Abstract Critical Infrastructures (CIs) are an integral part of our society and economy. Services like electricity supply or telecommunication services are expected to be available at all times and a service failure may have catastrophic consequences for society or economy. Current CI protection strategies are from a time when CIs or CI sectors could be operated more or less self-sufficient and interconnections among CIs or CI sectors, which may lead to cascading service failures to other CIs or CI sectors, where not as omnipresent as today. In this PhD thesis, a cross-sector CI model for on-line risk monitoring of CI services, called CI security model, is presented. The model allows to monitor a CI service risk and to notify services that depend on it of possible risks in order to reduce and mitigate possible cascading failures. The model estimates CI service risk by observing the CI service state as measured by base measurements (e.g. sensor or software states) within the CI service components and by observing the experienced service risk of CI services it depends on (CI service dependencies). CI service risk is estimated in a probabilistic way using a Bayesian network based approach. Furthermore, the model allows CI service risk prediction in the short-term, mid-term and long-term future, given a current CI service risk and it allows to model interdependencies (a CI service risk that loops back to the originating service via dependencies), a special case that is difficult to model using Bayesian networks. The representation of a CI as a CI security model requires analysis. In this PhD thesis, a CI analysis method based on the PROTOS-MATINE dependency analysis methodology is presented in order to analyse CIs and represent them as CI services, CI service dependencies and base measurements. Additional research presented in this PhD thesis is related to a study of assurance indicators able to perform an on-line evaluation of the correctness of risk estimates within a CI service, as well as for risk estimates received from dependencies. A tool that supports all steps of establishing a CI security model was implemented during this PhD research. The research on the CI security model and the assurance indicators was validated based on a case study and the initial results suggest its applicability to CI environments. / Tiivistelmä Tässä väitöskirjassa esitellään läpileikkausmalli kriittisten infrastruktuurien jatkuvaan käytön riskimallinnukseen. Tämän mallin avulla voidaan tiedottaa toisistaan riippuvaisia palveluita mahdollisista vaaroista, ja siten pysäyttää tai hidastaa toisiinsa vaikuttavat ja kumuloituvat vikaantumiset. Malli analysoi kriittisen infrastruktuurin palveluriskiä tutkimalla kriittisen infrastruktuuripalvelun tilan, joka on mitattu perusmittauksella (esimerkiksi anturi- tai ohjelmistotiloina) kriittisen infrastruktuurin palvelukomponenttien välillä ja tarkkailemalla koetun kriittisen infrastruktuurin palveluriskiä, joista palvelut riippuvat (kriittisen infrastruktuurin palveluriippuvuudet). Kriittisen infrastruktuurin palveluriski arvioidaan todennäköisyyden avulla käyttämällä Bayes-verkkoja. Lisäksi malli mahdollistaa tulevien riskien ennustamisen lyhyellä, keskipitkällä ja pitkällä aikavälillä, ja mahdollistaa niiden keskinäisten riippuvuuksien mallintamisen, joka on yleensä vaikea esittää Bayes-verkoissa. Kriittisen infrastruktuurin esittäminen kriittisen infrastruktuurin tietoturvamallina edellyttää analyysiä. Tässä väitöskirjassa esitellään kriittisen infrastruktuurin analyysimenetelmä, joka perustuu PROTOS-MATINE -riippuvuusanalyysimetodologiaan. Kriittiset infrastruktuurit esitetään kriittisen infrastruktuurin palveluina, palvelujen keskinäisinä riippuvuuksina ja perusmittauksina. Lisäksi tutkitaan varmuusindikaattoreita, joilla voidaan tutkia suoraan toiminnassa olevan kriittisen infrastruktuuripalvelun riskianalyysin oikeellisuutta, kuin myös riskiarvioita riippuvuuksista. Tutkimuksessa laadittiin työkalu, joka tukee kriittisen infrastruktuurin tietoturvamallin toteuttamisen kaikkia vaiheita. Kriittisen infrastruktuurin tietoturvamalli ja varmuusindikaattorien oikeellisuus vahvistettiin konseptitutkimuksella, ja alustavat tulokset osoittavat menetelmän toimivuuden. / Kurzfassung In dieser Doktorarbeit wird ein Sektorübergreifendes Modell für die