Indiana University-Purdue University Indianapolis (IUPUI) / In today's fast paced world, people have become increasingly interested in online communication to facilitate their lives and make it faster. This goes on from simple social interactions to more advanced actions like shopping on the internet. The presence of such activities makes it crucial for people to use their common sense and judgment to process all this information and evaluate what/who they trust and what/whom they do not. This process would have been much easier if the number of people in such networks is really small and manageable. However, there are millions of users who are hooked online every day. This makes the person very overwhelmed with his trusting decision, especially when it comes to interacting with strangers over the internet, and/or buying personal items, especially expensive ones. Therefore, many trust models have been proposed by computer scientists trying to evaluate and manage the trust between users using different techniques and combining many factors. What these computer scientists basically do is coming up with mathematical formulas and models to express trust in online networks and capture its parameters. However, social scientists are the people better trained to deal with concepts related to human behaviors and their cognitive thinking such as trust. Thus, in order for computer scientists to support their ideas and get a better insight about how to direct their research, people like social scientists should contribute. With this in mind, we realized in our group work the importance of such contribution, so we came up with the idea of my research work. In my search, I tried to find how these social scientists think and tackle a dynamic notion like trust, so we can use their findings in order to enhance our work and trust model. Through the chapters, I will discuss an already developed trust model that uses measurement theory in modeling trust. I will refer back to this model and see how other social scientists dealt with some of the issues encountered by the model and its functionality. Some small experiments have been done to show and compare our results with social scientists results for the same matter. One of the most important and controversial points to be discussed from social scientists' point of view is whether trust is transitive or not. Other points to be discussed and supported by social scientists' research include aggregation, reputation, timing effects on trust, reciprocity, and experience effects on trust. Some of these points are classified into trust mapping categories and others are related to trust management or decision making stages. In sum, this work is a multidisciplinary study of trust whose overall goal is to enhance our work and results, as computer scientists.

Apesar da significativa representatividade do setor da construção civil na economia, o gerenciamento dos resíduos sólidos gerados pelo setor ainda é um desafio na maioria dos municípios brasileiros. Os resíduos da construção civil (RCC) são gerados nas atividades relacionadas à construção, comércio e indústria de materiais da construção civil. Estes resíduos quando não recebem tratamento e destinação adequados além de causarem impactos ambientais, afetam direta ou indiretamente a saúde, segurança e o bem estar da população, interferindo nas atividades sociais e econômicas e na qualidade dos recursos ambientais. Neste contexto, a logística reversa é vista como alternativa para gestão adequada dos resíduos, quando bem planejada e executada. A logística reversa está prevista na Lei no 12.305/2010, que trata sobre a Política Nacional dos Resíduos Sólidos (PNRS). No entanto, a implantação da logística reversa ainda é um desafio para alguns setores devido às dificuldades inerentes a este sistema e a falta de informações quanto à operacionalização e regulamentação. Tendo em vista esta dificuldade, este trabalho tem como objetivo avaliar o potencial de aplicação dos preceitos da logística reversa ao setor da construção civil na cidade de Curitiba e propor um modelo conceitual, destacando as responsabilidades dos principais participantes da cadeia produtiva da construção civil. Na primeira etapa da pesquisa, profissionais da construção civil foram selecionados para responder, com auxílio da técnica Delphi, um questionário, elaborado com base na revisão da literatura, a fim de selecionar critérios relevantes para compor o sistema de logística reversa no setor da construção civil. Na primeira rodada Delphi os profissionais opinaram sobre a relevância dos critérios escolhidos para compor o sistema de logística reversa e na segunda rodada foi realizada a análise multicritério com auxílio do Processo de Análise Hierárquica (AHP) a fim de ponderar e hierarquizar os critérios selecionados. Os resultados foram analisados na ferramenta BPMS AHP Excel e exportados por meio de gráficos. Nesta etapa da pesquisa foi demonstrado que a aplicação do questionário Delphi em conjunto com o AHP auxilia a tomada de decisão dos agentes da cadeia produtiva da construção civil. Os resultados apontam a importância da relação colaborativa entre clientes e fornecedores na devolução materiais e as possíveis barreiras que podem dificultar a operacionalização do sistema de logística reversa no setor da construção civil como a falta de apoio do governo, conscientização da população e baixo incentivo para reutilização de RCC. Na etapa da idealização e elaboração do modelo conceitual, com o auxílio da ferramenta Free Mind, foi possível destacar o potencial de aplicação dos preceitos da logística reversa entre os principais agentes da cadeia produtiva da construção civil em Curitiba. O modelo proposto auxilia na compreensão do fluxo de materiais no sistema de logística reversa e as responsabilidades de cada prestador de serviço, na execução das atividades relacionadas à construção civil, incluindo o gerenciamento dos RCC, além do cumprimento da PNRS e minimização dos impactos ambientais. / Despite the significant representativeness of the construction sector in the economy, the management of solid waste generated by the sector is still a challenge in most Brazilian municipalities. Construction and Demoliton Waste (CDW) is generated in activities related to the construction, trade and construction materials industry. The CDW when not properly treated and destined besides causing environmental impacts can affect directly or indirectly the health, safety and welfare of the population, interfering in social and economic activities and the quality of environmental resources. In this context, reverse logistics is seen as one of the alternatives for proper waste management, when well planned and executed. Reverse logistics is provided for in Law 12.305/2010, which deals with the National Policy on Solid Waste (NPSW). However, the implementation of reverse logistics is still a challenge for some sectors due to the difficulties inherent in this system and the lack of information regarding operationalization and regulation. In view of this difficulty, this paper aims to evaluate the potential of applying the reverse logistics precepts to the civil construction sector in the city of Curitiba and to propose a conceptual model, highlighting the responsibilities of the main participants in the civil construction production chain. In the first stage of the research, professionals of construction industry were selected to answer, with the help of the Delphi technique, a questionnaire elaborated based on the literature review, in order to select relevant criteria to compose a reverse logistics system to the civil construction sector. In the first round of Delphi, the participants decided on the relevance of the criteria chosen to compose the reverse logistics system and in the second round a multicriteria analysis was carried out with the aid of Analytic Hierarchy Process (AHP) in order to weight and hierarchize the criteria selected. The results were analyzed in the BPMS AHP Excel tool and exported through graphs. In this stage of the research it was demonstrated that the application of Delphi questionnaire in conjunction with the AHP helps the decision making of the agents of the civil construction productive chain. The results point out the importance of the collaborative relationship between customers and suppliers in the return of materials and possible barriers that may hinder the operation of the reverse logistics system in the construction sector, such as a lack of government support, population awareness and a low incentive to CDW reuse. In the stage of idealization and elaboration of the conceptual model, with Free Mind tool, it was possible to highlight the potential of applying the reverse logistics precepts among the main agents of the civil construction production chain in Curitiba. The proposed model assists in understanding the flow of materials in the reverse logistics system and the responsibilities of each service provider in the execution of activities related to civil construction, including the management of CDW, besides compliance with NPSW and minimization of environmental impacts.