Philosophiae Doctor - PhD / Ways of enacting effective professional development (PD) and professional learning (PL) of teachers are diverse and often contested and therefore needs sustained inquiry (Schuck, Aubussona, Kearney, & Burden, 2013). The “quick fix” mentality that is endemic to most including those aimed at educational systems leads to very superficial implementation of improvement strategies, including teacher development. These strategies are usually bureaucratically mandated and superficially implemented in a top-down manner. One of the critical drawbacks of such superficial implementation of top-down improvement strategies is that it fails to appeal to teachers because of their historical experiences of such short term and intermittent improvement interventions. This study focussed on the development of a Professional Learning Community (PLC) as a possible continuous professional teacher development (CPTD) model with a promise to deliver effective CPTD. Literature in this regard indicates this model of CPTD as highly effective to support sustained teacher development. The efficacy a PLC is predicated on a collaborative and relational approach to teacher development and professional learning underpinned by a microclimate of commonality. The initiation of PLCs is a complex task. It requires a deep understanding of the processes involved in orientating teachers to processes that involve reflective dialogue and collaborative inquiry. Hence this study sought to investigate experiences of teachers in a PLC established through an alliance involving teachers, didacticians and education officials. This study found that the PLC signifier conveys significant meaning for teachers in terms of their engagement in the PLC. Moreover, teachers’ experiences of the PLC model confirmed the generally accepted features of a PLC. The importance of having a common vision, norms and standards was shown to be an important dimension of the PLC. Besides the fact that the active promotion of this shared vision by the PLC leadership and other education administrators was highlighted, teachers in general accepted the importance of being reflective practitioners. Despite this belief in the value of collaborative reflection, this study found that it does not take place as often as one would expect. This is, to some extent, due to the timetabling arrangements at most schools in the sample. Findings of this investigation provided evidence that it is possible in a PLC to effect a shift from professional development to professional learning. This is consistent with literature in this regard, for example, Benken & Brown (2010) support this argument by indicating that CPTD should be viewed as professional learning that is sustained over time. However, the issue of sustainability is an important challenge. This study revealed that teachers see sustainability as a function of three important variables, namely, recognition by school leadership and administrators, support from the organised teacher movements and subject organisations, and teacher commitment. Important affordances of a PLC identified through this study are relational agency, epistemic agency and a micro-climate of commonality. These affordances are viewed as important enablers of collaborative inquiry and reflective dialogue and underscores the community aspect of a PLC.

The changes brought by the democratic government in South Africa in 1994 have also brought considerable changes to the different sectors of the government and education was not different. There was a need to redress the imbalances of the past and the education system was to be reviewed so as to bring about the new assessment methods and approaches that would improve teaching and learning in the schools. Whenever any new idea enters education, it is usually aimed at improving the old school of thought. The challenge now remains the creation of new knowledge. Continuous assessment (CASS) with its greater weight requires an in-depth understanding by the teachers for correct implementation. This study was undertaken to determine the experiences of teachers with CASS in grade 9 Geography classrooms, by determining and exploring the way through which the assessment policy guides and informs the teachers in the implementation of CASS in Geography, the way the teachers implement CASS in the teaching, the requirements for CASS in terms of the NCS as well as the impact of CASS on the teaching-learning process. CASS is a prominent component of assessment that requires the teacher to understand its implementation in the classroom. It is the responsibility of the individual teachers and schools to read and interpret the assessment policy to ensure the correct implementation of CASS. A qualitative research design was employed and data was collected through literature review, questionnaires and interviews. The experiences of the teachers with CASS in the teaching of grade 9 Geography learners were investigated. From the literature review, it surfaced that Geography offers some interesting and fulfilling careers that teachers and learners can pursue. Career guidance is necessary to expose learners to these opportunities. Open-ended questions were used in both the questionnaires and interviews with the aim of obtaining an in-depth understanding of their experiences. Based on the findings of the questionnaire and interview data, it appears that the teachers still need support in understanding the policy of the Social Sciences. Though teachers appear to have information about the policy, they often misinterpret its correct meaning. The following are the dominant key words in this dissertation: learning outcomes, assessment standards, continuity, continuous assessment, curriculum, outcomes-based education, national curriculum statement, policy, progression, teaching strategies, assessment strategies. From this investigation, it can be inferred that there is a need for the results of this investigation to be used to guide the development of policies and that future researches be done in the area of CASS at all levels of the senior phase. / Dissertation (MEd)--University of Pretoria, 2011. / Science, Mathematics and Technology Education / unrestricted

