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Publications

Publications by CRAS

2016

A modelação aplicada à temática dos riscos naturais: O caso concreto de instituições de ensino superior em Portugal

Authors
Moutinho, SBG; Moura, RMM; Vasconcelos, CMdS;

Publication
Terrae Didatica

Abstract
O recurso à modelação como metodologia de ensino é relevante no processo de recriação e simulação de fenómenos naturais, nomeadamente fenómenos geológicos e ambientais. Pretendendo-se verificar se o recurso à modelação é uma metodologia significativa no sucesso da aprendizagem dos estudantes de riscos naturais do ensino superior português, foram analisadas as fichas das unidades curriculares que abordam temáticas de riscos naturais nas universidades públicas portuguesas, tendo-se optado por selecionar apenas unidades curriculares do primeiro ciclo de estudos – licenciatura. No total foram analisadas, com recurso a uma grade de análise, oito fichas de unidades curriculares, ministradas em sete universidades públicas portuguesas. Asevidências encontradas indicam que nenhum dos documentos em análise contempla a utilização da modelação como metodologia de ensino de temáticas de riscos naturais, predominando um ensino essencialmente tradicional, sobressaindo a necessidade de intervenção ao nível das metodologias de ensino valorizando-se a manipulação e a exploração de modelos no ensino superior.

2016

Odd-even Pole-pole array and 3D resistivity surveys in urban and historical areas

Authors
Almeida, F; Barraca, N; Moura, R; Matias, MJS;

Publication
22nd European Meeting of Environmental and Engineering Geophysics, Near Surface Geoscience 2016

Abstract
Modern and historical buildings may show some degree of subsidence resulting from foundation deterioration and local geological conditions. Hence, buildings stability can be affected and restoration plans must be envisaged. Resistivity methods have been used to investigate local conditions, providing 3D images of the soil under man made structures and hence contributing to the delimitation of hazardous areas and pathologies. However these techniques require the deployment of a grid of electrodes, which can be difficult to accomplish because of physical limitations and of the buildings nature that cannot be damaged. To overcome these problems special arrays have been used (L, Corner, Square arrays, etc). Here in it is proposed to use the "Odd-Even Pole-Pole Array" to study the ground under a contemporary building and under a high historical value XIV century Abbey, both showing evidence of subsidence. Field data quality is also addressed and it is proposed to identify low quality data to be expunged so that modelling is improved. It is also shown how to estimate resistivity values from data quality tests, to carry out further zonation, locate hazardous areas and to enhance modelling.

2016

Simulating an earthquake and its effects on soils and buildings: A practical activity to disseminate geosciences and its evaluation

Authors
Moutinho, S; Moura, R; Vasconcelos, C;

Publication
Geoscience Education: Indoor and Outdoor

Abstract
Model-based learning is a teaching methodology that facilitates the learning process through the construction of models, which represent the conceptual models taught in geosciences lessons, promoting the construction of students’ scientific knowledge and the development of a meaningful learning. It is crucial that teachers know how to apply it in schools in order to support students’ learning process, but also because models are important tools for dissemination of science concepts. Having this in mind, it becomes relevant, beyond the analysis of its importance for both teaching and disseminating geosciences in Portuguese high schools, to provide some guidelines and recommendations about the use of models in geosciences teaching, based on the literature, seeking to prepare teachers to apply the methodology in science lessons and for making them more informed about the importance of dissemination of science. To achieve this purpose, the attitudes of Portuguese high school students towards the importance of model-based learning in teaching and disseminating the dependence of earthquakes effects on soils and buildings were analysed. The data were collected through a scale for model evaluation named Seismological Models’ Evaluation Scale (SMES), applied to 126 students who participated in Faculty of Sciences’ Open Days to Schools. This instrument was validated by two experts in geosciences teaching, and its fidelity was also determined. © Springer International Publishing Switzerland 2016.

2016

MENTAL MODELS ABOUT SEISMIC EFFECTS: STUDENTS' PROFILE BASED COMPARATIVE ANALYSIS

Authors
Moutinho, S; Moura, R; Vasconcelos, C;

Publication
INTERNATIONAL JOURNAL OF SCIENCE AND MATHEMATICS EDUCATION

Abstract
Nowadays, meaningful learning takes a central role in science education and is based in mental models that allow the representation of the real world by individuals. Thus, it is essential to analyse the student's mental models by promoting an easier reconstruction of scientific knowledge, by allowing them to become consistent with the curricular models presented in the classroom. In this context, the study aims to examine, through the application of a diagnostic instrument (Two-Tier Diagnostic Test), what students consider to be the seismic effects on soils and buildings, to analyse and to compare their mental models about some of these issues related to seismology, applying a questionnaire to 52 students from a Portuguese University attending an undergraduate degree in Geology and a master course in Biology and Geology teaching. The analysis of the data allowed concluding that undergraduate students have more inconsistent mental models than master students, mainly concerning the factors which influence the seismic risk, such as hazard and vulnerability, and the soils characteristics which influence the intensity of earthquakes. During their academic formation in the university, teachers present some curricular models to students which allow them to reconstruct their mental models and turn them scientifically consistent, enhancing the educational implications of this study that points to the need for teachers to be aware of the importance of the diagnosis of the students' mental models and to promote meaningful learning and scientific literacy autonomously and dynamically.

2016

Underwater acoustic physical layer emulator to evaluate digital communication

Authors
Martins, Marcos Silva; Cabral, José; Lopes, Gil; Ribeiro, A. Fernando;

Publication

Abstract
In order to achieve underwater acoustic high data-rate and real time communications, it is essential to implement a system that operates both at high and wideband frequencies using digital modulations. Therefore, to reduce the time and cost of developing acoustic communications an emulator of a physical layer model was implemented, allowing to test in real time the performance of digital modulations. The model was composed of an emitter transducer, a hydrophone and the subaquatic medium and was integrated in a Field Programmable Gate Array (FPGA) in order to emulate the physical layer in the acoustic modem testing. The emitter transducer and the hydrophone models were designed to meet real prototype characteristics. The system prototype was implemented in order to compare the experimental trials results with those obtained in emulator, emulating the transmission of acoustic signals, using different types of digital modulations. The system was tested using Binary Phase-Shift Keying (BPSK), Binary Frequency Shift keying (BFSK) and Binary Amplitude Shift Keying (BASK) modulations with a 1 MHz carrier frequency resulting in a data rate of 125 kbps. It was verified that the implemented model represents a suitable approximation to the real subaquatic communication channel, allowing the evaluation of digital acoustic communications.

2016

Tracking sound source localization for a home robot application

Authors
Lopes, Gil; Albernaz, Andreia; Ribeiro, Hélder Ricardo Freitas; Ribeiro, A. Fernando; Martins, Marcos Silva;

Publication

Abstract
The future of robotics is now trending for home servicing. Nursing homes and assistance to elder peopleare areas where robots can provide valuable help in order to improve the quality of life of those who need it most. Calling a robot,for a person of age,can be a daunting task if the voice is failing and any resort to battery operated devices failsto comply. Using a simple mechanical apparatus,such as aClick trainerfordogs, a person can call a robot by pressing thebutton of a powerless device. The high pitch sound produced by this device can be captured and tracked down in order to estimate the person’s location within a room. This paper describes a method that provides good accuracy and uses simple and low cost technology,in order to provide an efficient positional value for an assistance robot to attend its caller. The robot does not need to search for the person in aroom as it can directly travel towards the Click’s sound source.

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