Advances in Electrical and Electronic Engineering
http://advances.utc.sk/index.php/AEEE
en-US<p>Authors who publish with this journal agree to the following terms:</p><ul><li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="http://creativecommons.org/licenses/by/3.0/" target="_new">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li></ul><ul><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li></ul><ul><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li></ul>advances@vsb.cz (Journal Redaction)advances@vsb.cz (Petr Siska)Thu, 20 Jul 2017 00:27:54 +0200OJS 2.3.6.0http://blogs.law.harvard.edu/tech/rss60Design and Control of Parallel Three Phase Voltage Source Inverters in Low Voltage AC Microgrid
http://advances.utc.sk/index.php/AEEE/article/view/1912
Design and hierarchical control of three phase parallel Voltage Source Inverters are developed in this paper. The control scheme is based on synchronous reference frame and consists of primary and secondary control levels. The primary control consists of the droop control and the virtual output impedance loops. This control level is designed to share the active and reactive power correctly between the connected VSIs in order to avoid the undesired circulating current and overload of the connected VSIs. The secondary control is designed to clear the magnitude and the frequency deviations caused by the primary control. The control structure is validated through dynamics simulations.The obtained results demonstrate the effectiveness of the control structure.El Hassane Margoum, Nissrine Krami, Luis Seca, Carlos Moreira, Hassan Mharzihttp://advances.utc.sk/index.php/AEEE/article/view/1912Tue, 18 Jul 2017 22:32:03 +0200The Determination of the Asynchronous Traction Motor Characteristics of Locomotive
http://advances.utc.sk/index.php/AEEE/article/view/1926
The article deals with the problem of the locomotive asynchronous traction motor control with the AC diesel-electric transmission. The limitations of the torque of the traction motor when powered by the inverter are determined. The recommendations to improve the use of asynchronous traction motor of locomotives with the AC diesel-electric transmission are given.Pavel Grigorievich Kolpakhchyan, Alexey Rifkatovich Shaikhiev, Alexander Evgenievich Kochin, Konstantin Stepanovich Perfiliev, Jan Otypka, Andrey Valerievich Sukhanovhttp://advances.utc.sk/index.php/AEEE/article/view/1926Tue, 18 Jul 2017 22:32:27 +0200Reliable Detection of Rotor Faults in IM Using Frequency Tracking and Zero Sequence Voltage
http://advances.utc.sk/index.php/AEEE/article/view/2044
The AC Alternating Current Induction Motor (IM) is the most commonly used AC motor in industrial applications because of its simplicity, robust construction, and relatively low manufacturing costs. To avoid expensive repairs in IM, early faults detection is needed. In this context, this paper presents a novel approach used to detect rotor asymmetries in induction motors. The Zero Sequence Voltage (ZSV) defined as the potential difference between the null point of the supply voltage system and the neutral of the star connection of IM stator winding is measured and employed for tracking the amplitude of the most sensitive harmonics in the spectrum of ZSV. This detection leads to make a criterion to take a decision about the state of the machine without a Prior knowledge. Simulation and experimental results obtained from real tests are presented to validate the study.Khalid Dahi, Soumia El Hani, Ilias Ouachtoukhttp://advances.utc.sk/index.php/AEEE/article/view/2044Tue, 18 Jul 2017 22:32:55 +0200A New Four Quadrant Field Orientation-Controlled Three-Phase Induction Motor Drive Based on Hysteresis Current Comparison
http://advances.utc.sk/index.php/AEEE/article/view/2128
A new four quadrant Field Orientation-Controlled (FOC) three-phase induction motor drive based on Hysteresis Current Comparison (HCC) has been developed. The direct relationship between current and torque in the Direct-Quadrature ($dq$) reference frames has been exploited to develop an HCC scheme that offers accurate tracking of current and torque based on the pulse width modulation technique. The parameters of the inner HCC and the outer Proportional-Integral (PI) speed controllers have been optimised to obtain effective current and torque tracking. The complete closed loop system being speed-controlled, four quadrant operation has been obtained using step speed input while the suitability of the developed model has been tested under full load stress during steady state. The results obtained satisfy the four quadrant operation requirements of advanced drives where controlled starts and stops are essential in both forward and reverse directions. This is evident in the effectiveness of current and torque tracking and ease of speed transition from motoring to regeneration and vice versa. The developed model finds applications in advanced industrial drives as an energy-efficient and cost-effective alternative to eliminate the effects of supply voltage drops and mechanical load variations.Cosmas Uchenna Ogbuka, Cajethan Maduabuchi Nwosu, Marcel Ugwoke Aguhttp://advances.utc.sk/index.php/AEEE/article/view/2128Tue, 18 Jul 2017 22:33:33 +0200Boost Converter Fed High Performance BLDC Drive for Solar PV Array Powered Air Cooling System