kontinuierliche Risikoabschätzung von kritische Infrastrukturen im laufenden Betrieb vorgestellt. Das Modell erlaubt es, Dienstleistungen, die in Abhängigkeit einer anderen Dienstleistung stehen, über mögliche Gefahren zu informieren und damit die Gefahr des Übergriffs von Risiken in andere Teile zu stoppen oder zu minimieren. Mit dem Modell können Gefahren in einer Dienstleistung anhand der Überwachung von kontinuierlichen Messungen (zum Beispiel Sensoren oder Softwarestatus) sowie der Überwachung von Gefahren in Dienstleistungen, die eine Abhängigkeit darstellen, analysiert werden. Die Abschätzung von Gefahren erfolgt probabilistisch mittels eines Bayessches Netzwerks. Zusätzlich erlaubt dieses Modell die Voraussage von zukünftigen Risiken in der kurzfristigen, mittelfristigen und langfristigen Zukunft und es erlaubt die Modellierung von gegenseitigen Abhängigkeiten, die im Allgemeinen schwer mit Bayesschen Netzwerken darzustellen sind. Um eine kritische Infrastruktur als ein solches Modell darzustellen, muss eine Analyse der kritischen Infrastruktur durchgeführt werden. In dieser Doktorarbeit wird diese Analyse durch die PROTOS-MATINE Methode zur Analyse von Abhängigkeiten unterstützt. Zusätzlich zu dem vorgestellten Modell wird in dieser Doktorarbeit eine Studie über Indikatoren, die das Vertrauen in die Genauigkeit einer Risikoabschätzung evaluieren können, vorgestellt. Die Studie beschäftigt sich sowohl mit der Evaluierung von Risikoabschätzungen innerhalb von Dienstleistungen als auch mit der Evaluierung von Risikoabschätzungen, die von Dienstleistungen erhalten wurden, die eine Abhängigkeiten darstellen. Eine Software, die alle Aspekte der Erstellung des vorgestellten Modells unterstützt, wurde entwickelt. Sowohl das präsentierte Modell zur Abschätzung von Risiken in kritischen Infrastrukturen als auch die Indikatoren zur Uberprüfung der Risikoabschätzungen wurden anhand einer Machbarkeitsstudie validiert. Erste Ergebnisse suggerieren die Anwendbarkeit dieser Konzepte auf kritische Infrastrukturen.

Our understanding of the physical world has evolved drastically over the last century and the microstructure described by subatomic physics has been found to be far stranger than we could previously have envisaged. However, our corresponding model of experience and its structure has remained largely untouched. The orthodox view conceives of our experience as made up of a number of different simpler experiences that are largely independent of one another. This traditional atomistic picture is deeply entrenched. But I argue that it is wrong. Our experience is extraordinarily rich and complex. In just a few seconds we may see, hear and smell a variety of things, feel the position and movement of our body, experience a blend of emotions, and undergo a series of conscious thoughts. This very familiar fact generates three puzzling questions. The first question concerns the way in which all these different things are experienced together. What we see, for example, is experienced alongside what we hear. Our visual experience does not occur in isolation from our auditory experience, sealed off and separate. It is fused together in some sense. It is co-conscious. We may then ask the Unity Question: What does the unity of consciousness consist in? The second question is the Counting Question: How many experiences does a unified region of consciousness involve? Should we think of our experience at a time as consisting in just one very rich experience, in a handful of sense-specific experiences, or in many very simple experiences? How should we go about counting experiences? Is there any principled way to do so?The third and final question, the Dependency Question, concerns the degree of autonomy of the various different aspects of our unified experience. For example, would one's visual experience be the same if one's emotional experience differed? Is the apparent colour of a sunset affected by the emotional state that we are in at the time? I offer a new answer to the Unity Question and argue that it has striking implications for the way that we address the Counting Question and the Dependency Question. In particular, it supports the view that our experience at a time consists in just one very rich experience in which all of the different aspects are heavily interdependent.

