Thesis (MPhil)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Knowledge management is an organisational science field that is viewed by many as a panacea to the challenge of successfully managing knowledge intensive organisations. Knowledge management is marked by a clear departure from traditional management thinking that viewed the ideal organisation as a bureaucracy with a clear hierarchical structure. Much of this has been the natural result of advances in information technology making new ways of working possible, but frequently, flatter structures are advocated on the assumption that knowledge work is necessarily stifled in hierarchical structures. The thesis sets out to show that whilst this assumption might be true, it can also be ideological if based on a naive conception of hierarchy and organisation. This is done by describing various notions of hierarchy that go beyond the pure bureaucratic form. Thereafter it is demonstrated that these more nuanced notions of hierarchy lie at the core of some of the foundational knowledge management theories. The first chapter gives an overview of management thinking; connecting and contrasting scientific management with knowledge management. The case is made for why many assume that knowledge management is inherently anti-hierarchical. The second chapter describes the various notions of hierarchy by tracing the historical origins of the word and exploring how it has found multiple meanings in the context of society and organisations. Four prominent usage contexts of the notion of hierarchy emerge. The first usage is that of control where hierarchy refers to bureaucracies. The second usage examines the use of hierarchy in identifying various organisational cultures (Markets, Clans, Adhocracies and Hierarchies). The third usage applies to organisation sensemaking levels. The fourth usage refers to the use of hierarchy as it applies to organisations as the coupling of systems and subsystems. In the third chapter it is demonstrated to what extent each of these notions of hierarchy informs selected mainstream knowledge management theories. It is argued that there are multiple contexts in which the notion of hierarchy can be used and observed in knowledge management thinking. The fourth chapter concludes by restating the multiple meanings of organisational hierarchy and discussing the implications for knowledge management. The thesis comes to the conclusion that the notion of hierarchy is readily acknowledged and used in knowledge management thinking, albeit in different contexts and in more nuanced ways than merely as control. What is needed is to take these various contexts into account before a claim can be made that hierarchy is bad or good for knowledge management. A better conceptualisation of what is meant by hierarchy shows that such blanket claims are neither accurate nor instructive. / AFRIKAANSE OPSOMMING: Kennisbestuur is 'n veld in organisasiestudies wat deur baie mense gesien word as die oplossing vir die bestuursprobleem van kennis-intensiewe organisasies. Kennisbestuur word gekenmerk deur 'n duidelike afwyking van die tradisionele bestuursdenke wat die ideale organisasie sien as 'n burokrasie met 'n duidelik hierargiese struktuur. Hierdie afwyking is waarskynlik die natuurlike resultaat van voortuitgang in informasietegnologie wat nuwe maniere van werk moontlik maak, maar soms word platter strukture bepleit op die basis van die aanname dat kenniswerk in beginsel deur hierargiese strukture benadeel word. Die tesis probeer wys dat alhoewel so 'n aanname wel waar kan wees, dit ook ideologies kan wees, veral wanneer gebaseer op 'n naïewe verstaan van hierargie en organisering. Dit word gedoen deur verskeie vorme van hierargie, wat verfynings van die burokratiese vorm is, te beskryf en daarna te demonstreer hoedat hierdie meer genuanseerde konsepsies van hierargie baie van die hoofstroom kennisbestuursteorieë informeer. Die eerste hoofstuk gee 'n oorsig van bestuursdenke vanaf wetenskaplike bestuur tot kennisbestuur. 'n Argument word gevoer oor hoekom baie mense aanvaar dat kennisbestuur in wese anti-hierargies is. Die tweede hoofstuk beskryf die verskeie vorme van hierargie deur die geskiedkundige oorsprong van die woord na te spoor en te wys op die vele maniere waarop dit neerslag gevind het in die samelewing en spesifiek in organisasies. Vier prominente gebruikskontekste word geïdentifiseer. Die eerste verwys na hierargie as kontrole in burokrasieë. Die tweede ondersoek die uitbreiding van hieragie as 'n manier om verskillende organisatoriese kulture te identifiseer (Markte, Klans, Adhokrasieë en Hierargieë). Die derde gebruikskonteks het te make met vlakke van organisatoriese singewing. Die vierdie konteks verwys na die gebruik van hierargie in die koppeling van sisteme en hulle subsisteme soos dit in organisasie-denke neerslag vind. Die derde hoofstuk demonstreer tot watter mate elkeen van hierdie gebruikskontekste geselekteerde hoofstroom kennisbestuursteorieë onderlê. Daar word geargumenteer dat daar 'n veelvoud van kontekste is waarbinne hierargie in kennisbestuur gebruik en waargeneem kan word. Die vierde hoofstuk sluit af deur die verskeie betekenisse van hierargie op te som en die implikasies vir kennisbestuur uit te stippel. Die tesis kom tot die slotsom dat hierargie in kennisbestuur erken en gebruik word, alhoewel in verskeie kontekste en in meer genuanseerde vorme as eenvoudige burokratiese kontrole. Wat nodig is, is om hierdie verskeie kontekste in ag te neem voordat afdoende antwoorde gewaag kan word of hierargie goed of sleg is vir die bestuur van kennis. 'n Beter konseptualisering van wat met hierargie bedoel word wys dat afdoende antwoorde in die verband waarskynlik onakkuraat is.

