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A (self-) adaptive system is a system that can dynamically adapt its behavior or structure during execution to "adapt" to changes to its environment or the system itself. From a security standpoint, there has been some research pertaining to (self-) adaptive systems in general but not enough care has been shown towards the adaptation itself. Security of systems can be reasoned about using threat models to discover security issues in the system. Essentially that entails abstracting away details not relevant to the security of the system in order to focus on the important aspects related to security. Threat models often enable us to reason about the security of a system quantitatively using security metrics. The structural adaptation process of a (self-) adaptive system occurs based on a reconfiguration plan, a set of steps to follow from the initial state (configuration) to the final state. Usually, the reconfiguration plan consists of multiple strategies for the structural adaptation process and each strategy consists of several steps steps with each step representing a specific configuration of the (self-) adaptive system. Different reconfiguration strategies have different security levels as each strategy consists of a different sequence configuration with different security levels. To the best of our knowledge, there exist no approaches which aim to guide the reconfiguration process in order to select the most secure available reconfiguration strategy, and the explicit security of the issues associated with the structural reconfiguration process itself has not been studied. In this work, based on an in-depth literature survey, we aim to propose several metrics to measure the security of configurations, reconfiguration strategies and reconfiguration plans based on graph-based threat models. Additionally, we have implemented a prototype to demonstrate our approach and automate the process. Finally, we have evaluated our approach based on a case study of our making. The preliminary results tend to expose certain security issues during the structural adaptation process and exhibit the effectiveness of our proposed metrics.

Baigiamajame darbe sudarytas uždarosios asinchroninės bejutiklės vektoriškai valdomos pavaros imitacinis modelis ir ištirtos charakteristikos. Teorinėje darbo dalyje yra aptariami asinchroninių elektros pavarų privalumai bei šiose pavarose naudojami greičio jutikliai. Aprašomi stebiklių privalumai bei trūkumai, pagrindžiamas jų naudojimas asinchroninėse pavarose. Nagrinėjami bejutiklių elektros pavarų ypatumai, aprašomi vektorinio valdymo bendrieji principai bei aprašomi bejutiklėse vektoriškai valdomose pavarose naudojamų stebiklių modeliai. Pateikiami du skirtingi asinchroninių variklių matematiniai modeliai. Tiriamojoje dalyje parenkamas asinchroninio variklio modelis, tiriant abiejų imitacinių modelių dinamines greičio charakteristikas. Sudaromas stebiklio imitacinis modelis. Tiriamos stebiklio greičio dinaminės charakteristikos, sudaroma uždaroji greičio reguliavimo sistema su stebikliu. Analizuojamos uždarosios greičio reguliavimo sistemos greičio charakteristikos be apkrovos, su šuoline apkrova ir harmoniškai kintančia apkrova. Nagrinėjama sistemos stiprinimo koeficiento įtaka uždarosios greičio reguliavimo sistemos greičio charakteristikų pereinamiesiams procesams. Magistro darbas baigiamas tyrimo išvadomis, kuriose aptariamas darbo rezultatų realaus pritaikymo galimybės. Darbą sudaro 8 dalys: įvadas, žymėjimai, literatūros šaltinių analizė, tyrimo tikslas ir uždaviniai, teorinė dalis, tiriamoji dalis išvados ir pasiūlymai, literatūros šaltiniai. / The final master degree thesis presents sensorless vector controlled induction motor drive simulation model and characteristics. In the analytic part of master thesis advantages of induction motor drives and speed sensors are described. Advantages and disadvantages of speed estimators are presented and purpose of using them are proved. Peculiarities of sensorless motor drives, principles of vector control and models of speed estimators are analyzed. Two simulation models of induction motor are proposed. In the research part characteristics of induction motors are compared and motor model is chosen. Characteristics of open loop induction motor drive are investigated and simulation model of closed loop induction motor drive with speed estimator is designed. Characteristics of closed loop control system at no load, constant load and harmonic load are analyzed and influence of speed controller gain is considered. Thesis is closed with conclusions about designed system application in real projects. Structure: introduction, list of symbols, literature review, the study aims and objectives, the theoretical part, research part, conclusions and proposals, references.

