Ciência da Computação
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/342
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Resultados da Pesquisa
Artigo de evento 1 Citação(ões) na Scopus Surface reconstruction for generating digital models of prosthesis(2011-03-05) DE AQUINO, L. C. M.; LEITE, D. A. T. Q.; GIRALDI, G. A.; CARDOSO, J. S.; Paulo Rodrigues; NEVES, L. A. P.The restoration and recovery of a defective skull can be performed through operative techniques to implant a customized prosthesis. Recently, image processing and surface reconstruction methods have been used for digital prosthesis design. In this paper we present a framework for prosthesis modeling. Firstly, we take the computed tomography (CT) of the skull and perform bone segmentation by thresholding. The obtained binary volume is processed by morphological operators, frame-by-frame, to get the inner and outer boundaries of the bone. These curves are used to initialize a 2D deformable model that generates the prosthesis boundary in each CT frame. In this way, we can fill the prosthesis volume which is the input for a marching cubes technique that computes the digital model of the target geometry. In the experimental results we demonstrate the potential of our technique and compare it with a related one.Artigo de evento 0 Citação(ões) na Scopus Expanding personas: How to improve knowledge about users(2013-07-22) MASIERO, A. A.; DESTRO, R. C.; CURIONI, O. A.; Plinio Thomaz Aquino JuniorPersona addresses one of the first challenges created by user-centered design, the creation of users profile to be used in the first design of user interface. This paper proposes a continuous process to evaluate and improve created personas, using additional information collected through interviews and dedicated software on each design interaction, to expand the knowledge about each persona, which means, the knowledge about the system users. The improvement on Expanded Persona was verified on a medical system developed by authors' team.Artigo de evento 1 Citação(ões) na Scopus A study of a firefly meta-heuristics for multithreshold image segmentation(2014-10-14) ERDMANN, H.; LOPES, L. A.; Guilherme Lopes; RIBEIRO, M. P.; Paulo Rodrigues© 2014 Taylor & Francis Group, London.Thresholding-based image segmentation algorithms are usually developed for a specific set of images because the objective of these algorithms is strongly related to their applications. The binarization of the image is generally preferred over multi-segmentation, mainly because it’s simple and easy to implement. However, in this paper we demonstrate that a scene separation with three threshold levels can be more effective and closer to a manually performed segmentation. Also, we show that similar results can be achieved through a firefly-based meta-heuristic. Finally, we suggest a similarity measure that can be used for the comparison between the distances of the automatic and manual segmentation.Artigo de evento 0 Citação(ões) na Scopus Automatic source code correction system focused on teacher's usability(2019-03-12) BELTRAME, F. S.; MAIA, R. F.; Guilherme LopesCopyright © 2019 by the International Institute ofInformatics and Systemics.In the Computing area many workout correction systems are used for automatic correction of source codes. However, one of the main impediments to the use of these tools is the inefficiency of the interface for the elaboration and use of the teacher in their discipline. In this project, we propose an automatic correction system for source codes so that the teacher can elaborate his own corrector in a practical manner. This corrector is used as a comparison guideline for submitted exercises.- Architectural design group decision-making in agile projects(2017-06-23) LOPES, S. V. F.; Plinio Thomaz Aquino Junior© 2017 IEEE.Software architecture has many definitions. One widely accepted definition of software architecture is that it is a composition of a set of architectural design decisions. Hence, designing a software architecture is a decision-making process. Agile methods drastically changed the way of designing a software architecture. In projects using agile methods (e.g. Scrum), making architectural design decisions is not the responsibility of a single person, but rather the whole development team. Despite the popularity of such methods in the industry, little research exists on how to make these decisions from the perspective of a group effectively. Current techniques usually focus on the identification of quality attributes and design alternatives, not addressing the whole decision-making process. The quality of decisions directly reflects the quality of the software architecture. Therefore poor decisions lead to bad software architectures. In this paper, we discuss current research on group decision-making in software architecture and the proposal of a combination of concepts from two architecture definition methods into a single approach that can be used in agile projects and addresses the most critical concerns of group decision-making. This proposal is part of a master's research project.
- Comparison of Bio-Inspired Algorithms from the Point of View of Medical Image Segmentation(2018) Wachs Lopes G.A.; Beltrame F.S.; Santos R.M.; Rodrigues P.S.© 2018 IEEE.As new technological challenges depending on the computational performance of bio-inspired algorithms emerge, the demand for more efficient heuristic solutions grows up at same rate. Specifically, the medical field is one of the most challenging, due to the fact of the pre-processing steps, such as multilevel segmentation of color spaces, require greater precision. Thus, many algorithms inspired by natural behavior have emerged successfully aiming to find approximate solutions compatible with optimal ones, but with much higher performance in terms of computational time. Although they perform well, some of these newer algorithms have not yet been analyzed from their practical applicability in one or more medical databases. This paper presents a comparative study from a practical point of view of three of these new algorithms: Cuckoo Search (CS), KH (Krill Herd) and EHO (Elephant Herd Optimization). Our results suggest that these three algorithms are compatible in terms of performance in medical databases, but with EHO showing the best performance among all three.
