Dinamica y manejo de poblaciones de malas hierbas

El presente trabajo es una revisión de la modelización de estudios de dinámica de poblaciones de malas hierbas, que fue presentada como ponencia en el XVIII Congresso Brasile iro de Herbicida s e Plant as Daninh as en 1991, Brasília. Partiendo de la población, como unidad básica de los ecosistemas agrarios, se relacionan diferentes modelos de dinámica incluyendo el fenómeno de competencia intra específica, la evolución del banco de semillas y aplicaciones a la asociación cultivo y mala hierba. A través de los diagramas de ciclos vitales, que relacionan los estados funcionales y los procesos demográficos, se llega al establecimiento del modelo matricial.

Curso de matematica para economistas: capitulo V: otimização dinamica

Os autores objetivam, com este trabalho, bem como com aqueles que lhe precederam (capítulos l, 2, 3 e 4) registrar as suas experiências ao longo dos últimos anos ministrando cadeiras de matemática nos cursos de pós-graduação em economia da Fundação Getúlio Vargas, da UFF (Universidade Federal Fluminense) e da PUC-RJ. Reveste-se de constante repetição em tais cursos a discussão sobre que pontos abordar, bem como com qual grau de profundidade e em que ordem. É neste sentido que os autores esperam. com a sequência didática aqui apresentada, trazer alguma contribuição para o assunto.

Uma metodologia para o controle de seguranca dinamica de sistemas de energia eletrica

This work presents an algorithm for the security control of electric power systems using control actions like generation reallocation, determined by sensitivity analysis (linearized model) and optimization by neural networks. The model is developed taking into account the dynamic network aspects. The preventive control methodology is developed by means of sensitivity analysis of the security margin related with the mechanical power of the system synchronous machines. The reallocation power in each machine is determined using neural networks. The neural network used in this work is of Hopfield type. These networks are dedicated electric circuits which simulate the constraint set and the objective function of an optimization problem. The advantage of using these networks is the higher speed in getting the solutions when compared to conventional optimization algorithms due to the great convergence rate of the process and the facility of the method parallelization. Then, the objectives are: formulate and investigate these networks implementations in determining. The generation reallocation in digital computers. Aiming to illustrate the proposed methodology an application considering a multi-machine system is presented.

El desarrollo regional diferenciado y la dinamica demografica en America Latina

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Estructura agraria y dinamica poblacional

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Estructura agraria y dinamica de poblacion; el sector rural en Brasil y Mexico: un enfoque de las relaciones entre el desarrollo agricola y el crecimiento poblacional

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Ecuador: dinamica de la poblacion economicamente activa, 1962-1974

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Algunos elementos para el diagnostico y prognosis de la dinamica demografica del Ecuador

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Dinamica demografica reciente y los problemas del desarrollo latinoamericano

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Análise cinemática e dinâmica para conversão de um VW saveiro em veículo elétrico

This work aims to kinematic and dynamic analysis of a VW Saveiro in order to estimate the power requested to the engine with the imposed movement conditions. Thus, the study will be the basis to the specification of the electric engine, on the conversion of the internal combustion vehicle into electric one. First of all, a literature review was done in order to understand the state of the art for this issue and come up with the technical features of the vehicle in question. The next step is the identification and calculation of all forces acting on the prototype in motion, from 0 to 120 km/h, in intervals of 10 km/h, under the defined conditions of path and time. Then, were determined the values of the torque and rotation of the components from the transmission system, as well as the engine power, for each speed range. The results show the most influential forces on the resistence of the movement in each speed range, and the behavior of the torque curve is verified. Finally, it was also analyzed the implementation of pinwheels on the frontal area of the vehicle, in order to convert wind energy into electrical energy to supply the lighting subsystem of the vehicle and the proposal was validated. Limiting the maximum speed of the vehicle to 90 km/h, it was finally concluded that the power of the electric engine should be 40 HP