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University of Algarve, Portugal

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28 Papers

Automatic Text Difficulty Classifier - Assisting the Selection Of Adequate Reading Materials For European Portuguese Teaching

Topics: Metrics and Performance Measurement; Tools for Educational Communication and Collaboration; Tools to Assess Learning

Authors: Pedro Curto ¹ , Nuno Mamede ¹ and Jorge Baptista ²

Affiliations: ¹ Universidade de Lisboa and INESC-ID Lisboa/L2F – Spoken Language Lab, Portugal , ² Universidade de Lisboa and Universidade do Algarve, Portugal

Digital Object Identifier: 10.5220/0005428300360044

Proceedings of CSEDU 2015, ISBN: 978-989-758-107-6

Quick Abstract

This paper describes a system to assist the selection of adequate reading materials to support European Portuguese teaching, especially as second language, while highlighting the key challenges on the selection of linguistic features for text difficulty (readability) classification. The system uses existing Natural Language Processing (NLP) tools to extract linguistic features from texts, which are then used by an automatic readability classifier. Currently, 52 features are extracted: parts-of-speech (POS), syllables, words, chunks and phrases, averages and frequencies, and some extra features. A classifier was created using these features and a corpus, previously annotated by readability level, using a five-levels language classification official standard for Portuguese as Second Language. In a five-levels (from A1 to C1) scenario, the best-performing learning algorithm (LogitBoost) achieved an accuracy of 75.11% with a root mean square error (RMSE) of 0.269. In a three-levels (A, B and C) scenario, the best-performing learning algorithm (C4.5 grafted) achieved 81.44% accuracy with a RMSE of 0.346.

Related Ontology Subjects/Areas/Topics (4)

Computer-Supported Education		Learning/Teaching Methodologies and Assessment		Metrics and Performance Measurement
Information Technologies Supporting Learning

Detection of Root Knot Nematodes in Microscopy Images

Topics: Quantitative Bioimaging; Image Processing Methods; Feature Recognition and Extraction Methods; Conventional Microscopy

Authors: Faroq AL-Tam ¹ , António dos Anjos ² , Stephane Bellafiore ³ and Hamid Reza Shahbazkia ⁴

Affiliations: ¹ University of Algarve and University of Thamar, Portugal , ² ISMAT and University of Algarve, Portugal , ³ IRD and LMI RICE, France , ⁴ University of Algarve and IRD, Portugal

Digital Object Identifier: 10.5220/0005209000760081

Proceedings of BIOIMAGING 2015/BIOSTEC, ISBN: 978-989-758-072-7

Quick Abstract

Object detection in microscopy image is essential for further analysis in many applications. However, images are not always easy to analyze due to uneven illumination and noise. In addition, objects may appear merged together with debris. This work presents a method for detecting rice root knot nematodes in microscopy images. The problem involves four subproblems which are dealt with separately. The uneven illumination is corrected via polynomial fitting. The nematodes are then highlighted using mathematical morphology. A binary image is obtained and the microscope lines are removed. Finally, the detected nematodes are counted after thresholding the non-nematode particles. The results obtained from the performed tests show that this is a reliable and effective method when compared to manual counting.

Related Ontology Subjects/Areas/Topics (6)

Bioimaging		Conventional Microscopy		Image Processing Methods
Biomedical Engineering		Feature Recognition and Extraction Methods		Quantitative Bioimaging

Integration of a Food Distribution Routing Optimization Software with an Enterprise Resource Planner

Topics: Decision Support Systems; Web Applications; Geographic Information Retrieval; Intelligent Data Fusion; Sensor Networks

Authors: Pedro J. S. Cardoso ¹ , Gabriela Schütz ¹ , Jorge Semião ² , Jânio Monteiro ² , João Rodrigues ¹ , Andriy Mazayev ¹ , Emanuel Ey Vieira ¹ , Micael Viegas ¹ , Carlos Neves ³ and Sérgio Anastácio ³

Affiliations: ¹ University of the Algarve, Portugal , ² University of the Algarve and INESC-ID, Portugal , ³ Business Solutions, Portugal

