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Wyszukujesz frazę "radon transform" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Radon‐wavelet based novel image descriptor for mammogram mass classification
Autorzy:
Obaidullah, Sk Md
Ahmed, Sajib
Gonçalves, Teresa
Rato, Luís
Powiązania:
https://bibliotekanauki.pl/articles/384195.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
image descriptor
radon transform
mammography
breast cancer
classification
Opis:
Mammography based breast cancer screening is very popular because of its lower costing and readily availability. For automated classification of mammogram images as benign or malignant machine learning techniques are involved. In this paper, a novel image descriptor which is based on the idea of Radon and Wavelet transform is proposed. This method is quite efficient as it performs well without any clinical information. Performance of the method is evaluated using six different classifiers namely: Bayesian network (BN), Linear discriminant analysis (LDA), Logistic, Support vector machine (SVM), Multilayer perceptron (MLP) and Random Forest (RF) to choose the best performer. Considering the present experimental framework, we found, in terms of area under the ROC curve (AUC), the proposed image descriptor outperforms, upto some extent, previous reported experiments using histogram based hand‐crafted methods, namely Histogram of Oriented Gradient (HOG) and Histogram of Gradient Divergence (HGD) and also Convolution Neural Network (CNN). Our experimental results show the highest AUC value of 0.986, when using only the carniocaudal (CC) view compared to when using only the mediolateral oblique (MLO) (0.738) or combining both views (0.838). These results thus proves the effectiveness of CC view over MLO for better mammogram mass classification.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2020, 14, 2; 74-80
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extension of separately analytic functions and applications to range characterization of the exponential Radon transform
Autorzy:
Öktem, Ozan
Powiązania:
https://bibliotekanauki.pl/articles/1294227.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
exponential Radon transform
range characterization
separately analytic functions
Opis:
We consider the problem of characterizing the range of the exponential Radon transform. The proof uses extension properties of separately analytic functions, and we prove a new theorem about extending such functions.
Źródło:
Annales Polonici Mathematici; 1998, 70, 1; 195-213
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
"Counterexamples" to the harmonic Liouville theorem and harmonic functions with zero nontangential limits
Autorzy:
Bonilla, A.
Powiązania:
https://bibliotekanauki.pl/articles/965789.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
nontangential limits
universal function
approximation
Liouville harmonic theorem
Radon transform
harmonic functions
Opis:
We prove that, if μ>0, then there exists a linear manifold M of harmonic functions in $ℝ^N$ which is dense in the space of all harmonic functions in $ℝ^N$ and lim_{{‖x‖→∞} {x ∈ S}} ‖x‖^{μ}D^{α}v(x) = 0 for every v ∈ M and multi-index α, where S denotes any hyperplane strip. Moreover, every nonnull function in M is universal. In particular, if μ ≥ N+1, then every function v ∈ M satisfies ∫_H vdλ =0 for every (N-1)-dimensional hyperplane H, where λ denotes the (N-1)-dimensional Lebesgue measure. On the other hand, we prove that there exists a linear manifold M of harmonic functions in the unit ball of $ℝ^N$, which is dense in the space of all harmonic functions and each function in M has zero nontangential limit at every point of the boundary of .
Źródło:
Colloquium Mathematicum; 2000, 83, 2; 155-160
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radon-Zernike moments method applied in postal application
Zastosowanie momentów Radona-Zernike do aplikacji pocztowych
Autorzy:
Miciak, M.
Wiatr, R.
Andrysiak, T.
Maszewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/389801.pdf
Data publikacji:
2013
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydawnictwo PB
Tematy:
character recognition
radon transform
Zernike moments
rozpoznawanie znaków
transformata Radona
momenty Zernike
Opis:
In this paper a new method of a handwritten characters recognition is introduced. The proposed algorithm is applied to classification of post mails on the basis of postal code information. In connection with this work the research was conducted with numeric characters used in real post code of mail pieces. Moreover, the article contains image processing, for instance, filtration of Radon transformation of the character. The main objective of this article is to use the Radon transform parameter space to obtain a set of moment features on basis of which postal code will be recognized.
W artykule przedstawiono nowe rozwiązanie zadania rozpoznawania znaków pisanych ręcznie dla zastosowań pocztowych. Zaproponowano algorytm klasyfikacji przesyłek pocztowych działający na podstawie informacji zawartej w zapisie kodu pocztowego. Główny nacisk położono na wykorzystanie transformaty Radona i momentów Zernike do uzyskania zbioru cech, na podstawie, których rozpoznawano kod pocztowy. Otrzymane wyniki eksperymentów pozwoliły wykazać skuteczno ść proponowanej metody.
Źródło:
Zeszyty Naukowe. Telekomunikacja i Elektronika / Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy; 2013, 17; 17-26
1899-0088
Pojawia się w:
Zeszyty Naukowe. Telekomunikacja i Elektronika / Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of advanced techniques of image processing based on automatic detection system and road sings recognition
Autorzy:
Smorawa, D.
Kubanek, M.
Powiązania:
https://bibliotekanauki.pl/articles/122301.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
image processing
image detection
radon transform
Hough transform
przetwarzanie obrazów
transformata Radona
transformata Hough'a
Opis:
This paper describes implementations of the Hough Circle Transform and the Radon Line Transform. The presented transforms were used to build a system for identifying road signs from selected images and recordings. This can be very important and especially useful for monitoring and prevention in driver assistance systems. The design of our system assumed that the objects should be found automatically from images or video sequence. Furthermore, the detection was based on the shapes of common traffic signs which correspond to used transforms. Additionally, the Huffman method was applied to encode the data before being compared. Consequently, the traffic signs were matched directly with the Euclidean distance.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2014, 13, 1; 103-113
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Circular Radon Transform Inversion Technique in Synthetic Aperture Ultrasound Imaging : an Ultrasound Phantom Evaluation
Autorzy:
Tasinkevych, J.
