Attention is one of the key competencies which has to be adequately developed in preschool children to support their good school adaptation and acceptation of school demands. This work describes current approaches to assessment of attention and related cognitive functions in children at preschool and early school years. On the basis of the methods which are accessible we introduce a new assessment tool, which could serve as screening of attention and other necessary competencies of children aged 5-7 years. The empirical part of this work shows results of a validization study of our method (Coloured trail making test for children), and its reliability the tool. Results proved strong correlations among our method and three other assessment tools from larger batteries of tests (Woodcock - Johnson Tests of Cognitive Abilities, IDS and CAS II). However, the outcomes of the tests are also different enough to conclude that each of four methods which we used can be important in the process of attention assessment in preschool children; and each of these methods can bring valid information about children's abilities. The work also includes normative data for Coloured trail making test for children, which can be used as a screening tool to detect minor difficulties of children's attention or it can help to...

Sous l’impact de contraintes photochimiques, thermiques, et hydrolytiques, les polymères subissent une dégradation souvent irréversible de leurs propriétés fonctionnelles. L’étude des mécanismes à l’origine de cette dégradation est indispensable pour la compréhension des phénomènes mis en jeu à toutes les échelles et pour la prévision de la durée de vie du matériau. L’enjeu de cette thèse est de comprendre les mécanismes à l’origine de la perte des propriétés d’aspect de matériaux en polypropylène teinté dans la masse soumis à un vieillissement photochimique, en suivant une approche multi-échelles et multi-critères. La composition des matériaux a été progressivement complexifiée au cours de l’étude, afin de pouvoir comprendre l’influence de l’ajout de pigments organiques, de stabilisants, et de talc, sur les modifications d’aspect des pièces sous irradiation. Grâce aux résultats obtenus et aux valeurs-seuils alors définies pour chaque critère de dégradation identifié, un modèle analytique d’étude du vieillissement de pièces en polypropylène teinté dans la masse a pu être proposé. / Under photochemical, thermal and hydrolytic stresses, polymers undergo an often-irreversible degradation of their functional properties. The study of the mechanisms governing the degradation of the properties is important, and understanding the involved phenomena at every scale is mandatory to predict the material lifetime. This PhD thesis aims at understanding the mechanisms underlying the loss of appearance properties of mass coloured polypropylene materials, using a multi-scale and multi-criteria approach. Formulations were progressively made more complex during this study, in order to understand the influence of organic pigments, stabilizers, and talc, on the appearance changes of the material under exposure. Thanks to the obtained results and to the threshold values determined for each identified criterion during degradation monitoring, an analytical model to study mass coloured polypropylene ageing could be proposed.

