AEEE. 2016, vol. 14

Permanent URI for this collectionhttp://hdl.handle.net/10084/111904

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Now showing 1 - 20 out of 75 results

Encapsulation of FBG sensor into the PDMS and its effect on spectral and temperature characteristics
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Nedoma, Jan; Fajkus, Marcel; Bednárek, Lukáš; Frnda, Jaroslav; Zavadil, Jan; Vašinek, Vladimír
Fiber Bragg Grating (FBG) is the most distributed type of fiber-optic sensors. FBGs are primarily sensitive to the effects of temperature and deformation. By employing different transformation techniques, it is possible to use FBG to monitor any physical quantity. To use them as parts of sensor applications, it is essential to encapsulate FBGs to achieve their maximum protection against external effects and damage. Another reason to encapsulate is increasing of sensitivity to the measured quantity. Polydimethylsiloxane (PDMS) encapsulation appears to be an interesting alternative due to convenient temperature and flexibility of the elastomer. This article describes an experimental proposal of FBG PDMS encapsulation process, also providing an analysis of the FBG spectral characteristics and temperature sensitivity, both influenced by high temperature and the process of polydimethylsiloxane curing itself. As for the PDMS type, Sylgard 184 was employed. Encapsulation consisted of several steps: allocation of FBG to PDMS in its liquid state, curing PDMS at the temperature of 80°C ± 5 %, and a 50-minute relaxation necessary to stabilize a Bragg wavelength. A broadband light source and an optical spectrum analyzer were both used to monitor the parameters during the processes of curing and relaxation. Presented results imply that such a method of encapsulation does not have any influence on the structure or functionality of the FBG. At the same time, a fourfold increase of temperature sensitivity was monitored when compared to a bare FBG.
Analysis of the applicability of singlemode optical fibers for measurement of deformation with distributed systems BOTDR
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Fajkus, Marcel; Nedoma, Jan; Bednárek, Lukáš; Frnda, Jaroslav; Vašinek, Vladimír
Distributed optical fiber sensors allow monitoring physical effects across the whole cable. The paper presents results obtained from the performed tests and shows that single mode fibers can provide analyses of the deformation changes, when distributed optical systems BOTDR used. We used standard optical fiber G.652.D with primary and secondary protected layers and specialized cable SMC-V4 designed for this purpose. The aim was to compare the deformation sensitivity and determine which fiber types are the best to use. We deformed the fiber in the longitudinal and transverse directions and mechanically stressed in orthogonal directions to find how to localize optical fibers. They could be deployed in real use. For achieving optimal results of mechanical changes and acting forces, sensor fibers have to be located carefully.
Impact of GoP on the video quality of VP9 compression standard for full HD resolution
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Uhrina, Miroslav; Bienik, Juraj; Vaculík, Martin
In the last years, the interest on multimedia services has significantly increased. This leads to requirements for quality assessment, especially in video domain. Compression together with the transmission link imperfection are two main factors that influence the quality. This paper deals with the assessment of the Group of Pictures (GoP) impact on the video quality of VP9 compression standard. The evaluation was done using selected objective and subjective methods for two types of Full HD sequences depending on content. These results are part of a new model that is still being created and will be used for predicting the video quality in networks based on IP.
Perceived quality of full HD video - subjective quality assessment
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Bienik, Juraj; Uhrina, Miroslav; Vaculík, Martin; Miždoš, Tomáš
In recent years, an interest in multimedia services has become a global trend and this trend is still rising. The video quality is a very significant part from the bundle of multimedia services, which leads to a requirement for quality assessment in the video domain. Video quality of a streamed video across IP networks is generally influenced by two factors “transmission link imperfection and efficiency of compression standards. This paper deals with subjective video quality assessment and the impact of the compression standards H.264, H.265 and VP9 on perceived video quality of these compression standards. The evaluation is done for four full HD sequences, the difference of scenes is in the content“ distinction is based on Spatial (SI) and Temporal (TI) Index of test sequences. Finally, experimental results follow up to 30% bitrate reducing of H.265 and VP9 compared with the reference H.264.
