Published Article / The objective of this study was to characterize meteorological droughts in the Central Region of South Africa, Modder River Basin, C52A quaternary catchment using two popular drought indices: Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI) and to compare the two indices. Drought events were characterized based on their frequency, duration, magnitude and intensity. The indices were computed for the time-scales that are important for planning and management of water resources, i.e. 3-, 6- and 12-month time-scales. The basic meteorological input data used in the computation of these indices were 57 years (1950-2007) of monthly precipitation and monthly temperature data which were recorded at The Cliff weather station in the quaternary catchment. It was found that both SPI and SPEI responded to drought events in similar fashion in all time-scales. During the analysis period, a total of 37, 26 and 17 drought events were identified in the area based on 3-, 6-, and 12-month times-scales, respectively. Considering event magnitude as severity parameter, results from both indices identified the periods 1984-1985, 1992-1993 and 2003-2005 as the severest drought periods in the area. However, when the effects of both drought duration and magnitude are considered (drought intensity), the most severest drought events were identified during the years 1982/83, 1966 and 1973 based on 3-, 6- and 12-month timescales, respectively. It was concluded that although the SPEI generally exhibits veracity over SPI by including, apart from precipitation, additional meteorological parameter, mean temperature, SPI should be adopted as an appropriate drought monitoring tool in an area, like Africa, where meteorological data are scarce.

Poverty persists as one of the critical challenges in South Africa, predominantly because it is inbred. Currently, the majority of South Africa’s children live in households that are incapable of providing basic needs. Children born from deprived households have a high chance of being trapped into the cycle of poverty. Thus, household poverty affects child differently from adults; children tend to be more vulnerable to deprivation and poverty. The purpose of this study was to analyse the relationship between household poverty and child deprivation in Jabulani, a South African township. The study used an asset index and a child deprivation index to measure the scope of household poverty and child deprivation in Jabulani Township. The main focus of the study was to determine if household poverty has an impact on the deprivation status of a child living in a particular household. Therefore, analysing demographics of the household and its poverty status was also important. The empirical analysis of the study was centred on data collected from Jabulani Township in May 2015 by means of a survey questionnaire with a sample of 178 randomly selected households. Several statistical methods were used such as descriptive statistics, correlations and regression analysis to identify the overlaps between household poverty and child deprivation. The asset index was used to determine the poverty status of the household by measuring its wealth, thus identifying if a child from a poor household will be deprived of certain items by comparing it to the child deprivation index. The child deprivation index was constructed based on specific items a child may lack. The relationship between household poverty and child deprivation was determined and it was found that most of the children from poor households are not severely deprived; they are either less deprived or moderately deprived at most. Similarly, there are children from the well-off households who are deprived moderately and severely. However, the majority of the children living in less poor households are also less deprived. Thus, it was concluded that household needs are different from child needs, hence we find children who are not deprived in poor households and vice versa. The Relationship between Household Poverty and Child Deprivation in Jabulani Township Page vii The extent of household poverty was determined and as defined by the asset index the study found that 59 percent of the households in Jabulani Township are not poor, 31.5 percent have poverty levels just below average (based on the asset index measuring long-term wealth) and 9.6 percent are poor. Furthermore, it was found that the majority of the sampled population of Jabulani Township has low income levels, most of the asset poor households were also found to be income poor and vice versa. The study revealed that females head most households in Jabulani Township; female heads of household were found to have lower poverty levels compared to male heads of household. It was found that the majority of the heads of household have no schooling and quite a few of them have tertiary level education. The largest source of income in Jabulani Township is child support grant (87.1 percent) and wages or salaries contribute 77 percent to household income. The prevalence of child deprivation was determined based on the child deprivation index. It was found that 62.9 percent of the children in Jabulani Township are less deprived, 29.2 percent are moderately deprived and only 9.9 percent of the children are severely deprived. Therefore, the majority of the children in Jabulani Township are not severely deprived. The regression analysis results revealed that the total income of the household is a significant determinant of the asset index and the child deprivation index. Based on these findings it is recommended that more investments should be made towards education in Jabulani Township, as this could be a great move towards the alleviation of household poverty and, in turn, child deprivation. There is a need for skills empowerment especially in baking and sewing as most of the unemployed heads of households are skilled in those areas, this will curb dependence on the government and create more job opportunities so that the parents can provide for the needs of their children.

