Wyniki wyszukiwania - Biblioteka Nauki

1

Recent measurements of soft X-ray emission from the DPF-1000U facility

100%

Surała W. , Sadowski M. J. , Paduch M. , Zielinska E. , Tomaszewski K.

Nukleonika

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2015

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tom 60

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nr 2

303-308

EN

Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF) experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°), and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various filters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confirmed the appearance of a filamentary fine structure in the PF discharges. In the past years the formation of such filaments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot-spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.

2

Geometric transformations in the shape analysis of selected biomedical structures

84%

Ogiela M.

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1998

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tom Vol. 4, no 3-4

27-36

EN

The article presents an algorithm of the transformation straightening outer contours of objects, allowing to transform bilogical structures of interest, visible in medical images, from two-dimensional space of the image into two-dimensional graph, representing contours of the straightened object with its possible outer morphological changes, indicating the progress of pathological processes. The developed method is based on a sequence of geometric transformations of the analyzed objects in the image, and its operation was described in detail and illustrated by examples of transformation of main pancreatic ducts, appearing in X-ray images acquired by ERCP, as well as by graphs showing outer morphology of blood vessels in the fundus of the eye and morphology of renal sinuses from kidneys roengenograms. The proposed method is universal, and due to the fact that the transformation preserves and exposes pathologic morphological changes, such as abnormal lateral branches, local dilatations or projections it can also be used in the recognition and analysis of other structure images acquired by various techniques of computer tomography, e.g. celebral vessels, bile ducts, coronary vessels of fragments of gastroin-testinal tract. The graphs of the structures of interest obtained as a result of the transformation straightening outer contours of objects are a starting point for the recognition of morphological changes, important for diagnosis, using syntactic methods of pattern recognition.

3

Zastosowanie deformowalnych struktur w analizie obrazów

84%

Szczypiński P. , Materka A.

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1998

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tom nr 3

37-49

PL

W artykule przedstawiono zwięzły przegląd metod analizy obrazów, wykorzystujących deformowalne struktury. Opisano struktury pozwalające rozpoznawać obiekty przedstawione na obrazach cyfrowych, wyznaczać ich położenie i kontury, jak też wyodrębniać i charakteryzować detale wchodzące w skład takich obiektów. Całość zilustrowano przykładami zastosowań, szczególnie uwzględniając wyniki analizy rentgenowskich obrazów ziaren zbóż.

EN

This paper is a short review of image analysis methods that use deformable structures. Structures are described that can be applied for digital image object recognition, for finding object position and contours, as well as for locating and characterising object details. Methods discussed are illustrated by application examples, with particular emphasis on analysis of wheat grain X-ray images.

4

Obrazowanie RTG stawów międzypaliczkowych wspomagane komputerowo jako metoda diagnostyki w chorobach zapalnych stawów

84%

Bauer J. , Boerner E. , Minkina S. , Podbielska H.

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2007

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tom Vol. 13, nr 3

191-193

PL

W pracy analizowano szerokość szpary stawowej w stawach międzypaliczkowych obu dłoni. Grupa badana liczyła 9 zdrowych osób, w tym 7 kobiet w wieku od 23 do 70 lat i 2 mężczyzn w wieku 22 i 72 lata. Średni wiek badanych kobiet wynosił 43 š18,3, zaś mężczyzn 47 š35,4. Wszystkie osoby były zdrowe i u żadnej nie stwierdzono reumatoidalnego zapalenia stawów. Na zdjęciach rentgenowskich również nie stwierdzono zmian charakterystycznych dla procesu chorobowego, takich jak np. zanik szpary stawowej, nadżerki etc. Wykazano, że szerokość szpary stawowej maleje z wiekiem. Wyniki potwierdzono też, analizując histogramy i trójwymiarowe łuminancje obrazu okolicy szpary stawowej stawu międzypaliczkowego bliższego II, III i IV palca lewej i prawej dłoni. Wyniki te powinny być brane pod uwagę przy diagnostyce obrazowej w reumatoidalnym zapaleniu stawów międzypaliczkowych.

EN

The width of interphalangeal joints was analyzed in the hands of 9 healthy volunteers, 7 females in age 23-70 years, and 3 males 22 and 72 years old. The mean age in women was 43 š18,3, and in men 47 š35,4. None of examined persons suffered from rheumatoid arthritis. No changes were observed on X-ray images, as well. It was stated that the width of interphalangeal joints is smaller for older subjects. These results are confirmed by analysis of 3-D luminance and histograms of the X-ray images of proximal interphalangeal joints of II, III, and IV finger. The results should be taken into account when diagnosing the rheumatoid arthritis basing on joints images.

5

Artificial intelligence methods in shape feature analysis of selected organs in medical images

67%

Ogiela M. , Tadeusiewicz R.

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2000

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tom Vol. 6, no 1-2

3-11

EN

The goal of this paper is a presentation of the possibilities of the application of syntactic methods of computer image analysis to the recognition of the local stenoses of the lumen of coronary arteries, and to the detection of pathological signs in upper parts of ureter ducts and renal calyxes. An analysis of the correct morphology of these structures is possible thanks to the application of sequence and tree methods from the group of syntactic methods of pattern recognition. In the case of the analysis of coronary artery images, the main objective is a computer-aided early diagnosis of the different forms of cardiac ischemic diseases. Such diseases may show themselves in the form of stable or unstable disturbances of heart rhythm or infarction. In the analysis of kidney radiograms the main goal is the recognition of local irregularities in ureter lumens, and an examination of the morphology of renal pelvis and calyxes.