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Wyszukujesz frazę "Fractal dimension" 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:
Seismo Magnetic Moment Fractal Dimension for Characterizing Shajara Reservoirs of the Permo-Carboniferous Shajara Formation, Saudi Arabia
Autorzy:
Alkhidir, Khalid Elyas Mohamed Elameen
Powiązania:
https://bibliotekanauki.pl/articles/1030683.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Capillary pressure fractal dimension
Seismo magnetic moment fractal dimension
Shajara Formation
Shajara Reservoirs
Opis:
The quality and assessment of a reservoir can be documented in details by the application of seismo magnetic moment. This research aims to calculate fractal dimension from the relationship among seismo magnetic moment, maximum seismo magnetic moment and wetting phase saturation and to approve it by the fractal dimension derived from the relationship among capillary pressure and wetting phase saturation. Two equations for calculating the fractal dimensions have been employed. The first one describes the functional relationship between wetting phase saturation, seismo magnetic moment, maximum seismo magnetic moment and fractal dimension. The second equation implies to the wetting phase saturation as a function of capillary pressure and the fractal dimension. Two procedures for obtaining the fractal dimension have been utilized. The first procedure was done by plotting the logarithm of the ratio between seismo magnetic moment and maximum seismo magnetic moment versus logarithm wetting phase saturation. The slope of the first procedure = 3- Df (fractal dimension). The second procedure for obtaining the fractal dimension was determined by plotting the logarithm of capillary pressure versus the logarithm of wetting phase saturation. The slope of the second procedure = Df -3. On the basis of the obtained results of the fabricated stratigraphic column and the attained values of the fractal dimension, the sandstones of the Shajara reservoirs of the Shajara Formation were divided here into three units.
Źródło:
World Scientific News; 2020, 139, 2; 186-200
2392-2192
Pojawia się w:
World Scientific News
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:
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 dimension and variant anatomy of the white matter of the human cerebellar hemisperes
Autorzy:
Maryenko, N. I.
Stepanenko, O. Yu.
Powiązania:
https://bibliotekanauki.pl/articles/765463.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydział Nauk o Ziemi i Gospodarki Przestrzennej. Katedra Kultury Fizycznej
Tematy:
human, cerebellum, fractal dimension, white matter, anatomical variability
Opis:
Introduction. Morphological changes of the cerebellar lobules are found in many congenital and acquired diseases of the cerebellum, but the information on the normal structure of the cerebellar lobules do not take into account the peculiarities of individual anatomical variability, sex and age characteristics.Aim – to investigate anatomical variability and fractal dimension of the white matter of the human cerebellar hemispheres.Material and methods. The study involved 100 cerebella of people of both sexes, who died of causes unrelated to brain pathology (20–99 years old). Parasagittal sections of the cerebellar hemispheres were investigated.Results. On parasagittal sections number of main branches of white matter is very varied and depends on peculiarities of structure of the hemispheric lobules. It was found that there is individual variability of the structure of the human cerebellar hemispheres, namely white matter branching features. We described variants of the branching of the main branches of white matter of the human cerebellar hemispheres.Fractal dimension of the white matter was determined. The white matter of the cerebellum is typical quasi-fractal structure that can be objectively described using fractal dimension. Fractal index of the white matter of the cerebellar hemispheres varies from 1.119 to 1.519; average fractal index is 1.370. Fractal analysis can be used as an objective morphometric criterion for the diagnosis of various diseases of the cerebellum and other structures of the central nervous system.Conclusions. Described variants of the cerebellar lobules and fractal dimension can be used as criteria for modern diagnostic imaging techniques for the diagnosis of various diseases of the CNS. The data can be used as the basis for atlases of serial sections of the cerebellum.
Źródło:
Journal of Education, Health and Sport; 2017, 7, 3
2391-8306
Pojawia się w:
Journal of Education, Health and Sport
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

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