Implementation of Adaptive Unsharp Masking as a pre-filtering method for watermark detection and extraction
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Jane, Onur; Ilk, Hakki Gokhan
Digital watermarking has been one of the focal points of research interests in order to provide multimedia security in the last decade. Watermark data, belonging to the user, are embedded on an original work such as text, audio, image, and video and thus, product ownership can be proved. Various robust watermarking algorithms have been developed in order to extract/detect the watermark against such attacks. Although watermarking algorithms in the transform domain differ from others by different combinations of transform techniques, it is difficult to decide on an algorithm for a specific application. Therefore, instead of developing a new watermarking algorithm with different combinations of transform techniques, we propose a novel and effective watermark extraction and detection method by pre-filtering, namely Adaptive Unsharp Masking (AUM). In spite of the fact that Unsharp Masking (UM) based pre-filtering is used for watermark extraction/detection in the literature by causing the details of the watermarked image become more manifest, effectiveness of UM may decrease in some cases of attacks. In this study, AUM has been proposed for pre-filtering as a solution to the disadvantages of UM. Experimental results show that AUM performs better up to 11\% in objective quality metrics than that of the results when pre-filtering is not used. Moreover; AUM proposed for pre-filtering in the transform domain image watermarking is as effective as that of used in image enhancement and can be applied in an algorithm-independent way for pre-filtering in transform domain image watermarking.
The evaluation of light conditions influence and corrections upon Doppler blood perfusion imagining
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Bryjová, Iveta; Kubíček, Jan; Moravec, Jiří; Štětinský, Jiří; Penhaker, Marek
The paper deals with theoretical and experimental research of the ambient light influence upon the measuring reliability of the perfusion maps by the laser Doppler method using the device PeriScan PIM 3. The main applicable result of the analysis is a set of recommendations for the standardization, the improving of reliability and the compactness of the blood perfusion measuring in the clinical practise. The improvement of examination brings more accurate results and contributes to the optimization of diagnostic process and therapy.
Toward designing a quantum key distribution network simulation model
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Mehić, Miralem; Fazio, Peppino; Vozňák, Miroslav; Chromý, Erik
As research in quantum key distribution network technologies grows larger and more complex, the need for highly accurate and scalable simulation technologies becomes important to assess the practical feasibility and foresee difficulties in the practical implementation of theoretical achievements. In this paper, we described the design of simplified simulation environment of the quantum key distribution network with multiple links and nodes. In such simulation environment, we analyzed several routing protocols in terms of the number of sent routing packets, goodput and Packet Delivery Ratio of data traffic flow using NS-3 simulator.
On limits of embedded systems in network packet processing
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Vondrouš, Ondřej; Macejko, Peter; Kocur, Zbyněk
The paper deals with a measurement of single-hop one way packet delay on embedded systems used for networking. The single-hop one way packet delay is essential parameter when we need to process packets with strict delivery time constrains. Comparison of different approaches to single-hop one way packet delay measurements is presented in this work along with discussion about strong and weak points in specific measurement approach. The impact of different types of system load and number of CPU cores are also covered by presented results. The presented results of measurement single-hop one way packet delay in embedded Linux system show that for the specific system configuration the packet processing delay depends (in different ways) on system load and network stack load.
On application of least-delay variation problem in ethernet networks using SDN concept
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Hégr, Tomáš; Kozák, Miloš; Boháč, Leoš
The goal of this paper is to present an application idea of SDN in Smart Grids, particularly, in the area of L2 multicast as defined by IEC 61850-9-2. Authors propose an Integer Linear Formulation (ILP) dealing with a Least-Delay-Variation multicast forwarding problem that has a potential to utilize Ethernet networks in a new way. The proposed ILP formulation is numerically evaluated on random graph topologies and results are compared to a shortest path tree approach that is traditionally a product of Spanning Tree Protocols. Results confirm the correctness of the ILP formulation and illustrate dependency of a solution quality on the selected graph models, especially, in a case of scale-free topologies.