Made available in DSpace on 2015-03-26T13:35:17Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1285375 bytes, checksum: 680d8058ac46b55b4e9e7e37f9fd0e1f (MD5) Previous issue date: 2012-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this thesis, we define and analyze certain surface and volumetric properties of the aggregates generated by three one-dimensional competing thin films deposition models (all with kinetics of surface in universality class KPZ). These models represent a competition between ballistic deposition pattern and another rule dependent on the deposition model. Each of these new rules introduced in two of the three models are related to the kinetic energy of incident particles. An interesting feature of two of our models is the existence of the restructuring of the particles that were already linked in the aggregate, these processes depend on the speed of the incident particles. We show that our models exhibit the same scaling behavior observed in other competitive models. We study in the models, the variation of surface and volumetric properties in terms of a parameter F, where F is the ratio between the amount of particles that obey the ballistic deposition rule and the total amount of particles deposited. Finally, we list some properties and volumetric surface and use a scaling law to characterize the pore morphology of the aggregates generated by our three models as a function of a specific length scale. / Nesse trabalho, definimos e analisamos algumas propriedades superficiais e volumétricas dos agregados gerados através de três modelos competitivos unidimensionais de deposição de filmes finos (todos com cinética de superfície na classe de universalidade KPZ). Tais modelos representam uma competição entre a deposição balística padrão e uma outra regra de deposição dependente do modelo. Cada uma dessas novas regras que introduzimos em dois dos três modelos estão relacionadas com a energia cinética das partículas incidentes. Uma característica interessante de dois dos nossos modelos é a existência de processos de reestruturação das partículas que já estavam ligadas no depósito; tais processos dependem da velocidade das partículas incidentes. Mostramos que os nossos modelos exibem o mesmo comportamento de escala observado em outros modelos competitivos. Estudamos, em cada um dos modelos, a variação das propriedades superficiais e volumétricas em função de um parâmetro F, em que F é a razão entre a quantidade de partículas que obedecem a regra de deposição balística padrão e a quantidade total de partículas depositadas. Por fim, relacionamos algumas propriedades superficiais e volumétricas e usamos uma lei de escala para caracterizar a morfologia dos poros dos agregados gerados pelos nossos três modelos como função de um comprimento de escala específico.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Esta pesquisa investiga alguns aspectos da difÃcil questÃo dos fatores pelos quais se pode considerar um enunciado inadequado à situaÃÃo de interaÃÃo em que à usado e à gramÃtica da lÃngua, conforme concepÃÃo funcionalista de gramÃtica como sistema sensÃvel Ãs pressÃes do uso. PropÃe uma tipologia que engloba os tipos de inadequaÃÃo encontrados no corpus de anÃlise, correlacionados a um quadro em que a inadequaÃÃo seja vista como nÃo-satisfaÃÃo de uma demanda funcional. A hipÃtese bÃsica, considerando que demandas internas e externas ao sistema competem entre si pela expressÃo morfossintÃtica (DUBOIS, 1985), à a de que essa competiÃÃo entre motivaÃÃes pragmÃticas, semÃnticas e morfossintÃticas pode nÃo se resolver satisfatoriamente em algumas situaÃÃes de uso da lÃngua, produzindo-se construÃÃes inadequadas quanto a algum tipo de motivaÃÃo. A anÃlise serve-se do instrumental teÃrico da GramÃtica Discursivo-Funcional (HENGEVELD; MACKENZIE, 2008), que, ao compreender a gramÃtica como parte de um modelo de interaÃÃo verbal, permite dar conta dos fatores cognitivos, interacionais e textuais que tÃm impacto nos aspectos gramaticais da predicaÃÃo. Trabalhamos com um corpus constituÃdo principalmente por um conjunto de enunciados considerados inadequados, retirados de um banco de redaÃÃes escolares de estudantes do Ensino MÃdio da rede pÃblica em Fortaleza, coletado por nÃs. / This research analyzes some aspects of the question of the factors through which it can be considered that a sentence is inadequate concerning the interaction event in which it is used and the grammar of the specific language, according to a functionalist view of language as a system flexible when faced with usage pressure. It proposes a typology contemplating the types of inadequate usages found in the corpus, related to a frame in which the inadequate usage is seen as the non-satisfaction of a functional demand. Considering that pragmatic and semantic motivations compete for the morphosyntactic expression (DUBOIS, 1987), the basic hypothesis is that competing motivations can be left unsolved so that an inadequate construction is produced. The analysis is based on the theory of Functional-Discourse Grammar (HENGEVELD; MACKENZIE, 2008). This theory comprehends the grammar as part of a wider model of verbal interaction, so that it can account of the cognitive, interactive and textual factors which have an impact on the grammatical aspects of the predication. The corpus takes a set of presumably inadequate sentences collected from a bank of high school studentsâ texts.

