Bachelor of Science

Nano-size carbon-based structures are widely regarded as the most promising materials for nanotechnology applications. Recently, various types of low dimensional carbon nanostructures have attracted enormous research interests because of their boundless, technologically important applications, including electron field emission displays, molecular electronic device components, novel composite materials with unique, enhanced mechanical properties, hydrogen storage devices, bio-imaging markers and smart drug delivery.

In this work, a novel and unique class of carbon crystals is described and their characteristics are investigated. Self organized, single crystal (001) carbon nanotips with the dimensions of the sharp tips ranging around 10 - 20 nm have been discovered in our Plasma Sources and Application Centre (PSAC). These nano-size graphite layered, sharp-tip crystals are fundamentally different from all carbon nanostructures reported to date. Scanning Electron Microscopy (SEM) reveals high density, vertically-aligned sharp-tip carbon crystal structures oriented along the conventional z-direction. High resolution Transmission Electron Microscopy (HRTEM) shows that these tips are made up of continuous horizontal planes (up to several thousand layers) perpendicular to the growth direction (001). Sharp tip carbon nanostructures are ideal for electron field emission displays (FEDs).

State-of-the-art First Principles calculations based on the local density approximation to the density functional theory (DFT) are performed. A sophisticated package, DMol3, calculates variational self-consistent solutions to the DFT equations, is employed to study the geometrical structures and stabilities of the low dimensional, single crystal carbon nanotips. Based on the SEM, HRTEM and XRD measurements of the carbon nanotips, we proposed atomistic models of such structures.

These atomic structures were geometry optimized and total energy calculations confirmed the existence of such structures. Results showed that hydrogen termination at the periphery edges stabilizes the geometry of the entire molecular network. Molecular orbital analysis reveals that the carbon nanotips are very narrow band gap (of the order of 0.01 to 0.05 eV) semiconductors. Doping of Group 111 and V impurities, in particular, boron and nitrogen impurities into the atomic structure was found to change the structures' electronic properties, which is useful for making molecular devices.

The purpose of this study was to examine the effects of individual's perceived motivational climate, goal orientations and perceived competence on enjoyment and anxiety. 145 female netball players who participated in a local netball competition took part in the study. They were aged between 12 - 16 years (M = 14.30, SD = .80) and represented their respective schools. They completed questionnaires assessing perceived motivational climate (PMCSQ-2; Newton, Duda & Yin, 2000), dispositional goal orientations (POSQ; Roberts, Treasure & Balague, 1998), intrinsic motivation (perceived competence, enjoyment and effort subscales of IMI; McAuley, Duncan & Tammen, 1989) and somatic and cognitive anxiety (SCAT; Martens, 1977). Results of the multiple regression showed that perceived motivational climate, goal orientation and perceived competence emerged as significant predictors of enjoyment. Specifically, athletes with high perception of mastery climate, high task orientation and high-perceived competence, tend to experience greater enjoyment. In terms of anxiety, ego orientation positively predicted somatic anxiety while perceived competence negatively predicted somatic anxiety. On the other hand, perceptions of competence also negatively predicted cognitive anxiety. This study showed that in order to promote enjoyment in sport, it is important to create a mastery-oriented learning environment, which emphasise on task mastery and self-improvement. The mastery experiences might, in turns, increase the perception of competence of the athletes and lead to reduce competitive anxiety.

This study investigated aerobic and anaerobic performance through measures of the Phosphate Decrement Test (PDT) and the Tri-level Fitness Profile ( m ). The subjects were 14 university soccer players, mean age of 24.3 years from the School of Physical Education, Nanyang Technological University. They were assigned as either midfield or non-midfield groups based on their training status and competitive experience in their respective playing positions. All subjects underwent a random order of tests which were the TFP, the Pre-Phosphate Decrement 40 m Test (Pre-PD40mT) and the PDT. The TFP was performed on a Repco EX-I0 cycle ergometer in three separate stages: the Aerobic Power Test, the 10-second Anaerobic Test and the 30-second Anaerobic Test. Work and power variables were derived from each stage of testing, During the Pre-PD40mT, the fastest of three 40 m sprint trials which was recorded and used in the calculation of the Phosphate Decrement Index (PDI) in the PDT. In the PDT, each subject executed 10 sprints of 40 m departing every 30 seconds. Additionally, the first six sprints were used to compute the Repeated Sprint Ability (RSA) score. Results revealed that midfielders were significantly taller, faster and showed less decrement as reflected in their RSA scores compared to non-midfielders. No statistical differences were found in other variables. The PDT did not show significant correlations with any of the anaerobic power and work variables measured by the TFP. Further research is recommended to determine the physiological mechanisms associated with the PDT. Both the TFP and PDT have the potential to be safe and effective tests used by soccer practitioners to assess the fitness of soccer players.