Digital Object Identifier: 10.5220/0005385901530161

Proceedings of GISTAM 2015, ISBN: 978-989-758-099-4

Quick Abstract

i3FR is a system for optimizing the distribution of fresh goods, using a fleet of vehicles, which must be integrated with an existing Enterprise Resource Planning (ERP) software, while avoiding disruption of established schedules and procedures. In terms of delivery optimization, the most similar problem in literature is the wellestablished and experimented Vehicle Routing Problem with Time Windows (VRPTW), which is, by nature, a multiple objective problem where the number of vehicles and the total traveled distance must be minimized. In this paper, the overall architecture of the i3FR system is presented, which includes several modules and services (such as ERP, routing optimization and data acquisition modules), and the communication between them. The novelty in the proposed architecture comprises: (i) the application to a fresh goods distribution network, with multiple restrictions on goods’ acclimatization; (ii) a data acquisition system which includes vehicle data and environmental data from the vehicles’ refrigerated volumes, such as temperature; and (iii) the integration of the VRPTW optimization system with an existing ERP. A case-study is described and validates the overall implementation. The main contribution of paper is the proposal of a multi-layered architecture to integrate existing ERP software with a route optimization and a temperature data acquisition module.

Related Ontology Subjects/Areas/Topics (4)

Applications		Sensor Networks		Web Applications
Pattern Recognition

Time-variant Adaptive Passive Time Reversal Equaliser and a Perspective for Environmental Focusing Method

Topics: Connectivity and Communication; Statistical and Adaptive Signal Processing

Authors: Lussac P. Maia , António Silva and Sérgio M. Jesus

Affiliation: University of Algarve, Portugal

Digital Object Identifier: 10.5220/0005330901030108

Proceedings of SENSORNETS 2015, ISBN: 978-989-758-086-4

Quick Abstract

High digital data throughput in Underwater Acoustic Communications (UAComm) is a challenging subject, specially in shallow water where the channel is a wave-guide causing multipath propagation and where Doppler effect usually occurs due to relative source-receiver motion jointly to ocean dynamics. The source and receiver sensors can be used for telemetry in point-to-point underwater communications or as nodes of an underwater acoustic network within the scope of oceanic research observatory or offshore activities. However, channel tracking is required for reliable digital underwater communications between the sensors, which is a hard task due to the complicated propagation of acoustic waves in the ocean. Equalisation is often required to perform a compensation method aiming to overcome the inter-symbol interference (ISI) caused by multipath propagation. The motivation of this work is to propose a compensation method deploying the adaptive passive time-reversal (ApTR) equaliser, aiming to perform ISI mitigation jointly to Doppler compensation in time-variant channels. The benefit given by ApTR processing would be the performance improvement in underwater communications between an active sensor and a vertical line array of receiver sensors, relying in well-succeed time-variant channel impulse response estimation. Furthermore, this position paper discusses the perspective of use an environmental focusing method for channel estimation within the ApTR equaliser, based on the idea that a set of oceanic acoustic physical parameters – which are generally estimated in low-frequency matched field processing problems like geoacoustic assessment, ocean tomography and source localization – could be conveniently used for channel compensation in high frequency underwater communications using a carefully chosen search space of replicas. The results are two fold: in one hand the equalisation shall improve the UAComm system, and in the other hand, the best match of channel parameters consequently yields a refined local environmental assessment.

Related Ontology Subjects/Areas/Topics (5)

Connectivity and Communication		Signal Processing		Statistical and Adaptive Signal Processing
Sensor Networks		Software and Architectures

A Visual Programming Language for Soccer

Topics: Domain-Specific Languages; Modeling Languages

Authors: António Belguinha , Pedro Rodrigues , P.J.S. Cardoso , J.M.F. Rodrigues and Domingos Paciência

Affiliation: University of the Algarve, Portugal

Digital Object Identifier: 10.5220/0005105901210127

Proceedings of ICSOFT-PT 2014/ICSOFT, ISBN: 978-989-758-037-6

Quick Abstract

The use of Information Technologies (IT) in high competition sports is an instrument often used. However, the majority of the performers, including technical teams, do not have skills to program those IT tools to their needs. In this paper we present the low level implementation of a visual programming language (VPL) that allows the user without programming expertise to produce relatively complex programs by drawing them on a web application. The VPL tool application is illustrated by applying it to detect programmed situations from a soccer game, using previously obtained tracking data. The tool can be applied to other collective ball sports.

