https://etalpykla.vilniustech.lt/handle/123456789/159392 2026-04-11T21:29:25Z https://etalpykla.vilniustech.lt/handle/123456789/159528 Comparison of Multi-Layer Perceptron and Cascade Feed-Forward Neural Network for Head-Related Transfer Function Interpolation Tamulionis, Mantas; Serackis, Artūras Acoustic Virtual Reality (AVR) is a popular field of today's research, and the technologies it explores allow users to experience the virtual reality even more interactively, creating a sense of being truly involved into a virtual acoustic field. Auralization is one of the most interesting and useful AVR techniques. This procedure makes it possible to simulate how sound waves will behave in a particular environment, including how the listener will perceive it. This is achieved by taking into account Head-related transfer function (HRTF), which is essential for creating the main auralization product - Binaural Room Impulse Response (BRIR). It is common to use pre-recorded HRTF databases, but the required HRTF value can also be modeled using Artificial Neural networks (ANN). This article presents an investigation on ANN application for HRTF interpolation from discrete measured functions. Two types of neural networks are investigated: a Multi-Layer Perceptron and a Cascade Feed-Forward Network. Experimental investigation has shown that additional feed of inputs to the hidden layer in cascade network does not improve the interpolation performance. The best results were received using Multi-Layer Perceptron having two hidden layers with 32 and 16 neurons respectively. 2019-01-01T00:00:00Z https://etalpykla.vilniustech.lt/handle/123456789/159527 Modelling of Six-phase Electric Drive with Fuzzy Controller Rinkevičienė, Roma; Mitkienė, Bronė; Udris, Dainius The paper presents MATLAB Simulink model of symmetrical six-phase motor drive controlled by the six- phase frequency converter and analyses its performance at indirect rotor flux field oriented control mode. The new control blocks not entering the Simulink library, were elaborated for control six-phase motor. Simulink model of the motor was elaborated with the actual parameters of real six-phase motor having displacement of phase windings sets 60 electrical degrees. The model of the field oriented control for six-phase motor with Fuzzy controllers is elaborated and simulation results are presented and analysed. Step response of controlled system has shorter settling time, less torque oscillations, system does not lose its benefits at small reference speed. The response of followup system to ramp input, sine wave input, trapezoidal shape input, were simulated and analysed. 2019-01-01T00:00:00Z https://etalpykla.vilniustech.lt/handle/123456789/159526 Estimation of Sound Source Direction of Arrival Map Using Convolutional Neural Network and Cross-Correlation in Frequency Bands Sakavičius, Saulius; Serackis, Artūras In this paper, we present an evaluation of the usage of a convolutional neural network (CNN) for the estimation of the sound source direction of arrival (DoA) map. Cross-correlations in different frequency bands, calculated for pairs of microphones were used as input features. We propose a technique for generating data for the CNN training, a means of presenting the direction of arrival information for an arbitrary number of sound sources and a viable CNN architecture. In our proposed approach for sound DoA estimation, there is no need for prior knowledge of the number of the active sound sources nor the properties of their signals. We present the results of the evaluation of the two distinct CNN architectures. 2019-01-01T00:00:00Z https://etalpykla.vilniustech.lt/handle/123456789/159525 Why SIEM is Irreplaceable in a Secure IT Environment? Podzins, Oskars; Romanovs, Andrejs The aim of the publication is to brief on the importance of a SIEM (Security Information and Event Management) solution. Its benefits but also taking time to reflect on this system drawbacks. All of which is intended for those who are looking into cybersecurity solution that will learn from entire IT infrastructure and be able to identify anomalies, like cyberattacks. Depending on the region and market, enterprise priorities tends to be different, but all mainly take into consideration TCO (Total Cost of Ownership), which in SIEM case is a key metric. If company/organization is serious about deploying a SIEM, then another key security technology they should think about is SOC. If deployed correctly than SOC (Security Operations Centre) is a full framework of technologies, people and processes to act like a well-oiled machine that identifies, protects, detects, responds and recovers from all security related incidents. 2019-01-01T00:00:00Z