http://advances.utc.sk/index.php/AEEE/article/view/2133
This paper proposes the utilization of a DC-DC boost converter as a mediator between a Solar Photovoltaic (SPV) array and the Voltage Source Inverters (VSI) in an SPV array powered air cooling system to attain maximum efficiency. The boost converter, over the various common DC-DC converters, offers many advantages in SPV based applications. Further, two Brushless DC (BLDC) motors are employed in the proposed air cooling system: one to run the centrifugal water pump and the other to run a fan-blower. Employing a BLDC motor is found to be the best option because of its top efficiency, supreme reliability and better performance over a wide range of speeds. The air cooling system is developed and simulated using the MATLAB/Simulink environment considering the steady state variation in the solar irradiance. Further, the efficiency of BLDC drive system is compared with a conventional Permanent Magnet DC (PMDC) motor drive system and from the simulated results it is found that the proposed system performs better.Shobha Rani Depuru, Muralidhar Mahankalihttp://advances.utc.sk/index.php/AEEE/article/view/2133Tue, 18 Jul 2017 22:33:58 +0200Austenitic Biomaterial Cracks Evaluation by Advanced Nondestructive Techniques
http://advances.utc.sk/index.php/AEEE/article/view/2186
The article deals with Non-Destructive Evaluation (NDE) of austenitic stainless steels. Eddy current, ultrasonic testing and non-contact magnetic field mapping methods are used for this purpose. ECA (Eddy Current Array) and TOFD (Time of Flight Diffraction) are methods that have become widely-used in the field of NDE and this is the reason for their utilization. Magnetic field mapping is nowadays an effective method of evaluation of surface-breaking defects mainly in ferromagnetic materials. The fluxgate sensor-based measurement is presented and discussed. The artificial fatigue and stress-corrosion materialâ€™s cracks are inspected. Experimental results are presented and discussed in this paper.Milan Smetana, Vladimir Chudacik, Radoslav Konar, Milos Micianhttp://advances.utc.sk/index.php/AEEE/article/view/2186Tue, 18 Jul 2017 22:34:43 +0200Material Tracking with Dynamic Torque Adaptation for Tension Control in Wire Rod Mill
http://advances.utc.sk/index.php/AEEE/article/view/2139
Material tracking is an important part of the automation control system which has a major impact on the product quality. This paper addresses a stand load identification in wire rod mill as a new algorithm added to existing control system. Tension control approaches are described and a modification of existing tracking system is proposed in order to eliminate tracking faults. Proposed method is based on dynamic torque calculation and its performance was experimentally verified on the industrial wire rod mill. Experimental results show significant reduction of the errors.Tomas Borovsky, Karol Kyslan, Frantisek Durovskyhttp://advances.utc.sk/index.php/AEEE/article/view/2139Tue, 18 Jul 2017 22:43:11 +0200Design of Sensor Systems for Long Time Electrodermal Activity Monitoring
http://advances.utc.sk/index.php/AEEE/article/view/2021
This article describes successive development of electrodermal activity monitoring sensor system. Our aim is to improve existing systems to be more practical and suitable for long-term monitoring. Therefore, compared to conventional devices, our system must be easily wearable, without limiting the examined person in ordinary life, with low power consumption, battery operated and reducing the impact of negative artefacts. Specifically, we describe here three devices. The first is serving mainly to familiarize with the methodology, extensive testing and optimization of measurement parameters. Based on the obtained result, we constructed second system in form of small ring - "EDA ring". Last sensor system is developed with the effort to integrate the monitoring of electrodermal activity in e-health and smart clothes.Erik Vavrinsky, Viera Stopjakova, Martin Donoval, Martin Daricek, Helena Svobodova, Jozef Mihalov, Michal Hanic, Vladimir Tvarozekhttp://advances.utc.sk/index.php/AEEE/article/view/2021Tue, 18 Jul 2017 22:43:42 +0200Integrated Association Rules Complete Hiding Algorithms
