threshold analysis identified areas of prime conservation concern for bald eagle nest presence within the defined study area. These areas provide the basis for a conservation management plan and for further scientific study.

Synthetic Aperture Radar (SAR) has been identified as a good candidate to provide high-resolution soil moisture information over extended areas. SAR data could be used as observations within a global Data Assimilation (DA) approach to benefit applications such as hydrology and agriculture. Prior to developing an operational DA system, one must tackle the following challenges of soil moisture estimation with SAR: (1) the dependency of the measured radar signal on both soil moisture and soil surface roughness which leads to an ill-conditioned inverse problem, and (2) the difficulty in characterizing spatially/temporally surface roughness of natural soils and its scattering contribution. The objectives of this project are (1) to develop a roughness measurement method to improve the spatial/temporal characterization of soil surface roughness, and (2) to investigate to what extent the inverse problem can be solved by combining multipolarization, multi-incidence, and/or multi-frequency radar measurements. The first objective is achieved with a measurement method based on Structure from Motion (SfM). It is tailored to monitor natural surface roughness changes which have often been assumed negligible although without evidence. The measurement method is flexible, a.ordable, straightforward and generates Digital Elevation Models (DEMs) for a SAR-pixel-size plot with mm accuracy. A new processing method based on band-filtering of the DEM and its 2D Power Spectral Density (PSD) is proposed to compute the classical roughness parameters. Time series of DEMs show that non-negligible changes in surface roughness can happen within two months at scales relevant for microwave scattering. The second objective is achieved using maximum likelihood fitting of the Oh backscattering model to (1) full-polarimetric Radarsat-2 data and (2) simulated multi-polarization / multi-incidence / multi-frequency radar data. Model fitting with the Radarsat-2 images leads to poor soil moisture retrieval which is related to inaccuracy of the Oh model. Model fitting with the simulated data quantifies the amount of multilooking for di.erent combinations of measurements needed to mitigate the critical e.ect of speckle on soil moisture uncertainty. Results also suggest that dual-polarization measurements at L- and C-bands are a promising combination to achieve the observation requirements of soil moisture. In conclusion, the SfM method along with the recommended processing techniques are good candidates to improve the characterization of surface roughness. A combination of multi-polarization and multi-frequency radar measurements appears to be a robust basis for a future Data Assimilation system for global soil moisture monitoring.

In order to evaluate and manage portfolio risk, we separated this project into three sections. In the first section we constructed a portfolio with 15 different stocks and six options with different strategies. The portfolio was implemented in Interactive Brokers and rebalanced weekly through five holding periods. In the second section we modeled the loss distribution of the whole portfolio with normal and student-t distributions, we computed the Value-at-Risk and expected shortfall in detail for the portfolio loss in each holding week, and then we evaluated differences between the normal and student-t distributions. In the third section we applied the ARMA(1,1)-GARCH(1,1) model to simulate our assets and compared the polynomial tails with Gaussian and t-distribution innovations.

In order to evaluate and manage portfolio risk, we separated this project into three sections. In the first section we constructed a portfolio with 15 different stocks and six options with different strategies. The portfolio was implemented in Interactive Brokers and rebalanced weekly through five holding periods. In the second section we modeled the loss distribution of the whole portfolio with normal and student-t distributions, we computed the Value-at-Risk and expected shortfall in detail for the portfolio loss in each holding week, and then we evaluated differences between the normal and student-t distributions. In the third section we applied the ARMA(1,1)-GARCH(1,1) model to simulate our assets and compared the polynomial tails with Gaussian and t-distribution innovations.

