Analysis of the radial operation of distribution systems considering operation with minimal losses

Electric power distribution systems, and particularly those with overhead circuits, operate radially but as the topology of the systems is meshed, therefore a set of circuits needs to be disconnected. In this context the problem of optimal reconfiguration of a distribution system is formulated with the goal of finding a radial topology for the operation of the system. This paper utilizes experimental tests and preliminary theoretical analysis to show that radial topology is one of the worst topologies to use if the goal is to minimize power losses in a power distribution system. For this reason, it is important to initiate a theoretical and practical discussion on whether it is worthwhile to operate a distribution system in a radial form. This topic is becoming increasingly important within the modern operation of electrical systems, which requires them to operate as efficiently as possible, utilizing all available resources to improve and optimize the operation of electric power systems. Experimental tests demonstrate the importance of this issue. (C) 2014 Elsevier Ltd. All rights reserved.

Application of reverse Monte Carlo simulations to diatomic molecules. Part 1. Noncomplete radial distribution functions

The reverse Monte Carlo (RMC) method generates sets of points in space which yield radial distribution functions (RDFS) that approximate those of the system of interest. Such sets of configurations should, in principle, be sufficient to determine the structural properties of the system. In this work we apply the RMC technique to fluids of hard diatomic molecules. The experimental RDFs of the hard-dimer fluid were generated by the conventional MC method and used as input in the RMC simulations. Our results indicate that the RMC method is only satisfactory in determining the local structure of the fluid studied by means of only mono-variable RDF. Also we suggest that the use of multi-variable RDFs would improve the technique significantly. However, the accuracy of the method turned out to be very sensitive to the variance of the input experimental RDF. © 1995.

A radial basis function network (RBFN) for function approximation

A radial basis function network (RBFN) circuit for function approximation is presented. Simulation and experimental results show that the network has good approximation capabilities. The RBFN was a squared hyperbolic secant with three adjustable parameters amplitude, width and center. To test the network a sinusoidal and sine function,vas approximated.

An analog implementation of radial basis function network appropriate for transducer linearizer

A circuit for transducer linearizer tasks have been designed and built using discrete components and it implements by: a Radial Basis Function Network (RBFN) with three basis functions. The application in a linearized thermistor showed that the network has good approximation capabilities. The circuit advantages is the amplitude, width and center.

Healing and expression of growth factors (TGF-β and PDGF) in canine radial ostectomy gap containing platelet-rich plasma

Objectives: To evaluate bone healing in an experimental radial ostectomy in dogs treated with autologous platelet-rich plasma (PRP), through histological, densitometric, radiographic studies, as well as expression of growth factors in the ostectomy gap. Methods: Twenty-one dogs were randomly divided into either a control or a PRP group. All underwent unilateral ostectomy of the radius to generate a gap of 2.0 mm, that was stabilized with external skeletal fixation. The ostectomy gap was either filled with PRP or left empty as a control. The radiographic and densitometric studies were performed after surgery, then at intervals until 60 days during the post-surgery period. Histological and immunohistochemical evaluations were performed at seven or 60 days post-surgery. Analyses were performed using a statistical analysis system, and the level of significance was set at p <0.05. Results: The median radiographic healing score in the PRP group increased significantly between day 0 and day 60. Furthermore, at 60 days, the median healing score and the proportion of healed ostectomies in the control group (score 1; 1/6 healed) and the PRP group (score 5; 4/5 healed) were significantly different. There were differences between groups in radiographic and densitometric values at days 45 and 60. The histological evaluation showed advanced bone healing at 60 days in the PRP group and signs of delayed union in the control group. Clinical relevance: Platelet-rich plasma can be used as an adjuvant therapy because it may promote better bone healing of a radial ostectomy treated with external skeletal fixation in dogs.

Análise comparativa de exposição do operador à radiação entre as técnicas radial, femoral e radial com dispositivo protetor em procedimentos de cardiologia intervencionista

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Obtenção de neurônios de redes neurais de base radial via agrupamento de dados por floresta de caminhos ótimos

Neste artigo é apresentada uma abordagem para aumentar a eficácia das Redes Neurais Artificiais de Funções de Base Radial utilizando um algoritmo de agrupamento de dados via Floresta de Caminhos Ótimos. Algumas técnicas comumente empregadas para essa tarefa, como o conhecido k-médias, requerem um determinado número de classes/agrupamentos prévio à sua execução. Embora o número de classes seja conhecido em problemas supervisionados, o número real de agrupamentos é difícil de ser encontrado, dado que uma classe pode ser representada por mais de um agrupamento. Experimentos em nove bases de dados, em conjunto com análises estatísticas, demonstraram que o classificador por Floresta de Caminhos Ótimos possui um melhor desempenho que a técnica k-médias, bem como encontra as médias das distribuições Gaussianas em posições muito similares às encontradas por este último. Entretanto, o classificador por Floresta de Caminhos Ótimos possui um custo computacional maior, dado que a sua etapa de treinamento é mais custosa que a da técnica k-médias.