<p>This study proposes that poor understanding of the structures, processes and outcomes of organisations seriously hampers collaboration between professional groups in care organisations. Three care settings were investigated: follow-up of patients with heart disease, an intensive care unit and care services for older people.</p><p>The overall aim was to investigate how people understand structures, processes and outcomes in care organisations. The participants were patients, patient representatives, healthcare professionals, managers and politicians.</p><p>A qualitative approach was used. Thematic analysis and grounded theory were employed in analysing the data.</p><p>Despite considerable efforts, no major changes took place over a 7-year period as to how cardiac follow-up services were understood. The system of cardiac follow-up services was found fragmented in its organisation and in the way individuals understood it. The results indicate that care professionals, patients and leaders have dissimilar understandings. The data suggest that care is organised from a professional-centred perspective rather than from a holistic worldview of the patients’ total context. Leaders in intensive care perceive their organisation as a learning organisation. However, in daily work healthcare tends to function to what can be described as a mass production approach to care. This state of conflict caused confusion and chaos among the leaders. The municipal elderly care services and the county council’s geriatric organisation had difficulties in co-ordination. Older people were perceived as passive recipients of healthcare, rather than as consumers whose well being and outcome were a reflection to the quality of the service.</p><p>The study concludes that despite the major changes that have taken place in the Swedish health and elderly care organisations over the past years, healthcare professionals’ understanding of their work has gone largely unchanged. Their understanding of care structures and processes did not change despite outside pressures. Lack of understanding of what others understand hampers development with the result that care organisations risk stagnation.</p>

<p>The present thesis follows an intensive care unit during four year of hard work and demanding organisational changes (1998-2001). The changes were mainly initiated by diminishing resources and a legislative claim to pay regard to the quality aspect of health care service. The process of implementing a quality system was the main focus for the thesis. Triangulation was used aiming at explore the process from different views. Two interviews studies were conducted one with the staff and another with the leadership. Both interviews were analysed thematically combined with a phenomenographic technique (e.g. using the how, and what aspect). A longitudinal quasi experimental time-series study was also accomplished. The correlation between staff variables and workload were measured once a year. The result show a 20 % increase in workload per staff and year. The staff judged the organisational climate for innovativeness stable over the period. Sick leave increased, and more so, than the general trend in the society. In spite of this increase the prevalence of stress related symptoms was the same. Two different systems emerged, a complex adaptive system and a mechanical system. The two systems exist and functions intertwined. Because of the construction of the patient register it is possible to see that the situation around a patients being admitted ≥ 5 days functions according to the complex systems character while the situation around the acute patients functions according to a mechanical system. Sick leave correlated with number of patient admitted ≥ 5 days (P=,000). It seemed the problem found had its root in the unawareness of the existing of a complex system. The result has implications for a need of increased awareness about how to manage the situation when the ICU is functioning according to the complex adaptive system.</p>

This study proposes that poor understanding of the structures, processes and outcomes of organisations seriously hampers collaboration between professional groups in care organisations. Three care settings were investigated: follow-up of patients with heart disease, an intensive care unit and care services for older people. The overall aim was to investigate how people understand structures, processes and outcomes in care organisations. The participants were patients, patient representatives, healthcare professionals, managers and politicians. A qualitative approach was used. Thematic analysis and grounded theory were employed in analysing the data. Despite considerable efforts, no major changes took place over a 7-year period as to how cardiac follow-up services were understood. The system of cardiac follow-up services was found fragmented in its organisation and in the way individuals understood it. The results indicate that care professionals, patients and leaders have dissimilar understandings. The data suggest that care is organised from a professional-centred perspective rather than from a holistic worldview of the patients’ total context. Leaders in intensive care perceive their organisation as a learning organisation. However, in daily work healthcare tends to function to what can be described as a mass production approach to care. This state of conflict caused confusion and chaos among the leaders. The municipal elderly care services and the county council’s geriatric organisation had difficulties in co-ordination. Older people were perceived as passive recipients of healthcare, rather than as consumers whose well being and outcome were a reflection to the quality of the service. The study concludes that despite the major changes that have taken place in the Swedish health and elderly care organisations over the past years, healthcare professionals’ understanding of their work has gone largely unchanged. Their understanding of care structures and processes did not change despite outside pressures. Lack of understanding of what others understand hampers development with the result that care organisations risk stagnation.

The present thesis follows an intensive care unit during four year of hard work and demanding organisational changes (1998-2001). The changes were mainly initiated by diminishing resources and a legislative claim to pay regard to the quality aspect of health care service. The process of implementing a quality system was the main focus for the thesis. Triangulation was used aiming at explore the process from different views. Two interviews studies were conducted one with the staff and another with the leadership. Both interviews were analysed thematically combined with a phenomenographic technique (e.g. using the how, and what aspect). A longitudinal quasi experimental time-series study was also accomplished. The correlation between staff variables and workload were measured once a year. The result show a 20 % increase in workload per staff and year. The staff judged the organisational climate for innovativeness stable over the period. Sick leave increased, and more so, than the general trend in the society. In spite of this increase the prevalence of stress related symptoms was the same. Two different systems emerged, a complex adaptive system and a mechanical system. The two systems exist and functions intertwined. Because of the construction of the patient register it is possible to see that the situation around a patients being admitted ≥ 5 days functions according to the complex systems character while the situation around the acute patients functions according to a mechanical system. Sick leave correlated with number of patient admitted ≥ 5 days (P=,000). It seemed the problem found had its root in the unawareness of the existing of a complex system. The result has implications for a need of increased awareness about how to manage the situation when the ICU is functioning according to the complex adaptive system.

