Non INESC TEC publications - Indexed Articles in Conferences

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Browsing Non INESC TEC publications - Indexed Articles in Conferences by Title

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    3D tendon strain estimation on high-frequency 3D ultrasound images a simulation and phantom study
    ( 2016) Catarina Brito Carvalho ; Bogaerts,S ; Scheys,L ; D'hooge,J ; Peers,K ; Suetens,P
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    Adoption of auditability as a proposal to identify false information on social networks [Adoção da auditabilidade como proposta para identificar informações falsas em redes sociais]
    ( 2016) Alexandre Hostand Souza ; Cappelli,C ; MacIel,C
    The lack of mechanisms made to check reliability of information on social networks is evidenced by the spread of misinformation and rumors in this kind of system. Given this scenario, the provision of tools to assist users with information auditability on social networks needs an emergencial approach. This article describes a catalog, followed by a guide of features that provide auditability on social networks. The guide contains guidelines for development of funcionalities in order to promote the adoption of auditability and enable users to identify false information and validate content on social networks. © 2016 for this paper by its authors.
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    Algoritmos Meméticos Aplicados à Identificação de Sistemas e Sintonização de Controladores PID
    ( 2018) Sousa,AL ; Vidal,JF ; Silva,OF ; Victor Silva Freitas ; 7194
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    Allocation of PEVs' Parking Lots in Renewable-Based Distribution System
    ( 2014) Nilufar Neyestani ; Damavandi,MY ; Shafie Khah,M ; João Catalão ; Contreras,J
    Emerging trends in electric vehicles both in science and industry, as well as increasing popularity of these devices among end-users have laid serious issues in front of a system operator or planner. Higher deployment of available resources in the system will lead to higher flexibility for system operator in its interactions, besides to higher level of user satisfaction. In this study, various states of a 13 bus radial distribution network have been considered for allocation of Plug-in Electric Vehicles' (PEVs') parking lots. As Renewable Energy Resources (RERs) are becoming a main element of power systems, it is investigated how the future distribution network planning has to be organized by employing both RERs and PEV parking lots. Also, it is investigated how the allocation of parking lots varies in the system where these resources exist. Moreover, the costs and revenues obtained by the system operator in such systems are also studied.
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    Analysing Traffic Flows Through Sampling: A Comparative Study
    ( 2015) João Marco ; Carvalho,P ; Lima,SR
    Understanding network workload through the characterization of network flows, being essential for assisting network management tasks, can benefit largely from traffic sampling as long as an accurate snapshot of network behavior is captured. This paper is devoted to evaluate the real applicability of using sampling to support flow analysis. Considering both classical and emerging sampling techniques, a comparative performance study is carried out to assess the accuracy of estimating flow parameters through sampling. After identifying the main building blocks of sampled-based measurements, a sampling framework has been implemented to provide a versatile and fair platform for carrying out the testing and comparison process. Through an encompassing coverage of representative sampling techniques, the present study aims to provide useful insights regarding the use of sampling in traffic flow analysis.
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    Analysis of Signal Saturation in a Fiber Ring Resonator integrating an Intensity Sensor
    ( 2017) Magalhaes,R ; Susana Oliveira Silva ; Orlando Frazão
    The proposed technique consists in an optical fiber resonator interrogated for sensor characterization, implementing an alternative technique for dynamic range improvement. Such technique relies on the analysis of an added-signal caused by signal saturation, which occurs due to the broadening of the laser pulse. A wide study for different pulse widths is presented in this work, namely for 100 ns, 5 mu s and 20 mu s, being the last one related to the emergence of an added-signal for the proposed configuration. The behavior of the waveform in the presence of an intensity sensor is also characterized.
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    Analyzing First-Person Stories Based on Socializing, Eating and Sedentary Patterns
    ( 2017) Herruzo,P ; Portell,L ; Soto,A ; Beatriz Remeseiro López
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    Analyzing the Effect of Various PEV Owner's Charging Tariffs on PEV PL's Market Equilibrium
    ( 2015) Nilufar Neyestani ; Damavandi,MY ; João Catalão
    In this paper, an innovative bi-level model is developed for the interactions of the plug-in electric vehicle (PEV) parking lot (PL) with the upstream markets through an aggregator in the system. The preferences of the PEVs on using the PL are also considered in the study. The PEVs have a choice in participating in grid-to-vehicle or vehicle-to-grid modes with fixed or flexible amount of departed state of charge (SOC). The PL assigns various tariffs for different requirements of the PEVs. In this study, the mutual effect of the variation of PEV tariffs and the PL's behavior in the market is investigated. It is shown that the preferences of PEVs can significantly affect the PL's strategy. The changes of the equilibrium prices for PL and aggregator interaction are thoroughly analyzed in response to changes in PEV tariffs to illustrate their influence on their behavior.