Poverty persists as one of the critical challenges in South Africa, predominantly because it is inbred. Currently, the majority of South Africa’s children live in households that are incapable of providing basic needs. Children born from deprived households have a high chance of being trapped into the cycle of poverty. Thus, household poverty affects child differently from adults; children tend to be more vulnerable to deprivation and poverty. The purpose of this study was to analyse the relationship between household poverty and child deprivation in Jabulani, a South African township. The study used an asset index and a child deprivation index to measure the scope of household poverty and child deprivation in Jabulani Township. The main focus of the study was to determine if household poverty has an impact on the deprivation status of a child living in a particular household. Therefore, analysing demographics of the household and its poverty status was also important. The empirical analysis of the study was centred on data collected from Jabulani Township in May 2015 by means of a survey questionnaire with a sample of 178 randomly selected households. Several statistical methods were used such as descriptive statistics, correlations and regression analysis to identify the overlaps between household poverty and child deprivation. The asset index was used to determine the poverty status of the household by measuring its wealth, thus identifying if a child from a poor household will be deprived of certain items by comparing it to the child deprivation index. The child deprivation index was constructed based on specific items a child may lack. The relationship between household poverty and child deprivation was determined and it was found that most of the children from poor households are not severely deprived; they are either less deprived or moderately deprived at most. Similarly, there are children from the well-off households who are deprived moderately and severely. However, the majority of the children living in less poor households are also less deprived. Thus, it was concluded that household needs are different from child needs, hence we find children who are not deprived in poor households and vice versa. The Relationship between Household Poverty and Child Deprivation in Jabulani Township Page vii The extent of household poverty was determined and as defined by the asset index the study found that 59 percent of the households in Jabulani Township are not poor, 31.5 percent have poverty levels just below average (based on the asset index measuring long-term wealth) and 9.6 percent are poor. Furthermore, it was found that the majority of the sampled population of Jabulani Township has low income levels, most of the asset poor households were also found to be income poor and vice versa. The study revealed that females head most households in Jabulani Township; female heads of household were found to have lower poverty levels compared to male heads of household. It was found that the majority of the heads of household have no schooling and quite a few of them have tertiary level education. The largest source of income in Jabulani Township is child support grant (87.1 percent) and wages or salaries contribute 77 percent to household income. The prevalence of child deprivation was determined based on the child deprivation index. It was found that 62.9 percent of the children in Jabulani Township are less deprived, 29.2 percent are moderately deprived and only 9.9 percent of the children are severely deprived. Therefore, the majority of the children in Jabulani Township are not severely deprived. The regression analysis results revealed that the total income of the household is a significant determinant of the asset index and the child deprivation index. Based on these findings it is recommended that more investments should be made towards education in Jabulani Township, as this could be a great move towards the alleviation of household poverty and, in turn, child deprivation. There is a need for skills empowerment especially in baking and sewing as most of the unemployed heads of households are skilled in those areas, this will curb dependence on the government and create more job opportunities so that the parents can provide for the needs of their children.

Thesis (MSc (Mathematics))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: See full text for abstract / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prominent neurobehavioral disorders of childhood that is heavily researched and often revised. Deficits in attention/concentration, impulsivity, inhibition, information processing speed, working memory and executive functioning manifest differently according to subtype diagnosis for both children and adults. As a result, previous attempts to construct a unifying theory of ADHD with neural correlates and quantifiable performance discrepancies have resulted in a proliferation of literature reviews citing both significant and insignificant research findings. The purpose of the current study was to construct a homogenous sample of children diagnosed with ADHD and examine purported subtype differences in working memory and information processing speed using the Wechsler Intelligence Scales for Children - Forth Edition (WISC-IV). Sixty participants were selected from archival data from two clinical sites and separated into three groups according to the current DSM-IV-TR ADHD subtype criteria: ADHD Predominately Inattentive type (ADHD-IN), ADHD Predominately Hyperactive/Impulsive type (ADHD-HY), and ADHD Combined type (ADHD-C). Significant differences within groups were revealed on the Coding subtest and Processing Speed Index (PSI) relative to performance on the Perceptual Reasoning Index (PRI). No significant between groups or interaction effects were revealed. While the goal of the current study was aimed at discovering evidence of greater deficits in processing speed by the ADHD-IN group compared to the other two groups, processing speed was reduced for the entire sample providing more evidence of a possible neurological deficit/basis inherent to ADHD. The results of the current study provided minimal evidence of differences on WISC-IV measures of working memory within the current sample. The current study was successful in correcting previous methodological flaws inherent in the relevant literature by constructing a truly homogenous sample of ADHD and provided strong evidence for the necessity of an accurate diagnosis of ADHD subtypes.

