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Wyszukujesz frazę "Fractal" wg kryterium: Temat


Tytuł:
On the relationship between fractal geometry of space and time in which a system of interacting cells exists and dynamics of gene expression.
Autorzy:
Waliszewski, Przemysław
Molski, Marcin
Konarski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1044188.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
complexity
neoplasia
fractal
differentiation
fractal dimension
Opis:
We report that both space and time, in which a system of interacting cells exists, possess fractal structure. Each single cell of the system can restore the hierarchical organization and dynamic features of the entire tumor. There is a relationship between dynamics of gene expression and connectivity (i.e., interconnectedness which denotes the existence of complex, dynamic relationships in a population of cells leading to the emergence of global features in the system that would never appear in a single cell existing out of the system). Fractal structure emerges owing to non-bijectivity of dynamic cellular network of genes and their regulatory elements. It disappears during tumor progression. This latter state is characterized by damped dynamics of gene expression, loss of connectivity, loss of collectivity (i.e., capability of the interconnected cells to interact in a common mode), and metastatic phenotype. Fractal structure of both space and time is necessary for a cellular system to self-organize. Our findings indicate that results of molecular studies on gene expression should be interpreted in terms of space-time geometry of the cellular system. In particular, the dynamics of gene expression in cancer cells existing in a malignant tumor is not identical with the dynamics of gene expression in the same cells cultured in the monolayer system.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 209-220
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal analysis of sandstone pore space geometry
Autorzy:
Figiel, M.
Lewandowska-Śmierzchalska, J.
Powiązania:
https://bibliotekanauki.pl/articles/298840.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
pore space
fractal structure
fractal dimension
lacunarity
thin-section
computer image analysis
Opis:
Fractal analysis is currently one of the fastest evolving branches of science. Numerous objects in nature exhibit a fractal structure. Additionally, the vast majority of rocks – especially reservoir rocks – take the form of a fractal. Computer image analysis based on thin-section images has been used for examining the fractal structure of pore spaces, directly applying the definition of the fractal box-counting dimension. For the examined sandstone sample, thin sections were made and photographed, and the corresponding values of the fractal dimension and lacunarity were calculated. Each of the photos was encompassed by porosity that was calculated based on the number of pixels. Furthermore, the volatility of the fractal dimension and lacunarity were studied as well as their relationships with the porosity. A correlation analysis between the fractal parameters and the porosity was carried out. The results were compared with the data obtained from a mercury porosimetry of the same sample of sandstone.
Źródło:
AGH Drilling, Oil, Gas; 2018, 35, 2; 377-389
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal Format for Bitmap Images
Autorzy:
Siwocha, A.
Cader, A.
Kolibabka, M.
Krupski, M.
Powiązania:
https://bibliotekanauki.pl/articles/108680.pdf
Data publikacji:
2012
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
fractal interpolation method
image recording formats
fractal dimension
multifractal analysis
non-local characteristics
Opis:
The conception of proposed recording format is the example of the theoretical and practical application of the FBS method, which was precisely described in thesis [18,19,20]. The foundation of the presented recording format is the use of a new method of fractal basis splines (FB-splines), which allows the reconstruction of complex geometric structures with the properties of fractals. Fractral basis splines method is based on the use of non-local characteristics to describe the interpolation nodes. With that the one-parameter family of fractal curves is used as the basic approximating elements.
Źródło:
Journal of Applied Computer Science Methods; 2012, 4 No. 2; 41-54
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania wymiaru fraktalnego do analizy konturu obiektów
The use of the fractal dimension for analysis of the contour of objects
Autorzy:
Omiotek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/407916.pdf
Data publikacji:
2012
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
fraktal
wymiar fraktalny
metoda pudełkowa
metoda masa-promień
fractal
fractal dimension
box-counting method
mass-radius method
Opis:
W artykule zaprezentowano wyniki analizy fraktalnej zbioru obrazów testowych podzielonych umownie na 12 kategorii. Celem badań bylo szacowanie wymiaru fraktalnego na podstawie konturu badanych obiektów, w oparciu o metodę pudełkową i metodę masa-promień. Wyniki analizy pokazały, iż łączne zastosowanie obu wspomnianych metod może być wykorzystane w procesie klasyfikacji obrazów.
