Background: Population level child measurement is an established international practice. However, there is limited clarity around the protocol and roles of school-based child measurement programmes (CMPs). Furthermore, questions remain about the positive and adverse outcomes associated with CMPs, as well as their longer-term sustainability. This research contributes new information by addressing these key unanswered questions. Methods: This thesis describes a three-part, mixed methods research project incorporating: a systematic literature review of existing CMPs; an in-depth case study of England’s National Child Measurement Programme; and the development, pilot implementation and evaluation of a CMP in Guernsey. This research was conducted sequentially; individual components informed and guided subsequent work. Results: Routine child measurement is a popular, complex and adaptive practice and offers significant epidemiological value. The principal roles of CMPs are delivery of local prevalence data and assessment of longitudinal trends. However, CMPs are often tasked with additional, diverse and changing roles that do not translate to acknowledged outcomes. Specifically, feedback of individual results represents an unproven programme element. Programme roles can evolve according to political, logistical, or other influences, without consideration of available evidence or wider-reaching implications. There is no evidence of short-term harm from CMPs. Evaluation of the pilot CMP in Guernsey demonstrated that these programmes are perceived to be feasible, acceptable and sustainable. Conclusions: To maximise the broader utility of CMPs, there should be clarity and consistency around their aims, roles and outcomes. Overall, surveillance reflects the preferred programme type. All CMPs should incorporate a standardised, rigorously applied protocol and routine evaluation. These features are essential to ensure the accuracy and comparability of resultant data, as well as programme credibility. Population level CMPs should not function in isolation; instead, they should be integrated into comprehensive strategies for obesity management. This research has important implications for CMP stakeholders and the wider public health arena.

Text in Afrikaans / Die doel van hierdie navorsing is, om te bepaal of gesyferdheid by kleuters binne `n speelgroepsituasie ontwikkel kan word deur middel van `n program wat wiskundige konsepte aan kleuters oordra. Ten einde hierdie doel te bereik is `n wiskunde program waarin verskillende hulpmiddels gebruik word, vir die kleuters aangebied. Die wiskunde program wat gebruik is, is saamgestel aan die hand van Charner, Murphy en Clark (2007) se “The Giant Encyclopedia of Math Activities for Children 3 to 6”. Die aktiwiteite wat tydens die voortoets en natoets gebruik is, is uit verskillende bronne op die internet verkry. Die aktiwiteite is uit gemelde bronne geneem en aangepas om by kleuters se ontwikkelingsvermoë te pas. Aan die einde van die wiskunde program kon daar `n verbetering in al die leerders se wiskunde vaardighede waargeneem word. Die resultate van die studie dui dus daarop dat kleuters se begrip en vaardigheid met wiskundige konsepte op `n vroeë ouderdom in `n speelgroep ontwikkel kan word. / The aim of this study was to determine whether numeracy can be developed among preschoolers in `n playgroup situation by means of a numeracy programme which introduces them to mathematical concepts. To achieve this aim a numeracy programme was used to introduce the mathematical concepts. The numeracy programme that was used is a programme compiled from “The Giant Encyclopedia of Math Activities for Children 3 to 6” by Charner, Murphy and Clark (2007). The activities which were used during the pre-test and post-test were taken from different sources on the internet. The activities taken from these different sources were adapted to the appropriate developmental phase of the preschoolers. At the end of the programme the post-test indicated an improvement in the mathematical competence of all the learners. The results of the study prove that preschoolers in a playgroup can improve their numeracy skills in the early years. / Teacher Education / M. Ed. (Didaktiek)

State estimation plays an important role in modern power systems. The errors in the telemetered measurements and the connectivity information of the network will greatly contaminate the estimated system state. This dissertation provides solutions to suppress the influences of these errors. A two-stage state estimation algorithm has been utilized in topology error identification in the past decade. Chapter II discusses the implementation of this algorithm. A concise substation model is defined for this purpose. A friendly user interface that incorporates the two-stage algorithm into the conventional state estimator is developed. The performances of the two-stage state estimation algorithms rely on accurate determination of suspect substations. A comprehensive identification procedure is described in chapter III. In order to evaluate the proposed procedure, a topology error library is created. Several identification methods are comparatively tested using this library. A remote measurement calibration method is presented in chapter IV. The un-calibrated quantities can be related to the true values by the characteristic functions. The conventional state estimation algorithm is modified to include the parameters of these functions. Hence they can be estimated along with the system state variables and used to calibrate the measurements. The measurements taken at different time instants are utilized to minimize the influence of the random errors. A method for auto tuning of measurement weights in state estimation is described in chapter V. Two alternative ways to estimate the measurement random error variances are discussed. They are both tested on simulation data generated based on IEEE systems. Their performances are compared. A comprehensive solution, which contains an initialization process and a recursively updating process, is presented. Chapter VI investigates the errors introduced in the positive sequence state estimation due to the usual assumptions of having fully balanced bus loads/generations and continuously transposed transmission lines. Several tests are conducted using different assumptions regarding the availability of single and multi-phase measurements. It is demonstrated that incomplete metering of three-phase system quantities may lead to significant errors in the positive sequence state estimates for certain cases. A novel sequence domain three-phase state estimation algorithm is proposed to solve this problem.

Text in Afrikaans / Die doel van hierdie navorsing is, om te bepaal of gesyferdheid by kleuters binne `n speelgroepsituasie ontwikkel kan word deur middel van `n program wat wiskundige konsepte aan kleuters oordra. Ten einde hierdie doel te bereik is `n wiskunde program waarin verskillende hulpmiddels gebruik word, vir die kleuters aangebied. Die wiskunde program wat gebruik is, is saamgestel aan die hand van Charner, Murphy en Clark (2007) se “The Giant Encyclopedia of Math Activities for Children 3 to 6”. Die aktiwiteite wat tydens die voortoets en natoets gebruik is, is uit verskillende bronne op die internet verkry. Die aktiwiteite is uit gemelde bronne geneem en aangepas om by kleuters se ontwikkelingsvermoë te pas. Aan die einde van die wiskunde program kon daar `n verbetering in al die leerders se wiskunde vaardighede waargeneem word. Die resultate van die studie dui dus daarop dat kleuters se begrip en vaardigheid met wiskundige konsepte op `n vroeë ouderdom in `n speelgroep ontwikkel kan word. / The aim of this study was to determine whether numeracy can be developed among preschoolers in `n playgroup situation by means of a numeracy programme which introduces them to mathematical concepts. To achieve this aim a numeracy programme was used to introduce the mathematical concepts. The numeracy programme that was used is a programme compiled from “The Giant Encyclopedia of Math Activities for Children 3 to 6” by Charner, Murphy and Clark (2007). The activities which were used during the pre-test and post-test were taken from different sources on the internet. The activities taken from these different sources were adapted to the appropriate developmental phase of the preschoolers. At the end of the programme the post-test indicated an improvement in the mathematical competence of all the learners. The results of the study prove that preschoolers in a playgroup can improve their numeracy skills in the early years. / Teacher Education / M. Ed. (Didaktiek)