AEEE. 2012, vol. 10

Permanent URI for this collectionhttp://hdl.handle.net/10084/95758

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Now showing 1 - 20 out of 57 results

Scanning probe microscopy as a tool for investigation of biomaterials
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Novotná, Veronika; Knápek, Alexandr; Tománek, Pavel; Šafářová, Šárka
Super-microscopic techniques like scanning tunnelling microscopy, atomic force microscopy or scanning near-field optical microscopy allows investigate micro- and/or nano-scale surfaces and structures. In this paper, both Environmental scanning electron microscope (ESEM) and Scanning near field optical microscope (SNOM) have been applied to more closely study of biomaterials. The results of visualization of human osteo-sarcoma cell line (U2OS) are compared. SNOM and ESEM yield different, however, comparable and complementary information on studied biological samples.
Evaluation of resonance properties of the human body models situated in the RF field
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Cocherová, Elena; Maličký, Gabriel; Kupec, Peter; Štofanik, Vladimír; Púčik, Jozef
The radio-frequency (RF) electromagnetic field absorption in the human body model is investigated in this article. Absorption of prolate model of the biological body exhibits resonance properties in the case of so called E polarization. This occurs in the arrangement when the longitudinal axis of the body is parallel with an electrical component of the electromagnetic field. Absorption properties of a homogeneous human model have been explored in the frequency range from 20 MHz to 500 MHz in the CST Microwave Studio programme environment. The simulation results of RF field absorption in the model of the human body are presented for ellipsoidal, cylindrical and anthropomorphic Laura model shapes, and for various heights and widths of the model body. The values of the resonance frequency and also whole-body absorption values at these frequencies are evaluated.
Voltage mode OTRA MOS-C single input multi output biquadratic universal filter
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Pandey, Rajeshwari; Pandey, Neeta; Paul, Sajal Kumar; Singh, Ajay; Sriram, Balamurali; Trivedi, Kaushalendra
In this paper, an Operational transresistance amplifier (OTRA) based MOS-C voltage mode single input multi output (SIMO) biquadratic universal filter configuration is proposed. The configuration is made fully integrated by implementing the resistors using matched transistors operating in the linear region. It exhibits the feature of orthogonal controllability of angular frequency and quality factor through gate bias voltage. The non-ideality analysis of the circuit is also given. Workability of the universal filter is demonstrated through PSPICE simulations using 0,5 μm CMOS process parameters provided by MOSIS (AGILENT).
The real implementation of NLMS channel equalizer into the system of software defined radio
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Martinek, Radek; Žídek, Jan
This paper deals with modern wireless transmission systems. It focusses on real implementation of NLMS channel equalizer into the system of software defined radio. The authors aimed to conduct a real measurement (BER vs. Eb/No) using modern modular PXI measuring apparatus. This sophisticated measuring system is built by vector-signal generator RF VSG NI PXI-5670 and vector-signal analyzer RF VSA NI PXI-5660. The results of experiments suggest that the channel equalizer with implemented NLMS algorithm has better results (balance between simplicity and performance) than conventionally most used LMS algorithm. This holds true if feasible computational complexity with respect to real time processes is assumed.
A new threshold switching scheme for a DVB-RCS Mobile return link in a terrestrian railway scenario
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Tropea, Mauro
Single input variable universe fuzzy controller with contraction-expansion factor for inverted pendulum in real time
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Dhanni, Yogesh Kumar
In Conventional Fuzzy Logic Controller (CFLC), input variables are the error (E) and the change-in-error (EC) regardless of the complexity of controlled plant. The rule table constructed for CFLC is two dimensional in input space. This two dimensional rule table can be reduced to a single dimension by the signed distance method. This method also reduces the number of rules significantly. In this paper, a fuzzy controller is designed with the signed distance input variable. Then to improve the performance of this controller the technique of variable universe of discourse is used. After using these two techniques simultaneous to design a fuzzy controller, it is implemented to stabilize inverted pendulum in real time.
An approach to personalized search within distributed repository of visual data
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Glowacz, Andrzej; Orzechowski, Tomasz Marcin
In this paper, we introduce functional assumptions of the distributed repository of visual data that are one of key aspects of SYNAT framework for digital libraries. The proposed system will provide innovative tools and extend capabilities of current repositories. Within this task, the personalized search system is discussed. Especially three different approaches were proposed for this system, such as: CF, CBF and DF. Idea behind personalization is that there is currently lack of such functionality whereas end users would benefit from it.