The article presents the results of fractal analysis of a set of test images which was divided conventionally into 12 categories. The aim of the study was to estimate the fractal dimension based on the contour of studied objects, using box-counting method and mass-radius method. The results showed that combination of both above methods can be used in the image classification process.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2012, 2; 8-11
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
BCFD - a Visual Basic program for calculation of the fractal dimension of digitized geological image data using a box-counting technique
Autorzy:
Verbovšek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2059206.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
program
Visual Basic
image analysis
fractal dimension
Opis:
The BCFD program was develped for the analysis of digitized objects using a box-counting algorithm, which has the largest number of applications among the fractal methods in the geosciences. Counting is performed by scanning of image pixels in boxes of different sizes, and the number of boxes is determined automatically from the image resolution. The program calculates the fractal dimension D of theobjects in the image, along with the coefficient of determination R2. Input files are thus transferred to ubiquitous BMP images, in a 1-bit monochrome for mat. The pro gram out puts the re sults on screen, into a text file and op tion ally also di rectly into MS Ex cel, where the data can be fur ther used in charts or other cal cu la tions. It was tested with three fractal and three Eu clid ean ob jects with known the o ret i cal val - ues, plus three geo log i cal im age data (a nat u ral river net work and two frac ture net works), and gave re sults with very high or per fect the o - ret i cal ac cu racy. Ap pli ca tion of data val ues ob tained is pre sented with sev eral ex am ples. BCFD is writ ten in Vi sual Ba sic 6.0. The source code is freely avail able, and is open for any mod i fi ca tions or in te gra tion with other soft ware pack ages that are pow ered by Vi sual Ba sic for Ap pli ca tions (VBA) or its equiv a lent.
Źródło:
Geological Quarterly; 2009, 53, 2; 241-248
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of comparison of surface texture based on fractal dimension and Hotelling’s T2 test
Autorzy:
Gogolewski, Damian
Powiązania:
https://bibliotekanauki.pl/articles/99764.pdf
Data publikacji:
2019
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
face milling
fractal dimension
surface roughness
test
Opis:
Comparative analysis of the surface texture of machine parts can be successfully carried out using statistical tests. The paper presents a methodology of method used to compare the surface texture by applying Hotelling’s T2 test as well as a method used to evaluate surface topography by applying fractal dimension. The tests were carried out on samples produced with the use of face milling process for four types of materials. The following types of steel were used: 40HM, C45, NC6 and WCL. For each type of material, four areas were machined with the same machining parameters. Based on these results a decision was made whether the surfaces, despite the same machining conditions, were significantly different from each other. Furthermore, the analysis indicated that the fractal dimension enabled to characterise signal irregularities in quantitative and qualitative way.
Źródło:
Journal of Machine Engineering; 2019, 19, 4; 82-90
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peculiarities of the radio signals and hindrances in the navigation system of the remote-piloted vehicles
Charakter sygnałów radiowych i utrudnień w systemach nawigacji w bezzałogowych statkach powietrznych
Autorzy:
Mykyjchuk, M.
Markiv, V.
Powiązania:
https://bibliotekanauki.pl/articles/407854.pdf
Data publikacji:
2018
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
radio signal
fractal analysis
remote-piloted vehicle
fractal dimension
sygnał radiowy
analiza fraktalna
bezzałogowy statek powietrzny
wymiar fraktalny
Opis:
The article dwells upon the peculiarities of radio signals concerning the use of remote-piloted vehicles. It is highlighted that it is important take into consideration the fractal analysis of remote-piloted vehicles based on diverse fractal dimensions. The significance of remote-piloted vehicle control system investigation based on radio signals is presented. Also it is highlighted that there are many hindrances during the remote-piloted vehicle flight and it is important to take them into consideration and develop methods in order to omit them. Also the vital role of remote-piloted vehicles in different spheres of life, for example, in environment research is depicted.