Trots, I.
Powiązania:
https://bibliotekanauki.pl/articles/176632.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
synthetic aperture focusing method
circular Radon Transform
delay and sum beamforming
range migration algorithm
Opis:
The paper presents an overview of theoretical aspects of ultrasound image reconstruction techniques based on the circular Radon transform inversion. Their potential application in ultrasonography in a similar way as it was successfully done in the x-ray computer tomography is demonstrated. The meth- ods employing Radon transform were previously extensively explored in the synthetic aperture radars, geophysics, and medical imaging using x-ray computer tomography. In this paper the main attention is paid to the ultrasound imaging employing monostatic transmit-receive configuration. Specifically, a single transmit and receive omnidirectional source placed at the same spatial location is used for generation of a wide-band ultrasound pulse and detection of back-scattered waves. The paper presents derivation of the closed-form solution of the CRT inversion algorithms by two different approaches: the range-migration algorithm (RMA) and the deconvolution algorithm (DA). Experimentally determined data of ultrasound phantom obtained using a 32-element 5 MHz linear transducer array with 0.48 mm element pitch and 0.36 mm element width and 5 mm height, excited by a 2 sine cycles burst pulse are used for comparison of images reconstructed by the RMA, DA, and conventional synthetic aperture focusing technique (SAFT). It is demonstrated that both the RMA and SAFT allow better lateral resolution and visualization depth to be achieved as compared to the DA approach. Comparison of the results obtained by the RMA method and the SAFT indicates slight improvement of the lateral resolution for the SAFT of approximately 1.5 and 1.6% at the depth of 12 and 32 mm, respectively. Concurrently, however, the visualization depth increase for the RMA is shown in comparison with the SAFT. Specifically, the scattered echo amplitude increase by the factor of 1.36 and 1.12 at the depth of 22 and 32 mm is demonstrated. It is also shown that the RMA runs about 30% faster than the SAFT and about 12% faster than the DA method.
Źródło:
Archives of Acoustics; 2014, 39, 4; 569-582
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tauberian theorems for vector-valued Fourier and Laplace transforms
Autorzy:
Chill, Ralph
Powiązania:
https://bibliotekanauki.pl/articles/1218589.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Tauberian theorem
Fourier transform
Laplace transform
asymptotically almost periodic
analytic Radon-Nikodym property
Cauchy problem
Opis:
Let X be a Banach space and $f ∈ L^1_loc(ℝ;X)$ be absolutely regular (i.e. integrable when divided by some polynomial). If the distributional Fourier transform of f is locally integrable then f converges to 0 at infinity in some sense to be made precise. From this result we deduce some Tauberian theorems for Fourier and Laplace transforms, which can be improved if the underlying Banach space has the analytic Radon-Nikodym property.
Źródło:
Studia Mathematica; 1998, 128, 1; 55-69
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Around Widders characterization of the Laplace transform of an element of $L^{∞}(ℝ^{+})$
Autorzy:
Kisyński, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1207972.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
operators from $L_{ϰ}^{1}(ℝ^{+})$ into a Banach space
complete monotonicity and positivity with respect to a cone
one-parameter semigroups of operators
vector measures
Gelfand space
Radon-Nikodym property
representations of the convolution algebra $L_{ϰ}^{1}(ℝ^{+})$
pseudoresolvents and their generators
real inversion formulas for the Laplace transform
Opis:
Let ϰ be a positive, continuous, submultiplicative function on $ℝ^{+}$ such that $lim_{t→∞} e^{-ωt}t^{-α}ϰ(t) = a$ for some ω ∈ ℝ, α ∈ $\overline{ℝ^{+}}$ and $a ∈ ℝ^{+}$. For every λ ∈ (ω,∞) let $ϕ_{λ}(t) =e^{-λt}$ for $t ∈ ℝ^{+}$. Let $L^{1}_{ϰ}(ℝ^{+})$ be the space of functions Lebesgue integrable on $ℝ^{+}$ with weight $ϰ$, and let E be a Banach space. Consider the map $ϕ_{•}: (ω,∞) ∋ λ → ϕ_{λ} ∈ L_{ϰ}^{1}(ℝ^{+})$. Theorem 5.1 of the present paper characterizes the range of the linear map $T → Tϕ_{•}$ defined on $L(L_{ϰ}^{1}(ℝ^{+});E)$, generalizing a result established by B. Hennig and F. Neubrander for $ϰ(t)=e^{ωt}$. If ϰ ≡ 1 and E =ℝ then Theorem 5.1 reduces to D. V. Widder's characterization of the Laplace transform of a function in $L^{∞}(ℝ^{+})$. Some applications of Theorem 5.1 to the theory of one-parameter semigroups of operators are discussed. In particular a version of the Hille-Yosida generation theorem is deduced for $C_0$ semigroups $(S_t)_{t ∈ \overline{ℝ^{+}}}$ such that $sup_{t ∈ \overline{ℝ^{+}}} (ϰ(t))^{-1}∥ S_t∥ < ∞$.
Źródło:
Annales Polonici Mathematici; 2000, 74, 1; 161-200
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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