O uso de modelos ocultos de Markov no estudo do fluxo de rios intermitentes

In this work, we present our understanding about the article of Aksoy [1], which uses Markov chains to model the flow of intermittent rivers. Then, we executed an application of his model in order to generate data for intermittent streamflows, based on a data set of Brazilian streams. After that, we build a hidden Markov model as a proposed new approach to the problem of simulation of such flows. We used the Gamma distribution to simulate the increases and decreases in river flows, along with a two-state Markov chain. The motivation for us to use a hidden Markov model comes from the possibility of obtaining the same information that the Aksoy’s model provides, but using a single tool capable of treating the problem as a whole, and not through multiple independent processes

Estimação paramétrica e não-paramétrica em modelos de markov ocultos

In this work we study the Hidden Markov Models with finite as well as general state space. In the finite case, the forward and backward algorithms are considered and the probability of a given observed sequence is computed. Next, we use the EM algorithm to estimate the model parameters. In the general case, the kernel estimators are used and to built a sequence of estimators that converge in L1-norm to the density function of the observable process

H-N2N : uma arquitetura hierárquica escalável para ambientes de realidade mista de grande porte

In this work, we propose a solution to solve the scalability problem found in collaborative, virtual and mixed reality environments of large scale, that use the hierarchical client-server model. Basically, we use a hierarchy of servers. When the capacity of a server is reached, a new server is created as a sun of the first one, and the system load is distributed between them (father and sun). We propose efficient tools and techniques for solving problems inherent to client-server model, as the definition of clusters of users, distribution and redistribution of users through the servers, and some mixing and filtering operations, that are necessary to reduce flow between servers. The new model was tested, in simulation, emulation and in interactive applications that were implemented. The results of these experimentations show enhancements in the traditional, previous models indicating the usability of the proposed in problems of all-to-all communications. This is the case of interactive games and other applications devoted to Internet (including multi-user environments) and interactive applications of the Brazilian Digital Television System, to be developed by the research group. Keywords: large scale virtual environments, interactive digital tv, distributed

A constituição desmilitarizada: democratização e reforma do sistema constitucional de segurança pública

The normative construction of the public security system in the Constituent Assembly of 1987-1988 preserved paradoxical normative space, the military police linked to the Army with a restrictive legal statute of the police offices citizenship through a hierarchical and disciplinary model that is anachronistic. This research originates from the following problem: How is it possible to tailor the constitutional system of public safety, specifically the Military Police, according to the democratic paradigms constructed by the Constituent from 1988 and carry the right to public safety under these molds? The militarists limitations of the Constitution allowed the growing militarization of police departments, organizational culture and authoritarian institutional practices. Underlying this, the problems related to difficulties in realization of Right to Public Safety, the strikes of the military police, the incomplete policy cycle started demanding from the constitutional-legal system appropriate responses. Utilizing the dialogical method and an interdisciplinary approach to the subject, and theoretically grounded in overcoming of the constitutional normativist juspositivism.It was found that the constructed infraconstitutional legislation was insufficient to supply the systemic shortcomings of constitutional law, when looking to create a single system of public security without giving due scope to the federal principle and expand the autonomy the Federated States, and even grant democratic legal status to the military police. Formal legal limits imposed by the Constitution constructed a legal anachronism, the military police. Thus, a democratic reading of military police institutions becomes inconceivable its existence in the constitutional regulatory environment. Thus, reform the Constitution in order to demilitarize the police and conduct a normative redesign of the public security system is fundamental to Brazilian constitutional democracy

Modelagem de usinas eólicas através de um processo de Markov e técnicas de confiabilidade para a estimativa anual da energia produzida

This study aims to use a computational model that considers the statistical characteristics of the wind and the reliability characteristics of a wind turbine, such as failure rates and repair, representing the wind farm by a Markov process to determine the estimated annual energy generated, and compare it with a real case. This model can also be used in reliability studies, and provides some performance indicators that will help in analyzing the feasibility of setting up a wind farm, once the power curve is known and the availability of wind speed measurements. To validate this model, simulations were done using the database of the wind farm of Macau PETROBRAS. The results were very close to the real, thereby confirming that the model successfully reproduced the behavior of all components involved. Finally, a comparison was made of the results presented by this model, with the result of estimated annual energy considering the modeling of the distribution wind by a statistical distribution of Weibull