A l’avenir, l'agriculture et l'environnement vont pouvoir bénéficier de plus en plus de données hétérogènes collectées par des réseaux de capteurs sans fil (RCSF). Ces données alimentent généralement des outils d’aide à la décision (OAD). Dans cette thèse, nous nous intéressons spécifiquement aux systèmes sensibles et adaptatifs au contexte basés sur un RCSF et un OAD, dédiés au suivi de phénomènes naturels. Nous proposons ainsi une formalisation pour la conception et la mise en œuvre de ces systèmes. Le contexte considéré se compose de données issues du phénomène étudié mais également des capteurs sans fil (leur niveau d’énergie par exemple). Par l’utilisation des ontologies et de techniques de raisonnement, nous visons à maintenir le niveau de qualité de service (QdS) des données collectées (en accord avec le phénomène étudié) tant en préservant le fonctionnement du RCSF. Pour illustrer notre proposition, un cas d'utilisation complexe, l'étude des inondations dans un bassin hydrographique, est considéré. Cette thèse a produit un logiciel de simulation de ces systèmes qui intègre un système de simulation multi-agents (JADE) avec un moteur d’inférence à base de règles (Jess). / In the future, agriculture and environment will rely on more and more heterogeneous data collected by wireless sensor networks (WSN). These data are generally used in decision support systems (DSS). In this dissertation, we focus on adaptive context-aware systems based on WSN and DSS, dedicated to the monitoring of natural phenomena. Thus, a formalization for the design and the deployment of these kinds of systems is proposed. The considered context is established using the data from the studied phenomenon but also from the wireless sensors (e.g., their energy level). By the use of ontologies and reasoning techniques, we aim to maintain the required quality of service (QoS) level of the collected data (according to the studied phenomenon) while preserving the resources of the WSN. To illustrate our proposal, a complex use case, the study of floods in a watershed, is described. During this PhD thesis, a simulator for context-aware systems which integrates a multi-agent system (JADE) and a rule engine (Jess) has been developed.Keywords: ontologies, rule-based inferences, formalization, heterogeneous data, sensors data streams integration, WSN, limited resources, DSS, adaptive context-aware systems, QoS, agriculture, environment.

Existing research suggests that when consumers encounter hybrid products or boundary-spanning products with attributes belonging to multiple categories, consumers tend to generate inferences based on only a single product category. Reliance on a single category for inferencing is termed as the “single category belief problem” which has been regarded as a vital marketing challenge because it leads consumers to underestimate the true utility of a hybrid product as certain product attributes are ignored. Our objective was to explore whether single category beliefs manifest in consumer choice for a hybrid product when strategically placed within varying contexts. The research used discrete choice experiment (DCE) to test hypotheses. Our research confirms that the single category belief is evident in consumer choice. We also found that the context the hybrid product is placed within has a major influence on what consumers preferred the most. Depending on the context a hybrid product was seen in had significant influence on how consumers evaluated product attributes and made purchase decisions. The findings for this research may be very beneficial for marketers.

The continued underperformance of many L2 students at primary, secondary and tertiary level is a cause for grave concern in South Africa. In an attempt to better understand the cognitivelinguistic conditions and processes that underlie academic performance and underperformance, this study looks at the problem of differential academic performance by focussing on the inferential ability of undergraduate L2 students during the reading of expository texts. The study works within a constructivist theory of reading, where the successful understanding of a text is seen to involve the construction of a mental representation of what the text is about. Inferencing plays an important role in constructing meaning during reading because it enables the reader to link incoming information with already given information, and it enables the reader to construct a mental representation of the meaning of a text by converting the linear input into a hierarchical mental representation of interrelated information. The main finding showed that the ability to make inferences during the reading of expository texts was strongly related to academic performance: the more inferences students made during the reading of expository texts, the better they performed academically. This relationship held across the making of various inferences, such as anaphoric inferences, vocabulary inferences, inferences about various semantic relations, and thematic inferences. In particular, the ability to make anaphoric, contrastive and causal inferences emerged as the strongest predictors of academic performance. The study provides strong empirical evidence that the ability to make inferences during reading enables a reader to construct meaning and thereby also to acquire new knowledge. Reading is not only a tool for independently accessing information in an information-driven society, it is fundamentally a tool for constructing meaning. Reading and inferencing are not additional tools that students need to master in the learning context- they constitute the very process whereby learning occurs. / Linguistics and Modern Languages / D.Litt. et Phil. (Linguistics)

PhD (Business Management) / Department of Business Management / This thesis demonstrates the researcher’s efforts to put into practice the theoretical foundations of information systems research, in order to come up with a context-aware business intelligence framework (CABIF), for the South African higher education institutions. Using critical realism as the philosophical underpinning and mixed methods research design, a business intelligence (BI) survey was deployed within the South African public higher education institutions to measure the respondents’ satisfaction and importance of business intelligence characteristics. The 258 respondents’ satisfaction and importance of the 34 observed business intelligence variables, were subjected to principal components analysis and design science research to come up with the CABIF. The observable BI variables were drawn from four latent variables namely technology and business alignment; organizational and behavioural strategies; business intelligence domain; and technology strategies. The study yielded good values for all the observed satisfaction and importance business intelligence variables as indicated by the Kaiser- Meyer-Olkin (KMO) Measure of Sampling Adequacy and the Bartlett Test of Sphericity. The data set collected from the survey deployed at the South African public higher education institutions, was reliable and valid based on the Cronbach α values which were all above 0.9. The researcher then used the descriptive and prescriptive knowledge of design science research, and the meta-inferences of the results from the principal components analysis to produce five contexts of CABIF. The BI contexts developed were, the Basic Context; the Business Processes Context which was divided into Macro and Micro business process contexts; the Business Intelligence Context; and the Governance Context. These contexts were extrapolated within the University of Venda’s business processes and this researcher concluded that the CABIF developed, could be inferred within the South African higher education institutions. At the University of Venda, this researcher managed to draw up CABIF based business intelligence tools that spanned from leveraging the existing ICT infrastructure, student cohort analysis, viability of academic entities, strategic enrolment planning and forecasting government block grants. The correlations and regression measures of the technology acceptance variables of the business intelligence tools modelled using CABIF at University of Venda, revealed high acceptance ratio. Overall, this research provides a myriad of conceptual and practical insights into how contextualised aspects of BI directly or indirectly impact on the quality of managerial decision making within various core business contexts of South African higher education institutions.