A sorting algorithm is considered as one of the more important branches of Computer Science due to its many indispensable applications in life. Sorting algorithms can be classified according to their complexities and improving its efficiency has been a top priority for researchers. In this paper, I will look at three different classes of sorting algorithm progressively. The main aim of looking into these classes of algorithms is to study the complexity of each class of sorting algorithm in a more detailed manner so that we can better understand and explain any differences between the theory we constructed and the result tabulated after executing the actual programme. In studying each algorithm, we will also make use of the most fundamental counting of lines method to prove the algorithm's complexity. Besides verifying the complexity for each class of sorting algorithm, another aim of this paper is to create a better and more efficient algorithm which is simpler in terns of its programming structure compared to renowned professional grade algorithms. We will also test and prove the validity of this new algorithm using the same fundamental counting of lines method. In all, we will find that the more specific and precise we are in programming a sorting algorithm, the better and more efficient the results will be, which is just like the case of the sorting algorithm created in this paper.

Despite an increasing body of literature about corporate sponsorship and research that investigates the nature of corporate sponsorship of sport from the perspective of the donor, no empirical research has been undertaken to address how Singaporean non-profit National Sport Organisations are positioning themselves to attract corporate sponsorship.

As this seminal first study aimed ?o identify the key strategies NS4s use to acquire corporate sponsorship, semi-structured interviews were conducted with the marketing personnel of three high profile NSAs. The discussions were recorded and manually transcribed word for word by the researcher and the data were analysed after each interview according to the three-stage coding process outlined by Strauss (1990).

Six imperatives, fundability, size of client base, volunteer appeal, support group appeal, equipment cost and affiliation fees were used to investigate the strategic types and approaches ofthe three NSAs selected (Thibault, Slack & Hinings, 1993, 1994).

Analysis of the data reveals two key factors that seem to motivate corporate sponsorship of NSAs. The factors are (1) international success of the sporting teams and (2) increasing participation rates. The discussion of the results provides the analysis of the two factors determinant to the success of sponsorship acquisitions and the model developed, using the six imperatives, could be used in future to further our understanding of the unique sponsorship acquisition of the NSAs in Singapore

The thesis deals with modelling of the dengue disease in Singapore. A basic dengue fever model is developed as a reasonable first approximation in describing the spread of the disease. The model is constructed based on the interaction between the population of the susceptible host (S), the population of the infected host (I), the population of the infected vector (M) and the population of the uninfected vector (N) during transmission of the dengue virus.

The results obtained from the simulation of the model is in qualitative agreement of a plausible model that describes the spread of the disease. Some vector control measures have also been recommended based on the findings. Possible refinements to the basic dengue model are also presented as future extension of the thesis.

The purpose of this study was to ascertain the contribution of lower limb power and strength, skill, technique and physique to the standing long jump (SLJ). It was hoped that with this information, the claims of the SLJ as a test of lower limb power could be validated. As such, a comparison was made between a group of elite jumpers (EJ, n = 4) and a group of non-elite jumpers (NJ, n = 5). Groups were formed based on the subjects' past two SLJ performances during the Individual Physical Proficiency Test (Mean ± SD; EJ, 2.76 ± 0.09 m; NJ, 2.29 ± 0.03 m). Kinematic, kinetic, isokinetic, temporal and anthropometric measurements were obtained through 2D-cinematographic techniques, force platform procedures, and isokinetic dynamometry. Significant differences between the EJ and NJ groups were found for the SLJ range (Rsu, p < .001), flight distance (FDx, p < .001), horizontal and resultant take-off velocity measured at the foot (p < ,001 and p < ,011 respectively), bodyweight-normalised peak and average isokinetic knee torque across four different angular speeds (all p < .01), and several temporal variables. Correlations were carried out to determine which variables were linearly related to the RSLJ and FDX. The analysis would reveal that lower limb power and strength were strongly related to SLJ performance. Skill was also found to be a significant factor. Technique, however, did not seem to greatly affect SLJ performance. Likewise, physique was not found to predispose an individual to particular levels of SLJ performance. These results indicate that good SLJ performance quires lower limb power, skill and some technique.