Orientador: Paulo Correa Lima / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-04T03:13:38Z (GMT). No. of bitstreams: 1 Marcondes_AndrezaBenatti_M.pdf: 5495313 bytes, checksum: a5a7651ef5e80d1a06695be92059dd0b (MD5) Previous issue date: 2003 / Resumo: As mudanças nos padrões de competitividade da indústria brasileira influenciaram os procedimentos na avaliação de investimentos em capital fixo das empresas. Neste sentido, a decisão de investir em determinado projeto não é baseada somente na relação entre uma taxa interna de retomo e uma taxa mínima de atratividade, mas deve-se levar em consideração fatores como tempo de resposta ao cliente, qualidade e custo. Para alcançar estes requisitos, a empresa deve reconfigurar seu processo de negócios e uma das áreas mais afetadas é o chão-de-fábrica. A abordagem da Toyota Motor Corporation para projeto de sistemas de manufatura, conhecida como manufatura enxuta, mostrou ser capaz de garantir resultados superiores. Os modelos de análise de investimento atuais, criados para atender a produção em massa, falham em apontar os resultados gerados pela produção enxuta. Este trabalho pretende entender o impacto financeiro de se converter uma fábrica do sistema de produção em massa para o sistema enxuto. Um caso de estudo de uma montadora que se tornou referência nas práticas enxutas é utilizado para verificar se ocorreram transformações na metodologia utilizada pela empresa / Abstract: The changes in the competitiveness standards in the Brazilian industry had influenced on the investment evaluation procedure of fixed capital in corporations. In this way, the decision to invest in a project must not be only based on a relation between the internal rate of return and attractiveness rate. It is necessary to consider factors as response time to customers orders, quality and cost. In order to achieve those requirements most companies need to reconfigure their business process and one of the most affected areas in the shop floor. Toyota Motor Corporation' s approach to manufacturing system design, a1so known as lean manufacturing, has been showing superior performance. The current investment ana1ysis models, created to support mass production, :fail in recognize the effectiveness of lean manufacturing. This work aims at understanding financial impact of restructuring a plant from mass to lean production. A case study of an automotive assembly company who become a benchmark on lean practices is used to check of investments methodologies had been reviewed to support manufacturing transformation / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Contexte : Dans les analyses de survie, un risque concurrent est un événement qui empêche l'observation de l'événement d'intérêt (le décès le plus souvent). Si la probabilité de survenue d'un risque concurrent dépend de la probabilité de l'événement d'intérêt, alors il ne peut pas être traité comme une censure. Les patients ayant une insuffisance rénale chronique terminale peuvent être traités par hémodialyse, dialyse péritonéale et greffe rénale. Ces traitements sont complémentaire et les patients peuvent passer d'une modalité de traitement à une autre au cours de leur prise en charge. La dépendance entre les changements de traitement et la probabilité de décès n'a pas été étudiée et ces changements sont traités comme des censures dans les analyses de survie.Objectifs : Analyser la dépendance entre les probabilités de décès en dialyse et de greffe rénale, et entre les probabilités de décès en dialyse péritonéale et de transfert en hémodialyse. Nous démontrerons les conséquences néfastes de la non-prise en compte de cette dépendance dans les analyses de survie en dialyse. Méthodes : (1) Nous avons comparé les estimations de probabilité d'événement obtenues par la méthode de Kaplan-Meier et la méthode de Kalbfleisch et Prentice sur 383 patient indicent consécutifs traités par dialyse péritonéale à Lille. (2) Nous avons analysé les données de 7318 patients incidents traités par hémodialyse en France grâce au registre national REIN. Nous avons utilisé un modèle multi-états pour analyse l'influence de l'inscription sur liste d'attente de greffe sur la probabilité de décès en dialyse. (3) Sur une cohorte de 2790 patients âgés de plus de 65 ans et traités par dialyse péritonéale issus du Registre de Dialyse Péritonéale de Langue Française (RDPLF), nous avons analysé les facteurs de contre-indication au transfert en HD en prenant en compte le décès comme risque concurrent à l’aide du modèle de Fine