In everyday situations individuals make decisions. For example, a tourist usually chooses a crowded or recommended restaurant to have dinner. Perhaps it is an individual decision, but the observed pattern of decision-making is a collective phenomenon. Collective behaviour emerges from the local interactions that give rise to a complex pattern at the group level. In our example, the recommendations or simple copying the choices of others make a crowded restaurant even more crowded. The rules of interaction between individuals are important to study. Such studies should be complemented by biological experiments. Recent studies of collective phenomena in animal groups help us to understand these rules and develop mathematical models of collective behaviour. The most important communication mechanism is positive feedback between group members, which we observe in our example. In this thesis, we use a generic experimentally validated model of positive feedback to study collective decision-making. The first part of the thesis is based on the modelling of decision-making associated to the selection of feeding sites. This has been extensively studied for ants and slime moulds. The main contribution of our research is to demonstrate how such aspects as "irrationality", speed and quality of decisions can be modelled using differential equations. We study bifurcation phenomena and describe collective patterns above critical values of a bifurcation points in mathematical and biological terms. In the second part, we demonstrate how the primitive unicellular slime mould Physarum Polycephalum provides an easy test-bed for theoretical assumptions and model predictions about decision-making. We study its searching strategies and model decision-making associated to the selection of food options. We also consider the aggregation model to investigate the fractal structure of Physarum Polycephalum plasmodia. / <p>Fel serie i tryckt bok /Wrong series in the printed book</p>

Ce mémoire de maîtrise s’applique à montrer comment la polyphonie narrative peut nous informer sur le vécu des employés en période de changement organisationnel. Pour être en mesure d’entendre ces multiples voix, nous avons fait l’étude des récits des employés et des dirigeants dans le cadre d’un tel processus. Nous voulions, à travers les récits des employés, illustrer empiriquement la manière dont ces récits constituent le changement organisationnel lui-même en mettant à jour les préoccupations qui alimentent le processus de changement et qui sont constitutives à la fois du changement et de l’entité organisationnels. Ces récits ont été analysés selon une perspective polyphonique, autrement dit, une approche mettant de l’avant l’existence de multiples voix en tensions, des voix composant ces récits. Pour procéder à l’analyse de ces récits, notre cadre théorique a mobilisé la notion de ventriloquie, tel que proposée et présentée dans les travaux de Cooren (2012, 2013). Ces préoccupations ont été analysées comme autant de voix animant et « auteurisant » (authoring) ces récits, fondant ainsi une polyphonie narrative que nous avons tenté de repérer et répertorier dans des entrevues. L’analyse de cette polyphonie par le repérage des voix, figures et tensions nous a permis de mettre à jour les préoccupations constitutives du changement lui-même. Dans ce mémoire, nous avons ainsi identifié puis analysé, les voix, les figures et les tensions qui illustrent le vécu de certains employés en période de changement organisationnel, comblant ainsi certaines lacunes repérées dans la littérature portant sur la polyphonie et le changement organisationnel. Comme nous le montrons, la littérature actuelle sur la polyphonie organisationnelle ne permet pas de saisir la manière dont les employés donnent voix à des préoccupations qui émergent du processus de changement et comment ces préoccupations interagissent et s’intègrent dans leurs récits organisationnels sur le changement. L’analyse de cette polyphonie par le repérage des voix, figures et tensions nous permet non seulement de mettre à jour les préoccupations constitutives du changement, mais aussi certains mécanismes communicationnels qui émergent de ce processus. En somme, l’étude de la polyphonie narrative nous permet de rendre compte de ce qui habite et préoccupe les employés en période de changement. Aussi, l’ensemble des préoccupations identifiées nous permet de brosser un portrait global du vécu des employés pendant cette période de changement tout en mettant à jour les tensions qui composent ce processus. / This master thesis illustrates the ways by which polyphonic narratives reveal some information about the employees’ experiences during a process of organizational change. In order to identify these multiple voices, we analyzed the employees’ and managers’ narratives. Through the employees’ narratives, we tried to empirically illustrate the way narratives are constitutive of organizational change. Furthermore, we sought to bring to light employees’ preoccupations that feed and are constitutive of the change process as well as the organizational entity. The employees’ stories were analyzed through a polyphonic perspective, that is, an approach that highlight the existence of multiple voices in tensions, voices that are part of the employees’ narratives. To help us investigate these stories, our theoretical framework was based on the ventriloquist approach, as proposed by Cooren (2012, 2013). These preoccupations were analyzed as several voices animating and authoring these narratives, hence creating a polyphonic narrative that we attempted to identify and categorize in our interviews. This polyphonic analysis, by the tracking of voices, figures and tensions allowed us to shed light on preoccupations that are constitutive of the change process. In this master thesis we identified and analyzed the voices, figures and tensions that illustrate the ways by which each employee experienced the process of organizational change. Consequently, we were able to contribute to the literature on polyphonic narratives and organizational change. As we show, this literature does not allow us to understand the way by which employees voice their concerns emerging from the change process and how these preoccupations interact with one another and integrate into organizational change narratives. Our findings suggest that all the employees’ preoccupations and concerns provide a global picture of their experiences during the process of organizational change and a better understanding of the tensions that are also part of the change process.