In 2000, the Minister of Education, Professor Kader Asmal announced that all learners exiting the Further Education and Training band as from 2001 must accumulate marks in the subjects offered at Grade 12 through a process of Continuous assessment (CASS) (DoE, 2001d). Apart from indicating the value of CASS to the external summative component in the ratio of 25% for CASS and 75% for the summative examination, there were and there still is no other policy to regulate the conduct of CASS at Grade 12 level. The situation is worsened by the non-preparation of educators to cope with the challenges of CASS implementation. This study focuses on the implementation of CASS in Mathematics and Science since there is a body of firm evidence, which indicates that, the results in Mathematics and Science in South Africa is not very good. The TIMSS-R study conducted in 1998/1999 indicates that South African learners performed poorly in Mathematics and Science when compared to other participating countries (Howie, 2001). Since it has been established that continuous assessment conducted in a formative manner in subjects such as Mathematics and Science can lead to improved academic performance (Black&Wiliam, 1998), it is essential that attention be given, and initiatives taken to improve the quality of assessment in these critical subjects. In the analysis of the 2001 Senior Certificate examination, it became evident that the CASS marks of learners in many instances were not valid (SAFCERT, 2000a). To address the concern of inflated CASS marks, Umalusi resorted to the use of statistical moderation to ensure that the CASS marks do not deviate drastically from the examination marks of learners. This predominantly quantitative study makes use of surveys to gather data on the problems and challenges experienced by Grade 12 educators in the effective implementation of CASS and the kinds of support provided to educators to strengthen and to sustain the effective implementation of CASS in the classroom. In addition, the study seeks to examine to what extent the Grade 12 CASS marks are fair, valid and reliable. Data was collected from a non - random sample of 21 subject advisors and 60 educators of Mathematics, Biology and Physical Science across six provinces namely, Eastern Cape, Northern Cape, Limpopo, KwaZulu - Natal, Gauteng and Mpumalanga and across all locations (rural, township and urban). Individual interviews were also conducted with four experts on CASS from national, provincial and district levels and an official from Umalusi. It is apt to end this abstract by indicating that, “our education system has been subjected to many far - reaching initiatives which, whilst taken in reaction to concerns about existing practices, have been based on little evidence about their potential to meet those concerns. In the study of formative assessment there can be seen, for once, firm evidence that indicates clearly a direction for change, which could improve standards of learning. Our plea is that national policy will grasp this opportunity and give a lead in this direction” (Black&Wiliam, 1998). / Dissertation (MEd (Assessment and Quality Assurance))--University of Pretoria, 2005. / Curriculum Studies / unrestricted

Cellular automata are systems of interconnected cells which are discrete in space, time and state. Cell states are updated synchronously according to a local rule which is dependent upon the current state of the given cell and those of its neighbours in a pre-defined neighbourhood. The local rule is common to all cells. Fuzzy cellular automata extend this notion to systems which are discrete in space and time but not state. In this thesis, we explore fuzzy cellular automata which are created from the extension of Boolean rules in disjunctive normal form to continuous functions. Motivated by recent results on the classification of these rules from empirical evidence, we set out first to show that fuzzy cellular automata can shed some light on classical cellular automata and then to prove that the observed results are mathematically correct. The main results of this thesis can be divided into two categories. We first investigate the links between fuzzy cellular automata and their Boolean counter-parts. We prove that number conservation is preserved by this transformation. We further show that Boolean additive cellular automata have a definable property in their fuzzy form which we call self-oscillation. We then give a probabilistic interpretation of fuzzy cellular automata and show that homogeneous asymptotic states are equivalent to mean field approximations of Boolean cellular automata. We then turn our attention the asymptotic behaviour of fuzzy cellular automata. In the second half of the thesis we investigate the observed behaviours of the fuzzy cellular automata derived from balanced Boolean rules. We show that the empirical results of asymptotic behaviour are correct. In fuzzy form, the balanced rules can be categorized as one of three types: weighted average rules, self-averaging rules, and local majority rules. Each type is analyzed in a variety of ways using a range of tools to explain their behaviours.

Continuous-time Markov chains (CTMC's) form a convenient mathematical framework for analyzing random systems across many different disciplines. A specific research problem that is often of interest is to try to predict maximum probability sequences of state transitions given initial or boundary conditions. This work shows how to solve this problem exactly through an efficient dynamic programming algorithm. We demonstrate our approach through two different applications - ranking mutational pathways of HIV virus based on their probabilities, and determining the most probable failure sequences in complex fault-tolerant engineering systems. Even though CTMC's have been used extensively to realistically model many types of complex processes, it is often a standard practice to eventually simplify the model in order to perform the state evolution analysis. As we show here, simplifying approaches can lead to inaccurate and often misleading solutions. Therefore we expect our algorithm to find a wide range of applications across different domains.

