5,842 research outputs found

    Log Skeletons: A Classification Approach to Process Discovery

    Get PDF
    To test the effectiveness of process discovery algorithms, a Process Discovery Contest (PDC) has been set up. This PDC uses a classification approach to measure this effectiveness: The better the discovered model can classify whether or not a new trace conforms to the event log, the better the discovery algorithm is supposed to be. Unfortunately, even the state-of-the-art fully-automated discovery algorithms score poorly on this classification. Even the best of these algorithms, the Inductive Miner, scored only 147 correct classified traces out of 200 traces on the PDC of 2017. This paper introduces the rule-based log skeleton model, which is closely related to the Declare constraint model, together with a way to classify traces using this model. This classification using log skeletons is shown to score better on the PDC of 2017 than state-of-the-art discovery algorithms: 194 out of 200. As a result, one can argue that the fully-automated algorithm to construct (or: discover) a log skeleton from an event log outperforms existing state-of-the-art fully-automated discovery algorithms.Comment: 16 pages with 9 figures, followed by an appendix of 14 pages with 17 figure

    Post-fire resprouting and mortality in cerrado woody plant species over a three-year period.

    Get PDF
    Made available in DSpace on 2018-05-30T00:51:01Z (GMT). No. of bitstreams: 1 SP19632ID30922.pdf: 169991 bytes, checksum: dc0950a61e058db7246595835c0fb030 (MD5) Previous issue date: 2009-02-0

    Testing for heteroskedasticity of the residuals in fuzzy rule-based models

    Get PDF
    International audienceIn this paper, we propose a new diagnostic checking tool for fuzzy rule-based modelling of time series. Through the study of the residuals in the Lagrange Multiplier testing framework we devise a hypothesis test which allows us to determine if the residual time series is homoscedastic or not, that is, if it has the same variance throughout time. This is another important step towards a statistically sound modelling strategy for fuzzy rule-based models

    Informações sobre polinizadores em mangueira no Vale do São Francisco,

    Get PDF
    Caracterização da Região; A Cultura da Mangueira; Socioeconomia; Floração, Morfologia e Biologia Floral; Formação e Desenvolvimento dos Frutos; Polinização da Mangueira ; Visitantes Florais na Região do Vale do São Francisco; Polinizadores Potenciais Recomendações de Manejo; Incremento da População de Polinizadores na Área oferta de Fonte Alimentar Alternativa;Sensibilização de Produtores e Técnicos; Criação de Abelhas Nativas em Ninhos Racionais.bitstream/CPATSA-2009-09/40159/1/SDC213.pd

    Retinal Nerve Fiber Layer Features Identified by Unsupervised Machine Learning on Optical Coherence Tomography Scans Predict Glaucoma Progression.

    Get PDF
    Purpose:To apply computational techniques to wide-angle swept-source optical coherence tomography (SS-OCT) images to identify novel, glaucoma-related structural features and improve detection of glaucoma and prediction of future glaucomatous progression. Methods:Wide-angle SS-OCT, OCT circumpapillary retinal nerve fiber layer (cpRNFL) circle scans spectral-domain (SD)-OCT, standard automated perimetry (SAP), and frequency doubling technology (FDT) visual field tests were completed every 3 months for 2 years from a cohort of 28 healthy participants (56 eyes) and 93 glaucoma participants (179 eyes). RNFL thickness maps were extracted from segmented SS-OCT images and an unsupervised machine learning approach based on principal component analysis (PCA) was used to identify novel structural features. Area under the receiver operating characteristic curve (AUC) was used to assess diagnostic accuracy of RNFL PCA for detecting glaucoma and progression compared to SAP, FDT, and cpRNFL measures. Results:The RNFL PCA features were significantly associated with mean deviation (MD) in both SAP (R2 = 0.49, P < 0.0001) and FDT visual field testing (R2 = 0.48, P < 0.0001), and with mean circumpapillary RNFL thickness (cpRNFLt) from SD-OCT (R2 = 0.58, P < 0.0001). The identified features outperformed each of these measures in detecting glaucoma with an AUC of 0.95 for RNFL PCA compared to an 0.90 for mean cpRNFLt (P = 0.09), 0.86 for SAP MD (P = 0.034), and 0.83 for FDT MD (P = 0.021). Accuracy in predicting progression was also significantly higher for RNFL PCA compared to SAP MD, FDT MD, and mean cpRNFLt (P = 0.046, P = 0.007, and P = 0.044, respectively). Conclusions:A computational approach can identify structural features that improve glaucoma detection and progression prediction

    How can one probe Podolsky Electrodynamics?

    Full text link
    We investigate the possibility of detecting the Podolsky generalized electrodynamics constant aa. First we analyze an ion interferometry apparatus proposed by B. Neyenhuis, et al (Phys. Rev. Lett. 99, (2007) 200401) who looked for deviations from Coulomb's inverse-square law in the context of Proca model. Our results show that this experiment has not enough precision for measurements of aa. In order to set up bounds for aa we investigate the influence of Podolsky's electrostatic potential on the ground state of the Hydrogen atom. The value of the ground state energy of the Hydrogen atom requires Podolsky's constant to be smaller than 5.6 fm, or in energy scales larger than 35.51 MeV.Comment: 12 pages, 2 figure

    Eficiência técnica e econômica do controle biológico da traça-do-tomateiro em ambiente protegido.

    Get PDF
    Made available in DSpace on 2011-04-09T16:13:24Z (GMT). No. of bitstreams: 1 medeiroseficiencia.pdf: 616069 bytes, checksum: 87514101cf11999fe994ffa4654fa536 (MD5) Previous issue date: 2006-11-2
    corecore