662 research outputs found
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No full textPoznańIn this paper, using the general master equation in the dipole interaction and the rotating-wave approximation, we will explain the experimental results obtained by Warsaw Group for Electromagnetically Induced Transparency in four-level lambda scheme of cold rubidium atoms. The theoretical calculations are in good agreement with the experimental data
No full textPoznańThe article presents the current state-of-the-art of the European HPC ecosystem design and implementation. It covers the benefits for all ecosystem stakeholders: scientific end-users, operational staff, architecture vendors, owners of the computational facilities. The PRACE – Partnership for Advanced Computing In Europe initiative has started the preparation of the background towards the legal form of the related activities. It benefits in the creation of the PRACE non-profit association AISBL, registered in Brussels. During the implementation phase of PRACE, the scientific community has been given free and transparent access to the world-class supercomputing systems in Europe. Polish scientists and researchers may apply for the computational cycles
No full textPoznańIt is no exaggeration to say that the PN-IEC 61124 standard is inapplicable in many branches e.g. electronic industry. It is because PN-IEC 61124 assumes failure rate to be constant in time. This paper rejects this assumption and presents mathematical foundation of an alternative of PN-IEC 61124 applicable in electronic industry
No full textPoznańThis paper presents the popular backup/archival service developed and operated in Poland by members of the PIONIER network consortium and its example application for outsourcing of the archival of the network traffic in the national academic network. The service is built upon the National Data Storage (NDS) system architecture deployed in the redundant, high-end, geographically distributed infrastructure of servers, network and data storage systems built within the confines of the PLATON project. The details of the NDS architecture and its features are discussed in the paper including the system components, their functionality and the system scalability aspects. The paper also presents how the NDS architecture is deployed in the data storage infrastructure of the PLATON project, with an extensive usage of servers and storage virtualization technologies. We discuss how the NDS system instantiation allows for flexible set up of the multiple instances of the popular backup/archival service, which can address various, often contradictory requirements of the service users, while sharing a common pool of physical resources. As an example the system set up for outsourcing the archival of the PIONIER network traffic is presented
No full textPoznańIn March 2010 the Digital Library of the Wielkopolska Region, the largest and one of the oldest Polish digital librariesreached the level of 100 000 objects available on-line. Since its inauguration in 2002, the dynamics of the development of Polish digital libraries has increased significantly. The common effort of several hundreds of scientific and cultural institutions in Poland led to the present situation in which there are over 50 publicly available digital libraries and together they give access to around 425 000 digital objects. Such a big number of similar network services lead to the need of integration mechanisms allowing to achieve a synergy effect perceptible for end users as well as for digital library creators and international digital library initiatives. Suchmechanism developed by PSNC and named PIONIER Network Digital Libraries Federation, has been available as a network servicesince June 22-nd, 2007 and can be reached at http://fbc.pionier.net.pl/. This paper shortly presents the history of development ofPolish digital libraries, showing the factors that have influenced the initial form and advancement of the Federation. It also describesthe Federation architecture, organizational aspects of its operation, and key challenges including the integration of Polish and European digital libraries infrastructures
No full textPoznańIn the initial part of the paper, the principles of the electromagnetically induced transparency (EIT) in basic three-level schemes are sketched, and some applications of this phenomenon are described. Next a presentation follows of a five-level EIT model of Bloch equations, which was developed to reconstruct multipeak cascade-EIT spectra registered in a sample of cold 85Rb atoms in MOT. The respective experiment is also described. The achieved good agreement between theory and performed experiment is documented and discussed
No full textPoznańIn is paper we present the set of dynamical equations of the Raman laser. The semi-classical theory in three-dimensional approach is of interest. The operating regime of the Stokes laser is investigated in some cases of the pumping rate