Le travail présenté dans cette thèse a lieu dans le domaine de développement basé sur les composants, il est une contribution à laspécification, l'adaptation et la vérification des systèmes à base de composants. Le but principal de cette thèse est la proposition d'uneapproche formelle pour construire progressivement des systèmes complexes en assemblant et en adaptant un ensemble de composants,où leur structure et leur comportement sont modélisés à l'aide de diagrammes SysML. Dans la première étape, nous avons défini uneapproche basée sur la méta-modélisation et la transformation des modèles pour vérifier la compatibilité des blocs ayant leurs protocolesd'interaction modélisés à l'aide de diagrammes de séquence SysML. Pour vérifier leur compatibilité, nous effectuons une transformationen automates d'interface (IAs), et nous utilisons l'approche optimiste définie sur les IA. Cette approche considère que deux composantssont compatibles s'il existe un environnement approprié avec lequel ils peuvent interagir correctement. Après cela, nous avons proposéde bénéficier de la hiérarchie, qui peut être présente dans les modèles de protocole d'interaction des blocs, pour alléger la vérification dela compatibilité des blocs. Dans l'étape suivante, nous avons pris en considération le problème des incohérences de noms de type one2oneentre les services des blocs. A ce stade, un adaptateur est généré pour un ensemble de blocs réutilisés qui ont leurs protocoles d'interactionmodélisés formellement par des automates d'interface. La génération de l'adaptateur est guidée par la spécification du bloc parent qui estfaite initialement par le concepteur. Notre approche est complétée par une phase de vérification qui nous permet de vérifier les exigencesSysML, exprimées formellement par les propriétés temporelles, sur les blocs SySML. Dans cette phase, nous avons exploité uniquementles adaptateurs générés pour vérifier la préservation des exigences initialement satisfaites par les blocs réutilisés. Ainsi, notre approchea l'intention de donner plus de chance d'éviter le problème de l'explosion de l'espace d'état au moment de la vérification. Dans le mêmecontexte, où nous avons un ensemble de blocs réutilisés et la spécification de leurs blocs parents, nous avons proposé d'utiliser des réseauxde Petri colorés (CPN) pour modéliser les interactions des blocs et générer des adaptateurs qui résolvent plus de types de problèmes. Dansce cas, l'adaptateur peut résoudre le problème de blocage en permettant le ré-ordonnancement des appels de services. / The work presented in this thesis takes place in the component-based development domain, it is a contribution to the specification,adaptation and verification of component-based systems. The main purpose of this thesis is the proposition of a formal approach tobuild incrementally complex systems by assembling and adapting a set of components, where their structure and behaviour are modelledusing SysML diagrams. In the first stage, we have defined a meta-model driven approach which is based on meta-modelling and modelstransformation, to verify the compatibility of blocks having their interaction protocols modelled using SysML sequence diagrams. To verifytheir compatibility, we perform a transformation into interface automata (IAs), and we base on the optimistic approach defined on IAs. Thisapproach consider that two components are compatible if there is a suitable environment with which they can interact correctly. Afterthat, we have proposed to benefit from the hierarchy, that may be present in the interaction protocol models of the blocks, to alleviate theverification of blocks compatibility. In the next stage, we have taken into consideration the problem of names mismatches of type one2onebetween services of blocks. At this stage, an adapter is generated for a set of reused blocks which have their interaction protocols modelledformally by interface automata. The generation of the adapter is guided by the specification of the parent block which is made initiallyby the designer. Our approach is completed by a verification phase which allows us to verify SysML requirements, expressed formallyby temporal properties, on SySML blocks. In this phase, we have exploited only the generated adapters to verify the preservation of therequirements initially satisfied by the reused blocks. Thus, our approach intends to give more chance to avoid the state space explosionproblem during the verification. In the same context, where we have a set of reused blocks and the specification of their parent blocks, wehave proposed to use coloured Petri nets (CPNs) to model the blocks interactions and to generate adapters that solve more type of problems.In this case the adapter can solve the problem of livelock by enabling the reordering of services calls.

