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Wyszukujesz frazę "Duch, W." wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
Similarity-based methods : a general framework for classification, approximation and association
Autorzy:
Duch, W.
Powiązania:
https://bibliotekanauki.pl/articles/206007.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
aproksymacja
klasyfikacja
optymalizacja
pamięć asocjacyjna
approximation
associative memory
classification
feature selection
kNN
optimization
similarity-based methods
Opis:
Similarity-based methods (SBM) are a generalization of the minimal distance (MD) methods which form a basis of several machine learning and pattern recognition methods. Investigation of similarity leads to a fruitful framework in which many classification, approximation and association methods are accommodated. Probability p(C|X; M) of assigning class C to a vector X, given a classification model M, depends on adaptive parameters and procedures used in construction of the model. Systematic overview of choices available for model building is presented and numerous improvements suggested. Similarity-Based Methods have natural neural-network type realizations. Such neural network models as the Radial Basis Functions (RBF) and the Multilayer Perceptrons (MLPs) are included in this framework as special cases. SBM may also include several different submodels and a procedure to combine their results. Many new versions of similarity-based methods are derived from this framework. A search in the space of all methods belonging to the SBM framework finds a particular combination of parameterizations and procedures that is most appropriate for a given data. No single classification method can beat this approach. Preliminary implementation of SBM elements tested on a real-world datasets gave very good results.
Źródło:
Control and Cybernetics; 2000, 29, 4; 937-967
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A survey of factors influencing MLP error surface
Autorzy:
Kordos, M.
Duch, W.
Powiązania:
https://bibliotekanauki.pl/articles/970445.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sieć neuronowa
powierzchnia błędów
wizualizacja
trajektoria uczenia się
neural networks
MLP
error surface
visualization
learning trajectory
Opis:
Visualization of neural network error surfaces and learning trajectories helps to understand the influence of numerous factors on the neural learning process. This understanding can be used to improve training and design of MLP networks. The following topics are discussed using a few benchmark datasets for illustration: general error surface properties including local minima, plateaus and narrow funnels, their dependence on network structure, input data, transfer and error functions, consequences of weight initialization, and interesting directions in the weight space. The error surfaces are shown in 3-dimensional PCA-based projections. Finally a possibility of effective weight number reduction is discussed.
Źródło:
Control and Cybernetics; 2004, 33, 4; 611-631
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Context search algorithm for lexical knowledge acquisition
Autorzy:
Szymański, J.
Duch, W.
Powiązania:
https://bibliotekanauki.pl/articles/206264.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
semantic memory
knowledge representation
international retrieval
knowledge acquisition
Opis:
A Context Search algorithm used for lexical knowledge acquisition is presented. Knowledge representation based on psycholinguistic theories of cognitive processes allows for implementation of a computational model of semantic memory in the form of semantic network. Knowledge acquisition using supervised dialog templates have been performed in a word game designed to guess the concept a human user is thinking about. The game that has been implemented on a web server, demonstrates elementary linguistic competencies based on lexical knowledge stored in semantic memory, enabling at the same time acquisition and validation of knowledge. Possible applications of the algorithm in domains of medical diagnosis and information retrieval are sketched.
Źródło:
Control and Cybernetics; 2012, 41, 1; 81-96
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heterogeneous distance functions for prototype rules : influence of parameters on probability estimation
Autorzy:
Blachnik, M.
Duch, W.
Wieczorek, T.
Powiązania:
https://bibliotekanauki.pl/articles/92882.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
prototype rules
probability estimation
heterogeneous distance functions
similarity-based methods
classification
data mining
Opis:
An interesting and little explored way to understand data is based on prototype rules (P-rules). The goal of this approach is to find optimal similarity (or distance) functions and position of prototypes to which unknown vectors are compared. In real applications similarity functions frequently involve different types of attributes, such as continuous, discrete, binary or nominal. Heterogeneous distance functions that may handle such diverse information are usually based on probability distance measure, such as the Value Difference Metrics (VDM). For continuous attributes calculation of probabilities requires estimations of probability density functions. This process requires careful selection of several parameters that may have important impact on the overall classification of accuracy. In this paper, various heterogeneous distance function based on VDM measure are presented, among them some new heterogeneous distance functions based on different types of probability estimation. Results of many numerical experiments with such distance functions are presented on artificial and real datasets, and quite simple P-rules for several heterogeneous databases extracted.
Źródło:
Studia Informatica : systems and information technology; 2006, 1(7); 19-30
1731-2264
Pojawia się w:
Studia Informatica : systems and information technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neural methods of knowledge extraction
Autorzy:
Duch, W.
Adamczak, R.
Grąbczewski, K.
Jankowski, N.