La communication humaine vise principalement à transmettre de l'information par le biais de l'utilisation de langues. Plusieurs chercheurs ont soutenu l'hypothèse selon laquelle les limites de la capacité du canal de transmission amènent les locuteurs de chaque langue à encoder l'information de manière à obtenir une répartition uniforme de l'information entre les unités linguistiques utilisées. Dans nos recherches, la stratégie d'encodage de l'information en communication parlée est connue comme résultant de l'interaction complexe de facteurs neuro-cognitifs, linguistiques, et sociolinguistiques et nos travaux s'inscrivent donc dans le cadre des systèmes adaptatifs complexes. Plus précisément, cette thèse vise à mettre en évidence les tendances générales, translinguistiques, guidant l'encodage de l'information en tenant compte de la structure des langues à trois niveaux d'analyse (macrosystémique, mésosystémique, et microsystémique). Notre étude s'appuie ainsi sur des corpus oraux et textuels multilingues dans une double perspective quantitative et typologique. Dans cette recherche, la langue est définie comme un système adaptatif complexe, régulé par le phénomène d'auto-organisation, qui motive une première question de recherche : "Comment les langues présentant des débits de parole et des densités d'information variés transmettent-elles les informations en moyenne ?". L'hypothèse défendue propose que la densité moyenne d'information par unité linguistique varie au cours de la communication, mais est compensée par le débit moyen de la parole. Plusieurs notions issues de la théorie de l'information ont inspiré notre manière de quantifier le contenu de l'information et le résultat de la première étude montre que le débit moyen d'information (i.e. la quantité moyenne d'information transmise par seconde) est relativement stable dans une fourchette limitée de variation parmi les 18 langues étudiées. Alors que la première étude propose une analyse de l'auto-organisation au niveau macro- systémique, la deuxième étude porte sur des sous-systèmes linguistiques tels que la phonologie et la morphologie : elle relève donc d'une analyse au niveau mésosystémique. Elle porte sur les interactions entre les modules morphologique et phonologique en utilisant les mesures de la complexité linguistique de ces modules. L'objectif est de tester l'hypothèse d'uniformité de la complexité globale au niveau mésosystémique. Les résultats révèlent une corrélation négative entre la complexité morphologique et la complexité phonologique dans les 14 langues et vont dans le sens de l'hypothèse de l'uniformité de la complexité globale d'un point de vue typologique holistique. La troisième étude analyse l'organisation interne des sous-systèmes phonologiques au moyen de la notion de charge fonctionnelle (FL) au niveau microsystémique. Les contributions relatives des sous-systèmes phonologiques (segments, accents, et tons) sont évaluées quantitativement en estimant leur rôle dans les stratégies lexicales. Elles sont aussi comparées entre 2 langues tonales et 7 langues non-tonales. En outre, la distribution interne de la charge fonctionnelle à travers les sous-systèmes vocaliques et consonantiques est analysée de façon translinguistique dans les 9 langues. Les résultats soulignent l'importance du système tonal dans les distinctions lexicales et indiquent que seuls quelques contrastes dotés d'une charge fonctionnelle élevée sont observés dans les distributions inégales de charge fonctionnelle des sous-systèmes dans les 9 langues. Cette thèse présente donc des études empiriques et quantitatives réalisées à trois niveaux d'analyse, qui permettent de décrire des tendances générales parmi les langues et apportent des éclaircissements sur le phénomène d'auto-organisation. / The main goal of using language is to transmit information. One of the fundamental questions in linguistics concerns the way how information is conveyed by means of language in human communication. So far many researchers have supported the uniform information density (UID) hypothesis asserting that due to channel capacity, speakers tend to encode information strategically in order to achieve uniform rate of information conveyed per linguistic unit. In this study, it is assumed that the encoding strategy of information during speech communication results from complex interaction among neurocognitive, linguistic, and sociolinguistic factors in the framework of complex adaptive system. In particular, this thesis aims to find general cross-language tendencies of information encoding and language structure at three different levels of analysis (i.e. macrosystemic, mesosystemic, and microsystemic levels), by using multilingual parallel oral and text corpora from a quantitative and typological perspective. In this study, language is defined as a complex adaptive system which is regulated by the phenomenon of self-organization, where the first research question comes from : "How do languages exhibiting various speech rates and information density transmit information on average ?". It is assumed that the average information density per linguistic unit varies during communication but would be compensated by the average speech rate. Several notions of the Information theory are used as measures for quantifying information content and the result of the first study shows that the average information rate (i.e. the average amount of information conveyed per second) is relatively stable within a limited range of variation among the 18 languages studied. While the first study corresponds to an analysis of self-organization at the macrosystemic level, the second study deals with linguistic subsystems such as phonology and morphology and thus, covers an analysis at the mesosystemic level. It investigates interactions between phonological and morphological modules by means of the measures of linguistic complexity of these modules. The goal is to examine whether the equal complexity hypothesis holds true at the mesosystemic level. The result exhibits a negative correlation between morphological and phonological complexity in the 14 languages and supports the equal complexity hypothesis from a holistic typological perspective. The third study investigates the internal organization of phonological subsystems by means of functional load (FL) at the microsystemic level. The relative contributions of phonological subsystems (segments, stress, and tones) are quantitatively computed by estimating their role of lexical strategies and are compared in 2 tonal and 7 non-tonal languages. Furthermore, the internal FL distribution of vocalic and consonantal subsystems is analyzed cross-linguistically in the 9 languages. The result highlights the importance of tone system in lexical distinctions and indicates that only a few salient high-FL contrasts are observed in the uneven FL distributions of subsystems in the 9 languages. This thesis therefore attempts to provide empirical and quantitative studies at the three different levels of analysis, which exhibit general tendencies among languages and provide insight into the phenomenon of self-organization.