Software implementation of a secure firmware update solution in an IoT context
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Kvarda, Lukáš; Hnyk, Pavel; Vojtěch, Lukáš; Lokaj, Zdeněk; Neruda, Marek; Zitta, Tomáš
The present paper is concerned with the secure delivery of firmware updates to Internet of Things (IoT) devices. Additionally, it deals with the design of a safe and secure bootloader for a UHF RFID reader. A software implementation of a secure firmware update solution is performed. The results show there is space to integrate even more security features into existing devices.
Ensuring the visibility and traceability of items through logistics chain of automotive industry based on AutoEPCNet Usage
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Staša, Pavel; Beneš, Filip; Švub, Jiří; Kang, Yong-Shin; Unucka, Jakub; Vojtěch, Lukáš; Kebo, Vladimír; Rhee, Jong-Tae
Traceability in logistics is the capability of the participants to trace the products throughout the supply chain by means of either the product and/or container identifiers in a forward and/or backward direction. In today's competitive economic environment, traceability is a key concept related to all products and all types of supply chains. The goal of this paper is to describe development of application that enables to create and share information about the physical movement and status of products as they travel throughout the supply chain. The main purpose of this paper is to describe the development of RFID based track and trace system for ensuring the visibility and traceability of items in logistics chain especially in automotive industry. The proposed solution is based on EPCglobal Network Architecture.
Performance evaluation of user selection protocols in random networks with energy harvesting and hardware impairments
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Nguyen, Tan Nhat; Duy, Tran Trung; Tran, Phuong Thanh; Vozňák, Miroslav
In this paper, we evaluate performances of various user selection protocols under impact of hardware impairments. In the considered protocols, a Base Station (BS) selects one of available Users (US) to serve, while the remaining USs harvest the energy from the Radio Frequency (RF) transmitted by the BS. We assume that all of the US randomly appear around the BS. In the Random Selection Protocol (RAN), the BS randomly selects a US to transmit the data. In the second proposed protocol, named Minimum Distance Protocol (MIND), the US that is nearest to the BS will be chosen. In the Optimal Selection Protocol (OPT), the US providing the highest channel gain between itself and the BS will be served. For performance evaluation, we derive exact and asymptotic closed-form expressions of average Outage Probability (OP) over Rayleigh fading channels. We also consider average harvested energy per a US. Finally, Monte-Carlo simulations are then performed to verify the theoretical results.
Traffic management by using admission control methods in multiple node IMS network
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Chamraz, Filip; Baroňák, Ivan
The paper deals with Admission Control methods (AC) as a possible solution for traffic management in IMS networks (IP Multimedia Subsystem) - from the point of view of an efficient redistribution of the available network resources and keeping the parameters of Quality of Service (QoS). The paper specifically aims at the selection of the most appropriate method for the specific type of traffic and traffic management concept using AC methods on multiple nodes. The potential benefit and disadvantage of the used solution is evaluated.
Admission control methods in IMS networks
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Čuba, Michal; Baroňák, Ivan
The article deals with solving the problem of ensuring Quality of Service (QoS) in IP Multimedia Subsystem (IMS) networks. Admission Control methods (AC) are used to prevent network congestion and the decrease of QoS. The main function of AC is to maximize utilization of network resources and to ensure the level of QoS. Four methods were chosen for comparison. These methods are described in the main part of the article. The last part deals with simulations of these methods in the software MATLAB.
Voice quality estimation in combined radio-VoIP networks for dispatching systems
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Vodrážka, Jiří; Kučerák, Ján
The voice quality modelling assessment and planning field is deeply and widely theoretically and practically mastered for common voice communication systems, especially for the public fixed and mobile telephone networks including Next Generation Networks (NGN - internet protocol based networks). This article seeks to contribute voice quality modelling assessment and planning for dispatching communication systems based on Internet Protocol (IP) and private radio networks. The network plan, correction in E-model calculation and default values for the model are presented and discussed.
