Bozidar Radenkovic

Effect of hydrostatic pressure on fluorescence lifetime for 0-0 line (5D0 → 7F0 transition) in SrFCl : Sm2+

Abstract The lifetime τ of fluorescence 0-0 line, 5 D 0 → 7 F 0 , in SrFCl:Sm 2+ has been measured under high pressure up 10 GPa. This study shows that τ decreases exponentially with pressure and can be expressed by exponential regression τ (s) = 0.1853 + 1.1923 exp(−0.1366P) (GPa).

The effect of pressure on the position and fluorescence lifetime for the transition in

The aim of this study was to assess the effect of pressure on the position and fluorescence lifetime for the transition in within the 0 - 104 kbar range. The relationship between the pressure and the line position is given by linear regression: (kbar). The change of the fluorescence lifetime for the transition with pressure can be expressed by an exponential decay: .

Application of Data Mining for Supply Chain Inventory Forecasting

This paper deals with data mining applications for the supply chain inventory management. It describes the use of business intelligence (BI) tools, coupled with data warehouse to employ data mining technology to provide accurate and up-to-date information for better inventory management decisions. The methodology is designed to provide out-of-stock forecasts at the store/product level. The first phase of the modelling process consists of clustering stores in the supply chain based upon aggregate sales patterns. After quality store-cluster models have been constructed, these clusters are used to more accurately make out-of-stock predictions at the store/product level using the decision trees and neural network mining algorithms. The methods for evaluation and accuracy measurement are described. Also, the specialized front-end BI web portal that offers integrated reporting, web analytics, personalization, customization and collaboration is described.

High pressure and lifetime of the 2E level in ruby

The influence of high pressure (0-200 kbar) on the lifetime τ of 2E metastable level of Cr3+ ion ruby is considered. The essentials of the pressure dependence of τ can be understood by assuming a change of oscillator strength, coordination number and effective charge of the Cr3+ ion under pressure. On the basis of these concepts the calculated results for τ are found in good agreement with experimental data up to 120 kbar.

Theoretical consideration of the pressure induced changing of fluorescence lifetime for Sm2+ 0-0 line (5D0 → 7F0 transition) in SrFCl

Abstract The effect of high pressure on the lifetime τ of fluorescence 0-0 line, 5 D 0 → 7 F 0 , in SrFCl : Sm2+ was theoretically considered up to 100 Kbar. The simple model describes the effect of pressure on τ. The starting points were the assumptions that the high pressure can cause the change of τ through a great influence on the energy of 5 D 0 → 7 F 0 transition, refractive index of crystal n and greatest inter-ionic separation R between the Sm2+ ion and surrounding ligand (Cl−). Calculated pressure-induced change of lifetime τ is in good agreement with the experimental data.

High-pressure optical studies of Y2O3:Eu3+ nanoparticles

Abstract The fluorescence spectra of Y2O3:Eu3+ nanoparticles have been measured under the pressure of up to 78 kbar at room temperature. In this pressure range, a red-shift of 0.02(1) nm/kbar−1 is noticed for the 0–2 line (5D0→7F2 transition). This shift is explained by the change of negative charge of the surrounding ligands. Compatibility between measured and calculated values for the 0–2 line position was obtained. The luminescence decay curves of the 5D0→7F2 transition were studied up to 78 kbar and were found to behave exponentially for all pressures studied. The fluorescence lifetime τ for the 0–2 line (5D0→7F2 transition) slowly decreased with pressure. The pressure effect on τ for the 0–2 line (5D0→7F2 transition) was explained by a model which considers the pressure effect on the line position, inter-ionic distance, ion volume and polarizability, molecular volume and polarizability, molecular refractive index and the refractive index medium n med of the surrounding hydrostatic medium. The fluorescence lifetime calculated by the present model is in close correspondence with the experimental values.

Providing services for student relationship management on cloud computing infrastructure

This paper presents an approach for providing student relationship management services on cloud computing infrastructure. Main goal of the paper is to design reliable, comprehensive and cost effective infrastructure that enhances realization of educational and collaboration processes. Model of student relationship management based on cloud computing infrastructure is described in details. As a proof of concept, the model was implemented in the e-learning system of E-business Lab, at Faculty of organizational sciences, University of Belgrade. Results show that the implemented model contributes to better collaboration and communication between students and educational institution and increases performances of the educational process, as well.

E-Business in the Regulation of Medicines in Serbia

This article describes the application of electronic business (e-business) in the regulation of medicines in Serbia, as one of the e-government services of Serbia. In addition to the development of the information society of Serbia, the article puts forward a methodological framework for the development of e-services, through the use of rational unified process methodology. The unified modeling language notation was used for the description of the system model. The article presents modeling of the process of marketing of medicines. The analysis of the marketing of medicines in Serbia was carried out from 2004 through 2007 by the Medicines and Medical Devices Agency of Serbia (the Agency for Medicines). We present the results of performance analysis of the development of e-business in the regulations concerning medicines, conducted by the Agency for Medicines in April 2007 and March 2008. The findings identify e-business as of particular significance in medicine regulation in Serbia.

An approach for specification of knowledge-based simulation models in the Web environment

We discuss basic concepts of a methodology for object-oriented specification of discrete-event simulation models in the World Wide Web (WWW) environment. As a specification tool the Java expert system shell (JESS) is proposed, which supports rule-based systems and can be tightly coupled with code written in the Java language. For performing simulation, a modified three-phase simulation strategy is used. The proposed methodology is explained using the example of a telephone switchboard.

Red fluorescence spectra as a new means of determining the rate of damage to photosynthesis apparatus in plants caused by stress

A new method is presented for determining the rate of damage to photosynthesis apparatus efficiency ε caused by stress using the red fluorescence spectra of plant leaves. A direct connection was found between the position of the red fluorescence maximum νmax and the photosynthesis apparatus efficiency ε. The method was tested on several examples and good results were obtained.