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Wyszukujesz frazę "fuzzy clustering" wg kryterium: Temat


Wyświetlanie 1-9 z 9
Tytuł:
Application of modified fuzzy clustering to medical data classification
Autorzy:
Jeżewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/333509.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
grupowanie rozmyte
klasyfikacja
dane medyczne
fuzzy clustering
classification
medical data
Opis:
Classification plays very important role in medical diagnosis. This paper presents fuzzy clustering method dedicated to classification algorithms. It focuses on two additional sub-methods modifying obtained clustering prototypes and leading to final prototypes, which are used for creating the classifier fuzzy if-then rules. The main goal of that work was to examine a performance of the classifier which uses such rules. Commonly used including medical benchmark databases were applied. In order to validate the results, each database was represented by 100 pairs of learning and testing subsets. The obtained classification quality was better in relation to the one of the best classifiers - Lagrangian SVM and suggests that presented clustering with additional sub-methods are appropriate to application to classification algorithms.
Źródło:
Journal of Medical Informatics & Technologies; 2011, 17; 51-57
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized fuzzy clustering method
Autorzy:
Przybyła, T.
Roj, D.
Jeżewski, J.
Matonia, A.
Powiązania:
https://bibliotekanauki.pl/articles/332927.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
grupowanie rozmyte
uogólniona funkcja kosztów
grupowanie nienadzorowane
fuzzy clustering
fuzzy meridian
fuzzy myriad
generalized cost function
unsupervised clustering
Opis:
This paper presents a new hybrid fuzzy clustering method. In the proposed method, cluster prototypes are values that minimize the introduced generalized cost function. The proposed method can be considered as a generalization of fuzzy c–means (FCM) method as well as the fuzzy c–median (FCMed) clustering method. The generalization of the cluster cost function is made by applying the Lp norm. The values that minimize the proposed cost function have been chosen as the group prototypes. The weighted myriad is the special case of the group prototype, when the Lp norm is the L2 (Euclidean) norm. The cluster prototypes are the weighted meridians for the L1 norm. Artificial data set is used to demonstrate the performance of proposed method.
Źródło:
Journal of Medical Informatics & Technologies; 2010, 16; 69-76
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Segmentation of biomedical signals using an unsupervised approach
Autorzy:
Przybyła, T.
Wróbel, J.
Czabański, R.
Horoba, K.
Pander, T.
Momot, M.
Powiązania:
https://bibliotekanauki.pl/articles/333275.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
atraktor
przestrzeń jądra
grupowanie rozmyte
embedded space
attractor
PCA
kernel space
fuzzy clustering
Opis:
The paper presents an unsupervised approach to biomedical signal segmentation. The proposed segmentation process consists of several stages. In the first step, a state-space of the signal is reconstructed. In the next step, the dimension of the reconstructed state-space is reduced by projection into principal axes. The final step involves fuzzy clustering method. The clustering process is applied in the kernel-feature space. In the experimental part, the fetal heart rate (FHR) signal is used. The FHR baseline and the acceleration or deceleration patterns are the main signal nonstationarities but also the most clinically important signal features determined and interpreted in computer-aided analysis.
Źródło:
Journal of Medical Informatics & Technologies; 2012, 19; 125-131
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach for the clustering using pairs of prototypes
Autorzy:
Jezewski, M.
Czabanski, R.
Leski, J.
Horoba, K.
Powiązania:
https://bibliotekanauki.pl/articles/333693.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
fuzzy clustering
pairs of prototypes
fuzzy rule-based classification
grupowanie rozmyte
pary prototypów
rozmyta klasyfikacja oparta na regułach
Opis:
In the presented work two variants of the fuzzy clustering approach dedicated for determining the antecedents of the rules of the fuzzy rule-based classifier were presented. The main idea consists in adding additional prototypes (’prototypes in between’) to the ones previously obtained using the fuzzy c-means method (ordinary prototypes). The ’prototypes in between’ are determined using pairs of the ordinary prototypes, and the algorithm based on distances and densities finding such pairs was proposed. The classification accuracy obtained applying the presented clustering approaches was verified using six benchmark datasets and compared with two reference methods.
Źródło:
Journal of Medical Informatics & Technologies; 2015, 24; 113-121
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy clustering based methods for nystagmus movements detection in electronystagmography signal
Autorzy:
Czabański, R.
Pander, T.
Horoba, K.
Przybyła, T.
Powiązania:
https://bibliotekanauki.pl/articles/332952.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
saccade detection
optokinetic nystagmus
fuzzy clustering
detekcja ruchów sakadowych
oczopląs optokinetyczny
grupowanie rozmyte
sygnał ENG
Opis:
The analysis of optokinetic nystagmus (OKN) provides valuable information about the condition of human vision system. One of the phenomena that is used in the medical diagnosis is optokinetic nystagmus. Nystagmus are voluntary or involuntarily eye movements being a response to a stimuli which activate the optokinetic systems. The electronystagmography (ENG) signal corresponding to the nystagmus has a form of a saw tooth waveform with fast components related to saccades. The accurate detection of the saccades in the ENG signal is the base for the further estimation of the nystagmus characteristic. The proposed algorithm is based on the proper filtering of the ENG signal providing a waveform with amplitude peaks corresponding the fast eyes rotation. The correct recognition of the local maxima of the signal is obtained by the means of fuzzy c-means clustering (FCM). The paper presents three variants of saccades detection algorithm based on the FCM. The performance of the procedures was investigated using the artificial as well as the real optokinetic nystagmus cycles. The proposed method provides high detection sensitivity and allows for the automatic and precise determination of the saccades location in the preprocessed ENG signal.
Źródło:
Journal of Medical Informatics & Technologies; 2013, 22; 277-283
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An approach to unsupervised classification
Autorzy:
Przybyła, T.
