نتایج جستجو برای: fractal group

تعداد نتایج: 1006942  

Journal: :Journal of applied physiology 2008
Kevin S Heffernan Jacob J Sosnoff Christopher A Fahs Kevin K Shinsako Sae Young Jae Bo Fernhall

With aging and disease, there is a breakdown of the natural fractal-like organization of heart rate (HR). Fractal-like correlation properties of HR can be assessed with detrended fluctuation analysis (DFA). A short-time scaling exponent (alpha(s)) value of 1 is associated with healthy HR dynamics, whereas values that deviate away from 1, in either direction, indicate fractal collapse. The purpo...

Journal: :Acta haematologica 2008
Adi Mashiah Ofir Wolach Judith Sandbank Orit Uziel Pia Raanani Meir Lahav

BACKGROUND Living cells can be viewed as complex adaptive systems that exhibit non-linear dynamics and fractal features. We investigated the fractal qualities of normal and malignant hematological cells and their potential as a tool for characterizing cell phenotype and clinical behavior. METHODS A mathematical algorithm and an optic tool for fractal analysis of nuclei were developed. A total...

2016
Francis Lopes Pacagnelli Ana Karênina Dias de Almeida Sabela Thaoan Bruno Mariano Guilherme Akio Tamura Ozaki Robson Chacon Castoldi Edna Maria do Carmo Robson Francisco Carvalho Loreta Casquel Tomasi Katashi Okoshi Luiz Carlos Marques Vanderlei

BACKGROUND Right-sided heart failure has high morbidity and mortality, and may be caused by pulmonary arterial hypertension. Fractal dimension is a differentiated and innovative method used in histological evaluations that allows the characterization of irregular and complex structures and the quantification of structural tissue changes. OBJECTIVE To assess the use of fractal dimension in car...

Antenna Miniaturization Using Fractals Richa Garg, AP ECE Deptt., [email protected], J.C.D.C.O.E., Sirsa ABSTRACTThe use of fractal geometry in designing antenna has been a resent topic of interest. Fractal shape has their own unique characteristics that the improved antenna performance can be achieved without degrading the antenna properties. Modern telecommunication system requires antenn...

The fractal degree of adsorption on the multi-walled carbon nanotube has been investigated. The fractal-like Langmuir kinetics model has been used to obtain the fractal degree of ion adsorption on multi-walled carbon nanotube. The behavior of the fractal-like kinetics equation was compared with some famous rate equations like Langmuir, pseudo-first-order and pseudo-second-order equations. It is...

In this work, SiO2 –ZrO2 mixed oxides was prepared by the polymeric sol–gel route. The characterization of pore structure, which determines the permeation process of membrane, is of great importance. So far, most investigations have focused on such pore structure as specific surface area and pore size distribution, but the surface fractal, the important parameter reflecting the roughness of por...

Journal: :galen medical journal 0
seyedabbas mirmalek assistant professor of general surgery, azad university of medical sciences and health services, boali hospital, tehran, iran niloofar sadat yarandi general practitioner, azad university of medical sciences and health services, boali hospital, tehran, iran mohammad tafazoli shadpour biomedical engineering, amirkabir university, tehran, iran minoo saatian pathologist, azad university of medical sciences and health services, boali hospital, tehran, iran homa raeesi pathologist, kasra hospital, tehran, iran esmaieel jafargholi rangraz biomedical engineering, amirkabir university, tehran, iran

many studies suggested that fractals could be brought in any structural anarchy, such as cancers, for diagnosis and prognosis evaluation by quantifying it and expressing it in terms of fractal geometry. in this study, we aimed to evaluate pathologic grades or breast carcinomas by fractal analysis. this cross-sectional study was performed on 60 women with breast ductal carcinoma. from all the pa...

2001
Michinobu Nagao Kenya Murase Takanori Kikuchi Manabu Ikeda Akihiko Nebu Ryuji Fukuhara Yoshifumi Sugawara Hitoshi Miki Junpei Ikezoe

This study describes a method for quantifying cerebral blood flow (CBF) distribution in Alzheimer’s disease (AD) from SPECT images obtained with 99mTc-hexamethylpropyleneamine oxime (HMPAO) by 3-dimensional fractal analysis (3D-FA). Methods: HMPAO SPECT was performed on 68 patients with probable AD and 14 healthy control subjects. We delineated the CBF images using 4 cutoff levels (35%, 40%, 45...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2001
Jyrki T Kuikka

UNLABELLED This study describes a method for quantifying cerebral blood flow (CBF) distribution in Alzheimer's disease (AD) from SPECT images obtained with (99m)Tc-hexamethylpropyleneamine oxime (HMPAO) by 3-dimensional fractal analysis (3D-FA). METHODS HMPAO SPECT was performed on 68 patients with probable AD and 14 healthy control subjects. We delineated the CBF images using 4 cutoff levels...

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