Optimum Path Forest Classifier Applied To Laryngeal Pathology Detection

Optimum path forest-based classifiers are a novel approach for supervised pattern recognition. The OPF classifier differs from traditional approaches by not estimating probability density functions of the classes neither assuming samples linearity, and creates a discrete optimal partition of the feature space, in which the decision boundary is obtained by the influence zones of the most representative samples of the training set. Due to the large number of applications in biomedical signal processing involving pattern recognition techniques, specially voice disorders identification, we propose here the laryngeal pathology detection by means of OPF. Experiments were performed in three public datasets against SVM, and a comparison in terms of accuracy rates and execution times was also regarded.249252A.A. Spadotto, J.P. Papa, A.R. Gatto, P.C. Cola, J.C. Pereira, R.C. Guido, and A.O. Schelp, Denoising swallowing sound to improve the evaluators qualitative analysis., Computers and Electrical Engineering: Advances on Computer-based Biological Signal Processing Techniques, 34, no. 2, pp. 148-153, 2008Spadotto, A.A., Pereira, J.C., Guido, R.C., Papa, J.P., Falcão, A.X., Gatto, A.R., Cola, P.C., Shelp, A.O., Oropharyngeal dysphagia identification using wavelets and optimum path forest (2008) Proceedings of the 3th IEEE International Symposium on Communications, Control and Signal Processing, , to appearHadjitodorov, S.T., Boyanov, B., Teston, B., Laryngeal pathology detection by means of class-specific neural maps (2000) IEEE Transactions on Information Technology in Biomedicine, 4 (1), pp. 68-73Boyanov, B., Hadjitodorov, S.T., Acoustic analysis of pathological voices. a voice analysis systemfor the screening of laryngeal diseases (1997) IEEE Transactions on Engineering in Medicine and Biology Magazine, 16 (4), pp. 74-82Godino-Llorente, J.I., Vilda, P.G., Senz-Lechn, N., Blanco-Velasco, M., Craz-Roldn, F., Ferrer-Ballester, M.A., (2005) Support vector machines applied to the detection of voice disorders, 3817, pp. 219-230Perrin, E., Berger-Vachon, C., Kauffmann, I., Collet, L., (2006) Acoustical recognition of laryngeal pathology using the fundamental frequency and the first three formants of vowels, 35 (4), pp. 361-368Mezzalama, M., Prinetto, P., Morra, B., (2006) Experiments in automatic classification of laryngeal pathology, 21 (5), pp. 603-611Hadjitodorov, S.T., Ivanov, T., Boyanov, B., Analysis of dysphony using objective voice parameter (1993) Proceedings of the II Balkan Conference on Operational Research, pp. 911-917Schlotthauer, G., Torres, M.E., Jackson-Menaldi, C., Automatic diagnosis of pathological voices (2006) Proceedings of the 6th WSEAS International Conference on Signal, Speech and Image Processing, pp. 150-155Boser, B.E., Guyon, I.M., Vapnik, V.N., A training algorithm for-optimal margin classifiers (1992) Proc. 5th Workshop on Computational Learning Theory, pp. 144-152. , New York, NY, USA, ACM PressDuan, K., Keerthi, S.S., Which is the best multiclass svm method? an empirical study (2005) Multiple Classifier Systems, pp. 278-285Papa, J.P., Falcão, A.X., Miranda, P.A.V., Suzuki, C.T.N., Mascarenhas, N.D.A., Design of robust pattern classifiers based on optimum-path forests (2007) Mathematical Morphology and its Applications to Signal and Image Processing (ISMM), pp. 337-348. , MCT/INPEPapa, J.P., Falcão, A.X., Suzuki, C.T.N., Mascarenhas, N.D.A., A discrete approach for supervised pattern recognition (2008) 12th International Workshop on Combinatorial Image Analysis (IWCIA), 4958, pp. 136-147. , SpringerJ.A. Montoya-Zegarra, J.P. Papa, N.J. Leite, R.S. Torres, and A.X. Falcão, Rotation-invariant texture recognition, in 3rd International Symposium on Visual Computing, Lake Tahoe, Nevada, CA, USA, Nov 2007, Part II, LNCS 4842, pp. 193-204, SpringerFalcão, A.X., Stolfi, J., Lotufo, R.A., The image foresting transform: Theory, algorithms, and applications (2004) IEEE Trans. on PAMI, 26 (1), pp. 19-29. , JanAllène, C., Audibert, J.Y., Couprie, M., Cousty, J., Keriven, R., Some links between min-cuts, optimal spanning forests and watersheds (2007) Proceedings of the ISMM'08, pp. 253-264Hadjitodorov, S.T., Mitev, P., Boyanov, B., (2005) Laryngeal databases, , http://www.informatics.bangor.ac.uk/~kuncheva, Available inCohen, J., A coefficient of agreement for nominal scales (1960) Educational and Psychological Measurement, 20, pp. 37-46Chang, C.C., Lin, C.J., (2001) LIBSVM: A library for support vector machines, , http://www.csie.ntu.edu.tw/~cjlin/libsvm, Software available at ur

