Sudden personal transformation (SPT) was defined as a subjectively reported, positive, profound, and lasting personal change that follows a relatively brief and memorable inner experience. Although such change has been described in numerous biographies, works of fiction, and religious and scholarly texts, a consistent definition and systematic program of research is lacking in the psychological literature. Moreover, almost nothing is known about what causes such change from the subjective point of view of individuals who have experienced it first hand. This study used semi-structured interviews and thematic analysis to explore the common beliefs of three participants about the factors that facilitated and the mechanisms that caused their SPT. Findings reveal that all participants reported a life transition, feeling miserable, feeling exhausted, feeling unable to resolve adverse circumstances, reaching a breaking point, and support from others facilitated their individual SPT’s. All participants also indicated that a formalized activity or ceremony as well as a process outside of their conscious control (either a higher power or a deep inner wisdom) produced or caused their SPT’s. Implications for future research and counselling practice are discussed. / Graduate

Les systèmes dynamiques discrets, œuvrant en itérations chaotiques ou asynchrones, se sont avérés être des outils particulièrement intéressants à utiliser en sécurité informatique, grâce à leur comportement hautement imprévisible, obtenu sous certaines conditions. Ces itérations chaotiques satisfont les propriétés de chaos topologiques et peuvent être programmées de manière efficace. Dans l’état de l’art, elles ont montré tout leur intérêt au travers de schémas de tatouage numérique. Toutefois, malgré leurs multiples avantages, ces algorithmes existants ont révélé certaines limitations. Cette thèse a pour objectif de lever ces contraintes, en proposant de nouveaux processus susceptibles de s’appliquer à la fois au domaine du tatouage numérique et au domaine de la stéganographie. Nous avons donc étudié ces nouveaux schémas sur le double plan de la sécurité dans le cadre probabiliste. L’analyse de leur biveau de sécurité respectif a permis de dresser un comparatif avec les autres processus existants comme, par exemple, l’étalement de spectre. Des tests applicatifs ont été conduits pour stéganaliser des processus proposés et pour évaluer leur robustesse. Grâce aux résultats obtenus, nous avons pu juger de la meilleure adéquation de chaque algorithme avec des domaines d’applications ciblés comme, par exemple, l’anonymisation sur Internet, la contribution au développement d’un web sémantique, ou encore une utilisation pour la protection des documents et des donnés numériques. Parallèlement à ces travaux scientifiques fondamentaux, nous avons proposé plusieurs projets de valorisation avec pour objectif la création d’une entreprise de technologies innovantes. / Discrete dynamical systems by chaotic or asynchronous iterations have proved to be highly interesting toolsin the field of computer security, thanks to their unpredictible behavior obtained under some conditions. Moreprecisely, these chaotic iterations possess the property of topological chaos and can be programmed in anefficient way. In the state of the art, they have turned out to be really interesting to use notably through digitalwatermarking schemes. However, despite their multiple advantages, these existing algorithms have revealedsome limitations. So, these PhD thesis aims at removing these constraints, proposing new processes whichcan be applied both in the field of digital watermarking and of steganography. We have studied these newschemes on two aspects: the topological security and the security based on a probabilistic approach. Theanalysis of their respective security level has allowed to achieve a comparison with the other existing processessuch as, for example, the spread spectrum. Application tests have also been conducted to steganalyse and toevaluate the robustness of the algorithms studied in this PhD thesis. Thanks to the obtained results, it has beenpossible to determine the best adequation of each processes with targeted application fields as, for example,the anonymity on the Internet, the contribution to the development of the semantic web, or their use for theprotection of digital documents. In parallel to these scientific research works, several valorization perspectiveshave been proposed, aiming at creating a company of innovative technology.

