Modelling of the Knitting Process during the Knitting-in of Elastomeric Threads Using Knitting Machines with Relanit and Classic Knitting Zone

An analysis of the knitting process during the knitting-in of elastomeric threads using knitting machines with a Relanit and classic knitting zone was made on the basis of simulations considering a numerical model which takes into account the most important parameters of the knitting process, viscoelastic properties of the thread and geometrical parameters of the knitting zone. The conditions of forming stitches from classic cotton yarn were presented for comparison. The results of the simulation tests were verified experimentally on a computer-aided knitting machine with a classic knitting zone

Architektura gridu bazodanowego oparta o podejście peer-to-peer

W artykule autorzy przedstawiają zaimplementowane i zweryfikowane poprzez w pełni funkcjonalny prototyp, podejście do realizacji obiektowego gridu bazodanowego przy wykorzystaniu wirtualnej sieci peer-to-peer omawiając szczegółowo najważniejszy element mechanizmu jakim jest proces integracji rozproszonych obiektów. W artykule przeprowadzono gruntowną analizę rozwiązań będących fundamentalnym zbiorem wiedzy na temat integracji danych. Zaprezentowano trójwarstwowy model intagracyjny oparty o aktualizowalne obiektowe perspektywy oraz prototyp gridowej warstwy pośredniej wykorzystującej sieć wirtualną peer-to-peer.In the article authors present an approach for realisation of object-oriented database grid using virtual peer-to-peer networking. The approach has been verified by implementation of fully functional prototype. The article shows in details a process for integration of distributed objects which is provided by the core mechanism of the prototype. Authors also described three-layer integration model based on obiect-oriented updateable views and middleware prototype containing mentioned peer-to-peer solution. Moreover the article contains analysis of solutions being the fundamental knowledge about integration of data

Przezroczysta integracja zasobów relacyjnych do obiektowego wirtualnego repozytorium

Prezentowana w artykule idea polega na wirtualnej integracji rozproszonych heterogenicznych zasobów bazodanowych w scentralizowaną, jednorodną, spójną i pozbawioną fragmentacji oraz nadmiarowości całość tworzącą wirtualne repozytorium zapewniające pewne powszechne funkcjonalności i usługi, włączając w to infrastrukturę zaufania (bezpieczeństwo, prywatność, licencjonowanie, płatności, itp.), Web Services, rozproszone transakcje, zarządzanie procesami (workflow management), itd. Opisane poniżej metody integracji skupiają się właśnie na najpopularniejszych zasobach relacyjnych, do których zostaje umożliwiony w pełni przezroczysty dostęp poprzez niezwykle elastyczny obiektowy język zapytań. Opracowane specjalnie do tego celu mechanizmy optymalizacyjne stanowią kombinację dedykowanych technik obiektowych z niezwykle wydajnymi optymalizatorami relacyjnymi.The presented idea aims to virtually integrate distributed heterogeneous database resources into a centralised consistent and non-fragmented and non-redundant whole creating a virtual repository. The repository provides common functionalities and services, including trust infrastructure (like security, privacy, licensing, payments), Web Services, distributed transactions, workflow management, etc. The described integration methods focus on the most popular and commonly used relational resources. Such resources become fully transparently accessible with an extremely flexible object-oriented query language. The dedicated optimisation mechanisms are a combination of object-oriented techniąues and very efficient relational optimisers

On distributed data processing in data grid architecture for a virtual repository

The article describes the problem of integration of distributed, heterogeneous and fragmented collections of data with application of the virtual repository and the data grid concept. The technology involves: wrappers enveloping external resources, a virtual network (based on the peer-topeer technology) responsible for integration of data into one global schema and a distributed index for speeding-up data retrieval. Authors present a method for obtaining data from heterogeneously structured external databases and then a procedure of integration the data to one, commonly available, global schema. The core of the described solution is based on the Stack-Based Query Language (SBQL) and virtual updatable SBQL views. The system transport and indexing layer is based on the P2P architecture

3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm

Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines connecting two detectors. As there is a multitude of detectors build-in typical PET tomograph structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Decisive improvement in PET image quality was reached with the introduction of iterative reconstruction techniques. This stage was reached already twenty years ago (with the advent of new powerful computing processors). However, three dimensional (3D) imaging remains still a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines-of-responce (LOR) and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.Comment: 10 pages, 7 figure

Studies of discrete symmetries in decays of positronium atoms

A positronium - a bound state of electron and positron - is an eigenstate of parity and charge conjugation operators which decays into photons. It is a unique laboratory to study discrete symmetries whose precision is limited, in principle, by the effects due to the weak interactions expected at the level of 10−14 and photon-photon interactions expected at the level of 10−9. The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging as well as for physics studies involving detection of electronpositron annihilation into photons. The physics case covers the areas of discrete symmetries studies and genuine multipartite entanglement. The J-PET detector has high angular and time resolution and allows for determination of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for studies of discrete symmetries in decays of positronium atoms

Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillator, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.Comment: 7 pages, 4 figure