Análise da estabilidade de jogos hedônicos

Orientadores: Rafael Crivellari Saliba Schouery, Eduardo Candido XavierDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Jogos hedônicos são jogos de formação de coalizão nos quais os agentes apenas se importam ou são influenciados pelos agentes na mesma coalizão que eles estão. Os agentes podem formar qualquer coalizão que eles queiram e cada agente tem um perfil de preferência, uma ordem fraca sobre o conjunto de coalizões que o contém indicando sua preferência. Um jogo hedônico é definido por um conjunto de agentes e seus perfis de preferência. Classicamente, o resultado de tais jogos é uma partição do conjunto de agentes. Nesta dissertação, nós revisamos alguns resultados da literatura a respeito da existência de resultados Nash estáveis, do preço da anarquia e estabilidade, da existência de partições no núcleo e da complexidade de computar um resultado que está no núcleo. Estudamos o modelo de jogos hedônicos que permite a formação de coalizões com sobreposição. Esta extensão permite a representação de vários cenários como interações sociais, grupos de trabalhos e formação de redes. Nós apresentamos um modelo para jogos fracionários com sobreposição de coalizões e mostramos que o núcleo não é vazio para jogos representados por circuitos, caminhos e grafos bipartidos com emparelhamento perfeito. Nós também apresentamos um modelo para jogos hedônicos aditivamente separáveis com sobreposição de coalizões. Mais ainda, mostramos que, para jogos hedônicos aditivamente separáveis simétricos com sobreposição de coalizões, o bem-estar social de qualquer estrutura de coalizão é no máximo o bem-estar social ótimo da versão do jogo sem sobreposição de coalizõesAbstract: Hedonic games are coalition formation games where the agents only care or are influenced by agents in the same coalition as they are. Agents may form any coalition they want, and every agent has a preference profile, a weak ordering on the set of coalitions that contains it. A hedonic game is defined by a set of agents and their profile preferences. Classically, the outcome of such games is a partition of the agent set. We review some literature results regarding the existence of Nash stable outcomes, the price of anarchy and stability, the existence of core stable partitions, and the complexity to compute a Core stable outcome. We extend the hedonic games model by allowing the formation of overlapping coalitions. This extension permits the representation of many scenarios by hedonic games, such as social interactions, working groups, and network formation. We give a model for fractional hedonic games with overlapping coalitions and we show that the core is not empty for games represented by cycles, paths, and bipartite graphs with perfect matching. We also give a model for additively separable hedonic games with overlapping coalitions. Moreover, we show that for symmetric additively separable hedonic games with overlapping coalitions, the social welfare of any coalition structure is at most the optimal social welfare of the game version without overlapping coalitionsMestradoCiência da ComputaçãoMestre em Ciência da ComputaçãoCAPE

Effects of tourism and globalization on land cover and the influence on the quality of life of Paphos area in Cyprus

Since 1960 most of the coastal area cites across the Mediterranean Sea concentrates people due mass immigration of people from the rural to urban areas. The extensive tourism development especially across the coastal areas, create demand of infrastructures and new work positions and intensive pressure to the environment. The new spirit of the globalization creates movability of people and goods around the word. The free transfer of people from countries with big population and low economical wealth, which are moved to areas where they can work. All the above generate demands of labor and Paphos is one of these areas where during the last decades was transformed from a small agriculture village in one excellent tourist destination. Across the coastal areas big tourist infrastructure was built and lot of different people travel from all areas around the word especially during the summer months. All these generate continuous changes to the environment, to the people and the society. The globalization of the universe commerce and the free transfer of goods and people modify the community stratification. The inflow of agricultures products from third countries reduces the local production and generates degradation and desertification of the rural areas. The periodical variation of the population of the area during the summer and winter periods affect to the environment. The increment demand of sources (water, energy and food) during the summer months pressurize the coastal strip area. By estimating a ratio of inflows by the outflows of goods, people and services of the study area and a ratio of the tourists by the local population, a general index can by arise which will clarify the effects on the environment on the study area. This paper presents the results obtained by this study by examining the effects of tourism on land cover and effects on quality of life for the Paphos area in Cyprus. The authors explores the potential of blending in the sustainability study the use of remote sensing especially on the land-cover effects

Evaluation of sustainability indices and indicators in the Paphos district area in Cyprus

During the last decades most of the coastal zones across the Mediterranean Sea concentrates population around polescities owing to the mass movement of people from the rural areas to urban areas. The extensive tourism development across the coast generates demand of new work positions and pressurizes the environment. The economic development increase the natural capital of the study areas increase the covered with buildings and infrastructures areas and as a consequence reduce the quality of life. All the above effects modify the density of the buildings and infrastructures, push and eliminate the free green covered areas and other open spaces. In order to measure the effects on the environment and the quality of life a composite index is developed which arises using combined indices using economical, social and environmental criteria. The above components give a realistic indicator of the effects on the environment. This unique index arises as a function of the ratios of a per capital income a ratio of cover area by the uncovered area and the density of people per unit area. Usually when the wealth is increased the demand of energy and goods also increased and the damage on environment becomes bigger. This paper explores how the application of sustainability indices can be used as a tool to assess the quality of life. The use of GIS and remote sensing is highlighted to support the application of the existing sustainability indices