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    Application of Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) technique to Land Deformation Monitoring in Warri metropolis, Delta State, Nigeria
    ( 2016) Mahmud,MU ; Yakubu,TA ; Oluwafemi,O ; Joaquim João Sousa ; Miguel Ruiz Armenteros,AM ; Arroyo Parras,JG ; Bakon,M ; Lazecky,M ; Perissin,D
    Warri is one of the mega cities in Delta State in the coastal region of Nigeria hosting many industries. One of the three of Nigeria oil refineries is located in Warn. This study reveals the occurence of land deformation in the Warri area which is not only because it was formed in a tectonic setting but because of the high demand of the underground water for indutrial and domestics uses, high population density and oil and gas exploration in the area. Land deformation in this area is currently being accelerated by this indiscriminate withdrawal of underground water from the aquifers and exploration of the oil and gas leading to the compacting sediments. In this study Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) technique was applied to monitor land deformation in Warri metropolis in the period between 09/02/2006 and 12/08/2010 with Envisat data obtained from European Space Agency (ESA). The processing was done using Stanford Method for Persistent Scatterers/Multi-Temporal InSAR (StaMPS). From the analysis of the results, land deformation is occurring in Warri metropolis at a moderate rates (+/-5 mm/yr). During the preliminary investigations, structures, particularly buildings, were physically observed subsiding while some others with cracks of various types and degrees. (C) 2016 The Authors. Published by Elsevier B.V.
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    Artificial Neural Networks Applied to an Earthwork Construction Database
    ( 2014) Manuel Afonso Parente ; Correia,AG ; Cortez,P
    This paper presents a study based on the application of cascade ANN prediction models to an earthwork construction database. Results show not only a good adjustment to the data, but also the influence of each earthwork construction process on the work rate of the global production line. Furthermore, the obtained results emphasize the importance of optimal resource allocation and management throughout earthwork construction phases. Following this framework, the study concludes with a demonstration of how the developed models can be integrated into a more complex system in order to pursue that purpose.
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    Assessment of PEV Owners' Preferences Impact on PEV Parking Lot Transactions
    ( 2015) Nilufar Neyestani ; Damavandi,MY ; João Catalão
    The inevitable need of new infrastructures for encouraging plug-in electric vehicles (PEVs) penetration into the system has drawn various attentions towards the required studies. In this regard, the PEVs parking lot (PL) has shown to have proper potentials. Other than providing a charging place for the PEVs, PLs can be considered as an integrated form of PEV batteries and act as storage in the system. However, the accuracy of PL's operation can be enhanced through detailed modeling of various affecting factors such as PEV's preferences on using the charging capability of the PL. In this study, a new model to add the PEVs' preferences in the PL's market participation problem is proposed. Various categories of PEVs are considering based on their arrival/departure pattern, duration of stay in the PL, and charging requirements. The results showed a considerable difference in PL's strategy in market participation, with and without considering PEVs' preferences.
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    Automatic Classification of Retinal Vessels Using Structural and Intensity Information
    ( 2013) Dashtbozorg,B ; Ana Maria Mendonça ; Aurélio Campilho
    This paper presents an automatic approach for artery/vein (A/V) classification based on the analysis of a graph representing the structure of the retinal vasculature. The entire vascular tree is classified by deciding on the type of each intersection point (graph node) and assigning one of two classes to each vessel segment (graph link). The final label for each vessel segment is accomplished by a combination of structural information taken from the graph (link class) with intensity features measured in the original color image. An accuracy of 88.0% was achieved for the 40 images of the INSPIRE-AVR dataset, thus demonstrating that our method outperforms state-of-the-art approaches for A/V classification.
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    Automatic Cyst Detection in OCT Retinal Images Combining Region Flooding and Texture Analysis
    ( 2013) Gonzalez,A ; Beatriz Remeseiro López ; Ortega,M ; Penedo,MG ; Charlon,P
    In this work Optical Coherence Tomography (OCT) retinal images are automatically processed to detect the presence of cysts. The methodology is composed by three phases: region of interest where cysts will be searched is delimited; a watershed algorithm is applied to find all the possible regions in the image which might conform cystic structures; finally, texture analysis is performed in each region from previous phase to final classification. Results show that accuracy achieved with this method is over 80%.
