Ciência da Computação

URI Permanente desta comunidade

https://repositorio.fei.edu.br/handle/FEI/342

Navegar

Agora exibindo 1 - 20 de 151

Planejamento de Ações para Automação Inteligente da Manufatura
(2002-12-05) TONIDANDEL, FLÁVIO; RILLO, MARCIO
Este artigo investiga o uso do sistema FAR-OFF na área da Automação da Manufatura. O sistema FAR-OFF possui característica similar aos sistemas de planejamento baseado em busca heurística, os quais têm apresentado excelentes resultados nos últimos anos na área de planejamento. Entretanto, em vez de ser um sistema generativo, o FAR-OFF é um sistema de planejamento baseado em casos que garante estabilidade para solucionar problemas em tempo aceitável. Os resultados apresentados pelo sistema no domínio de logística mostram que este é um sistema promissor para automação inteligente.
Futebol de Robôs: mais que um projeto, uma paixão tecnológica
(2004-10-05) TONIDANDEL, F.; BIANCHI, A. C. B.; DESTRO, R. DE C.
Case adaptation by segment replanning for case-based planning systems
(2005-08-26) Flavio Tonidandel; RILLO, M.
An adaptation phase is crucial for a good and reasonable Case-Based Planning (CBP) system. The adaptation phase is responsible for finding a solution in order to solve a new problem. If the phase is not well designed, the CBP system may not solve the desirable range of problems or the solutions will not have appropriate quality. In this paper, a method called CASER - Case Adaptation by Segment Replanning - is presented as an adaptation rule for case-based planning system. The method has two phases: the first one completes a retrieved case as an easy-to-generate solution method. The second phase improves the quality of the solution by using a generic heuristic in a recursive algorithm to determine segments of the plan to be replanned. The CASER method does not use any additional knowledge, and it can find as good solutions as those found by the best generative planners. © Springer-Verlag Berlin Heidelberg 2005.
Patterns de interface em PDA: Aplicação em coleta de dados de usabilidade
(2005-10-23) Plinio Thomaz Aquino Junior; FILGUEIRAS, L. V. L.; DE OLIVEIRA, E. C.; BELLO, T. R.
This poster describes interface patterns for PDA defined from usability studies at application developed from Usability Engineering Laboratory. The applications usability studies generated 15 interface patterns for PDA, with propose to create reliability during usability tests in Laboratory. When using defined patterns, it was gotten efficiency during the execution of the application.
On the use of UML.P for modeling a real application as a planning problem
(2006) VAQUERO, T. S.; Flavio Tonidandel; BARROS, L. N. DE; SILVA, J. R.
There is a great interest in the planning community to apply all developments already achieved in the area to real applications. Such scenario makes the community focus on Knowledge Engineering (KE) applied in modeling of planning problems and domains. In this paper, we propose the use of UML for Planning Approach, denominated UML.P, during planning domain modeling process. We also discuss the exposure of UML.P to a real application, e.g., the sequencing car problems in an assembly line. This modeling experience, using a classical manufacturing problem, provides some insights and considerations that can contribute to a general KE process for planning. Copyright © 2006, American Association for Artificial Intelligence (www.aaai.org). All rights reserved.
Reading PDDL, writing an object-oriented model
(2006-10-27) Flavio Tonidandel; VAQUERO, T. S.; SILVA, J. R.
There are many efforts towards a combination of planning systems and real world applications. Although the PDDL is in constant evolution, which improves its capability to describe real domains, it is still a declarative language that is not so simple to be used by the non-planning community. This paper describes a translation process that reads a domain specification in PDDL and transforms it into an object-oriented model, more specifically into a version of UML for planning approaches. This translation process can let a designer read PDDL domains and verify it with some powerful tool like itSIMPLE or GIPO, or it can allow a planning system that only reads object-oriented models to run in domains described in PDDL originally. © Springer-Verlag Berlin Heidelberg 2006.
Network anomaly detection using nonextensive entropy
(2007) ZIVIANI, A.; GOMES, A. T. A.; MONSORES, M. L.; RODRIGUES, Paulo
itSIMPLE2.0: An integrated tool for designing planning domains
(2007-09-26) VAQUERO, T. S.; ROMERO, V.; Flavio Tonidandel; SILVA, J. R.