Austin's Speech Act Theory is a valuable tool for the analysis of a literary text. In interaction, the intentionand purpose-success of linguistic communication can be gauged by establishing whether participants have met felicity conditions and have respected maxims. When the Co-operative Principle is ignored, special effects are achieved and receivers can only make sense of utterances through implicature and inferences based on background knowledge and mutual contextual beliefs. In the drama, Buzani kubawo, characters interact on four levels of time in space and place. They reveal themselves and convey theme through their speech and actions. Conflict is entrenched by lines of force drawn between opposing characters and between sub-worlds contrasted. Cohesion, determined by plot structure, and form, expressed on the endophoric and exophoric levels, give meaning to the drama. The micro-analysis of the wedding scene illustrates how communication can misfire should the playwright allow it! / African Languages / M.A. (African languages)

Design fixation is a phenomenon experienced by professional designers and engineering design students that stifles creativity and innovation through discouraging ideational productivity, fluency and diversity. During the design idea and concept generation phase of the design process, a reliance on perceptual surface feature similarities between design artefacts increases the likelihood of design fixation leading to design duplication. Psychologists, educators and designers have become increasingly interested in creative idea generation processes that encourage innovation and entrepreneurial outcomes. However, there is a notable lack of collaborative research between psychology, education and engineering design particularly on inductive reasoning of undergraduate engineering students in higher education. The data gathered and analysed for this study provides an insight into property inference decision-making preferences and decision switching (SWITCH) patterns of engineering undergraduates under similarity-based inductive judgements [SIM] and category-based inductive judgements [CAT]. For this psychology experiment, property induction tasks were devised using abstract shapes in a triad configuration. Participants (N = 180), on an undergraduate engineering programme in London, observed a triad of shapes with a target shape more similar-looking to one of two given shapes. Factors manipulated for this experiment included category alignment, category group, property type and target shape. Despite the cognitive development and maturation stage of undergraduate engineers (adults) in higher education, this study identified similarity-based inductive judgements [SIM] to play a significant role during inductive reasoning relative to the strength of category-based inductive judgements [CAT]. In addition to revealing the property inference decision-making preferences of a sample of undergraduate engineers (N = 180), two types of switch classification and two types of non-switch classification (SWITCH) were found and named SIM_NCC, SIM-Salient, Reverse_CAT and CAT_Switching. These different classifications for property inference switching and non-switching presented a more complex pattern of decision-making driven by the relative strength between similarity-based inductive judgements [SIM] and category-based inductive judgements [CAT]. The conditions that encouraged CAT_Switching is of particular interest to design because it corresponds to inference decision switching that affirms the sharing of properties between dissimilar-looking shapes designated as category members, i.e., in a conflicting category alignment condition (CoC). For CAT_Switching, this study found a significant interaction between a particular set of conditions that significantly increased the likelihood of property inference decisions switching to affirm the sharing of properties between dissimilar-looking shapes. Stimuli conditions that combined a conflicting category alignment condition (where dissimilar-looking shapes belong to the same category) with category specificity, a causal property and a target shape with merged (or blended) perceptual surface features significantly increased the likelihood of a property inference decision switching. CAT_Switching has important implications for greater ideational productivity, fluency and diversity to discourage design fixation within the conceptual design space. CAT_Switching conditions could encourage more creative design transformations with alternative design functions through inductive inferences that generalise between dissimilar artefact designs. The findings from this study led to proposing a Cartesian view of the concept design space to represent the possibilities for greater movements through flexible and expanding category boundaries to encourage conceptual combinations, greater ideational fluency and greater ideational diversity within a configuration design space. This study has also created a platform for further research into property inference decision-making, ideational diversity and category boundary flexibility under stimuli conditions that encourage designers and design students to make inductive generalisations between dissimilar domains of knowledge through a greater emphasis on causal relations and semantic networks.

Austin's Speech Act Theory is a valuable tool for the analysis of a literary text. In interaction, the intentionand purpose-success of linguistic communication can be gauged by establishing whether participants have met felicity conditions and have respected maxims. When the Co-operative Principle is ignored, special effects are achieved and receivers can only make sense of utterances through implicature and inferences based on background knowledge and mutual contextual beliefs. In the drama, Buzani kubawo, characters interact on four levels of time in space and place. They reveal themselves and convey theme through their speech and actions. Conflict is entrenched by lines of force drawn between opposing characters and between sub-worlds contrasted. Cohesion, determined by plot structure, and form, expressed on the endophoric and exophoric levels, give meaning to the drama. The micro-analysis of the wedding scene illustrates how communication can misfire should the playwright allow it! / African Languages / M.A. (African languages)