Elena Koleva

Model-based approach for the shape estimation of electron beam welding joints

This article discusses a modeling approach for the obtained by electron beam welding molten pool shapes, which is based on experimental data, type mathematical function and regression analysis. The process of electron beam multi-pool ...  read more

Model-driven development of event management system

Electron Beam Technologies Conference is an international conference, which originated in 1985. The challenge for the management of this event, as well as the numerous such events that are organized every year around the world, is to ...  read more

Analysis of the ergonomic quality of e-learning through statistical methods

A key factor in e-learning in the future will be a quality orientation that firstly places learners or users of education services. They have to take the lead in terms of quality concepts of e-learning, since their professional competence ...  read more

Neural network based approach for quality improvement of electron beam welding

Neural network models for the dependence of the geometry characteristics of welds from 38Cr2Ni2Mo high-strength steel, obtained at electron beam welding in presence of longitudinal beam deflection oscillations, are estimated. This methodology ...  read more

Analysis and Generalization of Scientific and Educational Information Book in the Field of Nano-Electronics

In this paper analysis and generalization of the scientific and educational properties of information textbooks on nano-electronics, created from the scientists of the Institute of Electronics at Bulgarian Academy of Sciences, the Power ...  read more

Study of Electron Beam Resists: Negative Tone HSQ and Positive Tone SML300

In this paper the contrast and sensitivity characteristics are investigated concerning the negative tone electron beam resist HSQ (hydrogen silsesquioxane) and the positive tone SML300 electron beam organic resist, designed for a high-aspect ...  read more

Optical and Structural Investigations of WOx Thin Films Deposited by Electron Beam Evaporation Process

Thin films of tungsten oxide are obtained at different technological parameters using electron beam evaporation process. Their optical and structure properties are investigated and the relation with process parameters is discussed. ...  read more

Model-Based Quality Optimization of EBW of steel

Experimental results (four series of experiments) for EBW of two types of steel – high strength steel of 38Cr2Ni2Mo type and stainless steel are obtained and used for the estimation of models, describing the dependencies of the ...  read more

Electron Beam Characterization at Changes of EBW Process Parameters

The characterization of the radial and the angular space distribution of particle trajectories (or respective current distributions) in powerful electron beams is an actual scientific and practical task, connected with the quality improvement ...  read more

Control of Electron Beam Welding of Plates, Using Current of the Back Plate Side

The conventional systems for control of throughout welds used beam current, that is passing through the crater in the liquid metal to the space on the back side of sample. In this paper a collector, situated not opposite the crater ...  read more