Finite element models applied in active structural acoustic control

This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controller design. The reduced structural model is combined with an acoustic model which uses the radiation mode concept. For a test case consisting of a rectangular plate with one piezo patch the model reduction technique is validated. The results show that the an accurate prediction of both the structural and acoustic response is predicted by the reduced model. The model is compact requiring small simulation times, which makes it attractive for control system design. Finally the control performances for both structural and acoustic error criteria are presented

Optimization strategy for actuator and sensor placement in active structural acoustic control

In active structural acoustic control the goal is to reduce the sound radiation of a structure by means of changing the vibrational behaviour of that structure. The performance of such an active control system is to a large extent determined by the locations of the actuators and sensors. In this work an approach is presented for the optimization of the actuator and sensor locations. The approach combines a numerical modelling technique, for predicting the control performance, and genetic optimization, to find the optimal actuator and sensor locations. The approach is tested for a setup consisting of clamped rectangular plate with a piezoelectric actuator and either structural or acoustic sensors. The results show that a control system with optimal actuator and sensor configuration outperforms an arbitrary chosen configuration in terms of reduction in radiated sound power

THE REGIONAL SECURITY COMPLEX OF SOUTH AMERICA: AN ANALYSIS FROM THE SOUTH AMERICAN DEFENSE COUNCIL OF UNASUR

Este artigo é resultado de uma investigação sobre o modelo de Complexo de Regional de Segurança (CRS) existente na América do Sul, em especial a partir da criação do Conselho de Defesa Sul-Americano (CDS), no âmbito da UNASUL – União das Nações Sul-Americanas. A partir de uma discussão teórica sobre os Complexos Regionais de Segurança, argumenta-se que a experiência sul-americana recente afirmou um modelo de “tipo extra”, na medida em que sua dinâmica não se identifica com a presença de uma potência regional com atuação proeminente em nível global, apesar da maior expressão econômica brasileira nos contextos regional e internacional.This article is the result of an investigation into the model of Regional SecurityComplex (RSC model in South America, especially since the creation of the SouthAmerican Defense Council (SDC), within UNASUR - Union of South AmericanNations. From a theoretical discussion on the Regional Security Complexes, it isargued that the recent South American experience affirmed an “extra type” model,since in its dynamics it is not identified a regional power that acts in a global leveldespite Brazilian’s greater economic expression in regional and international arena

ENMTML: An R package for a straightforward construction of complex ecological niche models

Ecological niche models (ENMs) is a popular method in ecology, mostly due to its broad applicability and the fact that required data is simple and easily accessible from digital databases. Nevertheless, there is an underlying methodological complexity, often overlooked by many scientists that rely on ENMs to achieve other objectives. We present here the package ENMTML, an Open Source R package. The main purpose of this package is to assemble all this methodological complexity spread over several papers and bring it into the spotlight in a simple way for people not used to the details of ENMs. The package contains several alternatives to different methodological steps, e.g., pseudo-absence allocation and accessible area delimitation, formulated within a single function, to make it accessible for people not used to the programming environment.Fil: Alves de Andrade, André Felipe. Universidade Federal de Goiás; BrasilFil: Velazco, Santiago José Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: De Marco Júnior, Paulo. Universidade Federal de Goiás; Brasi

The new mediatic flows of South Korean pop culture

The South Korean pop culture is one of the most important contemporary media phenomena. In the essays that comprise the book The Korean Wave: Korean Media Go Global, researchers of different nationalities investigate its main products, the unique characteristics and the formation processes,by organizing a comprehensive panel that examines and verifies the presence and importance of this phenomenon in the world today

Curvilinear coordinate system used to solve tritium dispersion in complex orographies

In this contribution we present progress on research concerning dispersion of tritium around the Angra Nuclear Power Plant (Angra dos Reis, Rio de Janeiro state, Brazil). In particular, we are interested in studying how dispersion behaves in scenarios with complex orography. Our proposal is to transform a problem with curvilinear boundaries into an equivalent problem with plane parallel boundaries. We modify the coordinate system through a diffeomorph conformal transformation. Consequently, the operators of the dynamical equations change according to the additional terms from the affine connection. To define the transformation it is necessary to satisfy strong constraints, i.e., boundaries shall be “smooth”. Even with restrictions, our model can be implemented in several situations. A flat region is a particular case of a curvilinear domain and can be studied, where the height of the boundary layer above rivers, lakes, basins is typically smaller and thus implies a varying boundary layer height, for example. Thus, even in flat regions variations in the boundary layer occur, which characterizes a case of a curvilinear domain. There are several nuclear power plants worldwide, that are located in mountainous regions, as for example in Japan and Brazil.We present a simulation of tritium dispersion specifically in the area where the Angra 2 Nuclear Power Plant is located and where the relief is characterized by a considerable complexity. With the intention of showing that the methodology is consistent, we will consider only the variation of the relief