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Open access

Tomáš Huszaník, Ján Turán and Ľuboš Ovseník

Abstract

Optical fiber has the great advantages of capacity and reliability. That is why network providers started to deploy FTTx (Fiber-To-The-x) optical access using various PON (Passive Optical Network) architectures. The leading technology right now is Gigabit PON (GPON). However, with increasing amount of multimedia we need to further develop existing technologies to go on with these high demands. Fiber-To-The-Home (FTTH) using 10G-PON technology for broadband access application is effective solution for high speed networks with high capacity. In this paper, we look at the passive optical network in the city of Košice and based on the real network we created simulation model of downlink of 10G-PON based FTTH with triple-play service.

Open access

Daniel Vamos, Stefan Oniga and Anca Alexan

Abstract

Personal activity tracker are nowadays part of our lives. They silently monitor our movements and can provide valuable information and even important alerts. But usually the user’s data is stored only on the activity tracker device and the processing done is limited by this modest processing power device. Thus it is very important that the user’s data can be stored and processed in the cloud, making the activity tracker an IOT node. This paper proposes a simple IOT gateway solution for a custom user monitoring device.

Open access

Victor D. N. Santos, Manuel Cerveira and Fernando Moita

Abstract

This paper presents a new electronic controller, devoted to solar water heating systems, that implements safety functions to prevent L. pneumophila bacteria outbreaks. The controller uses data retrieved from strategically located probes in order to implement the proposed safety actions. The electronic solution was integrated and validated on a solar system prototype bench that uses real equipment such as collectors, a water storage tank and expansion vessels. Moreover, two particular solar water heating installations were designed devoted to a house family and a nursing home both located on the Mealhada area. The methodology and reported technical solutions in this research could be a practical guide to promote mass market usage of the solar water heating systems in Portugal.

Open access

Jakub Oravec, Ján Turán and Ľuboš Ovseník

Abstract

This paper proposes an image encryption algorithm which uses four scans of an image during the diffusion stage in order to achieve total diffusion between intensities of image pixels. The condition of total diffusion is fulfilled by a suitable combination of techniques of ciphertext chaining and plaintext related diffusion. The proposed encryption algorithm uses two stages which utilize chaotic logistic map for generation of pseudo-random sequences. The paper also briefly analyzes approaches described by other researchers and evaluates experimental results of the proposed solution by means of commonly used measures. Properties of our proposal regarding modifications of plain images prior to encryption or modifications of encrypted images prior to decryption are illustrated by two additional experiments. The obtained numeric results are compared with those achieved by other proposals and briefly discussed.

Open access

Md. Jamil Uddin, Hadaate Ullah and Mohammad Arif Sobhan Bhuiyan

Abstract

The bandpass filter is one of the essential blocks of every modern RF transceiver. Performance of the transceiver greatly depends on the performance of the bandpass filter. A bandpass filter designed with passive inductors suffers from some drawbacks like large chip size, low-quality factor, less tenability etc. To prevail over these constraints, an active inductor-based bandpass filter circuit has been designed in GPDK-90nm CMOS technology utilizing cadence virtuoso environment. The simulation result shows that the active inductor-based bandpass filter circuit design achieves a gain of 6.79dB, a bandwidth of 5.05 GHz and a noise figure of 3.10dB. The circuit dissipates only 3.55mW power for its operation from a single 1.5V DC supply. By avoiding bulky inductor in the design helped to attain a very small chip area of 127.704μm2.

Open access

Michal Márton, Ľuboš Ovseník, Ján Turán and Michal Špes

Abstract

Communication technologies are growing for day to day because demand on data sharing is unstoppable. Users require availability of approach to network at all time. Implementation of smart technologies allows communication of all type of devices. Capacity of data flow have to grow. Video formats HD or 4K require transmit on high data speed. Based on the demands many types of different communication systems which are suitable for these speeds were designed. One of these systems is FSO (Free Space Optics). FSO system is based on transmission of optical beams which carry the information. This system allow high data speed comparable with standard optical fiber in range to 10km. One of drawbacks of this system is LOS (Light of Sight) between communication points. The other drawback is sensitivity to weather changes. Optical beams interfere with water particles and cause attenuation on transmission path. The solution is in implementation using hybrid FSO/RF system which combines optical communication system with RF (Radio Frequency) backup link. We realized FSO communication link on Technical University of Košice. Our research is focused on design of appropriate type of antenna for our RF backup link. Our results in this area were published.

Open access

Béla-Csaba Simon, Stefan Oniga and Iuliu Alexandru Pap

Abstract

This paper presents an Open Platform Activity and health monitoring systems which are also called e-Health systems. These systems measure and store parameters that reflect changes in the human body. Due to continuous monitoring (e.g. in rest state and in physical effort state), a specialist can learn about the individual's physiological parameters. Because the human body is a complex system, the examiner can notice some changes within the body by looking at the physiological parameters. Six different sensors ensure us that the patient's individual parameters are monitored. The main components of the device are: A Raspberry Pi 3 small single-board computer, an e-Health Sensor Platform by Cooking-Hacks, a Raspberry Pi to Arduino Shields Connection Bridge and a 7-inch Raspberry Pi 3 touch screen. The processing unit is the Raspberry Pi 3 board. The Raspbian operating system runs on the Raspberry Pi 3, which provides a solid base for the software. Every examination can be controlled by the touch screen. The measurements can be started with the graphical interface by pressing a button and every measured result can be represented on the GUI’s label or on the graph. The results of every examination can be stored in a database. From that database the specialist can retrieve every personalized data.

Open access

Acta Universitatis Sapientiae, Electrical and Mechanical Engineering

The Journal of Sapientia Hungarian University of Transylvania

Open access

Zsolt Horváth and András Edelmayer

Abstract

The objective of this paper is solving of the Modified Filter Algebraic Riccati Equation (MFARE) for calculating of the filter gain. The results are used for model-based fault detection filtering of faults in the air path of diesel engines. The Hinfinity optimization approach requires the solution of a linear-quadratic optimization problem that leads to the solution of MFARE. In our paper two basic concepts for solving MFARE are examined, namely the analytically implemented gamma-iteration and casting the problem as a convex optimization problem based on Linear Matrix Inequalities (LMIs).

The algorithms are implemented in MATLAB. Each algorithm has to ensure the condition for a global convergence and also has to deliver an optimal solution. Not at least, the computational cost has to be as small as possible.

Open access

Albert-Zsombor Fekete, András Kelemen and László Jakab-Farkas

Abstract

The paper presents in detail a unique multilevel control architecture designed for the comprehensive management of the DC magnetron sputtering process and of all subsystems of the sputtering equipment. The ultimate goal is to increase the repeatability, stability and the controllability of the complex process. The presented topics include embedded and distributed electronics, data acquisition and supervisory control, networking, data management, redundant local and remote data-archiving. There are presented platform independent algorithms managing the data exchange between computational devices, and conclusions are drawn regarding the efficiency of the various algorithms used.