Philosophiae Doctor - PhD / South African society is regulated by inequality and discrimination based on race. Fundamental human rights and privileges have been extended only to a small sector of the population. The majority of South African citizens remain constrained within a context of imposed inferiority in every aspect of their lives. Inequality, entrenched in political and economic apartheid structures, is also reflected in educational provision for Black citizens. Decades of apartheid schooling have resulted in a large population of illiterate, low-literate and educationally disadvantaged adults. Educational, political and economic discrimination all contribute to relegate Blacks to the lowest socioeconomic strata of South African society. Since numerous Blacks, particularly Africans, are restricted from effectively learning in South African schools, there is an escalating need for compensatory adult education Segregation and unequal educational provision have always characterized education in South Africa. The system of apartheid schooling was formalized by the government in 1953 when different education systems for distinct population groups were introduced. Inequalities in the structural features of apartheid schooling were evident in the discriminatory allocation of funds for public education. In 1953 government funds allocated for the education of each White child were approximately R128 (Rands), for every Indian and Coloured child R40, and for every African child R17 (a 7:1 ratio between the 'White and the African allocations). In 1976, the year of uprising by school children in Soweto, the discrepancy in allocation of educational funds had widened to a 10:1 ratio with the White allocation rising to R724, Indian to R357, Coloured to R226, and Africans to only R71 (Horrell, 1982, p. 115). At that time White, Indian and Coloured children were provided with at least ten years of free compulsory schooling. Nonetheless, the unequal distribution of educational funds afforded White children better educational facilities and better qualified teachers than those provided for other racial groups. The deliberate system of uneven educational provision for the various population registration groups was reinforced in the early 1960's with the progressive extension of free and compulsory schooling to Coloureds and Indians. This was done through the Coloured Person's Education Act of 1963 and the Indian Education Act of 1965. Africans, who constituted the majority of the population and who could least afford to pay for education, were not granted free and compulsory education until almost 20 years later. Not unexpectedly, failure and drop out rates among Africans within this system were very high, with the majority of school goers not staying beyond primary school (seven years) (Christie, 1986). Until the 1970's approximately 70 percent of Africans attending schools were attending primary school, and less than 1 percent of Africans were in Matric, the final year of formal schooling in South Africa (Christie, 1986, p. 56).In the late 1970's the White-controlled government was forced to make changes in Black education. In 1976 Black South African school children throughout the country demonstrated to the world their intolerance of the apartheid education system by rising up in protest. Continued school unrest into the 1980's not only revealed the need for an immediate and critical assessment of South African schooling, but also demanded an examination of the whole spectrum of education in South Africa. The immediate government response to these protests took the form of violent repression, student expulsions, school closures, teacher and student arrests, and the banning of 18 Black consciousness groups. Only in 1981 did the government react to the educational crisis in a more conciliatory manner with the establishment of the De Lange Commission of Inquiry. The proposals made by the Commission challenged the fundamental structures of apartheid society. The Commission recommended a single, unitary department of education for all South Africans and a changed school structure. After dragging its feet for two years, the government officially rejected the Commission's recommendation for a unitary education system for all South Africans.

Purpose of this master thesis is description of base parts of expert system with using Petri nets. Attention is mainly concentrate to knowledge base, way of storing knowledge. Next parts are describing main different between production base knowledge for planning or diagnostic expert system from Petri nets view. In this thesis conditions of using Petri nets and way of interpretation knowledge for inference mechanism in planning and diagnostic expert system are described. Using of high level Petri nets and language describing Petri nets structure and behaviour are demonstrated in next part of this thesis.

Satellites provide humanity with data to infer properties of the earth that were impossible a century ago. Humanity can now easily monitor the amount of ice found on the polar caps, the size of forests and deserts, the earth’s atmosphere, the seasonal variation on land and in the oceans and the surface temperature of the earth. In this thesis, new hypertemporal techniques are proposed for the settlement detection problem in South Africa. The hypertemporal techniques are applied to study areas in the Gauteng and Limpopo provinces of South Africa. To be more specific, new sequential (windowless) and non-sequential hypertemporal techniques are implemented. The time-series employed by the new hypertemporal techniques are obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, which is on board the earth observations satellites Aqua and Terra. One MODIS dataset is constructed for each province. A Support Vector Machine (SVM) [1] that uses a novel noise-harmonic feature set is implemented to detect existing human settlements. The noise-harmonic feature set is a non-sequential hypertemporal feature set and is constructed by using the Coloured Simple Harmonic Oscillator (CSHO) [2]. The CSHO consists of a Simple Harmonic Oscillator (SHO) [3], which is superimposed on the Ornstein-Uhlenbeck process [4]. The noise-harmonic feature set is an extension of the classic harmonic feature set [5]. The classic harmonic feature set consists of a mean and a seasonal component. For the case studies in this thesis, it is observed that the noise-harmonic feature set not only extends the harmonic feature set, but also improves on its classification capability. The Cumulative Sum (CUSUM) algorithm was developed by Page in 1954 [6]. In its original form it is a sequential (windowless) hypertemporal change detection technique. Windowed versions of the algorithm have been applied in a remote sensing context. In this thesis CUSUM is used in its original form to detect settlement expansion in South Africa and is benchmarked against the classic band differencing change detection approach of Lunetta et al., which was developed in 2006 [7]. In the case of the Gauteng study area, the CUSUM algorithm outperformed the band differencing technique. The exact opposite behaviour was seen in the case of the Limpopo dataset. Sequential hypertemporal techniques are data-intensive and an inductive MODIS simulator was therefore also developed (to augment datasets). The proposed simulator is also based on the CSHO. Two case studies showed that the proposed inductive simulator accurately replicates the temporal dynamics and spectral dependencies found in MODIS data. / Thesis (PhD(Eng))--University of Pretoria, 2012. / Electrical, Electronic and Computer Engineering / unrestricted