Oropharyngeal Dysphagia Identification Using Wavelets And Optimum Path Forest

The swallowing disturbers are defined as oropharyngeal dysphagia when present specifies signals and symptoms that are characterized for alterations in any phases of swallowing. Early diagnosis is crucial for the prognosis of patients with dysphagia and the potential to diagnose dysphagia in a noninvasive manner by assessing the sounds of swallowing is a highly attractive option for the dysphagia clinician. This study proposes a new framework for oropharyngeal dysphagia identification, having two main contributions: a new set of features extract from swallowing signal by discrete wavelet transform and the dysphagia classification by a novel pattern classifier called OPF. We also employed the well known SVM algorithm in the dysphagia identification task, for comparison purposes. We performed the experiments in two sub-signals: the first was the moment of the maximal peak (MP) of the signal and the second is the swallowing apnea period (SAP). The OPF final accuracy obtained were 85.2% and 80.2% for the analyzed signals MP and SAP, respectively, outperforming the SVM results. ©2008 IEEE.735740Logemann, J.A., (1983) Evaluation and treatment of swallowing disorders, , College- Hill PressPlatt, J., (2001) Dysphagia Management for Long-Term Care: A Manual for Nurses and Other Healthcare Professionals, Clinical and Educational ServicesFurkim, A.M., Silva, R.G., (1999) Programas de reabilitacão em disfagia neurogênica, , Frôntis EditorialChen, M.Y.M., Ott, D.J., Peele, V.N., Gelfand, D.W., Oropharynx in pacients with cerebrovascular disease: Evaluation with videofluoroscopy (1990) Radiology, 176, pp. 38-47J.B. Palmer and A.S. Duchane, Rehabilitation of swallowing disorders due to stroke, hys. Med. Rehab.Clin. N. Amer, 2, 1991Horner, J., Buoyer, F.G., Alberts, M.J., Helms, M.J., Dysphagia folowing brain stem stroke: Clinical correlates and outcome (1991) Arch Neurol, 48, pp. 1170-1173Buchhloz, D.W., (1997) Neurologic disordes of swallowing, pp. 37-62. , ppVeis, S.L., Logemann, J.A., Swallowing disorders in persons with cerebrovascular accident (1985) Arch Phys Med Rehabil, 66, pp. 372-376Gordon, C., Hewer, R.L., Wade, D.T., Dysphagia in acute stroke (1987) Brazilian Medical Journal, pp. 3411-3414Silva, R.G., Disfagia neurogênica em adultos: Uma proposta para avaliacão clínica (1999) Disfagias Orofaríngeas, pp. 35-47Cichero, J.A.Y., Murdoch, B.E., The physiologic cause of swallowing sounds: Answers from heart sounds and vocal tract acoustics (1998) Dysphagia, 13, pp. 39-52Youmans, S.R., Stierwalt, J.A.G., The physiologic cause of swallowing sounds: Answers from heart sounds and vocal tract acousticsan acoustic profile of normal swallowing (2005) Dysphagia, 20, pp. 195-209Lazareck, L.J., Moussavi, Z., Classification of normal and dysphagic swallows by acoustical means (2004) IEEE Transactions on Biomedical Engineering, 51Kuncheva, L.I., (2004) Combining Pattern Classifiers: Methods and Algorithms, , Wiley-InterscienceAboofazeli, M., Moussavi, Z., Automated extraction of swallowing sounds using a wavelet-based filter (2006) Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE, pp. 5607-5610Papa, J.P., Falcão, A.X., Miranda, P.A.V., Suzuki, C.T.N., Mascarenhas, N.D.A., Design of robust pattern classifiers based on pptimum-path forests (2007) Mathematical Morphology and its Applications to Signal and Image Processing (ISMM), pp. 337-348. , MCT/INPEPapa, J.P., Falcão, A.X., Suzuki, C.T.N., Mascarenhas, N.D.A., A discrete approach for supervised pattern recognition (2008) Proceedings of the 12th International Workshop on Combinatorial Image Analysis, , Accepted for publicationBoser, B.E., Guyon, I.M., Vapnik, V.N., A training algorithm for optimal margin classifiers (1992) Proc. 5th Workshop on Computational Learning Theory, pp. 144-152. , New York, NY, USA, ACM PressJ.A. Montoya-Zegarra, J.P. Papa, N.J. Leite, R.S. Torres, and A.X. Falcão, Rotation-invariant texture recognition, in 3rd International Symposium on Visual Computing, Lake Tahoe, Nevada, CA, USA, Nov 2007, Part II, LNCS 4842, pp. 193-204, SpringerVapnik, V.N., An overview of statistical learning theory (1999) Neural Networks, IEEE Transactions on, 10 (5), pp. 988-999Bazaraa, M.S., Sherali, H.D., Shetti, C.M., (2006) Nonlinear programming theory and algorithms, , Wiley-InterscienceBurges, C.J.C., A tutorial on support vector machines for pattern recognition (1998) Data Mining and Knowledge Discovery, 2 (2), pp. 121-167Falcão, A.X., Stolfi, J., Lotufo, R.A., The image foresting transform: Theory, algorithms, and applications (2004) IEEE Trans. on PAMI, 26 (1), pp. 19-29. , JanCormen, T., Leiserson, C., Rivest, R., (1990) Introduction to Algorithms, , MITAllène, C., Audibert, J.Y., Couprie, M., Cousty, J., Keriven, R., Some links between min-cuts, optimal spanning forests and watersheds (2007) Proceedings of the 8th Int. Symposium on Mathematical Morphology, pp. 253-264Addison, P.S., (2002), Institute of Physics Publishing Bristol and PhiladelphiaMallat, S.G., A theory for multiresolution signal decomposition: The wavelet representation (1989) IEEE Transactions on Pattern Analysis and Machine Intelligence, 11 (7), pp. 674-693Daubechies, I., The wavelet transform, time-frequency localization and signal analysis (1990) IEEE Transactions on Information Theory, 36 (5), pp. 961-1005I. Daubechies, Philadelphia, PA: Soc. Indus. Applied Math., 1992Daubechies, I., Orthonormal bases of compactly supported wavelets ii, variations on a theme (1993) SIAM J. Math. Anal, 24 (2), p. 499519Spadotto, A.A., Papa, J.P., Gatto, A.R., Cola, P.C., Pereira, J.C., Guido, R.C., Schelp, A.O., Denoising swallowing sound to improve the evaluators qualitative analysis (2007) Computers and Electrical Engineering, , accepted for publicationChang, C.C., Lin, C.J., (2001) LIBSVM: A library for support vector machines, , http://www.csie.ntu.edu.tw/~cjlin/libsvm, Software available at ur