http://advances.utc.sk/index.php/AEEE/article/view/2164
This paper presents database security approach for complete hiding of sensitive association rules by using six novel algorithms. These algorithms utilize three new weights to reduce the needed database modifications and support complete hiding, as well as they reduce the knowledge distortion and the data distortions. Complete weighted hiding algorithms enhance the hiding failure by 100%; these algorithms have the advantage of performing only a single scan for the database to gather the required information to form the hiding process. These proposed algorithms are built within the database structure which enables the sanitized database to be generated on run time as needed.Mohamed Refaat Abdellah, Hesham Aboelseoud Mohamed, Khalid Shafee Badran, Mohamed Badr Senousyhttp://advances.utc.sk/index.php/AEEE/article/view/2164Tue, 18 Jul 2017 22:44:24 +0200Method Maximizing the Spread of Influence in Directed Signed Weighted Graphs
http://advances.utc.sk/index.php/AEEE/article/view/1950
We propose a new method for maximizing the spread of influence, based on the identification of significant factors of the total energy of a control system. The model of a socio-economic system can be represented in the form of cognitive maps that are directed signed weighted graphs with cause-and-effect relationships and cycles. Identification and selection of target factors and effective control factors of a system is carried out as a solution to the optimal control problem. The influences are determined by the solution to optimization problem of maximizing the objective function, leading to matrix symmetrization. The gear-ratio symmetrization is based on computing the similarity extent of fan-beam structures of the influence spread of vertices v_i and v_j to all other vertices. This approach provides the real computational domain and correctness of solving the optimal control problem. In addition, it does not impose requirements for graphs to be ordering relationships, to have a matrix of special type or to fulfill stability conditions. In this paper, determination of new metrics of vertices, indicating and estimating the extent and the ability to effectively control, are likewise offered. Additionally, we provide experimental results over real cognitive models in support.Alexander Nikolaevich Tselykh, Vladislav Sergeevich Vasilev, Larisa Anatolievna Tselykh, Simon Antonovich Barkovskiihttp://advances.utc.sk/index.php/AEEE/article/view/1950Tue, 18 Jul 2017 22:45:38 +0200On Convergence of Inexact Augmented Lagrangians for Separable and Equality Convex QCQP Problems without Constraint Qualification
http://advances.utc.sk/index.php/AEEE/article/view/2219
The classical convergence theory of the augmented Lagrangian method has been developed under the assumption that the solutions satisfy a constraint qualification. The point of this note is to show that the constraint qualification can be limited to the constraints that are not enforced by the Lagrange multipliers. In particular, it follows that if the feasible set is non-empty and the inequality constraints are convex and separable, then the convergence of the algorithm is guaranteed without any additional assumptions. If the feasible set is empty and the projected gradients of the Lagrangians are forced to go to zero, then the iterates are shown to converge to the nearest well posed problem.Zdenek Dostal, Petr Beremlijskihttp://advances.utc.sk/index.php/AEEE/article/view/2219Tue, 18 Jul 2017 22:46:26 +0200Advanced Approach of Material Region Detections on Fibre-Reinforced Concrete CT-Scans
http://advances.utc.sk/index.php/AEEE/article/view/2319
Detections of material regions on CT-scans of solids are commonly treated manually by an expert. Although such manual detections have many advantages, some amount of human error is also incorporated. Moreover, expert opinions may vary significantly. We present an application of the k-means++ clustering as an alternative option to manual way of material area detections. k-means++ clustering is derived from k-means (the method of vector quantization, originally from signal processing), popular for cluster analysis in data mining and image processing communities. The algorithm s main advantages are its simple implementation and fast convergence to a local optimum of an objective function. We benchmark the suggested approach on transverse CT-scans of a fibre-reinforced concrete solid. Moreover, we introduce a technique for processing air distribution, such that the appropriate pixels detected as the pixels of air are converted into pixels representing concrete. The technique is based on the connected component algorithm. Benchmark and results of proposed method conclude the paper.Marek Pecha, Martin Cermak, Vaclav Hapla, David Horak, Jiri Tomcalahttp://advances.utc.sk/index.php/AEEE/article/view/2319Tue, 18 Jul 2017 22:46:57 +0200A Note on Massively Parallel Implementation of FETI for the Solution of Contact Problems