Related Ontology Subjects/Areas/Topics (5)

Domain-Specific Languages		Models		Software Engineering
Modeling Languages		Paradigm Trends

Region Segregation by Linking Keypoints Tuned to Colour

Topic: Clustering

Authors: M. Farrajota , J. M. F. Rodrigues and J. M. H. du Buf

Affiliation: University of the Algarve, Portugal

Digital Object Identifier: 10.5220/0004827002470254

Proceedings of ICPRAM 2014, ISBN: 978-989-758-018-5

Quick Abstract

Coloured regions can be segregated from each other by using colour-opponent mechanisms, colour contrast, saturation and luminance. Here we address segmentation by using end-stopped cells tuned to colour instead of to colour contrast. Colour information is coded in separate channels. By using multi-scale cortical endstopped cells tuned to colour, keypoint information in all channels is coded and mapped by multi-scale peaks. Unsupervised segmentation is achieved by analysing the branches of these peaks, which yields the best-fitting image regions.

Related Ontology Subjects/Areas/Topics (3)

Clustering

Pattern Recognition

Theory and Methods

A Biological Sound Source Localization Model

Topics: Neural Networks; Biometrics; Acoustic Signal Processing

Authors: A. Azarfar and J. M. H. du Buf

Affiliation: University of the Algarve, Portugal

Digital Object Identifier: 10.5220/0004247403330337

Proceedings of BIOSIGNALS 2013/BIOSTEC, ISBN: 978-989-8565-36-5

Quick Abstract

In this paper we address sound source localization in the azimuthal plane. Various models, from the cochlear nuclei to the inferior colliculi, are implemented to achieve accurate and reliable localization. Coincidence detector cells in the medial nuclei and cells sensitive to interaural level difference in the lateral nuclei of the superior olive are combined with models of V- and I-type neurons plus azimuth map cells in the inferior colliculus. An advanced cell distribution in the inferior colliculus is proposed to keep ITD functions at any frequency within the physiological range of the head. Additional projections from the dorsal nucleus of the lateral lemniscus and the medial nucleus of the superior olive are modeled such that interaural time differences in different frequency bands converge to a single result. Experimental results demonstrate good performance in case of a variety of normal sounds.

Related Ontology Subjects/Areas/Topics (23)

Acoustic Signal Processing	Health Engineering and Technology Applications	Pattern Recognition
Applications	Human-Computer Interaction	Physiological Computing Systems
Artificial Intelligence	Methodologies and Methods	Sensor Networks
Biomedical Engineering	Multimedia	Signal Processing
Biomedical Signal Processing	Multimedia Signal Processing	Soft Computing
Biometrics	Neural Networks	Telecommunications
Biometrics and Pattern Recognition	Neurocomputing	Theory and Methods
Computational Intelligence	Neurotechnology, Electronics and Informatics

Phase-differencing in Stereo Vision - Solving the Localisation Problem

Topics: Pattern Recognition; Wavelet Transform; Image Analysis and Processing

Authors: J. M. H. du Buf , K. Terzic and J. M. F. Rodrigues

Affiliation: University of the Algarve, Portugal

Digital Object Identifier: 10.5220/0004349702540263

Proceedings of BIOSIGNALS 2013/BIOSTEC, ISBN: 978-989-8565-36-5

Quick Abstract

Complex Gabor filters with phases in quadrature are often used to model even- and odd-symmetric simple cells in the primary visual cortex. In stereo vision, the phase difference between the responses of the left and right views can be used to construct a disparity or depth map. Various constraints can be applied in order to construct smooth maps, but this leads to very imprecise depth transitions. In this theoretical paper we show, by using lines and edges as image primitives, the origin of the localisation problem. We also argue that disparity should be attributed to lines and edges, rather than trying to construct a 3D surface map in cortical area V1. We derive allowable translation ranges which yield correct disparity estimates, both for left-view centered vision and for cyclopean vision.