"Univalent" is the complex analyst's term for "one-to-one" functions. A univalent function has a non-vanishing derivative. Riemann Mapping Theorem stated in 1851 could not find some interesting applications until P. Koebe in 1907 discovered that univalent analytic functions have nice property as given in the modified version of Riemann Mapping Theorem. Koebe found some very exciting and useful results for the functions which are analytic and univalent in a simply connected domain. This gave birth to the Theory of Univalent Functions. Unfortunately, there is a long struggle for its growth and development.Only in 1914, the opportunity for this theory to grow was provided when Grownwall discovered the Area Theorem. This theorem is concerned with functions of the form

z+Σbnz-n
n=0

that are both analytic and univalent in the open disk

Increasing affluence in Singapore during the last decade has led to a higher prevalence of coronary heart disease and obesity among Singaporeans. Recent evidence has suggested an unfavourable blood lipid / lipoprotein profile among Singaporean children and adolescents. Obesity and the physical fitness of Singaporean schoolchildren is of national concern. Very few studies, however, have examined the relationships between blood lipids / lipoproteins, obesity and cardiovascular fitness in Singaporean schoolchildren. Hence, the purpose of this study is to investigate these relationships in obese and non - obese Singaporean schoolchildren aged 13 to 15 years.

78 Chinese boys ( mean age = 13.52 + 0.6 SD ) were recruited for this study. AU subjects underwent 3 different tests : ( a ) body composition analysis - measurements of height and weight, 8 site skinfold thickness, and DEXA scanning to determine fat mass and lean body mass; ( b ) blood biochemistry analysis - drawing of 20ml of venous blood to analyse serum cholesterol, triglyceride, high density and low density lipoproteins, and apoproteins A1 and B ( c ) cardiovascular fitness testing - using the modified Balke protocol to determine 90zpeak of subjects.

Results showed that obese subjects had significantly higher levels of triglyceride and lower levels of VO2peak ( ml.kg-'min.' ) as compared to the non - obese subjects. A significant negative correlation also existed between VO2peak ( ml.kg-'.min-' ), triglyceride and obesity measures like BM1 and skinfold thickness. None of the other blood profile variables, however, had significant associations with obesity and cardiovascular fitness.

This study may be improved by examining the role of habitual physical activity on blood lipid I lipoprotein profile, obesity and cardiovascular fitness in Singaporean male adolescents.

This academic exercise is an introductory study of bootstrap methods on accuracy of point estimates, confidence intervals and hypothesis tests. We first look at the standard error of an estimate and explore three examples, namely the mean, the median and the correlation coefficient. More complicated data structures such as the two-sample problem and regression models are also discussed. In particular, for regression analysis, we investigated briefly two different bootstrapping processes, namely bootstrapping residuals and bootstrapping pairs of data. Another measure of statistical accuracy considered is the bias of an estimate We discussed the bootstrap method for estimating bias and looked into an improved version of this process. On interval estimation, we conducted a simulation study on three types of bootstrap confidence intervals, namely the bootstrap-t interval, the transformed bootstrap-t interval and the percentile interval. An example was given to illustrate the BCa (bias corrected and accelerated) and the ABC (approximate bootstrap confidence) intervals, which are two improved versions of the percentile method. On bootstrap hypothesis testing, we explored on tests concerning a single mean, difference between means and difference between variances. The bootstrap results are compared to those obtained by traditional parametric and non-parametric tests.