A great effort has been made today in the area of Artificial Intelligence for defining reliable automated planning systems that can be applied in real life applications. That leads to the need of a systematic design process, in which the initial phases are not neglected and where Knowledge and Requirement Engineering tools have a fundamental role for supporting designers. Following this principle, this paper presents the evolution of the tool itSIMPLE which implements a KE integrated environment where designers can perform knowledge acquisition, domain modeling, domain model analysis, model testing, maintenance and plan analysis processes by using different well-known languages such as UML, Petri Nets, PDDL and XML, each one of them with its best contribution. The tool supports users in an organized object-oriented domain design process with a friendly and easy-to-use interface. Copyright © 2007, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.
Dimensionality reduction, classification and reconstruction problems in statistical learning approaches
(2008) GIRALDI, G. A.; RODRIGUES, Paulo; KITANI, E. C.; THOMAZ, C.
Statistical learning approaches for discriminant features selection
(2008) GIRALDI, G. A.; RODRIGUES, Paulo; KITANI, E. C.; SATO, J. R.; THOMAZ, C. E.
Anti-patterns apoiando a documentação dos problemas de usabilidade
(2008) MASIERO, A. A.; LOPES, G.; GONÇALVES, M. H.; AQUINO JUNIOR, Plinio Thomaz
Este artigo descreve uma metodologia para documentação de barreiras encontradas em interfaces. A partir de uma avaliação realizada em qualquer interface é possível documentar estas barreiras utilizando o conceito de anti-patterns, gerando uma base de conhecimento para evitar re-trabalhos futuros e auxiliar no design de interfaces
Computing the q-index for tsallis nonextensive image segmentation
(2009-10-11) Paulo Rodrigues; GIRALDI, G. A.
The concept of entropy based on Shannon Theory of Information has been applied in the field of image processing and analysis since the work of T. Pun [1]. This concept is based on the traditional Boltzaman-Gibbs entropy, proposed under the classical thermodynamic. On the other hand, it is well known that this old formalism fails to explain some physical system if they have complex behavior such as long rang interactions and long time memories. Recently, studies in mechanical statistics have proposed a new kind of entropy, called Tsallis entropy (or non-extensive entropy), which has been considered with promising results on several applications in order to explain such phenomena. The main feature of Tsallis entropy is the q-index parameter, which is close related to the degree of system nonextensivity. In 2004 was proposed [2] the first algorithm for image segmentation based on Tsallis entropy. However, the computation of the q-index was already an open problem. On the other hand, in the field of image segmentation it is not an easy task to compare the quality of segmentation results. This is mainly due to the lack of an image ground truth based on human reasoning. In this paper, we propose the first methodology in the field of image segmentation for q-index computation and compare it with other similar approaches using a human based segmentation ground truth. The results suggest that our approach is a forward step for image segmentation algorithms based on Information Theory. © 2009 IEEE.
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.
Improving the non-extensive medical image segmentation based on Tsallis entropy
(2011) RODRIGUES, Paulo; GIRALDI, G. A.
Thresholding techniques for image segmentation is one of the most popular approaches in Computational Vision systems. Recently, M. Albuquerque has proposed a thresholding method (Albuquerque et al. in Pattern Recognit Lett 25:1059–1065, 2004) based on the Tsallis entropy, which is a generalization of the traditional Shannon entropy through the introduction of an entropic parameter q. However, the solution may be very dependent on the q value and the development of an automatic approach to compute a suitable value for q remains also an open problem. In this paper, we propose a generalization of the Tsallis theory in order to improve the non-extensive segmentation method. Specifically, we work out over a suitable property of Tsallis theory, named the pseudo-additive property, which states the formalism to compute the whole entropy from two probability distributions given an unique q value. Our idea is to use the original M. Albuquerque’s algorithm to compute an initial threshold and then update the q value using the ratio of the areas observed in the image histogram for the background and foreground. The proposed technique is less sensitive to the q value and overcomes the M. Albuquerque and k-means algorithms, as we will demonstrate for both ultrasound breast cancer images and synthetic data.
Image assessment of MSCT and CBCT scans for rapid maxillary expansion: A pilot study
(2011) Moura P.M.; Giraldi G.; Lira P.H.; Leite D.A.Q.; Rodrigues P.S.S.; Faria M.; Gutfilen B.