Powiązania:
https://bibliotekanauki.pl/articles/206250.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
diagnostyka medyczna
optymalizacja
reguła logiczna
reguła rozmyta
wspomaganie decyzji
data mining
decision support
fuzzy rules
logical rules
medical diagnosis
optimization
Opis:
Contrary to the common opinion, neural networks may be used for knowledge extraction. Recently, a new methodology of logical rule extraction, optimization and application of rule-based systems has been described. C-MLP2LN algorithm, based on constrained multilayer perceptron network, is described here in details and the dynamics of a transition from neural to logical system illustrated. The algorithm handles real-valued features, determining appropriate linguistic variables or membership functions as a part of the rule extraction process. Initial rules are optimized by exploring the accuracy/simplicity tradeoff at the rule extraction stage and the one between reliability of rules and rejection rate at the optimization stage. Gaussian uncertainties of measurements are assumed during application of crisp logical rules, leading to "soft trapezoidal" membership functions and allowing to optimize the linguistic variables using gradient procedures. Comments are made on application of neural networks to knowledge discovery in the benchmark and real life problems.
Źródło:
Control and Cybernetics; 2000, 29, 4; 997-1017
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification, Association and Pattern Completion Using Neural Similarity Based Methods
Autorzy:
Duch, W.
Adamczak, R.
Diercksen, G. H. F.
Powiązania:
https://bibliotekanauki.pl/articles/911147.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sieć neuronowa
klasyfikacja
rozpoznawanie obrazów
neural networks
classification
association
pattern recognition
Opis:
A framework for Similarity-Based Methods (SBMs) includes many classification models as special cases: neural networks of the Radial Basis Function type, Feature Space Mapping neurofuzzy networks based on separable transfer functions, Learning Vector Quantization, variants of the k nearest neighbor methods and several new models that may be presented in a network form. Multilayer Perceptrons (MLPs) use scalar products to compute a weighted activation of neurons, combining soft hyperplanes to provide decision borders. Distance-based multilayer perceptrons (D-MLPs) evaluate the similarity of inputs to weights offering a natural generalization of standard MLPs. A cluster- based initialization procedure determining the architecture and values of all adaptive parameters is described. Networks implementing SBM methods are useful not only for classification and approximation, but also as associative memories, in problems requiring pattern completion, offering an efficient way to deal with missing values. Non-Euclidean distance functions may also be introduced by normalization of the input vectors in an extended feature space. Both the approaches dramatically influence the shapes of decision borders. An illustrative example showing these changes is provided.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2000, 10, 4; 747-766
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simple cyclic movements as a distinct autism feature - computational approach
Autorzy:
Dobosz, K.
Mikołajewski, D.
Wójcik, G. M.
Duch, W.
Powiązania:
https://bibliotekanauki.pl/articles/305787.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
computational neuroscience
neural networks
attractor networks
motor control
repetitive movements
ion channels
Autism Spectrum Disorders
ASD
emergent simulator
GENESIS simulator
Opis:
A diversity of symptoms in autism dictates a broad definition of Autism Spectrum of Disorders (ASD). Each year, the percentage of children diagnosed with ASD is growing. One common diagnostic feature in individuals with ASD is the tendency to exhibit atypical simple cyclic movements.The motor brain activity seems to generate a periodic attractor state that is hard to escape. Despite numerous studies, scientists and clinicians do not know exactly if ASD is a result of a simple yet general mechanism or of a complex set of mechanisms (either on the neural, molecular and system levels). Simulations using the biologically - relevant neural network model presented here may help to reveal the simplest mechanisms that may be responsible for specific behavior. Abnormal neural fatigue mechanisms may be responsible for motor symptoms as well as many (or perhaps all) of the other symptoms observed in ASD.
Źródło:
Computer Science; 2013, 14 (3); 475-489
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational approach to understanding Autism Spectrum Disorders
Autorzy:
Duch, W.
Nowak, W.
Meller, J.
Osiński, G.
Dobosz, K.
Mikołajewski, D.
Wójcik, G. M.
Powiązania:
https://bibliotekanauki.pl/articles/305295.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
computational neuroscience
neural networks
autism
Autism Spectrum Disorders
ASD
Opis:
Every year the prevalence of Autism Spectrum of Disorders (ASD) is rising. Is there a unifying mechanism of various ASD cases at the genetic, molecular, cellular or systems level? The hypothesis advanced in this paper is focused on neural dysfunctions that lead to problems with attention in autistic people. Simulations of attractor neural networks performing cognitive functions help to assess system long-term neurodynamics. The Fuzzy Symbolic Dynamics (FSD) technique is used for the visualization of attractors in the semantic layer of the neural model of reading. Large-scale simulations of brain structures characterized by a high order of complexity requires enormous computational power, especially if biologically motivated neuron models are used to investigate the influence of cellular structure dysfunctions on the network dynamics. Such simulations have to be implemented on computer clusters in a grid-based architectures.
Źródło:
Computer Science; 2012, 13 (2); 47-61
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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