Modelo em dinâmica de sistemas para gestão de aeroportos brasileiros

The importance of the airport sector in the development of a country refers to the need for studies on management of airports, to aid the process of decision making. In Brazil, growth in passenger demand is why investments in order to balance the capacity of an airport with air demand. Thus, the study aims to develop a model for Dynamic Systems able to assist airport management in Brazilian sizing subsystems an airport (Passenger Terminal, Runway and Patio). The methodology of this work consists in the steps of defining the problem, formulating the hypothesis dynamic building simulation model, and validation experiments. Finally, we examined the status of each subsystem in thirteen Brazilian airports in scenarios current, most likely and optimistic for air passenger demand

Estudo de estratégias de otimização para poços de petróleo com elevação por bombeio de cavidades progressivas

The progressing cavity pump artificial lift system, PCP, is a main lift system used in oil production industry. As this artificial lift application grows the knowledge of it s dynamics behavior, the application of automatic control and the developing of equipment selection design specialist systems are more useful. This work presents tools for dynamic analysis, control technics and a specialist system for selecting lift equipments for this artificial lift technology. The PCP artificial lift system consists of a progressing cavity pump installed downhole in the production tubing edge. The pump consists of two parts, a stator and a rotor, and is set in motion by the rotation of the rotor transmitted through a rod string installed in the tubing. The surface equipment generates and transmits the rotation to the rod string. First, is presented the developing of a complete mathematical dynamic model of PCP system. This model is simplified for use in several conditions, including steady state for sizing PCP equipments, like pump, rod string and drive head. This model is used to implement a computer simulator able to help in system analysis and to operates as a well with a controller and allows testing and developing of control algorithms. The next developing applies control technics to PCP system to optimize pumping velocity to achieve productivity and durability of downhole components. The mathematical model is linearized to apply conventional control technics including observability and controllability of the system and develop design rules for PI controller. Stability conditions are stated for operation point of the system. A fuzzy rule-based control system are developed from a PI controller using a inference machine based on Mandami operators. The fuzzy logic is applied to develop a specialist system that selects PCP equipments too. The developed technics to simulate and the linearized model was used in an actual well where a control system is installed. This control system consists of a pump intake pressure sensor, an industrial controller and a variable speed drive. The PI control was applied and fuzzy controller was applied to optimize simulated and actual well operation and the results was compared. The simulated and actual open loop response was compared to validate simulation. A case study was accomplished to validate equipment selection specialist system

Mudanças nos modelos de gestão: a política educacional e dos (des)acertos da experiência no Rio Grande do Norte (1995-1999)

This work focuses on the educational policies, on the necessity of adopting new models of administration of the education, as well as the implementation of reforms in this filed during the 1990 s. It analyzes the strategies of decentralization of the education in Rio Grande do Norte, disclosing practices conceived in the governmental plans and programs. It also aims to evidence the aspects of the decentralization proposed in the educational system management model, adopted by the Department of Education and Culture of Rio Grande do Norte from 1995 to 1999. Bibliographic researches and documental analysis were used as sources and semi-structured interviews were held in order to collect data. This work also highlights the concepts of participation, autonomy and democratic management intrinsic to the process of decentralization in the education field. It is clear that decentralization, as the vector of democracy, requires not only certain conditions that assure the universal access to the necessary information, but also that all segments of the institution have a voice in the collegiates and that the management and decision-making processes be transparent. This analysis reveals the importance of creating means to promote autonomy, participation and democratic management in order to consolidate a decentralized system. It is also clear that these mechanisms have been proposed in a vague way by the governmental guidelines, which makes it harder to consolidate a democratic management model. Having this perspective as a parameter, it is possible to realize that the adoption of a management model prompted by the law hasn t established effective means of participation that, consequently, should provide decision centralizers which opposed to the democratic actions

Extração e Representação de Conhecimento de Séries Temporais de Demanda de Energia Elétrica Usando TSKR

The opening of the Brazilian market of electricity and competitiveness between companies in the energy sector make the search for useful information and tools that will assist in decision making activities, increase by the concessionaires. An important source of knowledge for these utilities is the time series of energy demand. The identification of behavior patterns and description of events become important for the planning execution, seeking improvements in service quality and financial benefits. This dissertation presents a methodology based on mining and representation tools of time series, in order to extract knowledge that relate series of electricity demand in various substations connected of a electric utility. The method exploits the relationship of duration, coincidence and partial order of events in multi-dimensionals time series. To represent the knowledge is used the language proposed by Mörchen (2005) called Time Series Knowledge Representation (TSKR). We conducted a case study using time series of energy demand of 8 substations interconnected by a ring system, which feeds the metropolitan area of Goiânia-GO, provided by CELG (Companhia Energética de Goiás), responsible for the service of power distribution in the state of Goiás (Brazil). Using the proposed methodology were extracted three levels of knowledge that describe the behavior of the system studied, representing clearly the system dynamics, becoming a tool to assist planning activities