We construct and examine a model of adoption of a product or policy using, firstly, a system of differential equations and then secondly, through simulation, an agent- based model. Awareness must come before adoption, and we model this as a simple epidemic type model, where information is spread through advertising and contact with other agents in the population. Adoption is then conditional on awareness and occurs only if the agent finds the perceived cost acceptable. After simulating the system using an agent-based model, we introduce heterogeneity through the model parameters, which are then considered individual attributes and include influence rates, effectiveness of advertising, price sensitivity, and speed of adoption. We also examine the effects of various network topologies by organizing individuals into lattice and preferential attachment networks. From there, we add two extra components to the adoption mechanism by introducing a social influence factor by which an agent can be influenced by the adoption patterns of their neighbourhood, as well as a green factor, which assumes an environmental product or policy being adopted and is the likelihood that an individual will adopt based on environmental reasons alone.

Our epidemiology research found that the incident and prevalent rates for Diabetes mellitus (DM) and Diabetic End Stage Renal Disease (DM-ESRD) were at rise in Saskatchewan between year 1980 and 2005. Combining concerns regarding the rising trends reported by research studies with the concerns of the significant health and financial burden imposed by DM-ESRD on individuals and societies, we sought to project the number of DM-ESRD patients in Saskatchewan up to year 2025 with the cost required for caring for those patients. An agent-based model (ABM) is developed to simulate DM to ESRD progression, treatments for DM-ESRD patients, and the assessments and waiting list processes preparing patients for kidney transplants. The model parameters were estimated from a wide variety of data sources. The agent based modeling approach is chosen for projections regarding the DM-ESRD situation in Saskatchewan because of its advantage in capturing heterogeneities of individual patients, ability to retain biographical information on patients, capacity to capture time-varying competing risks, better presentations features and easy integration with existing models built in either agent based or System Dynamic methods. The approach was also attractive due to its flexibility for future expansion to represent social networks. The model projects the incident and prevalent case count, cost, and person years lived for the DM-ESRD population in Saskatchewan between year 1980 and 2025. The projections captured the great challenges brought by the fast growing number of DM-ESRD patients and substantial cost associated with managing the disease. In addition to producing projection results, the research presented here demonstrates how the model can be used by policy makers to experiment and evaluate different policy/interventions in a safe context. By capturing both the individual level records and population level statistics, the model provide a wealth of data for detailed analysis, which can help health policy makers gain insights in the current and future diabetic-ESRD situation in the province, aiding in resources planning for managing the fast-growing ESRD population and the growing need for dialysis services.

Land use and cover change (LUCC) is increasingly recognised as one of the most visible impacts of humans on nature. In rural areas, most of the observed LUCC is associated with agricultural activities. This has traditionally been attributed to the interplay of the socio-economic and political milieu, and the opportunities and constraints arising from the climatic conditions and physical attributes of land. Although there is no doubt that these factors influence farmer decisions, the mosaic of farming systems suggests that farmers do not always behave uniformly, even in areas with comparable socio-economic and environmental conditions. While the multi-facetted and varying nature of farmer decision-making is considered to be established knowledge in rural sociology, it is often neglected in LUCC models that typically describe it as homogeneous and rational in economic terms. This thesis presents an application of mixed-method social survey which aims at improving the representation of the diversity and complexity of farmer decision-making process in LUCC models. Different data collection methods (in-depth, semi-structured interviews, questionnaire) and analyses (thematic analysis, principal components analysis, cluster analysis, choice-based conjoint analysis) were used complementarily to identify the factors that facilitate or constrain farmer participation in environmental management practices (a), to identify the dominant farmer profiles (b) and to assess farmer preferences that influence land use decisions (c). Data collection was conducted in a study area located in the Canton of Aargau, Switzerland, where there is limited knowledge about farmer decision-making drivers and actions. Research findings were used to empirically inform an agent-based model that simulates farmer decisions. Paremeterised storylines were used to explore farmer decisions in alternative futures. An advanced and context-specific representation of human agents in modeling frameworks can make LUCC models valuable tools both for landscape analysis and policy making. In the face of new policy reforms, this thesis contributes to the achievement of this objective, by presenting an approach to explore and organize the heterogeneity of farmer behaviour and to make this usable in agent-based modeling frameworks.

Univ., Diss.--Louvain-la-Neuve, 2007.

Eidgenössische Techn. Hochsch., Diss.--Zürich, 2007. / Zsfassung in dt. Sprache.