http://advances.utc.sk/index.php/AEEE/article/view/2321
The paper deals with the solution of large multibody contact problems using massively parallel computers and domain decomposition methods. These methods can solve the problems discretized by billions of nodal variables at the cost nearly proportional to the number of variables using up to thousands cores before the communication costs start to dominate the computational costs. The paper describes the ingredients essential for efficient massively parallel implementation that increases the parallel scalability beyond the limit mentioned above. The improvements were enhanced into a new software package PERMON which is based on PETSc. The performance of the algorithm is demonstrated on the solution of an academic benchmark discretized by nearlybillion of nodal variables.David Horak, Vaclav Hapla, Jakub Kruzik, Radim Sojka, Martin Cermak, Jiri Tomcala, Marek Pecha, Zdenek Dostalhttp://advances.utc.sk/index.php/AEEE/article/view/2321Tue, 18 Jul 2017 22:47:20 +0200On the Efficient Reconstruction of Displacements in FETI Methods for Contact Problems
http://advances.utc.sk/index.php/AEEE/article/view/2322
The final step in the solution of contact problems of elasticity by FETI-based domain decomposition methods is the reconstruction of displacements corresponding to the Lagrange multipliers for ''gluing'' of subdomains and non-penetration conditions. The rigid body component of the displacements is usually obtained by means of a well known but quite complex formula, the application of which requires reassembling and factorization of some large matrices. Here we propose a simple formula which is applicable to many variants of the FETI based algorithms for contact problems. The method takes a negligible time and avoids reassembling or factorization of any matrices.David Horak, Zdenek Dostal, Radim Sojkahttp://advances.utc.sk/index.php/AEEE/article/view/2322Tue, 18 Jul 2017 22:47:34 +0200Proximal Bundle Method for Contact Shape Optimization Problem
http://advances.utc.sk/index.php/AEEE/article/view/2320
From the mathematical point of view, the contact shape optimization is a problem of nonlinear optimization with a specific structure, which can be exploited in its solution. In this paper, we show how to overcome the difficulties related to the nonsmooth cost function by using the proximal bundle methods. We describe all steps of the solution, including linearization, construction of a descent direction, line search, stopping criterion, etc. To illustrate the performance of the presented algorithm, we solve a shape optimization problem associated with the discretized two-dimensional contact problem with Coulomb's friction.Nikola Plivova, Petr Beremlijskihttp://advances.utc.sk/index.php/AEEE/article/view/2320Tue, 18 Jul 2017 22:47:48 +0200Global Optimization Using Space Filling Curves
http://advances.utc.sk/index.php/AEEE/article/view/2303
The existence of space filling curves opens the way to reducing multivariate optimization problems to the minimization of univariate functions. In this paper, we analyze the Hoelder continuity of space filling curves and exploit this property in the solution of global optimization problems. Subsequently, an algorithm for minimizing univariate Hoelder continuous functions is presented and analyzed. It is shown that the algorithm computes the approximate minimum with the guaranteed precision. The algorithm is tested on some types of two-dimensional functions.Michaela Bailova, Jiri Bouchala, Petr Vodstrcilhttp://advances.utc.sk/index.php/AEEE/article/view/2303Tue, 18 Jul 2017 22:48:39 +0200Inverse Problem Solution using Bayesian Approach with Application to Darcy Flow Material Parameters Estimation
http://advances.utc.sk/index.php/AEEE/article/view/2236
