Acoustic emission and reception unit (AERU)

SiPLAB Report 02/10, FCT, University of Algarve,2010.This document describes a data acquisition/data generation system, which consists of a portable waterproof case with all the integrated electronics. It features a high power battery, a precision DAQ board, a state-of-the-art GPS board and a complete computer system. Acquired data can be stored in the internal hard drive and download into another storage device or directly to another computer using the Ethernet connection. It is intended to be used with the Portable Acoustic Source Unit (PASU) for acoustic data transmission and with single or multiple hydrophones for acoustic data acquisition. The system also features a easy and ready-to-use graphical user interface that allows the user to use the system using the integrated LCD touch screen. A user manual is included as an installation, setup and maintenance guide for the system and its practical applications. The developed hardware and software is described in detail. Detailed schematics and designs can be found in the final section of this document, which can be used to further develop the system, perform maintenance, purchase spare parts or perform any type of modifications. A support equipment named OCU (Outdoor Communications Unit) is also described in this document. The OCU consists of a waterproof case that can be used to supply the AERU or the PASU and to add wireless connectivity to the AERU it can also provide a handy solution to charge the batteries of the AOB2 buoys in a wet deck environment. ACKNOWLEDGMENT:This work was supported by project UAN (Underwater Acoustic Network) from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement # 225669

Portable acoustic source unit

SiPLAB Report 05/09, FCT, University of Algarve,2009.This document describes a Portable Acoustic Source Unit, which is a system composed of an acoustic projector (Lubell LL916C) and a waterproof case containing all the electronics. The waterproof case contains an audio amplifier, an impedance converter, a switching regulator, measuring equipment and a high power battery to supply the whole system in a vessel or on shore in a field test standalone configuration. This is a system that can be used to transmit acoustic signals generated by a computer or by another system such as the AERU which has also been developed for the UAN project. A user manual is included as an installation, setup and maintenance guide for the system and its practical applications. The developed hardware and software is described in detail. Detailed schematics and designs can be found in the final section of this document, which can be used to further develop the system, perform maintenance, purchase spare parts or perform any type of modifications

Transportation in Social Media: an automatic classifier for travel-related tweets

In the last years researchers in the field of intelligent transportation systems have made several efforts to extract valuable information from social media streams. However, collecting domain-specific data from any social media is a challenging task demanding appropriate and robust classification methods. In this work we focus on exploring geo-located tweets in order to create a travel-related tweet classifier using a combination of bag-of-words and word embeddings. The resulting classification makes possible the identification of interesting spatio-temporal relations in S\~ao Paulo and Rio de Janeiro

Characterizing Geo-located Tweets in Brazilian Megacities

This work presents a framework for collecting, processing and mining geo-located tweets in order to extract meaningful and actionable knowledge in the context of smart cities. We collected and characterized more than 9M tweets from the two biggest cities in Brazil, Rio de Janeiro and S\~ao Paulo. We performed topic modeling using the Latent Dirichlet Allocation model to produce an unsupervised distribution of semantic topics over the stream of geo-located tweets as well as a distribution of words over those topics. We manually labeled and aggregated similar topics obtaining a total of 29 different topics across both cities. Results showed similarities in the majority of topics for both cities, reflecting similar interests and concerns among the population of Rio de Janeiro and S\~ao Paulo. Nevertheless, some specific topics are more predominant in one of the cities