Related Ontology Subjects/Areas/Topics (17)

Applications and Services	Health Engineering and Technology Applications	Pattern Recognition
Artificial Intelligence	Human-Computer Interaction	Physiological Computing Systems
Biomedical Engineering	Medical Image Detection, Acquisition, Analysis and Processing	Sensor Networks
Biomedical Signal Processing	Methodologies and Methods	Soft Computing
Computer Vision, Visualization and Computer Graphics	Neurocomputing	Wavelet Transform
Data Manipulation	Neurotechnology, Electronics and Informatics

MINIMALISTIC VISION-BASED COGNITIVE SLAM

Authors: Mário Saleiro , J. M. F. Rodrigues and J. M. H. du Buf

Affiliation: University of the Algarve (ISE and FCT), Portugal

Digital Object Identifier: 10.5220/0003881306140623

Proceedings of SSIR 2012/ICAART, ISBN: 978-989-8425-95-9

Quick Abstract

The interest in cognitive robotics is still increasing, a major goal being to create a system which can adapt to dynamic environments and which can learn from its own experiences. We present a new cognitive SLAM architecture, but one which is minimalistic in terms of sensors and memory. It employs only one camera with pan and tilt control and three memories, without additional sensors nor any odometry. Short-term memory is an egocentric map which holds information at close range at the actual robot position. Long-term memory is used for mapping the environment and registration of encountered objects. Object memory holds features of learned objects which are used as navigation landmarks and task targets. Saliency maps are used to sequentially focus important areas for object and obstacle detection, but also for selecting directions of movements. Reinforcement learning is used to consolidate or enfeeble environmental information in long-term memory. The system is able to achieve complex tasks by executing sequences of visuomotor actions, decisions being taken by goal-detection and goal-completion tasks. Experimental results show that the system is capable of executing tasks like localizing specific objects while building a map, after which it manages to return to the start position even when new obstacles have appeared.

OVERVIEW OF COMPUTER-ASSISTED LANGUAGE LEARNING FOR EUROPEAN PORTUGUESE AT L2F

Topics: Web-Based Learning, Wikis and Blogs; e-Learning Platforms, Portals; Technology Enhanced Learning

Authors: Thomas Pellegrini ¹ , Wang Ling ² , André Silva ¹ , Rui Correia ² , Isabel Trancoso ³ , Jorge Baptista ⁴ and Nuno Mamede ³

Affiliations: ¹ Instituto de Engenharia de Sistemas e Computadores - Investigação e Desenvolvimento, Portugal , ² Instituto de Engenharia de Sistemas e Computadores - Investigação e Desenvolvimento, Instituto Superior Técnico and Carneggie Mellon University, Portugal , ³ Instituto de Engenharia de Sistemas e Computadores - Investigação e Desenvolvimento and Instituto Superior Técnico, Portugal , ⁴ Universidade do Algarve, Portugal

Digital Object Identifier: 10.5220/0003921505380543

Proceedings of SGoCSL 2012/CSEDU, ISBN: 978-989-8565-07-5

Quick Abstract

In this paper, we give an overview of our research in Computer-Assisted Language Learning for European Portuguese, to show how our long-time experience in spoken language processing allowed to propose multimedia documents as learning material. Beside a reading activity module that provides learners with individualized readings from a digital libray, Web-based serious game were introduced to cover aspects of listening, reading, and writing skills. One fundamental aspect of all our tools remains in the fully-automatic generation of the curriculum. This is very valuable for teachers, saving them time in search for motivating materials of appropriate quality, level and topic. A Web portal was recently created to make all our tools publicly available at http://call.l2f.inesc-id.pt/reap.public.

Related Ontology Subjects/Areas/Topics (9)

Computer-Supported Education	Information Technologies Supporting Learning	Technology Enhanced Learning
e-Learning	Simulation and Modeling	Ubiquitous Learning
e-Learning Platforms	Simulation Tools and Platforms	Web-Based Learning, Wikis and Blogs

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