Standard numerical methods for solving inverse problems in partial differential equations do not reflect a possible inaccuracy in observed data. However, in real engineering applications we cannot avoid uncertainties caused by measurement errors. In the Bayesian approach every unknown or inaccurate value is treated as a random variable. This paper presents an application of the Bayesian inverse approach to the reconstruction of a porosity field as a parameter of the Darcy flow problem. However, this framework can be applied to a wide range of problems that involve some amount of uncertainty. Here the material field is modeled as a Gaussian random field, which is expressed as a function of several random variables. The information about these random variables is given by the resulting posterior distribution, which is then studied using the Cross-Entropy method and samples are generated using the Metropolis-Hastings algorithm.Simona Domesova, Michal Bereshttp://advances.utc.sk/index.php/AEEE/article/view/2236Tue, 18 Jul 2017 22:48:56 +0200The Stochastic Galerkin Method for Darcy Flow Problem with Log-Normal Random Field Coefficients
http://advances.utc.sk/index.php/AEEE/article/view/2280
This article presents a study of the Stochastic Galerkin Method (SGM) applied to the Darcy flow problem with a log-normally distributed random material field given by a mean value and an autocovariance function. We divide the solution of the problem into two parts. The first one is the decomposition of a random field into a sum of products of a random vector and a function of spatial coordinates; this can be achieved using the Karhunen-Loeve expansion. The second part is the solution of the problem using SGM. SGM is a simple extension of the Galerkin method in which the random variables represent additional problem dimensions. For the discretization of the problem, we use a finite element basis for spatial variables and a polynomial chaos discretization for random variables. The results of SGM can be utilised for the analysis of the problem, such as the examination of the average flow, or as a tool for the Bayesian approach to inverse problems.Michal Beres, Simona Domesovahttp://advances.utc.sk/index.php/AEEE/article/view/2280Tue, 18 Jul 2017 22:49:10 +0200Coupling of Finite and Boundary Elements for Transient Eddy Current Problems
http://advances.utc.sk/index.php/AEEE/article/view/2262
A symmetric coupling of methods of finite and boundary elements for numerical solution of transient eddy current problems is described. This is an essential step in modelling of electromagnetic forming of metalic sheets. The finite element method is employed in the conducting region of the metalic sheet. The boundary element method relies on the Stratton-Chu representation formula and it models the electromagnetic field in the air including its decay at infinity. We impose external currents by the Biot-Savart law.Dalibor Lukas, Petr Kacor, Lubomir Ivanek, Veleslav Mach, Christian Schefflerhttp://advances.utc.sk/index.php/AEEE/article/view/2262Tue, 18 Jul 2017 22:49:25 +0200Finding Zeros of Analytic Functions and Local Eigenvalue Analysis Using Contour Integral Method in Examples
http://advances.utc.sk/index.php/AEEE/article/view/2252
A numerical method for computing zeros of analytic complex functions is presented. It relies on Cauchy's residue theorem and the method of Newton's identities, which translates the problem to finding zeros of a polynomial. In order to stabilize the numerical algorithm, formal orthogonal polynomials are employed. At the end the method is adapted to finding eigenvalues of a matrix pencil in a bounded domain in the complex plane. This work is based on a series of papers of Professor Sakurai and collaborators. Our aim is to make their work available by means of a systematic study of properly chosen examples.Erika Strakova, Dalibor Lukas, Petr Vodstrcilhttp://advances.utc.sk/index.php/AEEE/article/view/2252Tue, 18 Jul 2017 22:49:37 +0200Energetic Spectrum of a Particle in Three-dimensional Infinite Potential Square Well in Point of View of Number Theory and Bayesian Statistics
http://advances.utc.sk/index.php/AEEE/article/view/2248
Using results of number theory we develop an approximate statistical model of energy levels of particles in a three-dimensional infinite potential well depending on whether there is exactly one particle or more than one particles in the well. The model is used to perform a statistical inference about the number of particles in the well. The estimation procedure is developed within the Bayesian framework.Pavel Jahoda, Jan Kracik, David Ulcakhttp://advances.utc.sk/index.php/AEEE/article/view/2248Tue, 18 Jul 2017 22:50:04 +0200A survey of tools detecting the dynamical properties of one-dimensional families
http://advances.utc.sk/index.php/AEEE/article/view/2314
One-dimensional dynamical systems attract researches for more than half a century and the topic was inspired by many real problems. Mainly piecewise linear and polynomial maps were considered and researched under several motivations from different scientific fields. As a main aim of the paper, the Logistic (polynomials of the second order) and the Tent (piecewise linear maps with two pieces) families are considered and studied. The dynamical properties of both families are derived using bifurcation diagrams, Lyapunov exponents, and newly established techniques like the 0-1 test for chaos and recurrence matrices.Marek Lampart, Tomas Martinovichttp://advances.utc.sk/index.php/AEEE/article/view/2314Tue, 18 Jul 2017 22:50:24 +0200Tensor Approximation of Slater-Type Orbital Basis Functions