Obesity is a risk factor for the development of many modem day lifestyle diseases including atherosclerosis. C-Reactive Protein (CRP) is an acute phase protein produced mainly by hepatocytes arid is usually present during inflammations. Recent studies suggested that obesity, an inflammatory disorder is associated with elevated levels of CRP which could be involved in the pathogenesis of atherosclerosis. Limited studies done in western countries suggested an association between CRF levels and functional capacity, also termed as physical fitness levels. However, these studies employed non-laboratory measure of functional capacity. To date. not much data are available regarding the relationship between CRP levels and functional capacity of Asian male adolescents. This study involved 14 normal (BMIi25) and 16 obese (BMI>30) male adolescents, of Asian descent aged between 14- 18 years. Fasting serum CRF' and blood lipids profile (Total cholesterol, High Density Lipoprotein-Cholesterol (HDL), Low Density Lipoprotein-Cholesterol (LDL) and Tnglyceride) were determined. Sub-maximal cardiovascular fitness (Predicted Work Capacity at heart rate 170bpm. PWC170) and body composition assessments (Skinfold measurements and Dual Energy X-Ray absorptiometry, DEXA) were also determined. Statistically significant differences in CRP levels, lipid profiles and functional capacity between obese and normal lcan adolescents were observed. Obese adolescents exhibited higher levels of CRF, despite normal levels of LDL, as compared to normal lean adolescents, which may suggest a higher risk of developing cardiovascular disease. There is a significant inverse correlation( r = -0.45 1, p<0.05) between CRP levels and functional capacity. The significant inverse correlation (r = -0.601, p<0.05) between CRP levels and functional capacity in only obese individuals was also observed. In the context of this study, it is suggested that improved functional capacity levels may be a useful therapeutic option in lowering CRP levels, hence reducing the risk of developing cardiovascular diseases.

Amorphous diamond-like carbon thin films have been deposited using the pulsed action of 1064 nrn Nd-YAG laser to ablate graphite target. The plasma plume that comes out fiom the target surface is condensed onto different substrate materials; silicon (100), microscope glass slides, and quartz crystal, at room as well as elevated temperatures, and thin films with varying degree diamond-like character were synthesized. Thickness of the films ranges between 600-24002. Raman spectroscopy was used to determine the degree of diamond-like character, i.e. the fraction of sp3 bonded carbon atoms within the films. Transparencies of films in the electromagnetic spectrum were measured using the Fourier Transform Infrared (FTIR) and the Ultraviolet-Visible (UVV) spectroscopies. Results showed that films have high sp3 bonding fraction (between 75% to 80%) and high transparency over a large portion of the IR and optical region. Tauc plots indicate optical bandgap energy of around 1 eV for films deposited at room temperature. Scanning from the Atomic Force Microscope revealed that films contain significant amount of micro particulates, and films deposited at room temperature showed smoother surface morphologies. Results showed that increased substrate-temperatures promote graphitization of the films, producing films with low sp3 bonding fraction. This results in films with higher electrical conductivity and higher optical absorbance. Hardness of the films was not accurately determined due to inadequate thickness of our deposited films.

Category theory provides a common framework for many branches of mathematics, especially topology and algebra. In this thesis, we mainly deal with those categories in algebra. Locally, the study of category theory helps in the understanding of the essence of important concepts in algebra such as injective mappings, subjective mappings, isomorphisms, identity elements and products, etc. Globally, it gives a way of comparing categories that used to be regarded as absolutely different things. The thesis yields a deeper understanding of the categories arising in algebra through the application of fundamental concepts in category theory, namely functors, natural transformations and adjoint functors.

Onchidium tumidium is an osmoconformer and that it is able to regulate its volume at 10% or 90% seawater (SW). However, it is a more effective volun2e regulator in 90% SW than in 10% SW. Results indicate that after an upward transfer from 50% to 90% SW, there were significant increases in the total free amino acids (TFAA) in the whole animal, coelomic plasma (CP), body wall (BW) and internal organs (10). Increased proteolysis was more likely to occur in the I0 than in the BW of 0. tumidium exposed to 90% SW as reflected by a lowered water-soluble protein content in the I0 of slugs exposed to 90% SW compared to those of slugs exposed to 50% SW. It is probable that the higher TFAA in the BW of O.tumidium exposed to 90% SW compared to that of slugs exposed to 50% SW was partially due to NH4+ trapping by α-ketoglutarate in the presence of glutamate dehydrogenase to form glutamate as indicated by a significantly higher amination deamination-1 ratio. Glutamate could then be channeled to form other amino acids via transaminases. When being confronted with a downward transfer from 50% SW to 10% SW, there was possibly a release of free amino acids (FAA) from the BW of 0. tumidium into the CP as indicated by the increase in TFAA in the CP and a decrease in TFAA in the BW. The significantly lower amination deamination-1 ratio in the I0 shows that it is most probably involved in the breakdown of FAA during hypoosmotic stress.

