On the dynamics of the Furuta pendulum

The Furuta pendulum, or rotational inverted pendulum, is a system found in many control labs. It provides a compact yet impressive platform for control demonstrations and draws the attention of the control community as a platform for the development of nonlinear control laws. Despite the popularity of the platform, there are very few papers which employ the correct dynamics and only one that derives the full system dynamics. In this paper, the full dynamics of the Furuta pendulum are derived using two methods: a Lagrangian formulation and an iterative Newton-Euler formulation. Approximations are made to the full dynamics which converge to the more commonly presented expressions. The system dynamics are then linearised using a Jacobian. To illustrate the influence the commonly neglected inertia terms have on the system dynamics, a brief example is offered.Benjamin Seth Cazzolato and Zebb Prim

Active control of structural sound radiation using a spatial control method with multiple structural sensors

This paper introduces a method to control structural sound radiation using multiple structural sensors. Tonal radiation from a vibrating arbitrary structure is considered in this paper. Based on the estimation of the vibration profile of a noise radiating structure, spatial signals that represents radiated pressure field can be generated. These spatial signals can also be spatially weighted to control radiated noise at some far-field regions more than at others. Numerical studies on a simply-supported plate were performed which demonstrate the ability of the proposed method to control sound radiation that is spatially weighted over certain regions in the far-field.Dunant Halim and Ben S. Cazzolat

A multipole array magnetic spring

© 2005 IEEE.This paper presents research on a magnetic spring concept, which has application to the development of a vibration isolation table. Features of the design are scalable, noncontact load bearing and a single degree of instability.Will Robertson, Ben Cazzolato, and Anthony Zande

A model-based method for damage detection with guided waves

Abstract not availablePouria Aryan, Andrei Kotousov, Ching-Tai Ng and Benjamin Cazzolat

Techniques for effective and efficient fire detection from social media images

Social media could provide valuable information to support decision making in crisis management, such as in accidents, explosions and fires. However, much of the data from social media are images, which are uploaded in a rate that makes it impossible for human beings to analyze them. Despite the many works on image analysis, there are no fire detection studies on social media. To fill this gap, we propose the use and evaluation of a broad set of content-based image retrieval and classification techniques for fire detection. Our main contributions are: (i) the development of the Fast-Fire Detection method (FFDnR), which combines feature extractor and evaluation functions to support instance-based learning, (ii) the construction of an annotated set of images with ground-truth depicting fire occurrences -- the FlickrFire dataset, and (iii) the evaluation of 36 efficient image descriptors for fire detection. Using real data from Flickr, our results showed that FFDnR was able to achieve a precision for fire detection comparable to that of human annotators. Therefore, our work shall provide a solid basis for further developments on monitoring images from social media.Comment: 12 pages, Proceedings of the International Conference on Enterprise Information Systems. Specifically: Marcos Bedo, Gustavo Blanco, Willian Oliveira, Mirela Cazzolato, Alceu Costa, Jose Rodrigues, Agma Traina, Caetano Traina, 2015, Techniques for effective and efficient fire detection from social media images, ICEIS, 34-4

A baseline-free and non-contact method for detection and imaging of structural damage using 3D laser vibrometry

Abstract not availableP. Aryan, A. Kotousov, C. T. Ng and B. S. Cazzolat

The Difficulties of the Non Governmental Organizations’ Management

O principal objetivo deste artigo é apresentar uma análise da gestão das organizações não-governamentais (ONG) brasileiras, a partir de um breve histórico e da conceituação destas organizações. Assim, foram apresentados os principais aspectos que devem compor sua estrutura administrativa para melhoria dos processos de gestão, considerando-se as dificuldades que o setor enfrenta em meio a um mercado competitivo e globalizado. Para tanto, a metodologia utilizada foi uma pesquisa bibliográfica com autores da área e análise de dados secundários. Esta pesquisa conclui que o preparo adequado do gestor líder da ONG, a formação de sua missão e objetivos, sua comunicação institucional e a captação de recursos são processos relevantes para que sua gestão seja eficiente e eficaz.The main objective of this paper is to present an analysis of the non-governmental organizations’ (NGOs) management in Brazil, beginning a brief historical and conceptualization of these organizations. Therefore, were presented the main aspects that should make its administrative structure to improve management processes, considering the difficulties facing the industry in the midst of a competitive and globalized scenario. However, the methodology used was a literature with authors in the field and analysis of secondary data. This research concludes that the appropriate preparation of NGO’s leader manager, the formation of its mission and goals, its institutional communication and fundraising processes are relevant to their management be efficient and effective

A generalized approach to modal filtering for active noise control - Part II: Acoustic sensing

Copyright © 2002 IEEEFor pt. I see ibid., vol.2, no.6, p.577-89 (2002). Scaling laboratory-sized active noise control systems into industrial-sized implementations is a difficult exercise. Problems relating to sensing system design account for some of the difficulty. In the first part of this paper, an alternative approach to sensing system design was presented where acoustic radiation patterns are decomposed using fundamental acoustic quantities, rather than structural modal based quantities. In this paper, the approach is tackled in the acoustic domain instead of structural vibration. The technique has been simulated in the time and frequency domains using acoustic sensors and implemented experimentally.Simon G. Hill, Scott D. Snyder, Ben S. Cazzolato, Nobuo Tanaka and Ryoji Fukud

Acoustic absorption behaviour of a tall carbon nanotube forest

Previous investigations have shown that a 3-mm-high carbon nanotube (CNT) forest has an acoustic absorption coefficient of about 5-10% within the frequency range 125 Hz-4 kHz, which is above that of conventional acoustic materials on a per-mass basis. It was hypothesised that a CNT array of greater height, lower density, and with a non-uniform arrangement of the nanotubes could enhance the amount of acoustic absorption. In order to investigate this hypothesis, an impedance tube test was conducted to measure the acoustic absorption coefficient of a relatively tall 6-mm CNT forest. The results indicate that a greater length and lower density of CNTs may improve the absorption performance of CNT-based acoustic absorbers. Analyses of the results showed anomalies in the measured acoustic absorption coefficient compared with previous investigations. Theoretical analyses were performed based on classical models of acoustic absorption to explain the anomalies. This study describes the factors that may affect the acoustic absorption behaviour of nanomaterials.M. Ayub, A. C. Zander, C. Q. Howard, B. S. Cazzolato, D. M. Huang, N. T. Alvarez, and V. N. Shano

O caminho das verbas público-partidárias e o custo do voto

Tem-se como objetivo descobrir o custo do voto para o Brasil com base nos dados publicados pelo TSE referentes aos prefeitos eleitos em 2012 nas capitais. Para tanto, foi preciso entender o processo eleitoral sob a ótica financeira e legislativa, investigando o quanto o país investe em campanhas eleitorais e na manutenção dos partidos. Buscou-se colocar em evidência o caminho que a verba público-partidária percorre após sair do Orçamento Geral da União e, além disso, analisar como ela é composta e distribuída. A pesquisa documental e a pesquisa empírica indicaram que as campanhas dos prefeitos eleitos nas capitais foram financiadas por aproximadamente 74% de recursos públicos e, em média, o voto custou R$ 5,14 para o Brasil