Objectives: The accuracy of cone-beam technique, cone-beam computed tomography (CBCT), compared with that of the multislice spiral CT (MSCT), for image-based linear measurements of midpalatal suture was assessed. Material and Methods: Two measurements were performed by one investigator on the dry skull by using one digital caliper and in the axial cuts by using software. A 2D object-based image registration process was applied to determine the best affine transformation that maps a 2D input image (CBCT) in a reference image (MSCT). Results: The value of the intraclass correlation coefficient was approximately 0.9%. The results suggest that differences between two scanners did not exist (observation 1, p = 0.964 and observation 2, p = 0.795).With regard to the dry skull and the image, the significance probabilities equaled zero (observation 1, p = 0.002 and observation 2, p = 0.004), therefore, indicating significant differences. Conclusion: Measurements acquired in the images were similar and these findings contribute to stimulate the use of CBCT for evaluation of the maxillary expansion procedure. © 2011 Taylor & Francis.
CARES 2.0: Completely automated robust edge snapper for cimt measurement in 300 ultrasound images-a two stage paradigm
(2011) MOLINARI, F.; ACHARYA, U. R.; ZENG, G.; MEIBURGER, K. M.; RODRIGUES, P. S.; SABA, L.; SURI, J. S.
The carotid intima-media thickness (IMT) is a widely used marker associated to the risk of cardiovascular diseases and to atherosclerosis progression. IMT measurement requires high accuracy and reproducibility. Computer-aided measurements improve accuracy and precision, but usually require user interaction. In this paper we proposed an improved method (called CARES 2.0) over the previously developed technique (called CARES 1.0). CARES 2.0 is a two stage process: Stage-I adapts an integrated approach of intelligent image feature extraction and line fitting for far adventitia border detection. Stage-II is a first order absolute moment (FOAM 1.0) coupled to a novel and improved heuristic search for the lumen-intima (LI) and media-adventitia (MA) peaks. CARES 2.0 brings in two novel scientific contributions: (a) ability to improve Stage-I to compare jugular vein versus carotid artery and (b) introduction bi-directional and robust FOAM. The improved method is a fully automated IMT measurement technique, and was validated on a multi-institutional database of 300 images exhibiting normal and pathologic carotids. We benchmarked CARES 2.0 against previously developed CALEX 1.0 and user-driven FOAM 1.0. CARES 2.0 showed an IMT measurement bias equal to -0.032±0.178 mm, which was better than CALEX 1.0 (0.070±0.331 mm), FOAM 1.0 (-0.091±0.161 mm) and CARES 1.0 (0.035±0.198 mm), respectively. Thus CARES 2.0 showed an improvement of 54% over CALEX 1.0, 65% over stand alone FOAM 1.0 and 9% over CARES 1.0. Compared to CARES 1.0, CARES 2.0 improved the reproducibility by 10%. CARES 2.0 ensured complete automation and increased the reproducibility of the IMT measurement, a step closer for clinical usage. Copyright © 2011 American Scientific Publishers.
Automated carotid artery intima layer regional segmentation
(2011) MEIBURGER, K. M.; MOLINA, F.; ACHARYA, U. R.; SABA, L.; RODRIGUES, P.; LIBONI, W.; NICOLAIDES, A.; SURI, J. S.
Evaluation of the carotid artery wall is essential for the assessment of a patient's cardiovascular risk or for the diagnosis of cardiovascular pathologies. This paper presents a new, completely user-independent algorithm called carotid artery intima layer regional segmentation (CAILRS, a class of AtheroEdge™ systems), which automatically segments the intima layer of the far wall of the carotid ultrasound artery based on mean shift classification applied to the far wall. Further, the system extracts the lumen-intima and media-adventitia borders in the far wall of the carotid artery. Our new system is characterized and validated by comparing CAILRS borders with the manual tracings carried out by experts. The new technique is also benchmarked with a semi-automatic technique based on a first-order absolute moment edge operator (FOAM) and compared to our previous edge-based automated methods such as CALEX (Molinari et al 2010 J. Ultrasound Med. 29 399-418, 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CULEX (Delsanto et al 2007 IEEE Trans. Instrum. Meas. 56 1265-74, Molinari et al 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CALSFOAM (Molinari et al Int. Angiol. (at press)), and CAUDLES-EF (Molinari et al J. Digit. Imaging (at press)). Our multi-institutional database consisted of 300 longitudinal B-mode carotid images. In comparison to semi-automated FOAM, CAILRS showed the IMT bias of -0.035 0.186 mm while FOAM showed -0.016 0.258 mm. Our IMT was slightly underestimated with respect to the ground truth IMT, but showed uniform behavior over the entire database. CAILRS outperformed all the four previous automated methods. The system's figure of merit was 95.6%, which was lower than that of the semi-automated method (98%), but higher than that of the other automated techniques. © 2011 Institute of Physics and Engineering in Medicine.
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.
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.
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.

Navegar

Navegando Ciência da Computação por Data de Publicação

Resultados por página

Opções de Ordenação