This work deals with automated deployment of web appliactions in PHP. There is not any wide used standard tool for deploying of web application wrote in PHP. That is way the main objective of work is to create automated and universal solution which can be used for application with various database systems or frameworks. For purpose of design this tool I describe at the beginning of this work individual components of web application. It is source code of application, HTML templates and CSS, grafic files, data and database schema. Next I write about posibilities of uploading application to server. This chapter is based on Sharar Evron's talk at conference ZendCon 2010 named Best Practices in PHP deployment. For individual components of application I try to find specific steps which are necessary or usefull to do during application deployment. It is e.g. JavaScript and CSS files minification, database schema modification or secure data injecting in application's configuration files. In fourth and fifth chapter I write about implementation of these steps and connection them in process of application deployment and rollback. For this implementation I use tool Phing.

The express purpose for doing this project was to develop methods for the continuous culture of E. coli and P. aeruginosa as a mixed population, and to apply these methods in studying the effects of pH and substrate upon the growth of these two organisms in mixed continuous culture.

Succinic Acid (SA) was continuously produced using glucose and a Mg2CO3(OH)2 slurry as feed. Glucose feed concentrations of 20 and 40 g ℓ-1 were employed with corresponding Mg2CO3(OH)2 slurry concentrations of 60 and 120 g ℓ-1. The reactor pH was passively maintained between 6,4 and 6,8 by the buffer properties of the slurry in conjunction with the pH adjusted glucose feed. The suspended cell (SC) reactor was operated at 37°C with dilution rates varying between 0,04 h-1and 0,6 h-1. Groperl® particles were used as inert supports in the biofilm reactor; dilution rates of 0,11 h-1 to 1 h-1 were investigated. Two SC fermentations were conducted for the 20 g ℓ-1 glucose feed concentration and one for the 40 g ℓ-1. All SC fermentation runs were operated in excess of 12 days, while the biofilm run lasted 6,5 days. Fermentations were terminated only after contamination by lactic acid bacteria was observed. SC fermentations with the glucose feed concentration of 20 g ℓ-1 achieved a maximum SA productivity of 5,2 g ℓ-1h-1 at 0,6 h-1 with a corresponding SA yield of 0,65 g g-1. SC fermentations with the glucose feed concentration of 40 g ℓ-1 achieved a maximum SA productivity of 3,76 g ℓ-1h-1 at 0,4 h-1 with a SA yield of 0,82 g g-1. The results were comparable to the other continuous studies with Actinobacillus succinogenes, despite the fact that either biofilms or membranes were employed in these studies. The preliminary biofilm study demonstrated the capability of A. succinogenes to produce SA in high productivities and yields. SA productivities and yields for the dilution rates of 0,33 h-1 and 1,0 h-1, were 5,72 g ℓ-1h-1 (0,95 g g-1) and 12 g ℓ-1h-1 (1,0 g g-1), respectively. The biofilm reactor at 0,33 h-1 achieved twice the SA productivity of the SC reactor at 0,3 h-1 with a 42 % increase in SA yield. Copyright / Dissertation (MEng)--University of Pretoria, 2012. / Chemical Engineering / unrestricted

Continuous fermentations were performed in an external-recycle, biofilm reactor using glucose and CO2 as carbon substrates. The nitrogen source for the auxotrophic Actinobacillus succinogenes was a combination of yeast extract (YE) and corn steep liquor (CSL), and sometimes only YE or CSL was used. In this study, the succinic acid productivity of A. succinogenes decreased by 67% as the amount of YE in the complex nitrogen source mixture decreased from 16 g·L-1 to 0 g·L-1. Succinic acid production increased as the CSL concentration in the nitrogen source increased, and the mass ratio of succinic acid to acetic acid exceeded the theoretical maximum limit of 3,93 g·g-1 when only CSL was used as the nitrogen source. The mass ratio of formic acid to acetic acid was consistently within the theoretical yield limitations (0,77 g·g−1) and decreased as the CSL concentration in the nitrogen source increased. The highest SA concentration in this study was 22,57 g·L-1 when only YE was used as the nitrogen source in the growth medium, and the highest SA productivity obtained in this study was 1,58 g·L-1·h-1 when a combination of YE and CSL was used as a nitrogen source. The highest mass ratio of SA to AA achieved was 8,3 g·g-1 when CSL was the sole nitrogen source. The mass ratio of FA to AA was consistently less than 0,77 g·g-1, approaching 0 g·g-1, as the CSL concentration in the nitrogen source increased. / Dissertation (MSc)--University of Pretoria, 2016. / National Research Foundation (NRF) / Chemical Engineering / MSc / Unrestricted

The notion of rare continuity was introduced by Popa {15} as a new generalization of weak continuity {7}. In this paper, we introduce a new class of functions called rarely pre- θ -continuous functions as a new generalization of the class of strongly θ -precontinuous functions and investigate some of its fundamental properties.