This thesis is about the multicolored gradients seen when using certain dichroic color lters with artificial light. As of now, this phenomenon lacks a unambiguous descriptor, and “Goniochromatic Gradient” is proposed. With help of optical physics, the science of color vision and information about dichroic products, principles for the relationship between goniochromatic gradients and dichroic filters are formulated for anyone interested in exploring this visual phenomenon.

No description available.

This thesis is a biographical study of Erika Theron (1907-1990), an Afrikaner woman who played a significant role in many aspects of public life in South Africa in a critical time in the country‘s history. The study seeks to give recognition to her achievements, which have received scant attention in a historiography with a masculine bias. At the same time it examines her changing role from collaborator to critic of the apartheid system. Certain defining features of Theron‘s life have been highlighted. First, Theron grew up in a staunchly Afrikaner nationalist, service-oriented family which encouraged loyalty to her own people and civic responsibility. Second, she was unusual among Afrikaner women of her generation, in that she was highly educated, independent and ready to assume leadership roles. She became a pioneer in a number of fields, attaining high professional rank and holding important public offices – frequently as the first woman to do so in the country. The thesis focuses on five areas of Theron‘s public life. After returning from post-graduate studies abroad, she worked with Hendrik Verwoerd in the campaign to uplift poor whites, particularly the rehabilitation and re-integration of the Afrikaner poor. She thereafter commenced a long career as a social work academic, which included a number of milestones for her new discipline, for the profession of social work and for the advancement of women in academia. From the 1950s she served on the town council of Stellenbosch, including terms as deputy mayor and mayor. She played an important role in historic conservation but was also instrumental in the rigorous institution of apartheid structures in the town during the early days of National Party rule. In the early 1970s she served as chairman of the Commission of Enquiry into Coloured Affairs which influenced her personal views on the country‘s race policies. She became a public critic of many aspects of the apartheid system and vocal advocate for coloured rights. / History / D. Litt. et Phil. (History)

Summaries in Afrikaans and English / The aim was to establish factors related to learning motivation and learning attitude of learners in historically coloured schools. An eclectic approach was followed because theoretical views on motivation could not furnish a comprehensive theory. The definition emerging from this approach states that motivation is a process started within a person to create a state of need for satisfaction and happiness that can be reached by instigating and sustaining goal-directed activity. The link between learning and motivation, as well as related factors, was ascertained. Determinants of high and low levels of learning motivation were established. Programmes aimed at higher motivation levels were explored. Empirically it was proven that grade 9 learners in historically coloured schools leaned more towards an extrinsic orientation; grade 12's more intrinsic. An intervention programme is suggested. / Die doel was om vas te stel watter faktore hou verband met die leermotivering en leerhouding van leerders in histories bruin sekondere skole spesifiek. 'n Eklektiese benadering is gevolg omdat die teoretiese beskouings oor leerrnotivering nie 'n bevredigende allesomvattende teorie kon verskaf nie. Die werksdefinisie van motivering is 'n gevolg daarvan en lui as volg: motivering is die proses wat in die persoon aan die gang gesit word om 'n staat van behoefte na tevredenheid en geluk te skep wat bereik kan word deur doelgerigte aktiwiteit aan te stig en aan die gang te hou. Die verband tussen leer en motivering is bepaal asook die faktore wat verband hou met leermotivering. Bepalers van hoe en lae leermotiveringsvlakke is vasgestel en ingrypingsprogramme gemik op verhoogde motivering is ondersoek. Empiries is bewys dat die graad 9-leerders meer geneig is tot ekstrinsieke orienterings rakende leermotivering; graad 12-leerders meer intrinsiek. 'n lngrypingsprogram word voorgestel. / Teacher Education / M. Ed. (met spesialisering in Voorligting)