In medical diagnostic studies, the area under the Receiver Operating Characteristic (ROC) curve (AUC) and Youden index are two summary measures widely used in the evaluation of the diagnostic accuracy of a medical test with continuous test results. The first half of this dissertation will highlight ROC analysis including extension of Youden index to the partial Youden index as well as novel confidence interval estimation for AUC and Youden index in the presence of covariates in induced linear regression models. Extensive simulation results show that the proposed methods perform well with small to moderate sized samples. In addition, some real examples will be presented to illustrate the methods. The latter half focuses on the application of empirical likelihood method in economics and finance. Two models draw our attention. The first one is the predictive regression model with independent and identically distributed errors. Some uniform tests have been proposed in the literature without distinguishing whether the predicting variable is stationary or nearly integrated. Here, we extend the empirical likelihood methods in Zhu, Cai and Peng (2014) with independent errors to the case of an AR error process. The proposed new tests do not need to know whether the predicting variable is stationary or nearly integrated, and whether it has a finite variance or an infinite variance. Another model we considered is a GARCH(1,1) sequence or an AR(1) model with ARCH(1) errors. It is known that the observations have a heavy tail and the tail index is determined by an estimating equation. Therefore, one can estimate the tail index by solving the estimating equation with unknown parameters replaced by Quasi Maximum Likelihood Estimation (QMLE), and profile empirical likelihood method can be employed to effectively construct a confidence interval for the tail index. However, this requires that the errors of such a model have at least finite fourth moment to ensure asymptotic normality with n1/2 rate of convergence and Wilk's Theorem. We show that the finite fourth moment can be relaxed by employing some Least Absolute Deviations Estimate (LADE) instead of QMLE for the unknown parameters by noting that the estimating equation for determining the tail index is invariant to a scale transformation of the underlying model. Furthermore, the proposed tail index estimators have a normal limit with n1/2 rate of convergence under minimal moment condition, which may have an infinite fourth moment, and Wilk's theorem holds for the proposed profile empirical likelihood methods. Hence a confidence interval for the tail index can be obtained without estimating any additional quantities such as asymptotic variance.

Three-dimensional (3D) whole body scanners are increasingly used as precise measuring tools for the rapid quantification of anthropometric measures in epidemiological studies. We analyzed 3D whole body scanning data of nearly 10,000 participants of a cohort collected from the adult population of Leipzig, one of the largest cities in Eastern Germany. We present a novel approach for the systematic analysis of this data which aims at identifying distinguishable clusters of body shapes called body types. In the first step, our method aggregates body measures provided by the scanner into meta-measures, each representing one relevant dimension of the body shape. In a next step, we stratified the cohort into body types and assessed their stability and dependence on the size of the underlying cohort. Using self-organizing maps (SOM) we identified thirteen robust meta-measures and fifteen body types comprising between 1 and 18 percent of the total cohort size. Thirteen of them are virtually gender specific (six for women and seven for men) and thus reflect most abundant body shapes of women and men. Two body types include both women and men, and describe androgynous body shapes that lack typical gender specific features. The body types disentangle a large variability of body shapes enabling distinctions which go beyond the traditional indices such as body mass index, the waist-to-height ratio, the waist-to-hip ratio and the mortality-hazard ABSI-index. In a next step, we will link the identified body types with disease predispositions to study how size and shape of the human body impact health and disease.

The site-specific management of alfalfa has not been well-evaluated, despite the economic importance of this crop. The objectives of this work were to i) characterize the effects of soil moisture deficits on alfalfa and alfalfa yield components and ii) evaluate the use of canopy reflectance patterns in measuring treatment-induced differences in alfalfa yield. A randomized complete block design with five replicates of subsurface drip irrigation (SDI) and rainfed treatments of alfalfa was established at the University of Kentucky Animal Research Center in 2003. Potassium, as KCl, was broadcast on split-plots on 1 October 2004 at 0, 112, 336, and 448 kg K2O ha-1. In the drought year of 2005, five harvests (H1 - H5) were taken from each split-plot and from four locations within each SDI and rainfed plot. One day prior to each harvest, canopy reflectance was recorded in each plot. Alfalfa yield, yield components, and leaf area index (LAI) were determined. In 2005, dry matter yields in two harvests and for the seasonal total were increased (Pandlt;0.05) by SDI, but SDI did not affect crown density. Herbage yield was strongly associated with yield components but yields were most accurately estimated from LAI. Canopy reflectance within blue (450 nm), red (660 nm) and NIR bands were related to LAI, yield components, and yield of alfalfa and exhibited low variance (cv andlt; 15%) within narrow ( 0.125 Mg ha-1) yield ranges. Red-based Normalized Difference Vegetation Indices (NDVIs) and Wide Dynamic Range Vegetation Indices (WDRVIs) were better than blue-based VIs for the estimation of LAI, yield components, and yield. Decreasing the influence of NIR reflectance in VIs by use of a scalar (0.1, 0.05, or 0.01) expanded the range of WDRVI-alfalfa yield functions. These results indicate that VIs may be used to estimate LAI and dry matter yield of alfalfa within VI-specific boundaries.