Pander, T.
Horoba, K.
Kupka, T.
Matonia, A.
Powiązania:
https://bibliotekanauki.pl/articles/333363.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
klasyfikacja
grupowanie rozmyte
klasyfikacja nienadzorowana
klasyfikator najbliższych sąsiadów
classification
fuzzy clustering
unsupervised classification
nearest neighbour classifier
Opis:
Classification methods can be divided into supervised and unsupervised methods. The supervised classifier requires a training set for the classifier parameter estimation. In the case of absence of a training set, the popular classifiers (e.g. K-Nearest Neighbors) can not be used. The clustering methods are considered as unsupervised classification methods. This paper presents an idea of the unsupervised classification with the popular classifiers. The fuzzy clustering method is used to create a learning set. The learning set includes only these patterns that are the best representative of each class in the input dataset. The numerical experiment uses an artificial dataset as well as the medical datasets (PIMA, Wisconsin Breast Cancer) and illustrates the usefulness of the proposed method.
Źródło:
Journal of Medical Informatics & Technologies; 2011, 17; 105-111
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsupervised clustering for fetal state assessment based on selected features of the cardiotocographic signals
Autorzy:
Przybyła, T.
Jeżewski, J.
Roj, D.
Powiązania:
https://bibliotekanauki.pl/articles/333112.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
klasyfikacja algorytmów bez nadzoru
grupowanie danych
monitoring płodu
kardiotokografia
unsupervised classification
fuzzy clustering
principal component analysis
fetal monitoring
Opis:
In modern obstetrics the cardiotocography is a routine method of fetal condition assessment based mainly on analysis of the fetal heart rate signals. The correct interpretation of recorded traces from a bedside monitor is very difficult even for experienced clinicians. Therefore, computerized fetal monitoring systems are used to yield the quantitative description of the signal. However, the effective techniques enabling automated conclusion generation based on cardiotocograms are still being searched. The paper presents an attempt to diagnose the fetal state basing on seventeen features describing the cardiotocographic records. The proposed method applies the unsupervised classification of signals. During our research we tried to classify the fetal state using the fuzzy c-means (FCM) clustering. We also tested how the efficiency of classification could be influenced by application of principal component analysis (PCA) algorithm. The obtained results showed that unsupervised classification cannot be considered as a support to fetal state assessment.
Źródło:
Journal of Medical Informatics & Technologies; 2009, 13; 157-162
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Knowledge-based clustering as a conceptual and algorithmic environment of biomedical data analysis
Autorzy:
Pedrycz, W.
Gacek, A.
Powiązania:
https://bibliotekanauki.pl/articles/333706.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
wiedza i dane
grupowanie rozmyte
bliskość
włączenie
nadzór częściowy
niepewność
entropia
knowledge and data
fuzzy clustering
guidance mechanisms
proximity
inclusion
partial supervision
uncertainty
entropy
Opis:
While a genuine abundance of biomedical data available nowadays becomes a genuine blessing, it also posses a lot of challenges. The two fundamental and commonly occurring directions in data analysis deal with its supervised or unsupervised pursuits. Our conjecture is that in the area of biomedical data processing and understanding where we encounter a genuine diversity of patterns, problem descriptions and design objectives, this type of dichotomy is neither ideal nor the most productive. In particular, the limitations of such taxonomy become profoundly evident in the context of unsupervised learning. Clustering (being usually regarded as a synonym of unsupervised data analysis) is aimed at determining a structure in a data set by optimizing a given partition criterion. In this sense, a structure emerges (becomes formed) without a direct intervention of the user. While the underlying concept looks appealing, there are numerous sources of domain knowledge that could be effectively incorporated into clustering mechanisms and subsequently help navigate throughout large data spaces. In unsupervised learning, this unified treatment of data and domain knowledge leads to the general concept of what could be coined as knowledge-based clustering. In this study, we discuss the underlying principles of this paradigm and present its various methodological and algorithmic facets. In particular, we elaborate on the main issues of incorporating domain knowledge into the clustering environment such as (a) partial labelling, (b) referential labelling (including proximity and entropy constraints), (c) usage of conditional (navigational) variables, (d) exploitation of external structure. Presented are also concepts of stepwise clustering in which the structure of data is revealed via a series of refinements of existing domain granular information.
Źródło:
Journal of Medical Informatics & Technologies; 2004, 7; KB13-22
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Granular representation of biomedical signals using numerical differentiation methods
Autorzy:
Momot, M.
Momot, A.
Gacek, A.
Powiązania:
https://bibliotekanauki.pl/articles/332925.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
grupowanie
liczby rozmyte
granulacja informacji
interpolacja
kryterium odbudowy
clustering
fuzzy number
information granulation
interpolation
reconstruction criterion
Opis:
This work presents the general idea of granular description of temporal signal, particularly biomedical signal sampled with constant frequency. The main idea of presented method is based on using triangular fuzzy numbers as information granules in temporal and amplitude spaces. The amplitude space contains values of first few derivatives of underlying signal. The construction of data granules is performed using the optimization method according to some objective function, which balances the high coverage ability and the low support of fuzzy numbers. The granules (descriptors) undergo the clustering process, namely fuzzy c-means. The centroids of created clusters form a granular vocabulary and the quality of description is quantitatively assessed by reconstruction criterion. There are presented results of experiments with the electrocardiographic signal, digitally sampled and stored in MIT-BIH database. The method of numerical differentiation of function based on finite set of its values is employed, which incorporates polynomial interpolation. The paper presents results of numerical experiments which show the impact of method parameters, such as temporal window length, degree of polynomial, fuzzification parameter, on the reconstruction ability of presented method.
Źródło:
Journal of Medical Informatics & Technologies; 2010, 16; 43-49
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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