Univ., Diss.--Karlsruhe, 2007.

Ecole Polytechnique Federale, Diss.--Lausanne, 2007.

Zugl.: Vallendar, WHU - Otto Beisheim School of Management, 2008.

Zugl.: Göttingen, Universiẗat, Diss., 2008.

En ce début de XXIe siècle, le vin et la vigne constituent une richesse importante pour bon nombre de pays. Les territoires viticoles, tout en conservant leurs qualités d'espace de production, développent des stratégies d'adaptation à la globalisation du marché et aux attentes des consommateurs toujours plus versatiles. Or en raison de conditions orographiques particulières, les territoires de montagne et de fortes pentes voient leurs marges de manœuvre réduites. En effet, une grosse partie de leurs coûts de production reste bien souvent incompressible par rapport à la viticulture de plaine. Paradoxalement ces paysages viticoles, image du construit social et des équilibres environnementaux, participent à leur reconnaissance internationale. Le travail présenté ici est né en réponse à la sensibilité croissante de ces vignobles de fortes pentes. En nous appuyant sur deux territoires d'étude, en France le vignoble de la Côte Vermeille et en Italie le val di Cembra, nous questionnons les spécificités de la viticulture de fortes pentes. Notre approche met l'accent sur les possibilités offertes par des méthodes empiriques de modélisation à base d'agents pour proposer un regard renouvelé sur le rôle des interactions société-environnement dans le maintien et le développement de ces territoires sous contraintes. A travers une constellation de modèles multi-agents issus des questionnements récurrents des acteurs de la filière, et selon une démarche exploratoire et incrémentale, nous nous intéresserons ici à trois grands types de questions posées aux territoires viticoles de fortes pentes. Le premier concerne la place du marché et ses conséquences sur les dynamiques de couvert végétal à petite échelle. Le second type de questionnement explore également les dynamiques spatiales du couvert végétal, mais se place à mezzo-échelle, et propose de s'intéresser à la définition des règles socio-économiques simples qui sous-tendent les dynamiques foncières à l'échelle de quelques communes. Enfin le dernier volet de ce travail se place à grande échelle et s'intéresse à des phénomènes très descriptifs. L'ensemble de ces réflexions nous amènera ensuite à utiliser la modélisation co-construite avec les acteurs pour proposer une vision prospective globale pour les territoires de montagne et de fortes pentes. Cette approche prospective sera conduite en parallèle avec certains acteurs de la filière ce qui nous permettra de délimiter les variables structurelles propres aux systèmes de fortes pentes telles qu'elles sont ou non vécues par les acteurs. Basés sur la délimitation de ces variables, nous proposons enfin quatre scenarii prospectifs pour la viticulture en fortes pentes. / Wine and wineyards stand nowadays as a significant wealth for a number of countries. While retaining their properties as production space, vine-growing regions are developing adaptation strategies to market globalisation and to the ever more versatile consumer expectations. Yet, due to the corresponding specific orographic conditions in steep slope and mountain regions, actor's relative leeway is reducing ,. Comparatively to plain wine-growing, a large part of their production costs often remains indeed incompressible. On the other hand, these vine-growing landscape take advantage of such harsh conditions in terms of international recognition, as images of social construct and environmental equilibrium. The work presented here emerged as a response to this steep slope vineyards' sensitivity. This investigation relies on two study areas: the Côte Vermeille vineyards in France, and the val di Cembra in Italy. Our approach focuses on the opportunities granted by agent-based empirical modelling methods, in order to put forward a renewed look at the role of society-environment interactions in the sustainability and development of territories subject to constraints. Using an exploratory and incremental method, three significant issues of steep slope vine-growing regions have been addressed, thanks to a constellation of multi-agent models, derived from questioning actors of this sector. The first considers the market's impacts on the small-scale plant cover dynamics. The second issue focuses on meso-scale plant cover dynamics and questions the definition of simple socio-economic ruleset, within the frame of land property dynamics and applied to the scale of a few municipalities. The last section of this work is dedicated to some descriptive phenomena within a large scale. Thus, the sum of these reflections leads us to exploit co-designed modelling with the stakeholders in order to propose a global prospective vision for mountain and steep slope regions. This prospective approach is conducted in association with some of the players in the sector, thus allowing us to delineate the structural variables linked to steep slope vineyards' systems in agreement with their experience. Based on these delineated variables, four prospective scenarii are put forward for the steep slope vine-growing activity.