Influence of scattering enhancement particles CaCO3, CaF2, SiO2 and TiO2 on color uniformity of white LEDs
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Nhan, Nguyen Huu Khanh; Minh, Tran Hoang Quang; Anh, Nguyen Doan Quoc
In this paper, the influence of scattering enhancement particles CaCO3, CaF2, SiO2 and TiO2, adding to YAG:Ce phosphor compounding, on color uniformity of white LEDs (W-LEDs) was presented. Firstly, the physical model of multi-chip W-LEDs is simulated and demonstrated by using commercial LightTools 8.1.0 program. After that, the influence of scattering enhancement particles on color uniformity is calculated and analyzed. With using the Monte Carlo simulation and the Mie-scattering theory, the color uniformity improvement of an 8500~K W-LEDs is demonstrated convincingly. From the researched results, the best color uniformity can be accomplished with TiO2 articles. The results and discussions provided a practical approach for higher-quality manufacturing W-LEDs.
Enhancing lighting performance of white LED lamps by green emitting Ce,Tb phosphor
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Anh, Nguyen Doan Quoc; Minh, Tran Hoang Quang; Nhan, Nguyen Huu Khanh
With the development of high-efficiency and high-power Light-Emitting Diodes (LEDs), it has become possible to use LEDs in lighting and illumination. In last decades, developing a new method for improving lumen output and Angular Color Uniformity (ACU) is the main direction in LED technology. In this paper, an innovative approach for enhancing lighting performance (lumen output and angular color uniformity) of Multi-Chip White LED lamps (MCW-LEDs) was proposed and demonstrated by mixing the green Ce0.67Tb0.33MgAl11O19: Ce,Tb (CeTb) phosphor into their phosphor compounding. With varying CeTb concentration, ACU and lumen output with Conformal Phosphor Package (CPP) and In-cup Phosphor Package (IPP) are calculated, displayed and analyzed. The results show that the lumen output and the ACU of 7000 K and 8500 K MCW-LEDs increased remarkably in comparison with the older works. Using green CeTb is a prospective method for improving lighting performance of MCW-LEDs in future.
Non-destructive fiber-optic sensor system for the measurement of speed in road traffic
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Nedoma, Jan; Fajkus, Marcel; Bednárek, Lukáš; Vašinek, Vladimír
Fiber-optic sensors offer an attractive option to existing sensors for the measurement of the vehicle speed in road traffic. This article describes the measuring scheme of two interferometric sensor units including input-output components for the measurement of the vehicle speed. The interferometric sensors operate on a principle of Mach-Zehnder interferometer. The sensors are constructed to detect a vibration caused by vehicles moving on roads. The sensor system processes the vibrational response, and the vehicle speed is calculated in a time domain. DFB laser was used with a wavelength of 1550 nm and output power of 1--5~mW. The solution provides very high sensitivity. The performance of the proposed system was verified by a series of experimental measurements of the speed. The vehicle speed was monitored by GPS. The highest relative difference of the evaluated speed against GPS data was 7.7 %, the smallest was 1.36 %. When recalculated on kph, the absolute error ranged in the tolerance ± 3 kph, which denotes segmental measuring systems in CZE.
An investigation of a new social networks contact suggestion based on face recognition algorithm
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Zelinka, Ivan; Šaloun, Petr; Stonawski, Jakub; Ondrejka, Adam
Automated comparison of faces in the photographs is a well established discipline. The main aim of this paper is to describe an approach whereby face recognition can be used in suggestion of a new contacts. The new contact suggestion is a common technique used across all main social networks. Our approach uses a freely available face comparison called "Betaface" together with our automated processig of the user´s Facebook profile. The research´s main point of interest is the comparison of friend´s facial images in a social network itself, how to process such a great amount of photos and what additional sources of data should be used. In this approach we used our automated processing algorithm Betaface in the social network Facebook and for the additional data, the Flickr social network was used. The results and their quality are discussed at the end.
The detection properties comparison for the SnO2 gas sensor in different heating regimes and the step change in concentration
(Vysoká škola báňská - Technická univerzita Ostrava, 2016) Gajdošík, Libor
Non-periodical heating regimes and also periodical heating regimes were applied for the sensors TGS 813 and SP 11. Ethanol vapour in air was used as a detected substance. It was found that the sensitivity is better in the periodical square-wave heating regime among the tested regimes. The stabilisation of the sensor conductivity, when the concentration abruptly varies its value, takes longer compared to the constant heating regime at maximum heating voltage.

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