et Gray. Cette analyse a été complétée par un questionnaire réalisé auprès 55 des néphrologues pratiquant la dialyse péritonéale en France. Résultats : (1) La méthode de Kaplan Meier surestimait systématiquement la probabilité de décès du fait de la violation de l'hypothèse d'indépendance entre le décès et les risques concurrents. Cette méthode n'apparaît donc pas valide dans les analyses de survie en dialyse. La méthode de Kalbfleisch et Prentice était valide mais l'interprétation des incidences cumulées doit prendre en compte tous les risques concurrents. (2) La greffe rénale est un risque concurrent dépendant de la probabilité de décès des patients. Les patients inscrits sur liste d'attente de greffe avaient un risque de décès significativement plus bas que les autres patients, après ajustement sur l'âge et la présence de comorbidités. (3) Le transfert en hémodialyse est un risque concurrent qui semble dépendre de la probabilité de décès des patients. En effet, l'âge et la présence de comorbidités étaient à la fois des facteurs de risque de décès et des facteurs de contre-indications au transfert en hémodialyse. De plus, la plupart des néphrologues ayant répondu à notre enquête ont déclaré qu'une espérance de vie limitée pouvait constituer une contre-indication au transfert. Conclusion : Dans les études de cohorte de patients en insuffisance rénale chronique terminale, les analyses de survie devraient prendre en compte les changements de traitement car ce sont des risques concurrents dépendants de la probabilité de décès. Notre travail a montré que les modèles multi-états sont des outils statistiques flexibles qui permettent de bien représenter l'inter-dépendance entre les différentes modalités de traitement entre dialyse péritonéale, hémodialyse, greffe rénale et décès. / In survival analysis, a competing risk is an event that hinders the observation of the event of interest (usually death). If the probability of a competing risk depends on the probability of the event of interest, then it can not be treated as censoring. Patients with ESRD can be treated with hemodialysis, peritoneal dialysis and renal transplantation. These treatments are complementary and patients can move from one treatment modality to another. The dependence between changes in treatment modality and the probability of death has not been studied and these changes are censored in survival analysis.Objectives: To analyze the dependence between the probability of death in dialysis and kidney transplant, and the probability of death on peritoneal dialysis and transfer to hemodialysis. We demonstrate the negative consequences if this dependence is not taken into account in the survival analysis. Methods: (1) We compared estimates of event probability obtained by the Kaplan-Meier method and Kalbfleisch and Prentice on 383 consecutive indicent patients treated by peritoneal dialysis in Lille. (2) We analyzed data on 7318 incident patients undergoing hemodialysis in France from the national registry REIN. We used a multistate model to analyze the influence of inclusion on the transplant waiting list on the probability of death on dialysis. (3) In a cohort of 2790 patients aged over 65 and treated with peritoneal dialysis from the registry of the French Language Peritoneal Dialysis (RDPLF), we analyzed the factors against transfer-indication in HD taking into account death as competing risk using the Fine and Gray model. This analysis was complemented by a survey conducted among 55 nephrologists practicing Peritoneal dialysis in France.Results: (1) The Kaplan-Meier method systematically overestimated the probability of death due to violation of the assumption of independence between death and competing risks. This method does not appear valid in the analyzes of survival on dialysis. The method of Kalbfleisch and Prentice was valid but the interpretation of cumulative impacts must take into account all the competing risks. (2) Kidney transplantation is a competing risk depending on the probability of dying patients. Patients on the transplant waiting list had a risk of death significantly lower than other patients, after adjustment for age and comorbidity. (3) The transfer is a risk in hemodialysis competitor who seems to depend on the probability of dying patients. Indeed, age and comorbidities were both risk factors and death factors against transfer-indications for hemodialysis. Moreover, most nephrologists who responded to our survey reported that limited life expectancy could be an indication to the transfer-cons.Conclusion: In cohort studies of patients with ESRD, the survival analyzes should take into account changes in treatment because they are competing risks dependent on the probability of death. Our work has shown that multi-state models are statistical tools that enable flexible to adequately represent the interdependence between the different modalities of treatment for peritoneal dialysis, hemodialysis, kidney transplantation and death.