Efeito do condicionamento osmótico de sementes de soja sobre a habilidade competitiva da cultura com as plantas daninhas Soybean seed osmoconditioning effect on the crop competitive ability against weeds

Este trabalho teve como objetivo avaliar os efeitos do condicionamento osmótico de sementes de soja sobre o desempenho da cultura e sua habilidade competitiva com as plantas daninhas. As sementes de soja, da variedade UFV 16, colhidas nos estádios fenológicos R8 e R8 + 15 dias, foram submetidas ao condicionamento osmótico em solução de polietileno glicol (PEG 6000), a -0,8 MPa e 20ºC, por 96 horas. Como testemunha foram utilizadas sementes sem tratamento de pré-embebição, colhidas nos mesmos estádios fenológicos. Em laboratório, a germinação e o vigor das sementes foram avaliados pelo teste-padrão de germinação, utilizando-se o delineamento inteiramente casualizado, no esquema fatorial 2x2, com quatro repetições. A campo foram realizados dois experimentos, utilizando sementes com e sem condicionamento osmótico, colhidas também nos estádios fenológicos R8 e R8+15, respectivamente. Em ambos os experimentos, utilizando o delineamento de blocos casualizados com quatro repetições, foram avaliados os efeitos de diferentes períodos (0, 15, 30, 45, 60 e 125 dias após a emergência da soja) de convivência da soja com as plantas daninhas. Os maiores valores de germinação e vigor, de estande inicial e final e de rendimento de grãos foram observados nos tratamentos com as sementes condicionadas e colhidas no estádio fenológico R8. As demais características agronômicas avaliadas (altura de plantas, número de nós, número de vagens por planta, número de sementes por planta, número de sementes por vagem e peso de 100 sementes) não foram alteradas pelo condicionamento. O efeito competitivo cultura-planta daninha foi verificado pelos menores valores de biomassa seca de plantas daninhas, nos tratamentos em que foram utilizadas as sementes colhidas no estádio R8 e condicionadas osmoticamente.<br>This work aimed to evaluate the effects of the osmotic conditioning of soybean seeds on its performance and competitive ability against weeds. Soybean seeds, variety UFV 16, were harvested at the phenological stages R8 and R8 + 15 days and submitted to osmotic conditioning in a polyethylene glycol (PEG 6000) solution, at -0.8 Mpa, and 20ºC, for 96 hours. Seeds without pre-hydration treatment harvested at the same phenological stage were used as control. Seed germination and vigor were analyzed under laboratory conditions through the standard germination test, using a randomized complete design, 2x2 factorial, with 4 repetitions. Two experiments were conducted under field conditions, using seeds with and without osmotic conditioning, also harvested at the phenological stages R8 and R8 + 15 days, respectively. In both the experiments using randomized blocks with four repetitions, the effects of different weed coexistence periods (0, 15, 30, 45, 60 and 125 days after soybean emergence) with the soybean crop were evaluated. The highest germination and vigor values related to initial and final stands and to grain yield were found in the treatments of seeds conditioned and harvested at the phenological stage R8. Other characteristics evaluated (plant height, number of nodes, number of pods per plant, number of seeds per plant, number of seeds per pod and 100-seed weight) were not altered by conditioning. The competitive effect between weed and crop was verified by the lowest dry biomass values of the weeds, in the treatments in which seeds were harvested at the phenological stage R8 and were osmotically conditioned

Densidade e características morfológicas de plantas de picão-preto na previsão de perdas de rendimento de grãos de soja por interferência Density and morphological plant characteristics of beggarticks in predicting soybean grain yield losses due to interference

A utilização de sistemas para manejo integrado de plantas daninhas depende da habilidade em se prever o impacto da infestação de plantas daninhas no potencial de rendimento de grãos da cultura. O objetivo deste trabalho foi comparar diferentes variáveis explicativas para uso no modelo da hipérbole retangular, a fim de identificar aquela que forneça melhor previsão da interferência de picão-preto (Bidens pilosa e Bidens subalternans, em infestações mistas) em soja. Foram realizados experimentos em dois ambientes, localizados em Passo Fundo e Eldorado do Sul, RS. Utilizaram-se densidades variáveis de picão-preto e três épocas de semeadura da soja (3, 7 e 11 dias após a dessecação da cobertura vegetal das áreas). Avaliou-se a densidade das plantas daninhas aos 20 e 30 dias após a emergência da soja (DAE) e na pré-colheita e características morfológicas de plantas de picão-preto, como densidade de folhas, área foliar e cobertura foliar do solo aos 20 DAE. Constatou-se que a variável explicativa densidade de plantas de picão-preto propiciou ajustes satisfatórios do modelo; no entanto, ela não integra os efeitos de ambientes e de épocas de semeadura da cultura, diferentemente do que ocorreu para as características morfológicas. Dentre estas, destacam-se a densidade de folhas e a de área foliar como as de maior potencial de utilização como variáveis explicativas na previsão da perda de rendimento de grãos de soja por interferência de picão-preto.<br>The adoption of integrated weed management systems depends on the ability to foresee the impact of weeds on crop grain yield potential. The objective of this research was to compare different explicative variables to use in adjusting the rectangular hyperbolic model, in order to identify which one would provide best prediction of beggarticks (Bidens pilosa and Bidens subalternans, occurring in mixed infestations) interference on soybean crop. Experiments were carried out in two environments, located at Passo Fundo and Eldorado do Sul, RS, Brazil. Various beggartick densities and three soybean seeding times (3, 7, and 11 days after cover crops desiccation) were used. Evaluations carried out were beggartick densities 20 and 30 days after soybean emergence (DAE) and at crop harvesting time, and weed plant morphological characteristics, such as leaf density, leaf area, and soil leaf coverage, all performed 20 DAE. It was detected that the explicative variable beggartick plant density provided satisfactory adjustments of the equation model; nevertheless, it does not integrate the effects of environments nor of crop seeding time, differently of what happened with the morphological characteristics. Among them, leaf density and leaf area showed greater potential for use as explicative variables in predicting soybean grain yield losses due to beggartick interference