W artykule został poruszony temat cech sygnałów radiowych w przypadku ich zastosowania w bezzałogowych statkach powietrznych. W pracy podkreśla się istotność bazowania na fraktalnych wymiarach podczas analizy fraktalnej bezzałogowych statków powietrznych. Podkreślono znaczenie sygnałów radiowych w systemach sterowania. Przedstawiono istnienie wielu utrudnień podczas lotów bezzałogowych statków powietrznych oraz wskazano na konieczność uwzględniania i opracowania metod uniknięcia tych utrudnień. Podkreślono również istotną rolę bezzałogowych statków powietrznych w różnych sferach życia, na przykład w badaniach środowiska.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2018, 8, 1; 40-43
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Complexity of Creole Languages: The Fractal Approach
Autorzy:
Pietraszewska, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/504770.pdf
Data publikacji:
2016
Wydawca:
Komisja Nauk Filologicznych Polskiej Akademii Nauk, Oddział we Wrocławiu
Tematy:
fractal dimension
language complexity
creole languages
time series
Opis:
The current paper aims to compare the complexity of texts translated into English-based creole languages and English. The main motivation for the choice of topic was the growing body of evidence that languages and language phenomena, such as texts, may be regarded as complex adaptable systems of signs. These systems may display some fractal properties, such as self-similarity at different scales. In consequence, texts may be analysed in the same manner as other fractal objects. It is possible, for instance, to estimate their fractal dimensions which, to some extent, reflect the degree of their structural complexity. Such an assumption enables one to calculate and compare fractal dimensions of parallel translations of texts to various languages in order to compare their complexity levels. Methods which enable comparisons of complexity of texts in different languages are particularly important with regard to creole languages, since the complexity of contact languages is still the subject of debate. In the following study, ten parallel translations of passages from the New Testament were mapped onto time series plots based on the length and the frequency rank of words. The values of Hurst exponent as well as fractal dimension were estimated and it was found that the studied time series did not differ significantly between English and English-based creoles with respect to their fractal dimensions. The results lend support to the idea that creole languages are simply new languages which are merely different from their superstrate language rather than being less complex, at least with regard to their lexical patterns.
Źródło:
Academic Journal of Modern Philology; 2015, 4; 73-80
2299-7164
2353-3218
Pojawia się w:
Academic Journal of Modern Philology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fractal dimension of red blood cell aggregates in dextran 70 solutions
Autorzy:
Bosek, M.
Szołna-Chodór, A.
Antonova, N.
Grzegorzewski, B.
Powiązania:
https://bibliotekanauki.pl/articles/173260.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
red blood cells
aggregation
fractal dimension
dextran 70
Opis:
Fractal dimension of three dimensional red blood cell aggregates were determined by measurement of their size and sedimentation velocity. The sedimentation of the aggregates was investigated with red blood cells suspended in dextran 70 solutions at concentrations from 2 to 5 g/dL, at hematocrit 5% and 10%. The aggregate velocity and size were measured using an image analysis technique. The velocity vs. radius dependence of the aggregates exhibited a scaling behavior. This behavior showed the fractal structure of the aggregates. It is shown that the fractal dimension of the three dimensional red blood cell aggregates depends on the dextran concentration in the suspension. This parameter exhibited a minimum at dextran concentration between 3 and 4 g/dL. Thus the fractal dimensions increased as the aggregation extent decreased. The obtained results show that the sedimentation experiment together with image analysis is a promising technique to determine the fractal dimension of the three dimensional red blood cell aggregates.
Źródło:
Optica Applicata; 2018, 48, 3; 477-488
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on fractal dimensions and convergence in fuzzy control systems
Autorzy:
Schuster, A.
Blackburn, W.
Prieto, M.S.
Powiązania:
https://bibliotekanauki.pl/articles/309243.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
fuzzy control systems
chaos theory
convergence
fractal dimension
Opis:
This paper addresses a problem in the area of intelligent, knowledge-based systems, namely the generation of knowledge, by presenting a proposal for the automation of this task. The proposed approach is limited however by focusing on fuzzy control systems (FCSs). Results obtained from different experimental investigations indicate the potential of the approach.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 3; 30-36
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal dimension and rheological properties of cereal starches
Autorzy:
Mazurkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/24663.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
fractal dimension
rheological property
cereal starch
starch
thixotropy
Źródło:
International Agrophysics; 2011, 25, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal Analysis of Noise Signals of Sampo and John Deere Combine Harvesters in Operational Conditions
Autorzy:
Boroujeni, Farzad Mahdiyeh
Maleki, Ali
Powiązania:
https://bibliotekanauki.pl/articles/176317.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound
combine
fractal dimension
engine speed
sliding window
Opis:
Combine harvesters are the source a large amount of noise in agriculture. Depending on different working conditions, the noise of such machines can have a significant effect on the hearing conditio of drivers. Therefore, it is highly important to study the noise signals caused by these machines and find solutions for reducing the produced noise. The present study was carried out is order to obtain the fractal dimension (FD) of the noise signals in Sampo and John Deere combine harvesters in different operational conditions. The noise signals of the combines were recorded with different engine speeds, operational conditions, gear states, and locations. Four methods of direct estimations of the FD of the waveform in the time domain with three sliding windows with lengths of 50, 100, and 200 ms were employed. The results showed that the Fractal Dimension/Sound Pressure Level [dB] in John Deere and Sampo combines varied in the ranges of 1.44/96.8 to 1.57/103.2 and 1.23/92.3 to 1.51/104.1, respectively. The cabins of Sampo and John Deere combines reduced and enhanced these amounts, respectively. With an increase in the length of the sliding windows and the engine speed of the combines, the amount of FD increased. In other words, the size of the suitable window depends on the extraction method of calculating the FD. The results also showed that the type of the gearbox used in the combines could have a tangible effect on the trend of changes in the FD.