Performance evaluation of INACT - INDECT advanced image cataloguing tool
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Michalek, Libor; Grega, Michal; Bryk, Damian; Grabowski, Bartłomiej
In this article, we describe the performance evaluation of INACT tool which is developed for cataloguing of high-level and low-level metadata of the evidence material. INACT tool can be used by police forces in the cases of prosecution of such crimes as as possession and distribution of child pornography (CP). In live forensic cases, the time to first hit (time when the first image containing e.g. CP is found) is important, as then further legal actions are justified (such as arrest of the suspect and his hardware). The performance evaluation of first hit was performed on real data with the cooperation of Czech Police, Department of Internet Crime.
Eigenvalue criterion-based feature selectionin principal component analysis of speech
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Viszlay, Peter; Janečko, Jozef; Juhár, Jozef
This article presents a specific approach for selecting a limited set of most relevant, information rich speech data from the whole amount of training data. The proposed method uses Principal Component Analysis (PCA) to optimally select a lower-dimensional data subset with similar variances. In this paper, three selection algorithms, based on eigenvalue criterion are presented. The first one operates and analyzes the data at the entire speech-recording level. The second one additionally segments each of the recordings into experimentally sized blocks, which theoretically divides a record level into several smaller information richer/poorer blocks. Finally, the third one analyzes all the speech records at the feature vector level. These three approaches represent three different criterion-based selection techniques from the coarsest to the finest data level. The main aim of the presented experiments is to show that PCA trained with the limited subset of data achieves comparable or even better results than PCA trained with the entire speech corpus. In fact, this approach can radically speed up the learning of PCA with much smaller memory and computational costs. All methods are evaluated in Slovak phoneme-based large vocabulary continuous speech recognition task.
Dual shots detection
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Vozáriková, Eva; Juhár, Jozef; Čižmár, Anton
The identification of a special kind of acoustic events such as dual gunshots and single gunshots in the traffic background is described in this work. The recognition of dangerous sounds may help to prevent the abnormal or criminal activities that happened near to the public transport stations. Therefore in this paper the methodology of dual shots detection in a noisy background was developed and evaluated. For this purpose, we investigated various feature extraction methods and combinations of different feature sets. These approaches were evaluated by the widely used classification technique based on the Hidden Markov Models.
Analysis of morph-based language modeling and speech recognition in Slovak
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Staš, Ján; Hládek, Daniel; Juhár, Jozef; Zlacký, Daniel
The inflection of the Slovak language causes a large number of unique word forms, which produces not only a large vocabulary, but also a number of out-of-vocabulary words. Morph-based language models solve this problem by decomposition of inflected word forms into small sub-word units and resolve the general problem of sparsity the training data. In this paper, we present several rule-based and data-driven approaches to the automatic segmentation of words into morphs. These data are later used in the modeling of the Slovak language for large vocabulary continuous speech recognition. Preliminary results show a significant decrease in the number of out-of-vocabulary words and reduction of resultant language model perplexity.
IP telephony based danger alert communication system and its implementation
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Řezáč, Filip; Kolenovský, Filip; Mikulec, Martin; Vozňák, Miroslav; Rozhon, Jan; Vychodil, Jiří; Tomala, Karel; Šafařík, Jakub
The paper deals with development of a web application allowing to deliver pre-recorded voice messages by using SIP generator. The developed application is a part of complex system, which has been evolved in Dpt. of Telecommunications, Technical University of Ostrava for last three years. Our intent is focused on disaster management, the message, which should be delivered within specified time span, is typed in the application and text-to-speech module ensures its transormation to a speech format, after that a particular scenario or warned area is selected and a target group is automatically unloaded. For this purpose, we have defined XML format for delivery of phone numbers which are located in the target area and these numbers are obtained from mobile BTS's (Base transmission stations). The advantage of this aproach lies in controlled delivery and finally the list of unanswered calls is exported and these users are informed via SMS. In the paper, the core of the danger alert system is described including algorithms of the voice message delivery.
Improvement of network efficiency on the grounds of change communication protocol
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Vychodil, Jiří; Mikulec, Martin; Šafařík, Jakub; Vozňák, Miroslav
This article deals with both theoretical and practical application of Extensible Messaging and Presence Protocol instead of different solution described detailed in the article. It uses periodically HTTP method POST to gain information about a state, which a client stands in. During this process a new connection is created and closed, what enormously makes network traffic mote intensive. Instead of this we used XMPP, this technology eliminates disadvantages of synchronous HTTP connection by its adapting for real time connection. It uses stable connection, what does not need to create it any time any information needs to be sent. It decreased amount of transported data through a network and a time, in which is a client informed about an event due to a fact, that the new solution works in real time.