Den militära kulturen definieras i hög grad av en stark hierarki och behov av kontroll. Dessa är ideal och värderingar som konkurrerar med innovationsbenägenhet. Tänkande i nya banor begränsas ofta av en uppsättning vedertagna övertygelser som strikt upprätthålls. Metoder och tillvägagångsätt riskerar att bli förutsägbara när organisationer inte är innovativa och anpassar sig efter förändrade förutsättningar. Denna studie syftar till att skapa förståelse för antaganden och värderingar som begränsar utveckling och tänkande i nya banor. Studien använder en historisk tillbakablick, observationer av den svenska Försvarsmaktens (FM) kommunikation och gruppdiskussioner för att spåra antaganden och värderingar som påverkar innovationsbenägenhet. Studiens resultat visar att kontroll och stabilitet är viktiga drivkrafter inom FMs kultur. Det finns en kultur som innebär att erfarenhet ges högt förtroende samt en obenägenhet att ta risker, vilket hämmar kritisk tänkande och utvecklande av nya beteenden. Det finns även en differens mellan antagna värderingar i styrande dokument och rådande grundläggande antaganden.

Diploma thesis is focusing on the declared and actually perceived organizational culure. Theoretical part defines the concet of organizational culture, focuses on description of individual attributes of the organizational culture and its structure. Attention is paid also to some typologies of the organizational culture, and to an overview of current level of knowledge regarding the area of declared and actually percieved organizational culture. In the empirical part, a case study of a chosen organization has been conducted, attempting to describe given phenomena. Content analysis has been used to study declared organizational culture, actually percieved organizational culture has been measured by OCAI and way of employees' understanding of this phenomenon has been reviewed in transcriptions of interviews with employess. Further, possible areas of future research have been suggested. Keywords: Organizational culture, competing values framework, university, case study

Metaphorically, the idiom “you cannot have your cake and eat it too” describes fundamental tensions at the heart of today’s organizations. Engaging tensions may seem implausible or even impossible. However, there exists evidence, given the increasingly complex environment, that both are vital to organizational success. To succeed, therefore, requires that organizations be able to manage, embrace, and transcend tensions. Consequently, the overall purpose of this thesis is to advance our understanding of tensions in general, and in creativity-based contexts in particular. The purpose is achieved through five self-contained yet complementary papers. The conceptual parts, which resulted in three papers, include a literature review on tensions, from which inspirations and ideas from different disciplines have been drawn in order to add value to the literature specifically addressing tensions. In parallel with this conceptual work, I explore tensions (a paradox, to be specific) in a specific context (architecture), an effort that results in two papers. Consequently, in the conceptual work, I focus on what “could be,” while in the empirical work I focus on “what is.” The findings highlight that first, theorizing about tensions calls for conceptual clarity. This was accomplished by identifying and then assembling core features that scholars use to conceptualize tensions. In doing so, the thesis contributes to the ways in which tensions are “represented” by reducing confusion and by making the assumptions behind tensions clear. Second, the thesis establishes that dealing with tensions productively requires a shift from thinking (and doing) based on a contingency approach towards contemporary approaches. Given the nature of the empirical context and the challenges therein, a true shift of this order necessitates framing tensions as paradoxes. In the same vein, the thesis indicates the need to rethink the central question; currently, that question is predominantly “how can we accommodate both A and B?” Given the nature of the empirical context, the question can be shifted to “why not C?” Doing so breaks away from focusing on the existing competing options and turns the focus towards something new. Moreover, dealing with tensions through this lens prevents neutralizing them and settling for a bland halfway point between one extreme and the other. Third, the thesis challenges the taken-for-granted assumption in the literature that dealing with tensions as paradoxes necessitates temporal compromise, separation, or resolution. In the thesis, I argue that dealing with paradoxes is possible without separating. This is so because simultaneously engaging paradoxes allows organizations to tap their energy