Źródło:
Archives of Acoustics; 2019, 44, 1; 89-98
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal analysis of tropical karst relief : South China Karst case study
Autorzy:
Andreychouk, Viacheslav
Blachowicz, Tomasz
Dłużewski, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/2058635.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
fractal dimension
cover factor
tropical karst
South China Karst
Opis:
Areas of tropical karst create the most spectacular earth landscapes from a geomorphological perspective. These areas are characterized by a variety of specific forms resulting from the long-term karst-erosion dismemberment of terrains in favourable humid tropical conditions. Tropical karst areas are extremely diverse from a geomorphological point of view both in terms of local conditions of development and developmental stages. Among the many types of karst relief, the following two basic types can be recognized: fenglin (tower karst) and fengcong (cone karst). The other types can be treated as a mixture of these two basic types. To find potential quantitative rates characterizing the two main types, as well as the mixed types, we calculated fractal dimensions and cover factors of 17 areas located within the two well-known regions of South China Karst - Guilin and Huanjiang. The calculations show that the numerical characteristics obtained, especially the cover factor parameter, can be useful as complementary tools in the recognition and typology of tropical karst relief and landscapes.
Źródło:
Geological Quarterly; 2019, 63, 4; 729--740
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative analysis of the relationship between shear strength and fractal dimension of solidified dredger fill with different fly ash content under monotonic shear
Autorzy:
Yang, S.
Liu, W.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/258498.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
curing agent
fly ash
shear strength
fractal dimension
SEM
Opis:
The dredger fill of Shanghai Hengsha Island Dongtan is solidified by curing agents with different fly ash content, and the shear strength index of solidified dredger fill is measured by the direct shear test. The microscopic images of solidified dredger fill are obtained by using SEM. The microscopic images are processed and analyzed by using IPP, and the fractal dimension including particle size fractal dimension Dps, aperture fractal dimension Dbs and particle surface fractal dimension Dpr is calculated by fractal theory. The quantitative analysis of the relationship between shear strength index and fractal dimension of solidified dredger fill is done. The research results show that the internal friction angle and the cohesion are closely related to the fly ash content λ and the curing period T, and the addition of fly ash can improve the effect of curing agent; There is no obvious linear relationship between the internal friction angle and the three fractal dimensions; The smaller particle surface fractal dimension Dpr and particle size fractal dimension Dps, the larger aperture fractal dimension Dbs, the greater the cohesion, and the cohesion has a good linear relationship with three fractal dimensions, and the correlation coefficient R2 is above 0.91.
Źródło:
Polish Maritime Research; 2018, S 2; 132-138
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal Features and Structural, Morphological, Optical Characteristics of Sol-Gel Derived Silica Nanoparticled Thin Films
Autorzy:
Uysal, B.
Pekcan, Ö.
Powiązania:
https://bibliotekanauki.pl/articles/1029990.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
fractal dimension
silica
sol-gel method
size-dependence
thin films
Opis:
Nanostructured silica films using a simple and effective sol-gel spin coating technique were synthesized and the influence of ammonia/sol ratios on the particle size and thickness of this film was investigated. In addition, fractal dimensions of the prepared films were determined using the scattering response technique. The samples were characterized by atomic force microscopy and UV-vis spectroscopy. Comparing optical method and image analysis of atomic force microscopy micrographs, the fractal dimension of silica nanoparticled thin films was determined. The fractal dimensions of the films verified by atomic force microscopy analysis were found to be around 2.03 which is very close to the values (2.0358, 2.0325, and 2.0335) obtained using optical method. As a result of these findings, precise determination of the nanoparticled silica thin films fractal dimension using both optical and surface analysis methods was realized.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1160-1164
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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