E-model MOS estimate precision improvement and modelling of jitter effects
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Kováč, Adrián; Halas, Michal
This paper deals with the ITU-T E-model, which is used for non-intrusive MOS VoIP call quality estimation on IP networks. The pros of E-model are computational simplicity and usability on real-time traffic. The cons, as shown in our previous work, are the inability of E-model to reflect effects of network jitter present on real traffic flows and jitter-buffer behavior on end user devices. These effects are visible mostly on traffic over WAN, internet and radio networks and cause the E-model MOS call quality estimate to be noticeably too optimistic. In this paper, we propose a modification to E-model using previously proposed Pplef (effective packet loss) using jitter and jitter-buffer model based on Pareto/D/1/K system. We subsequently perform optimization of newly added parameters reflecting jitter effects into E-model by using PESQ intrusive measurement method as a reference for selected audio codecs. Function fitting and parameter optimization is performed under varying delay, packet loss, jitter and different jitter-buffer sizes for both, correlated and uncorrelated long-tailed network traffic.
Fundamental frequency extraction method using central clipping and its importance for the classification of emotional state
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Partila, Pavol; Vozňák, Miroslav; Mikulec, Martin; Zdrálek, Jaroslav
The paper deals with a classification of emotional state. We implemented a method for extracting the fundamental speech signal frequency by means of a central clipping and examined a correlation between emotional state and fundamental speech frequency. For this purpose, we applied an approach of exploratory data analysis. The ANOVA (Analysis of variance) test confirmed that a modification in the speaker's emotional state changes the fundamental frequency of human vocal tract. The main contribution of the paper lies in investigation, of central clipping method by the ANOVA.
Markov model M/M/m/K in contact center
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Chromý, Erik; Diežka, Ján; Kavacký, Matej
Our paper deals with a contact center dimensioning. The main task of a contact center is to offer services to customers. The most simple and genuine way of communication with the contact center agent is by phone. From the customer satisfaction point of view, the shortest serving time is the most important factor. It is known that the highest operating costs of the contact center are costs for agents. Therefore, we need to choose the right number of agents and effectively utilize them. For contact center dimensioning we can use various models. In this paper, we introduce the Markov M/M/m/K model which offers the broad range of parameters suitable for the contact center sizing, e.g. required number of agents based on the probability of call refusal and probability of call enqueue.
Modelling the probability density function of IPTV traffic packet delay variation
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Halas, Michal; Kľučik, Stanislav
This article deals with modelling the Probability density function of IPTV traffic packet delay variation. The use of this modelling is in an efficient de-jitter buffer estimation. When an IP packet travels across a network, it experiences delay and its variation. This variation is caused by routing, queueing systems and other influences like the processing delay of the network nodes. When we try to separate these at least three types of delay variation, we need a way to measure these types separately. This work is aimed to the delay variation caused by queueing systems which has the main implications to the form of the Probability density function.
Impact of compression on the video quality
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Uhrina, Miroslav; Hlubík, Ján; Vaculík, Martin
This article deals with the impact of compression on the video quality. In the first part, a short characteristic of the most used MPEG compression standards is written. In the second part, the parameter Group of Picture (GOP) with particular I, P, B frames is explained. The third part focuses on the objective metrics which were used for evaluating the video quality. In the fourth part, the measurements and the experimental results are described.
Objective assessment of IP video calls with Asterisk
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Kapičák, Lukáš; Nevlud, Pavel; Mikulec, Martin; Zdrálek, Jaroslav
The paper deals with an objective assessment of IP video calls transmission over GSM and UMTS networks. Video transmission is affected by many factors in mobile network. Among these factors belong packet loss, latency and transmission rate of the mobile network. Network properties were simulated by Simena network simulator. Our team have developed a unique technique for finding defects in video appearing in video calls. This technique is built on modified Asterisk SW PBX with enabled video recording and playback functions. Transmitted video files are compared with original video file by means of size of transmitted video file and in-video-defects. We are using MSU VQMT software for finding in video defects; more precisely we are using VQM method for comparing two video sources.
Adapting the streaming video based on the estimated motion position
(Vysoká škola báňská - Technická univerzita Ostrava, 2012) Aziz, Hussein Muzahim; Fiedler, Markus; Grahn, Hakan; Lundberg, Lars
In real time video streaming, the frames must meet their timing constraints, typically specified as their deadlines. Wireless networks may suffer from bandwidth limitations. To reduce the data transmission over the wireless networks, we propose an adaption technique in the server side by extracting a part of the video frames that considered as a Region Of Interest (ROI), and drop the part outside the ROI from the frames that are between reference frames. The estimated position of the selection of the ROI is computed by using the Sum of Squared Differences (SSD) between consecutive frames. The reconstruction mechanism to the region outside the ROI is implemented in the mobile side by using linear interpolation between reference frames. We evaluate the proposed approach by using Mean Opinion Score (MOS) measurements. MOS are used to evaluate two scenarios with equivalent encoding size, where the users observe the first scenario with low bit rate for the original videos, while for the second scenario the users observe our proposed approach with high bit rate. The results show that our technique significantly reduces the amounts of data are streamed over wireless networks, while the reconstruction mechanism will provides acceptable video quality.

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