Text in English, abstracts and keywords in English, Afrikaans and Zulu / Secondary educational institutions need to constantly scan their environment for crises that could hamper their operations and hinder the achievement of their organisational objectives. These institutions should also engage their strategic stakeholders in a mixed motive communication to collaboratively discuss the crises and find amicable solutions; thereby avoiding crises like the proliferating student strikes in secondary educational institutions in Kenya. This study explored the need for a customised Proactive Crisis Communication Process (PCCP) framework for secondary educational institutions in Kenya to avoid student strikes. A two-phased approach was adopted to collect the data. The first phase involved 12 one-on-one semi-structured interviews with the principals of the secondary educational institutions in Mirangine Sub-County, while the second phase involved five focus group discussions with the students of Ruiru Secondary School. The results indicated that student strikes in secondary educational institutions in Kenya were proliferating and that despite this, these institutions lack proactive measures to avoid strikes. Hence, this study posited a PCCP framework that proposed various proactive measures to avoid student strikes in secondary educational institutions in Kenya. / Sekondêre opvoedkundige instellings moet konstant hul omgewing ondersoek vir krisisse wat hul bedrywighede kan belemmer en die bereiking van hul organisatoriese doelwitte kan verhinder. Hierdie instellings moet ook hul strategiese belanghebbers by gemengdemotief- kommunikasie betrek om gesamentlik die krisisse te bespreek en minlike oplossings te vind; en sodoende krisisse soos die toenemende studentestakings in sekondêre opvoedkundige instellings in Kenia te vermy. In hierdie studie is die nodigheid vir ʼn doelgemaakte ProaktieweKrisiskommunikasieproses (PCCP)-raamwerkvir sekondêre opvoedkundige instellings in Kenia ondersoek om studentestakings te voorkom. ʼn Tweefase-benadering is gevolg om die data in te samel. Die eerste fase het 12 halfgestruktureerde onderhoude behels wat een-tot-een met die hoofde van die sekondêre opvoedkundige instellingsin Mirangine Sub-Countygevoer is, terwyl die tweede fase bestaan het uit vyf fokusgroepbesprekings met die studente van RuiruSecondarySchool. Die resultate het getoon dat studentestakings in sekondêre opvoedkundige instellingsin Kenia vinnig toeneem en dat hierdie instellings, ten spyte daarvan, nie oor proaktiewe maatstawwe beskik om stakings af te weer nie.Gevolglik het hierdie studie ʼn PCCP-raamwerk aangeneem wat verskeie proaktiewe maatstawwe voorstel om stakings deur studente in sekondêre opvoedkundige instellings in Kenia te verhoed. / Izikhungo zemfundoyomkhakhawamasekhondari kumele zihlale ziqaphele ukuthi akukho yini endaweniezikuyookungasusaudweshubesekuphazamisaukusebenzakwazokuvimbe impumeleloyazoezinhloswenizayo.Lezizikhungokumelezibuyezisebenzisane nabathintekayo balawule amasu okusebenza ukuba kubenokuxhumana okunhlobonhlobo kuxoxwe ngokubambisana ngodweshu olungavela nokuthi lungasonjululwa kanjani ngendlela egculisayo; ngaleyo ndlela-ke ingagwemeka imibhikisho yabafundi elokhu isabalala ezikhungwenj zamasekhondari eKenya. Lolu cwaningoluhlola isidingo sohlaka lwekhethelo lokusheshe kusukunyelweudweshu lungakenzeki,i-Proactive Crisis Communication Process (PCCP) olungasebenza ezikhungweni zemfundo yamasekhondari eKenya ukuze kugwenywe imibhikisho yabafujni. Kwemukelwaindlela ezigaba zimbili yokuqoqainingwane. Isigaba sokuqala ngokuxoxisana okuyi-12 komuntu ebhekene nomuntu okuthi akuhleleke nje, okwenziwa nothishanhloko bezukhungo zemfundi yamasekhondaribaseMiringane Sub-County, kanti isigaba sesibili sabandakanya izingxoxo eziyisihlanu zamaqembu agxike kokuthile nje, zenziwa nabafundi besikole iRuri Secondary School. Imiphumela yaveza ukuthi imibhikisho ezikhungweni zemfundo yamasekhondari eKenya yabe yanda nokuthi nangaphandle kwalokhu izikhungo lezi zazingenazo izinyathelo ezingazithatha ngaphambi kwesikhathi ukuvimba ukwenziwa kwemibhikisho. Yikho-ke lolu cwaningo luphakamisa uhlaka lwe-PCCP oluncoma izinyathelo ezahlukene okumele zisheshe zithathwe ukugwema imibhikisho yabafundi ezikhungweni zamasekhondari eKenya. / Communication / M.A. (Communication)

In this thesis I hope to provide a clear and concise introduction to Feigenbaum scaling accessible to undergraduate students. This is accompanied by a description of how to obtain numerical results by various means. A more intricate approach drawing from renormalization theory as well as a short consideration of some of the topological properties will also be presented. I was furthermore trying to put great emphasis on diagrams throughout the text to make the contents more comprehensible and intuitive.