Mit dem Begriff der Intersektionalität wird die Verschränkung verschiedener Ungleichheit generierender Strukturkategorien, wie Geschlecht, Ethnizität, Klasse, Nationalität, Sexualität, Alter etc. erfasst. Er soll aufzeigen, dass keine dieser Kategorien alleine steht, sondern sowohl für sich als auch im Zusammenspiel mit den anderen einen die gesellschaftlichen Machtverhältnisse mitkonstituierenden Effekt hat. Die historischen Wurzeln liegen im 19. Jahrhundert und gehen auf die Erfahrungen Schwarzer Frauen und Lesben zurück, die sich im Feminismus westlicher weißer Mittelschichtsfrauen nicht wiederfanden. Leslie McCall unterscheidet drei methodologische Zugänge: den anti-kategorialen Ansatz, den intra-kategorialen Ansatz und den inter-kategorialen Ansatz.

In theory, the South African government advocates additive bilingual education over subtractive bilingual education. However, this study shows that subtractive bilingual education supersedes additive bilingual education mainly because the official African languages of South Africa are being marginalised and not utilised as languages of teaching and learning in schools. The majority of isiZulu speaking learners in KwaZulu-Natal are underperforming academically under a subtractive bilingual educational system. The findings of this study acknowledge that there are numerous contributing factors to this problem, but the most obvious is that isiZulu speaking learners are compelled to write their examinations in English. This study employed a triangulation approach where various literary sources were consulted to illustrate how English has emerged as a dominant language on the local and global stage, and how this has affected the status and use of minority languages. Qualitative approaches were used to gather data from Grade 10 to 12 isiZulu speaking learners who attend the so-called 'Black schools' in the district of Pinetown, in KwaZulu-Natal. Questionnaires and experimental tests were used as the main instruments for gathering data from learners. One-on-one interviews were conducted with educators and other relevant stakeholders. The observation technique was also utilised to monitor the behaviour of isiZulu speaking learners in both affluent and previously disadvantaged schools. By examining Cummins’ interdependency hypothesis (1979, 1996 and 2000) as a theoretical framework, this research study has proven that the continued use of English as the only language of teaching and learning in South African ‘Black schools’ has a negative impact on the academic achievements of the KwaZulu-Natal isiZulu speaking learners. The study, therefore, calls for the introduction of a language policy that will promote dual bilingual education where both isiZulu and English are used as the languages of teaching and learning throughout the KwaZulu-Natal isiZulu speaking learners’ scholastic years. The study has proven that this approach to education will facilitate better understanding of the subject matter and thus curb the high failure rate, especially in the so called 'Black schools'. / African Languages / D. Litt. et Phil. (African Languages)

In theory, the South African government advocates additive bilingual education over subtractive bilingual education. However, this study shows that subtractive bilingual education supersedes additive bilingual education mainly because the official African languages of South Africa are being marginalised and not utilised as languages of teaching and learning in schools. The majority of isiZulu speaking learners in KwaZulu-Natal are underperforming academically under a subtractive bilingual educational system. The findings of this study acknowledge that there are numerous contributing factors to this problem, but the most obvious is that isiZulu speaking learners are compelled to write their examinations in English. This study employed a triangulation approach where various literary sources were consulted to illustrate how English has emerged as a dominant language on the local and global stage, and how this has affected the status and use of minority languages. Qualitative approaches were used to gather data from Grade 10 to 12 isiZulu speaking learners who attend the so-called 'Black schools' in the district of Pinetown, in KwaZulu-Natal. Questionnaires and experimental tests were used as the main instruments for gathering data from learners. One-on-one interviews were conducted with educators and other relevant stakeholders. The observation technique was also utilised to monitor the behaviour of isiZulu speaking learners in both affluent and previously disadvantaged schools. By examining Cummins’ interdependency hypothesis (1979, 1996 and 2000) as a theoretical framework, this research study has proven that the continued use of English as the only language of teaching and learning in South African ‘Black schools’ has a negative impact on the academic achievements of the KwaZulu-Natal isiZulu speaking learners. The study, therefore, calls for the introduction of a language policy that will promote dual bilingual education where both isiZulu and English are used as the languages of teaching and learning throughout the KwaZulu-Natal isiZulu speaking learners’ scholastic years. The study has proven that this approach to education will facilitate better understanding of the subject matter and thus curb the high failure rate, especially in the so called 'Black schools'. / African Languages / D. Litt. et Phil. (African Languages)