http://advances.utc.sk/index.php/AEEE/article/view/2235
This paper deals with a tensor representation of the Slater-type orbital basis functions. Localized basis systems are primarily used in electronic structure calculations. A choice of the system is usually limited to Gaussian-type orbitals due to the impossibility of the analytical evaluation of necessary integrals using other basis types. Unfortunately, it is not possible to use direct discretization techniques due to the dimensionality of the problem so the numerical integration is problematic. Tensor Numerical Methods overcome this problem by using special data representations, which are discussed. Finally, it is demonstrated how to use these methods to construct a tensor approximation of Slater-type orbital basis functions including an error estimate and its numerical verification.Martin Mrovechttp://advances.utc.sk/index.php/AEEE/article/view/2235Tue, 18 Jul 2017 22:50:39 +0200Elastic Image Registration Based on Domain Decomposition with Mesh Adaptation
http://advances.utc.sk/index.php/AEEE/article/view/2281
Medical images are increasingly used within healthcare for diagnosis, planning treatment, and monitoring disease progression. The images acquired at different times, with different imaging modalities, from different subjects etc. often provide an additional clinical information that is not revealed in the separate images. The spatial relation between the images has to be found and this process is called image registration. In our contribution, we use elastic registration which assumes that the images are two different observations of an elastic body which is discretized by the finite element method. We are especially interested in the problems where the requirements on the registration prevent the application of standard FFT based solvers to the solution of auxiliary linear problems, which is the case when the part of the two observations can be related by a rigid body motion. Because the medical images usually contain a large area of background and a small area of changes, a regular discretization results in waste of computational resources due to the fine refinement of the space outside the region of interest (especially in 3D). To avoid this, we use coarser grid with local refinement that takes into account specific features of the images and their differences. The related elasticity problems are solved by TFETI, which is a variant of the Finite Element Tearing and Interconnecting (FETI) domain decomposition method for massively parallel numerical solution of elliptic Partial Differential Equations (PDE) with optimal complexity.Ales Ronovsky, Alena Vasatovahttp://advances.utc.sk/index.php/AEEE/article/view/2281Tue, 18 Jul 2017 22:50:53 +0200Handicap Labelings of 4-Regular Graphs
http://advances.utc.sk/index.php/AEEE/article/view/2263
Let G be a simple graph, let <i> f : V(G)→{1,2,...,|V(G)|}</i> be a bijective mapping. The weight of <i>v ∈ V(G)</i> is the sum of labels of all vertices adjacent to <i>v</i>. We say that <i>f</i> is a distance magic labeling of <i>G</i> if the weight of every vertex is the same constant <i>k</i> and we say that <i>f</i> is a handicap magic labeling of <i>G</i> if the weight of every vertex <i>v</i> is <i>l + f(v)</i> for some constant l. Graphs that allow such labelings are called distance magic or handicap, respectively. Distance magic and handicap labelings of regular graphs are used for scheduling incomplete tournaments. While distance magic labelings correspond to so called equalized tournaments, handicap labelings can be used to schedule incomplete tournaments that are more challenging to stronger teams or players, hence they increase competition and yield attractive schemes in which every games counts. We summarize known results on distance magic and handicap labelings and construct a new infinite class of 4-regular handicap graphs.Petr Kovar, Michal Kravcenko, Matej Krbecek, Adam Silberhttp://advances.utc.sk/index.php/AEEE/article/view/2263Tue, 18 Jul 2017 22:51:09 +0200Non-Invasive Fiber-Optic Biomedical Sensor for Basic Vital Sign Monitoring
http://advances.utc.sk/index.php/AEEE/article/view/2131
