14 research outputs found
Application of open multi-commodity market data model on the communication bandwidth market, Journal of Telecommunications and Information Technology, 2007, nr 4
In the paper the market model for balancing communication bandwidth trade (BCBT) is analyzed in the form of multi-commodity market data model (M3). The distinguishing feature of BCBT model is that it assumes that market players can place buy offers not only for isolated network resources – inter-node links, but also for end-to-end network paths of predefined capacity, that is, every offer concerns a point-to-point bandwidth connection between a pair of specified locations in a communication network. The model enables effective balancing of sell and buy offers for network resources in a way which maximizes global economic welfare. The open multi-commodity market data model provides efficient and clear mechanisms, which support the environment of auctions and multi-commodity exchanges, especially when the trade is constrained by the infrastructure resources. Thus the model may be used in designing open information systems for market balancing and clearing in the context of multicommodity trade in various network infrastructure sectors
Simulating NEMA characteristics of the modular total-body J-PET scanner -- an economic total-body PET from plastic scintillators
The purpose of the presented research is estimation of the performance
characteristics of the economic Total-Body Jagiellonian-PET system (TB-J-PET)
constructed from plastic scintillators. The characteristics are estimated
according to the NEMA NU-2-2018 standards utilizing the GATE package. The
simulated detector consists of 24 modules, each built out of 32 plastic
scintillator strips (each with cross section of 6 mm times 30 mm and length of
140 cm or 200 cm) arranged in two layers in regular 24-sided polygon
circumscribing a circle with the diameter of 78.6 cm. For the TB-J-PET with an
axial field-of-view (AFOV) of 200 cm, a spatial resolutions of 3.7 mm
(transversal) and 4.9 mm (axial) are achieved. The NECR peak of 630 kcps is
expected at 30 kBq/cc activity concentration and the sensitivity at the center
amounts to 38 cps/kBq. The SF is estimated to 36.2 %. The values of SF and
spatial resolution are comparable to those obtained for the state-of-the-art
clinical PET scanners and the first total-body tomographs: uExplorer and
PennPET. With respect to the standard PET systems with AFOV in the range from
16 cm to 26 cm, the TB-J-PET is characterized by an increase in NECR
approximately by factor of 4 and by the increase of the whole-body sensitivity
by factor of 12.6 to 38. The TOF resolution for the TB-J-PET is expected to be
at the level of CRT=240 ps (FWHM). For the TB-J-PET with an axial field-of-view
(AFOV) of 140 cm, an image quality of the reconstructed images of a NEMA IEC
phantom was presented with a contrast recovery coefficient (CRC) and a
background variability parameters. The increase of the whole-body sensitivity
and NECR estimated for the TB-J-PET with respect to current commercial PET
systems makes the TB-J-PET a promising cost-effective solution for the broad
clinical applications of total-body PET scanners.Comment: 31 pages, 11 figures, 6 tables, submitted to Physics in Medicine and
Biology 202
Transformation of PET raw data into images for event classification using convolutional neural networks
In positron emission tomography (PET) studies, convolutional neural networks (CNNs) may be applied directly to the reconstructed distribution of radioactive tracers injected into the patient's body, as a pattern recognition tool. Nonetheless, unprocessed PET coincidence data exist in tabular format. This paper develops the transformation of tabular data into
-dimensional matrices, as a preparation stage for classification based on CNNs. This method explicitly introduces a nonlinear transformation at the feature engineering stage and then uses principal component analysis to create the images. We apply the proposed methodology to the classification of simulated PET coincidence events originating from NEMA IEC and anthropomorphic XCAT phantom. Comparative studies of neural network architectures, including multilayer perceptron and convolutional networks, were conducted. The developed method increased the initial number of features from 6 to 209 and gave the best precision results (79.8) for all tested neural network architectures; it also showed the smallest decrease when changing the test data to another phantom
Possibilities of Utilization the Risk – Based Techniques in the Field of Offshore Wind Power Plants
In the article the risk-based concept that may be applicable to offshore wind power plants has been presented. The aim of the concept is to aid designers in the early design and retrofit phases of the project in case of lack or insufficient information in relevant international standards. Moreover the initial classification of components within main system parts of offshore wind power plant has been performed. Such classification is essential in order to apply risk-based concept. However further scientific researches need to be performed in that field to develop detailed concept useful for future practical applications
Human Alveolar Echinococcosis in Poland: 1990–2011
<div><h3>Background</h3><p>Alveolar echinococcosis (AE) caused by <em>Echinococcus multilocularis</em> infections is a dangerous old disease in the Northern Hemisphere. The aim of the paper was to collect and analyze data on human AE in Poland in the last two decades.</p> <h3>Methodology/Principal Findings</h3><p>The sources of data were both the cases officially registered and detected by an active field and laboratory surveillance. The cases were verified by clinical, epidemiological, and laboratory criteria. Altogether 121 human cases of AE were detected. Among these 83 (68,6%) cases were classified as confirmed, 16 as probable and 22 as possible. During the two decades a continuous increase in detection rate was noticed. The cases were 6–82 years old at the time of diagnosis (mean - 47.7 years). Sex ratio M/F was 0.86/1.0. The AE was fatal in 23 (19%) patients (mean age at death - 54.1 years). Family agglomeration of AE was found in 4 foci, involving 9 patients. Seventy six of the cases were diagnosed in an advanced stage of disease. In all cases the liver was the primary location of AE. In 30 (24.8%) patients a spread to other organs was observed. Ninety four of the patients were treated with albendazole. In 73 (60%) patients a surgical operation was performed, including 15 liver transplantations.</p> <h3>Conclusions/Significance</h3><p>The studies confirmed that AE is an emerging disease in Poland, which is the fourth country in Europe with over 120 cases detected. The results also indicate the need of a wider national programme for implementation of screening in the highest AE risk areas (north-eastern Poland) with an effort to increase the public awareness of the possibility of contracting <em>E. multilocularis</em>, and above all, training of the primary care physicians in the recognition of the risk of AE to allow for an early detection of this dangerous disease.</p> </div
Geographical distribution of human AE cases in Poland.
<p><b>A – Number of AE cases in each province.</b> Localizations of three patients could not be determined. A – Pomorskie Province; B – Varmia-Masuria Province; C- Podlaskie Province. <b>B – Distribution of 65 AE cases in the Varmia - Masuria Province.</b> Global area amounts to 24 173 km<sup>2</sup>, and population 1 426 155 (2008). a – Elbląski district; b – Lidzbarski district; c – Kętrzyński district; d – Węgorzewski district; e – Iławski district.</p
Age of 117 patients in the year of AE diagnosis and death of 21 persons.
<p>Age of 117 patients in the year of AE diagnosis and death of 21 persons.</p
Human AE cases in Poland diagnosed in 5-year interval.
<p>Human AE cases in Poland diagnosed in 5-year interval.</p