Construction of compact step down voltage converter in terms of EMC

At the present there is a wide variety of step down converters on market. Due to differences in converter's prices, parameters and principles of function, it is not that easy to choose a proper one suitable for a concrete application. Moreover, really strict standards are applied in order to achieve high EMC compatibility between different devices. This article tries to show the possibilities of a really low-end DC/DC converter controller AOZ 1284. The set of measurements according to the set specifications and standard EN 61000-6-3 are presented together. Moreover, measures needed to comply to limits of the standard are shown along with it's results. © 2016 The Authors, published by EDP Sciences.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; Internal Grant Agency at TBU in Zlin [IGA/FAI/2016/036

Remote controlled gate controller using a GSM network and Arduino platform

Most remote controllers for entrance gates operate on free frequencies 433 or 868 MHz. However, this technology limits the user comfort, as it is usually not common that bi-directional communication is established. A higher comfort of controlling the entrance gates can be achieved by employing the GSM network for transmission of commands and messages between the gate controller and the user. In this case, only a conventional GSM cellular phone is needed to control the gate. A description of such a controller based on the GSM module and Arduino controller is provided in this paper.Ministry of Education, Youth and Sports of the Czech Republic within The National Sustainability Programme Project [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

Comparison of tracking algorithms implemented in OpenCV

Computer vision is very progressive and modern part of computer science. From scientific point of view, theoretical aspects of computer vision algorithms prevail in many papers and publications. The underlying theory is really important, but on the other hand, the final implementation of an algorithm significantly affects its performance and robustness. For this reason, this paper tries to compare real implementation of tracking algorithms (one part of computer vision problem), which can be found in the very popular library OpenCV. Moreover, the possibilities of optimizations are discussed.Technology Agency of the Czech Republic (TA CR) within the Visual Computing Competence Center - V3C project [TE01020415]; Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; Internal Grant Agency at TBU in Zlin [IGA/FAI/2016/036

Virtualization as a teaching tool for IT-based courses

Virtualization, VMware, VirtualBox, XEN, Virtual PC, VNC, NoMachine NX server, Paravirtualization, Operating systemsNowadays, the virtualization technologies are more and more often used in many informatics areas. They are applied for better utilization of existing hardware or software resources, servers? consolidation and for security reasons as well. This article shows the possibility of the virtualization technology usage also in the academic environment as a support of laboratory exercises of two academic courses. The case study is based on the idea of virtualization of the physical computer for lower costs and security reasons. The VMware products are used nowadays in our university and the article want to show other, especially free, alternatives to this commercial product like VirtualBox, Microsoft Virtual PC, XEN etc. Described approaches and techniques can be applied to many others similar subjects, not only in these two courses

Compact step down voltage converter constructed in terms of EMC

Designing of compact step down voltage converter must be provided according to the variety of standards and other requirements. Moreover, the constructed converter usually have to accomplish a set of opposite requirements defined by a target project or a target user (small size vs. high maximum level of provided current, etc.). Therefore the designing of converter could be really tricky. This paper tries to show the possibilities of a really low-end DC/DC converter based on controller AOZ 1284. Moreover, the constructed device is a subject for set of measurement. These measurements are performed in order to confirm that the device meet all requirements defined by standard EN 61000-6-3. All measurement results together with some necessary measures are presented at the end of this paper.MSMT-7778/2014, ERDF, European Regional Development Fun

Real-time fire detection in camera stream using statistical analysis

The paper describes a new algorithm designed to be fast and efficient for detecting fire. It is based on finding and investigating suspicious regions in each frame of video stream. The investigation consists of tracking regions across frames and performing statistical analysis on their trajectory. If the trajectory has characteristic similar to fire, a test on persistence is performed. If the fire-like characteristics persists, the alarm is triggered. This criterion enables to eliminate a large proportion of false alarms. Given it’s simplicity, the algorithm can be used separately in some environments and can improve existing algorithms as well. © 2017, World Scientific and Engineering Academy and Society. All rights reserved.CZ.1.05/2.1.00/03.0089, ERDF, European Regional Development Fund; MSMT-7778/2014, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchov

Comparison of integrated and composed step-down converter in terms of EMC

Stabilized voltage sources, even linear or working on a switching principle, are an integral part of almost all electronic devices. Hand in hand with the pressure of environmental protection, there comes an emphasis on reducing energy consumption, resulting in preference of switching solutions. On the other hand, considering the issues on electromagnetic compatibility, each switching-mode operated power source produces considerable amount of interferences. In the framework of the hereby described experiment, the authors of the paper tested several voltage sources operating on the switching principle. This paper provides a description of the experiment and the obtained results. © The Authors, published by EDP Sciences, 2017

Docker as platform for assignments evaluation

Programming courses are significant part of IT experts' education process. To being able to provide adequate teaching quality in such courses, lecturers should be exempted from routine tasks like source code compilation, testing and grading. Current computers are equipped with enough computational power to automat. These routine tasks. This paper discusse. The analysis and realization of such a system for user submitted automatic source code evaluation. The main system requirement wa. The safe runtime environment (sandbox) for executing potentially dangerous programs. Container based platform Docker was selected after research of ready to use sandbox technologies. This platform simplifies access to isolation mechanism which are implemented i. The current Linux kernel and provides API for system integration. The implemented system around Docker platform is named APAC (Automatic Programming Assignment Checker). I. The paper APAC's architecture and implementation are described and discussed. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article unde. The CC BY-NC-ND license

Detecting fire in video stream using statistical analysis

The real time fire detection in video stream is one of the most interesting problems in computer vision. In fact, in most cases it would be nice to have fire detection algorithm implemented in usual industrial cameras and/or to have possibility to replace standard industrial cameras with one implementing the fire detection algorithm. In this paper, we present new algorithm for detecting fire in video. The algorithm is based on tracking suspicious regions in time with statistical analysis of their trajectory. False alarms are minimized by combining multiple detection criteria: pixel brightness, trajectories of suspicious regions for evaluating characteristic fire flickering and persistence of alarm state in sequence of frames. The resulting implementation is fast and therefore can run on wide range of affordable hardware. © The Authors, published by EDP Sciences, 2017

Context sensitive fire protection system

This paper deals with design of context sensitive fire protection system, which should be able to detect and localize fir in industrial areas, especially in large factory halls. The "context sensitive" means that the system will be able to detec the fire, but also recognize the fire type and decide whether the detected fire is intended (as a part of standard productio process) or it is an accident. Moreover, a remote controlled master stream device is part of the designed system; therefore the system can directly start fire-fighting. The main feature of this system will be extremely low level of false positiv actions and minimal collateral damage to the environment surrounding the fire