and opens up new possibilities. In this case, the thesis contributes to the literature by empirically studying architectural firms. This empirical study shows that dealing with paradoxes requires an intricate interplay between what I call paradoxical mindsets and practices—which comprise organization members’ emotions, cognition, and behaviors—and organizational conditions that embed such mindsets and practices into the organization’s system. Fourth, the thesis makes a point that not all tensions require an action move. Accordingly, the thesis establishes that dealing with paradoxes may not necessarily entail action moves but rather a space to engage in dialogue so as to connect opposites, move outside of them, and situate them in a new relationship. In doing so, the presence of tension is appreciated and complementarity is sought. That is, the challenge is to be able to embrace paradoxes and not to resolve them. The thesis concludes that although it is challenging to tap the power of paradoxes, it is not impossible. This thesis shows that this goal can be accomplished by accepting that paradoxes are normal, and then seeking to transcend them. In so doing, organizations can unleash the “slices of genius” in their members.

The presented dissertation reports the findings of a quantitative study on shared values of a multinational corporation across its Middle East and Sub-Saharan subsidiaries. The study is based on the Competing Values Framework (Quinn &Rohrbaugh, 1983; Cameron&Quinn, 1999) with 24 shared values superimposed upon the Competing Values Framework (McDonald&Gandz, 1992). The presented work argues that an organisation can increase its competitiveness by understanding its shared value system and by managing the organisation accordingly. In return, the organisation due to an increased competitiveness would realise a competitive advantage by understanding the shared value composition. In understanding the shared values composition one can attract and retain staff due to a greater person organisation fit, which in turn would lead to a reduction in staff turnover, skilling and training cost in return yielding a competitive advantage. The research found that there seems to be a common shift or trend in the Cape Town, Johannesburg and Middle East subsidiaries. The trend is that the subsidiaries value those shared values most that fits into the clan and market culture quadrants with some elements of the adhocracy and hierarchy cultures type resembled. The latter not being as dominant as the clan and market culture types. The Pretoria and Turkey subsidiaries regarded the values of the clan and adhocracy culture quadrants higher than those within the market and hierarchy culture quadrants. This is unexpected to a degree as the subsidiaries are across multiple nations encompassing different cultures. The subsidiaries believe in culture of collaboration and competition with the purpose of group cohesion and the pursuit of objectives. Copyright / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

Dynamic optimisation problems are problems where the search space does not remain constant over time. Evolutionary algorithms aimed at static optimisation problems often fail to effectively optimise dynamic problems. The main reason for this is that the algorithms converge to a single optimum in the search space, and then lack the necessary diversity to locate new optima once the environment changes. Many approaches to adapting traditional evolutionary algorithms to dynamic environments are available in the literature, but differential evolution (DE) has been investigated as a base algorithm by only a few researchers. This thesis reports on adaptations of existing DE-based optimisation algorithms for dynamic environments. A novel approach, which evolves DE sub-populations based on performance in order to discover optima in an dynamic environment earlier, is proposed. It is shown that this approach reduces the average error in a wide range of benchmark instances. A second approach, which is shown to improve the location of individual optima in the search space, is combined with the first approach to form a new DE-based algorithm for dynamic optimisation problems. The algorithm is further adapted to dynamically spawn and remove sub-populations, which is shown to be an effective strategy on benchmark problems where the number of optima is unknown or fluctuates over time. Finally, approaches to self-adapting DE control parameters are incorporated into the newly created algorithms. Experimental evidence is presented to show that, apart from reducing the number of parameters to fine-tune, a benefit in terms of lower error values is found when employing self-adaptive control parameters. / Thesis (PhD)--University of Pretoria, 2012. / Computer Science / unrestricted