Städte sind aufgrund der zunehmend negativen Auswirkungen des Verkehrs auf die Umwelt an vorderster Front der nachhaltigen Entwicklung und der nachhaltigen Mobilität. In den Städten Subsahara-Afrikas scheinen jedoch die Akteure und Hauptvertreter nachhaltiger Mobilität den Herausforderungen bei der Erreichung nachhaltiger Mobilitätsziele im öffentlichen Verkehr nicht gewachsen zu sein. Vor diesem Hintergrund untersucht diese vergleichende Studie die institutionellen Antworten auf das Erfordernis nachhaltiger Mobilitätslösungen im öffentlichen Verkehr in der Stadtregion Accra (Ghana) und der Stadt Dar es Salaam (Tansania) im Hinblick auf die vorhandenen Kapazitäten der Institutionen, Koordinations sowie Kommunikationsmechanismen. Die Studie folgt einem qualitativen Forschungsdesign und wendet Methoden an, die mit den wesentlichen Grundannahmen qualitativer sozialwissenschaftlicher Forschung übereinstimmen. Die Ergebnisse der Studie zeigen, dass nachhaltiger ÖPNV in beiden Städten als die Nutzung von Fahrzeugen mit höherer Auslastung, klar definierten lokalen Zielen für nachhaltigen ÖPNV und ganzheitlichen Regulierungssystemen wahrgenommen wird. Die vergleichende Analyse der beiden Städte in Bezug auf das Schlüsselthema Governance zeigt, dass im Fall der Stadt Accra das Fehlen eines Stadtrats mit einem entsprechenden Stadtoberhaupt oder einem Champion wie im Fall der Stadt Dar es Salaam ein wichtiger limitierender Faktor ist, der Entwicklungsprogramme, -pläne und -projekte verzögert. Die unzureichende Koordinierung zwischen den Institutionen wiederum führt im Fall von Dar es Salaam trotz des Vorhandenseins eines Stadtrats zu doppelten Strukturen und zur Zersplitterung der knappen Ressourcen. Folglich werden kurzfristige, mittelfristige und langfristige Strategien für Entwicklungsmaßnahmen in der Stadtregion Accra und der Stadt Dar es Salaam vorgeschlagen. / Cities are at the forefront of sustainable development and sustainable mobility due to the rising negative impacts of transportation to the environment. Actors and key stakeholders for sustainable mobility in cities in Sub-Sahara Africa however seem not ready for the associated challenges towards the attainment of sustainable mobility for public transport. It is against this background that this study comparatively investigates the institutional responses to sustainable mobility for public transport in Accra city-region (Ghana) and Dar es Salaam city (Tanzania) in the light of existing capacity of the institutions, coordination and communication mechanisms. This study adopts the qualitative research design and methodological choices that are in conformity with the ideologies of this design in Social Science Research. Findings from the study reveal that both cities perceive sustainable public transport as use of higher occupancy vehicles, clearly defined local goals on sustainable public transport and holistic regulation regime. The comparative overview analysis of the two cities in line with the key issue of governance indicates that in the case of Accra city region, the absence of a city council with a respective city head or champion as in the case of Dar es Salaam city is a major limiting factor retarding development programmes, plans, and projects. Inadequate coordination among institutions, on the other hand, results in duplication of efforts and dispersal of scarce resources in the case of Dar es Salaam despite the presence of a city council. Consequently, short term policies, medium term policies, and long-term policies are proposed for development interventions in Accra city-region and Dar es Salaam city.