This article focuses on the functionality verification of a novel non-invasive fibre-optic sensor monitoring basic vital signs such as Respiratory Rate (RR), Heart Rate (HR) and Body Temperature (BT). The integration of three sensors in one unit is a unique solution patented by our research team. The integrated sensor is based on two Fiber Bragg Gratings (FBGs) encapsulated inside an inert polymer (non-reactive to human skin) called PolyDiMethylSiloxane (PDMS). The PDMS is beginning to find widespread applications in the biomedical field due to its desirable properties, especially its immunity to ElectroMagnetic Interference (EMI). The integrated sensor's functionality was verified by carrying out a series of laboratory experiments in 10 volunteer subjects after giving them a written informed consent. The Bland-Altman statistical analysis produced satisfactory accuracy for the respiratory and heart rate measurements and their respective reference signals in all test subjects. A total relative error of 0.31% was determined for body temperature measurements. The main contribution of this article is a proof-of-concept of a novel noninvasive fiber-optic sensor which could be used for basic vital sign monitoring. This sensor offers a potential to enhance and improve the comfort level of patients in hospitals and clinics and can even be considered for use in Magnetic Resonance Imaging (MRI) environments.Jan Nedoma, Marcel Fajkus, Radek Martinek, Vladimir Vasinekhttp://advances.utc.sk/index.php/AEEE/article/view/2131Tue, 18 Jul 2017 22:52:10 +0200Biometric Image Recognition Based on Optical Correlator
http://advances.utc.sk/index.php/AEEE/article/view/2084
The aim of this paper is to design a biometric images recognition system able to recognize biometric images-eye and DNA marker. The input scenes are processed by user-friendly software created in C# programming language and then are compared with reference images stored in database. In this system, Cambridge optical correlator is used as an image comparator based on similarity of images in the recognition phase.David Solus, Lubos Ovsenik, Jan Turan, Tomas Ivaniga, Jakub Oravec, Michal Martonhttp://advances.utc.sk/index.php/AEEE/article/view/2084Tue, 18 Jul 2017 22:52:23 +0200Fluorescence Properties of Chlorella sp. Algae
http://advances.utc.sk/index.php/AEEE/article/view/2015
Water quality and its fast and reliable monitoring is the challenge of the future. Design of appropriate biosensors that would be capable of non-invasive identification of water pollution is an important prerequisite for such challenge. Chlorophylls are pigments, naturally presented in all plants that absorb light. The main forms of chlorophyll in algae are chlorophyll a and chlorophyll b, other pigments include xantophylls and beta-carotenes. Our aim was to characterize endogenous fluorescence of the Chlorella sp. algae, present naturally in drinking water. We recorded spatial, spectral and lifetime fluorescence distribution in the native algae. We noted that the fluorescence was evenly distributed in the algae cytosol, but lacked in the nucleus and reached maximum at 680-690 nm. Fluorescence decay of chlorella sp. was double-exponential, and clearly shorter than that of its isolated pigments. For the first time, fluorescence lifetime image of the algae is presented. Study of the fluorescence properties of algae is aimed at the improvement of water supply contamination detection and cleaning.Tibor Teplicky, Miroslava Danisova, Martin Valica, Dusan Chorvat, Alzbeta Marcek Chorvatovahttp://advances.utc.sk/index.php/AEEE/article/view/2015Tue, 18 Jul 2017 22:52:52 +0200Proximity Effect in Gate Fabrication Using Photolithography Technique
http://advances.utc.sk/index.php/AEEE/article/view/2024
In the paper the technological factors influencing test structure gate length were described. The influence of test structure gate placement (Schottky metallization between ohmic contacts, on mesa and on GaN surface) was analyzed and discussed. Moreover, various distances between ohmic contacts paths were tested. Except for experimental investigations, simulations using finite elements method in COMSOL were performed for the same structure. The modelling results revealed crucial impact of a gap beyond the mask on the electric field distribution in photoresist layer. The smallest value of relative error of test finger lengths was observed for finger parts placed between ohmic paths on mesas. It was explained by thicker lift-off double layer between ohmic paths and the smallest Y-gap compared to test fingers placed on mesa and outside of it. Simulation did not bring an explanation of larger values of relative error for smaller distance between ohmic paths.Joanna Prazmowska, Kornelia Indykiewicz, Bogdan Paszkiewicz, Regina Paszkiewiczhttp://advances.utc.sk/index.php/AEEE/article/view/2024Tue, 18 Jul 2017 22:52:58 +0200