Opportunistic selection is a practically appealing technique that is often used in multi-node wireless systems such as scheduling and rate adaptation in cellular systems and opportunistic wireless local area networks, wireless sensor networks, cooperative communications, and vehicular networks. In it, each node maintains a local preference number called metric that is function of its channel gains, and the best node with the highest metric is selected. Identifying the best node is challenging as the information about a node's metric is available only locally at each node. In our work, we focus on the popular, simple, and low feedback timer scheme for selection. In it, each node sets a timer as a function of its metric and transmits a packet when the timer expires. The metric-to-timer mapping maps larger metric values to smaller timer values, which ensures that the best node's timer expires first. However, it can fail to select the best node if another node transmits a packet within D s of the transmission by the best node. In this thesis, we make three contributions to the design and understanding of the timer-based selection scheme. Firstly, we introduce feedback overhead-aware contention resolution in the timer-based selection scheme. The outcome is a novel selection scheme that is faster than the splitting scheme and more reliable than the timer-based selection scheme. We analyze and minimize the average time required by the scheme to select the best node. Secondly, we characterize the optimal metric-to-timer mapping when the number of nodes in the system is not known, as is the case in several practical deployments. When the prior distribution of the nodes is known, we propose an optimal mapping that maximizes the success probability averaged over the distribution on the number of nodes. When even the prior distribution is not known, we propose a robust mapping that maximizes the worst case average success probability over all possible probability distributions on the number of nodes. In both cases, we show that the timers can expire only at 0, D, 2D, ... in the optimal timer mapping. For the known prior case, we develop recursive techniques to effectively compute the optimal timer mapping for binomial and Poisson priors. Lastly, we consider a discrete rate adaptive system and design an optimal timer scheme to maximize the end-to-end performance measure of system throughput. We derive several novel, insightful results about the optimal mapping that culminate in an iterative algorithm to compute it. We show that the design of the selection scheme is intimately related to the rate adaptation rule and the selection policy used. In all cases, extensive benchmarking with several ad hoc schemes proposed in the literature shows the significant gains that the proposed designs can deliver.

Many of the technological and social systems our society has come to depend on can be classified as complex adaptive systems (CAS). These systems are made of many individual parts that self-organize to respond and adapt to changing outside and inside influences affecting the system and its actors. These CAS can be placed on a spectrum ranging from loosely- to tightly-coupled, depending on the degree of interrelatedness and interdependence between system components. This research has explored how the process of collaboration occurs in both a loosely- and tightly-coupled setting using one exemplar of each system. The loosely-coupled exemplar related to disaster risk reduction in two Canadian communities while the tightly-coupled one involved the implementation of a surgical information management system in a Canadian hospital. A list of core elements of collaboration that should be considered essential to the success of all collaborative endeavours was developed as a result: Engagement, Communication, Leadership, Role Clarity, Awareness, Time, and Technical Skills and Knowledge. Based on observing how the core elements of collaboration interacted with one another within each of these example systems, two models were created to represent their relationships. A list of considerations that collaborative tool designers should consider was also developed and the implications of these considerations were discussed. As businesses and other organizations increasingly incorporate team-based work models, they will come to depend more heavily on technology-based solutions to support collaboration. By incorporating collaborative technologies that properly support the activity of these teams—based on the specific type of complex adaptive system in which their organization exists—organizations can avoid wasting time and resources developing tools that hinder collaboration.