This exploratory study employed Dale's (1996) phenomenological approach to examine (a) the beliefs and attitudes of PE teachers concerning character development, (b) what PE teachers are actually doing in schools with regards to character development, and (c) explore the reasons why PE teachers are not teaching character development. To achieve its objective, open-ended interviews with PE teachers (N = 4) teaching in Singapore, were required. Generally, the interviews with teachers provided insight into the attitudes and behaviors concerning character development in PE. Majority reported that ad-hoc teaching was more realistic compared to one, who deliberately taught character development during PE. The teachers also felt that the biggest drawbacks in trying to teach character development are insufficient time, a lack of resources and different expectations. Altogether, the study highlighted the nature of character development in the various PE curriculums in a small sample of schools. The results contributed to the body of literature as it highlighted the relationships between the role of PE teachers, their beliefs and behaviors and character development.

This study examined student, teacher and programme characteristics that may be associated with students' high fitness achievement in three secondary girls' schools that were ranked within the top 5 positions in their physical fitness levels in 1999. It explored students' attitudes toward PE lessons, PE teachers and their self-perceived physical fitness, teachers' values and beliefs toward teaching PE and schools' physical fitness programme context.

The subjects (n = 120) were a group of secondary 3 girls, PE teachers (n = 10), PE HODS (n = 2) and a sport secretary. Two questionnaires: "Students' Attitudes Questionnaire" and "Teachers' Attitudes Questionnaire," were respectively administered to the students and PE teachers. A set of 10 interview questions was designed to find out about the schools' fitness programme context from the HODS and sport secretary. Descriptive statistics involving frequencies. percentages, means and standard deviations were calculated for the students' and teachers' attitudes questionnaires. The responses from the interview questions were analysed for key themes.

The results showed that students had positive attitudes toward their PE lessons and felt that their PE teachers involved them in the decision making. Generally, the students perceived highly of their overall physical fitness. PE teachers valued self-actualisation/individual development as the most important outcome goals while physical activity and fitness collectively was ranked second. The HODS attributed a vibrant school environment, a jogging programme and a team of dedicated and responsible PE teachers to the schools' high fitness levels. It is hoped that while accounting for contextual variations these findings would indicate to low fitness achieving schools ways to model or adopt some methods of success.

Some recommendations for further research in this area might include a longitudinal study on the attitudes of students and their physical fitness and a study of the relationship between teachers' belief systems and what is taught in their classes. Case studies of high fitness achieving schools could also he conducted to provide greater contextual data.

The objective of this experimental campaign is to characterize a multiple radiation source. As the soft x-ray emission has been reported in other work, this thesis reports the results and discussions of the neutrons and hard x-ray emitted from a 3.2 kJ Mather type plasma focus (NX2).

The average total neutron yield is measured using an indium foil activation detector at pressure ranging from I to 36 mbar and at various combinations of voltages (8.5 - 14.5 kV), copper anode lengths (2.5 - 6.5 cm) and insulator sleeve length (5.4 - 6.6 cm). A remarkable average maximum neutron yield of (7 ± 1) X 108 neutrons per shot is achieved using a 3.5 cm copper anode with insulator sleeve length of 6.0 cm and operating voltage and pressure of 14.5 kV and 20 mbar respectively. Not only that this is a very good result for a 3.2 kJ device, but the extremely high pressure operating regime at which the optimum production is obtained ensures reproducible results, while preventing the failure of the sensitive components of the high voltage insulation.

The neutron energy, neutron anisotropy and hard x-ray are measured using five scintillator-photomultiplier systems. The average peak neutron energy for the axial direction (Oo), radial direction (90") and backward direction (180") is (2.89 ± 0.25) MeV, (2.49 ± 0.20) MeV and (2.1 1 ? 0.12) MeV respectively. The higher average peak neutron energy of 2.89 MeV in the axial direction can be accounted for by the high energy deuteron ions that are generated and accelerated in the axial direction due to the presence of strong electric fields in the m = 0 instability zone with the stationary deuteron or deuterium target. The average neutron anisotropy, F = - Y ( 0 " ) is found to be (1.46 ± 0.28). The results obtained from neutron energy and anisotropy measurement Y (90 ") suggest that the neutron production mechanism may be predominantly beam target as found by other authors on different machines. The amount and energy of 1 MeV of hard x-ray are also measured and it is found that the average maximum total energy of the x-ray photons is 3 X 10' MeV. The higher neutron yield from the 3.2 kJ machine as compared to the UNU-ICTP Benchmark machine must be due to a more efficient production of high energy deuterons as supported by the fact that higher hard x-ray yield is being obtained.