- Synthesizing 3D face shapes using tensor-based multivariate statistical discriminant methods(2011-11-14) MONOI, J.-L.; Plinio Thomaz Aquino Junior; GILLIES, D. F.We have implemented methods to reconstruct and model 3D face shapes and to synthesize facial expressions from a set of real human 3D face surface maps. The method employed tensor-based statistical shape modelling and statistical discriminant modelling methods. In the statistical shape modelling approach, new face shapes are created by moving the surface points along the appropriate expressive direction in the training set space. In the statistical discriminant model, new face shapes, such as facial expressions, can be synthesized by moving the surface points along the most discriminant direction found from the classes of expressions in the training set. The advantage of the tensor-based statistical discriminant analysis method is that face shapes of varying degrees can be generated from a small number of examples available in the 3D face shape datasets. The results of the reconstructions and synthesis of three-dimensional faces are illustrated in the paper. © 2011 Springer-Verlag.
- CARES 3.0: A two stage system combining feature-based recognition and edge-based segmentation for CIMT measurement on a multi-institutional ultrasound database of 300 images(2011-08-30) MOLINARI, F.; MELBURGER, K. M.; ACHARYA, U. R.; ZENG, G.; Paulo Rodrigues; SABA, L.; NICOLAIDES, A.; SURI, J. S.The intima-media thickness of the carotid artery (CIMT) is a validated marker of atherosclerosis. Accurate CIMT measurement can be performed by specifically designed computer algorithms. We improved a previous CIMT measurement technique by introducing a smart heuristic search for the lumen-intima (LI) and media-adventitia (MA) interfaces of the carotid distal wall. We called this new release as CARES 3.0 (a class of AtheroEdge™ system, a patented technology from Global Biomedical Technologies, Inc., CA, USA). CARES 3.0 is completely automated and adopts an integrated approach for carotid location in the image frame, followed by segmentation based on edge snapper and heuristic search. CARES 3.0 was benchmarked against three other techniques on a 300 image multi-institutional database. One of the techniques was user-driven. The CARES 3.0 CIMT measurement bias was -0.021±0.182 mm, which was better than that of the semi automated method (-0.036±0.183 mm). CARES 3.0 outperformed the other two fully automated methods. The Figure-of-Merit of CARES 3.0 was 97.4%, better than that of the semi-automated technique (95.4%). © 2011 IEEE.
- On source code completion assistants and the need of a context-aware approach(2017-07-09) ARREBOLA, F. V.; Plinio Thomaz Aquino Junior© Springer International Publishing AG 2017.Source code completion assistance is a popular feature in modern IDEs. However, despite their popularity, there is little research about their key characteristics and limitations. There is also little research about the way software developers interact with code completion assistants, especially when considering the different techniques assistants use to populate the list of possible completions. This paper presents a study about the features of currently available code assistants and an experiment targeting professional Java developers familiar with the Eclipse platform that aims to collect and interpret usage data of two popular code completion assistants during the execution of three programming tasks. Results indicate that half the interactions with code assistants are either dismissed, interrupted or the completion proposals displayed have no direct contribution to the completion of the programming task. In that sense, we argue that code assistants still have a long road to pursue, since they seem to diminish the importance of the ultimate goals of the task at hand and also lack the ability of identifying and exploring the concepts of context-aware computing theory. The results of this paper can drive future HCI research to the design of adaptive code completion assistants that are able to respond to end user behaviors and preferences.
- A reference process to design information systems for sustainable design based on LCA, PSS, social and economic aspects(2010) SANTAMA, F. S.; BARBERATO, C.; SARAIVA, A. M.© IFIP International Federation for Information Processing 2010.The purpose of Sustainable Design, SD, is to satisfy customer needs while reducing environmental impacts. The main challenge is to integrate Life Cycle Assessment, Product Service Systems, social and economic aspects while considering the tensions and trade-offs of each activity in depth. SD requires data from many sources in addition to many software tools to perform each analysis. In order to provide information systems for SD, the adoption of a Service-Oriented Architecture, SOA, is appropriate because of its integration requirements. SOA best practices recommend the design of a reference process prior to architectural definitions, so as to identify the complexities and provide a comprehensive solution to the problem. A reference process is presented here as the first step for building information systems for SD. In addition, the reference process presents a list of activities to be performed during the design stage and is very helpful as a guide for SD beginners.