Enligt vår teoretiska referensram samt enligt en undersökning som genomfördes åt Statensoffentliga utredninger, (SOU 1997:188), kan ett samband mellan motionsutövande och hälsapåvisas. Det finns däremot ingen entydig forskning som visar på att motionsutövande leder tillminskad sjukfrånvaro. Vår studie utgår från grundhypotesen att det finns ett positivt sambandmellan företagssubventionerad friskvård och minskad sjukfrånvaro. Genom enenkätundersökning där 48 ICA-butiker medverkade samt där butikernas årsredovisningargranskades, insamlades data relaterad till butikernas friskvårdssubventionering ochsjukfrånvaro. Enligt ett Chi-square test kunde ett svagt samband mellanfriskvårdssubventionering och sjukfrånvaro skönjas, och även beräkningarna för korrelationenmellan de två variablerna för den insamlade datamängden påvisade ett samband.Nyttjandegraden av friskvårdsbidraget visade sig vara högst vid en subventioneringsnivå på3000 kr per år och anställd, och uppgick vid nämnda nivå till i genomsnitt 30 procent. Vid engrov schablonberäkning av kostnadsbesparingarna som den minskade sjukfrånvaron medför,fann vi att en subventioneringsnivå på maximalt 1000 kronor per år och anställd är olönsammedan en motsvarande nivå på 3000 kronor i bidrag per år och anställd gav ett positivtnettoresultat på nära 3000 kronor per anställd. Vi rekommenderar därför ensubventioneringsnivå på 3000 kronor per år och anställd då den nivån visade sig generera bästlönsamhet och även högst nyttjandegrad bland de anställda.

The criteria used to grade college essays have been the subject of research for over three decades. Using quantatative data, this study investigated the differences in essay-grading criteria and essay-grading policy among full-time faculty members who teach English composition in Tennessee's community colleges. This study revealed beliefs about the importance of essay-grading criteria and beliefs about written and unwritten essay-grading policies among those who teach developmental English, college-level English, and those who teach both levels of English. This study hypothesized that there were no differences among the English composition teacher's beliefs about the importance of the twenty essay-grading criteria nor in their beliefs regarding written and unwritten grading policies. Chi-square analysis of the non-parametric data collected during this study indicated statistically significant differences among the English teachers regarding only one of the essay-grading criteria and no statistically significant differences regarding the essay-grading policies.

The relative power of goodness-of-fit test statistics has long been debated in the literature. Chi-Square type test statistics to determine 'fit' for categorical data are still dominant in the goodness-of-fit arena. Empirical Distribution Function type goodness-of-fit test statistics are known to be relatively more powerful than Chi-Square type test statistics for restricted types of null and alternative distributions. In many practical applications researchers who use a standard Chi-Square type goodness-of-fit test statistic ignore the rank of ordinal classes. This thesis reviews literature in the goodness-of-fit field, with major emphasis on categorical goodness-of-fit tests. The continued use of an asymptotic distribution to approximate the exact distribution of categorical goodness-of-fit test statistics is discouraged. It is unlikely that an asymptotic distribution will produce a more accurate estimation of the exact distribution of a goodness-of-fit test statistic than a Monte Carlo approximation with a large number of simulations. Due to their relatively higher powers for restricted types of null and alternative distributions, several authors recommend the use of Empirical Distribution Function test statistics over nominal goodness-of-fit test statistics such as Pearson's Chi-Square. In-depth power studies confirm the views of other authors that categorical Empirical Distribution Function type test statistics do not have higher power for some common null and alternative distributions. Because of this, it is not sensible to make a conclusive recommendation to always use an Empirical Distribution Function type test statistic instead of a nominal goodness-of-fit test statistic. Traditionally the recommendation to determine 'fit' for multivariate categorical data is to treat categories as nominal, an approach which precludes any gain in power which may accrue from a ranking, should one or more variables be ordinal. The presence of multiple criteria through multivariate data may result in partially ordered categories, some of which have equal ranking. This thesis proposes a modification to the currently available Kolmogorov-Smirnov test statistics for ordinal and nominal categorical data to account for situations of partially ordered categories. The new test statistic, called the Combined Kolmogorov-Smirnov, is relatively more powerful than Pearson's Chi-Square and the nominal Kolmogorov-Smirnov test statistic for some null and alternative distributions. A recommendation is made to use the new test statistic with higher power in situations where some benefit can be achieved by incorporating an Empirical Distribution Function approach, but the data lack a complete natural ordering of categories. The new and established categorical goodness-of-fit test statistics are demonstrated in the analysis of categorical data with brief applications as diverse as familiarity of defence programs, the number of recruits produced by the Merlin bird, a demographic problem, and DNA profiling of genotypes. The results from these applications confirm the recommendations associated with specific goodness-of-fit test statistics throughout this thesis.