There is a need for chemical sensors for monitoring volatile organic compounds (VOCs) in air. Acute and chronic inhalation of toxic VOCs can cause adverse health effects in humans, so monitoring these analytes is important for ensuring that their concentrations are maintained below maximum permissible levels. Chemical sensors using polydimethylsiloxane (PDMS) to extract VOCs with partial selectivity, coupled with label-free optical detection methods based on refractive index, can overcome the limitations of conventional VOC detection methods. A variety of tunable and high refractive index PDMS materials were developed by incorporating a range of titanium and zirconium concentrations (2.5 – 30 mol % and 2.5 – 15 mol %, respectively) using a simple sol-gel synthesis and by incorporating a range of titanium concentrations (2.5 – 10 mol %) into naphthyl-functionalized PDMS. These materials ranged in refractive index from 1.4023 ± 0.0002 to 1.5663 ± 0.0001 at 635 nm and 1.3942 ± 0.0003 to 1.5510 ± 0.0007 at 1550 nm. The ability to use tunable refractive index PDMS films to differentiate between m-xylene and cyclohexane was demonstrated by monitoring changes in refractive index and thickness following absorption of these analytes using a refractometer at 1550 nm. The sensitivity of the refractive index response to an analyte using a particular PDMS film was dependent upon the difference between the refractive index of the analyte and film, as well as the film-air partition coefficient of the analyte. The detection limits for m-xylene and cyclohexane were 81 ppm and 4940 ppm, respectively, using PDMS-titanium-oxo nanocomposites with 5 and 10 mol % Ti, respectively. A simple planar waveguide sensor with an input grating coupler was developed to monitor changes in refractive index of the cladding through shifts in peak resonance wavelength. Using high refractive index PDMS materials as the waveguide core, we monitored changes in refractive index arising from absorption of VOCs into the grating. Here, the sensitivity of the waveguide response was dependent upon the difference in refractive index of the analyte and polymer, as well as the film-air partition coefficient of the analyte. The detection limits for m-xylene and cyclohexane were 1980 ppm and 18000 ppm, respectively. / Thesis (Master, Chemistry) -- Queen's University, 2013-08-24 11:45:57.642

本研究以2002至2013年11個球季NBA聯盟的球隊，來探討球隊內薪資不平均化程度，分別與球隊的例行賽及季後賽戰績的關聯性如何?以及球隊總薪資超越豪華稅門檻多寡，分別與例行賽及季後賽戰績的關聯性如何? 實證結果發現在控制球員人數、觀眾人數、總教練因素以及球隊過去的戰績，薪資不平均程度與例行賽勝率、晉級季後賽有著顯著的正相關，但與季後賽的戰績則沒有顯著的關聯，且將球隊以薪資不平均程度(以HHI作為衡量指標)分為高低中三個群組，在最高的群組，付出的豪華稅越多，越能幫助球隊晉級季後賽。同時根據logistic 廻歸研究結果發現HHI指標及GINI係數每增加1%，打進季後賽的機率分別會增加1.152%及1.049%的機率打進季後賽，另外就HHI就最不平均組別而言，球隊總薪資超過豪華稅門檻時，每多支付100萬美元的薪資可增加1.002%機率打入季後賽。本研究認為決定球賽的勝負，薪資策略固然重要，但只運用薪資策略本身來提升球隊例行賽勝率有限，必須考慮球隊本身特質、有效利用相關資源才能增加球隊勝率。 / This research uses NBA’s past 11 seasons (2002 to 2013 season) to explore the association with NBA team's salary structure and its performance. The research also tries to analysis the association between luxury tax and NBA team’s performance. The empirical results show that after control the number of players, audience, coach, and the last season’s winning percentage, the regular season’s performance has positive highly corrected with salary’s HHI and GINI index. However, the playoff’s performance does not associate with salary’s HHI and GINI index. The logistic regression model predicts that when a team increases 1 percent of HHI and GINI index, then the team increases 1.152% and 1.049% opportunity to make in the NBA playoff. The highest HHI group’s logistic model predicts that when a team increases 100 million salaries over luxury tax cap, the team can increase 1.002% opportunity to make in the NBA playoff. We believe that although the strategy of NBA’s salary is important, however, the salary strategy itself is not enough to dramatic increase team’s performance. In order to improve the performance of a team, the characteristic of a team, the coach, audience and the team winning history maybe play the more important role in increasing winning percentage.