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    Automatic Estimation of the Arteriolar-to-Venular Ratio in Retinal Images Using a Graph-Based Approach for Artery/Vein Classification
    ( 2013) Dashtbozorg,B ; Ana Maria Mendonça ; Aurélio Campilho
    The Arteriolar-to-Venular Ratio (AVR) is a well known index for the diagnosis of diseases such as diabetes, hypertension or cardiovascular pathologies. This paper presents a fully automatic AVR estimation method which uses a graph-based artery/vein classification approach to classify the retinal vessels by a combination of structural information taken from the vasculature graph with intensity features from the original color image. This method was evaluated on the images of the INSPIRE-AVR dataset. The mean error and the correlation coefficient of obtained results with respect to the reference AVR values were identical to the ones obtained by the second observer using a semi-automated system, which demonstrate the potential of the herein proposed solution for clinical application.
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    Automatic meal intake monitoring using Hidden Markov Models
    ( 2016) Costa,L ; Trigueiros,P ; António Cunha
    In the latest years, the number of elderly people that has been living alone and need regular support has highly increased. Meal intake monitoring is a well-known strategy that enables premature detection of health problems. There are several attempts to develop automatic meal intake monitoring systems, but they are inadequate to monitor elderly people at home. In this context, we propose an automatic meal intake monitoring system that helps tracking people's eating behaviors, and is adequate for elderly remote monitoring at home due to its nonintrusive features. The system uses the MS Kinect sensor that provides the coordinates of the user's sitting skeleton during his meals. It analyzes the coordinates, detects eating gestures, and classifies them using Hidden Markov Models (HMMs) to estimate the user's eating behavior. A demonstrative prototype for detection and classification of gestures was implemented and tested. The detection module got satisfactory percentages of sensitivity, having a minimum of 72.7% and a maximum of 90%. The Classification module was tested with 3 proposed methods and the best method had a good average percentage of success (approximately 83%) in the classification of Soup and Main dish; regarding the left hand transporting Liquids, the results were less successful. (C) 2016 The Authors. Published by Elsevier B.V.
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    An Automatic Method for the Estimation of Arteriolar-to-Venular Ratio in Retinal Images
    ( 2013) Dashtbozorg,B ; Ana Maria Mendonça ; Aurélio Campilho
    This paper presents an automatic approach for the estimation of Arteriolar-to-Venular Ratio (AVR) in retinal images. The method was assessed using the images of the INSPIRE-AVR database. A mean error of 0.05 was obtained when the method's results were compared with reference AVR values provided with this dataset, thus demonstrating the adequacy of the proposed solution for AVR estimation.
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    Automatic tear film segmentation based on texture analysis and region growing
    ( 2014) Beatriz Remeseiro López ; Oliver,KM ; Martin,E ; Tomlinson,A ; Villaverde,DG ; Penedo,MG
    Dry eye syndrome is a prevalent disease characterized by symptoms of discomfort and ocular surface damage. It can be identified by several types of diagnostic tests, one of which consists in capturing the appearance of the tear film by means of the Doane interferometer. Previous research has demonstrated that this manual test can be automated, with the benefits of saving time for experts and providing unbiased results. However, most images are made up of a combination of different patterns which makes their classification into one single category per eye not always possible. In this sense, this paper presents a first attempt to segment tear film images based on the interference patterns, and so to detect multiple categories in each individual subject. The adequacy of the proposed methodology was demonstrated since it provides reliable results in comparison with the practitioners’ annotations. © Springer International Publishing Switzerland 2014.
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    BiFluX: A Bidirectional Functional Update Language for XML
    ( 2014) Hugo Pereira Pacheco ; Zan,T ; Hu,Z
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    BreachRadar: Automatic Detection of Points-of-Compromise
    ( 2017) Miguel Ramos Araújo ; Almeida,Miguel ; Ferreira,Jaime ; Silva,LuisMoura ; Bizarro,Pedro
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    Bridging Automation and Robotics: an Interprocess Communication between IEC 61131–3 and ROS
    (IEEE, 2018) Pinto, Tiago ; Arrais, Rafael ; Veiga, Germano
    The contemporary adoption of Cyber-Physical Systems and improvements in robotic applications in industrial scenarios demands for horizontal integration mechanisms with already existing automation equipment, controlled by PLCs. This paper aims to shorten the gap between the automation and robotics domain, by proposing an Interprocess Communication method to establish interoperability between robotic systems and automation equipment in a reliable and straightforward manner. In particular, this paper introduces a novel approach for linking ROS and IEC 61131-3 by way of shared memory interfaces, enabling and promoting their interactions. Moreover, this paper addresses the applied synchronization mechanism for handling concurrent accesses to the shared memory location, explores data type mapping between ROS and IEC 61131-3, and identifies some practical industrial applications.