Graphical representation of multivariate data has been widely used in preliminary data analysis since it helps to bring out the hidden nature of the data and expose any unanticipated characteristics of the data.

This Academic Exercise aims at understanding the use and application of one particular form of graphical representation - Chernoff faces.

Chapter 1 presents a general introduction to the use of Chernoff faces and the advantages and disadvantages of using this representation.

Chapter 2 discusses the computing aspects of Chernoff faces. A review of the various computer programs used in drawing the Chemoff faces is presented. More importantly, the Visual Basic program used to construct and plot the Chernoff faces in this Academic Exercise is illustrated. Comparisons of the Visual Basic program to the Java Applets available on the internet and other programs are also made.

Chapter 3 discusses the use of Chernoff faces in explaining two data sets - a set of car data and a set of real life school data. For the car data, each Chemoff face represents the characteristics (comfort, performance and price) of a car. The Chemoff faces plotted suggest that the grouping of correlated variables to the same facial feature provides a better graphical representation. For the real life data, two different sets of Chernoff faces are presented. First, the faces are employed in such a way that the expressions on the Chernoff faces show the social studies achievement of pupils of the various streams (EM1, EM2 or EM213) for 2 situations - before and after cooperative learning is implemented. In the second set, the Chernoff faces allow the observer to deduce the classroom climate of the various streams before and after the use of cooperative learning. Correlation analysis is performed on the classroom climate data and the groupings of correlated variables to the same facial feature reveal more characteristics of the data that is not detected previously.

Some of the findings of the Academic Exercise are :

1. A better graphical representation is presented if correlated variables are mapped to the same facial feature.

2. In correlation analysis of data, Chemoff faces could complement sophisticated statistical methods such as principal component analysis and factor analysis by transforming their complex results generated from standard statistical program such as SPSS to easily interpreted faces.

The purpose of this study was to validate the Children's OMNI Scale of Perceived Exertion (Category 0 to 10) using obese adolescent males. The cohort covered 18 obese, clinically normal adolescent males, 12 to14 years of age. A stratified sample, perceptual estimation paradigm using a single multi-stage cycle ergometer test utilizing a submaximal till exhaustion protocol was used. Heart rate (HR; beats-min.'), oxygen uptake (~02rnl*min-')b, ody weight relative oxygen uptake (V02 ml.kg-'.min-l) and WE for the overall body (WE-0), legs (WE-L), and chest @PE-C) were determined at the end of each continuously administered 3-min power outputs (PO) test stage. After completion of 4 submaximal PO stages (25,50,75, and 100W), subjects cycled to exhaustion. Stage 7 (175W) was the highest PO stage completed. RPE responses for the 7 stages ranged from 0 to 10. Simple linear regression was used to separately regress HR, ~0zml-min.' and V02 ml-kg-'-min.' against WE-0, RPE-L and WE-C. Data from the first 4 stages of submaximal exercise were analyzed using ANOVA with repeated measures to determine differences between WE-0, WE-L and WE-C at each PO stage and differences of each WE over the different PO stages. Linear regression analysis demonstrated that WE-0, WE-L and WE-C distributed as positive linear functions of V02 ml-min.', V02 ml.kg-'.min.', and HR. Linear regression coefficients for WE-0, WE-L and WE-C ranged from 0.974 to 0.996. All regression functions were statistically significant (significance levels varied between P < 0.05 and P < 0.01). ANOVA with repeated measures revealed no significant differences between WE-0, WE-C and WE-L at each PO stage and individual WEs were significantly different (P < 0.001) at every PO stage. The Children's OMNI Scale of Perceived Exertion is valid for use with 12-14 year-old obese adolescent males. Obese adolescent males, 12-14 years old, do not differentially rate perceived exertion.