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Acta polytechnica HungaricaVolume 10, Issue No. 4 (2013.)


  • Jimoh Pedro ,
    John Ekoru :

    DOI: 10.12700/APH.10.04.2013.4.1

    Abstract: In this paper, the performance of a nonlinear, 4 degrees-of-freedom, servo-hydraulic half-car active vehicle suspension system is compared with that of a passive vehicle suspension system with similar model parameters. The active vehicle suspension system is controlled by an indirect adaptive Neural Network-based Feedback Linearization controller (NARMA-L2). Hydraulic actuator force tracking is guaranteed by an inner Proportional+Integral+Derivative-based force feedback control loop. The output responses of the vehicles are presented and analyzed in the frequency and time domains, in the presence of model uncertainties in the form of variation in vehicle sprung mass loading. The results show that the NARMA-L2-based active vehicle suspension system performed better than the passive vehicle suspension system within the constraints.

    Keywords: Neural Networks; NARMA-L2; PID Control; Nonlinear Vehicle Suspension System; Hydraulic Actuator Dynamics; Model Uncertainty

  • Sándor Kovács ,
    Valéria Mertinger :

    DOI: 10.12700/APH.10.04.2013.4.2

    Abstract: In this paper, the algorithmic realization of complex optimization objective functions of parameters of multi-step wire cold drawing technology is described. As a result of utilizing two types of optimization, either identical optimum cone-angles can be obtained in each pass or the (variable) optimum cone angles having an optional size in each pass can be obtained. The calculation time of objective functions was investigated, as it is one of the most important factors of non-linear optimization. The optimum technological parameters obtained by using the two types of objective functions were compared, and the cases in which it is worth using the complex optimization having a shorter calculation time were defined.

    Keywords: analytical explicit model; drawing force; drawing temperature; multi-step wire drawing; complex optimization; technology planning

  • Rudolf Andoga ,
    Ladislav Főző ,
    Ladislav Madarász ,
    Tomáą Karoµ :
    A Digital Diagnostic System for a Small Turbojet Engine45-58en [734.23 kB - PDF]EPA-02461-00042-0030

    DOI: 10.12700/APH.10.04.2013.4.3

    Abstract: During the lifecycle of a system not only functionality but also other aspects like safety and reliability are very important. These terms are even more important when connected to aviation in engine and avionic systems control. The reason is simple, a failure must not cause a shutdown of a system during the flight as it would cause a catastrophe. The article deals with the proposal of a progressive diagnostics/backup system using a modified voting method with computational backup models using neural networks. The proposed architecture is expected to be suitable for turbojet engines and was tested on a laboratory object, a small turbojet engine MPM-20 with positive results under operational conditions.

    Keywords: digital control; diagnostics; backup; neural network, turbojet engine

  • Sándor Szénási ,
    Zoltán Vámossy :

    DOI: 10.12700/APH.10.04.2013.4.4

    Abstract: The processing of microscopic tissue images and especially the detection of cell nuclei is nowadays done more and more using digital imagery and special immunodiagnostic software products. One of the most promising image segmentation methods is region growing, but this algorithm is very sensitive to the appropriate setting of different parameters, and the long runtime due to its high computing demand reduces its practical usability. As a result of our research, we managed to develop a data-parallel region growing algorithm that is two or three times faster than the original sequential version. The paper summarizes our results: the development of an evolution-based algorithm that was used to successfully determine a set of parameters that could be used to achieve significantly better accuracy than the already existing parameters.

    Keywords: tissue image segmentation; data parallel algorithm; GPGPU, genetic algorithm; distributed system

  • Tinzar Thaw ,
    Sanjay Misra :
    Measuring the Reusable Quality for XML Schema Documents87-106en [573.11 kB - PDF]EPA-02461-00042-0050

    DOI: 10.12700/APH.10.04.2013.4.5

    Abstract: eXtensible Markup Language (XML) based web applications are widely used for data describing and providing internet services. The design of XML schema document (XSD) needs to be quantified with software with the reusable nature of XSD. This nature of documents helps software developers to produce software at a lower software development cost. This paper proposes a metric Entropy Measure of Complexity (EMC), which is intended to measure the reusable quality of XML schema documents. A higher EMC value tends to more reusable quality, and as well, a higher EMC value implies that this schema document contains inheritance feature, elements and attributes. For empirical validation, the metric is applied on 70 WSDL schema files. A comparison with similar measures is also performed. The proposed EMC metric is also validated practically and theoretically. Empirical, theoretical and practical validation and a comparative study proves that the EMC metric is a valid metric and capable of measuring the reusable quality of XSD.

    Keywords: XML; XSD; WSDL; Software Metrics; Entropy

  • János Simon ,
    Goran Martinović :

    DOI: 10.12700/APH.10.04.2013.4.6

    Abstract: In the current work we present an algorithmic proposal for mobile robot navigation using a Wireless Sensor Network (WSN) for the location of a mobile measuring station in a controlled microclimatic environment. Another point of consideration is determining the navigation strategy. Publications in this field of robotics offer a large number of localization methods, mainly focusing on two fields: navigating locally and globally. Navigating locally will determine the mobile robot’s position and orientation by implementing a series of sensors. Once we start from an initial position, the robot’s position and orientation are updated continuously through the given time frame. Global navigation will ensure that the robot is able to determine its own position and orientation without having previously studied a map or being given some specific information.

    Keywords: Localization;Sun SPOT; WSN; Mobile robot; RSSI

  • A. Ersan Oguz ,
    Hakan Temeltas :

    DOI: 10.12700/APH.10.04.2013.4.7

    Abstract: In this paper, EKF Based A-SLAM concept is discussed in detail by presenting the formulas and MATLAB Simulink model, along with results. The UAV kinematic model and state-observation models for the EKF Based A-SLAM are developed to analyze the consistency. The covariance value caused by the EKF structure is analyzed. This value was calculated by filtering with error between the UAV’s actual and estimated positions. It is concluded that the calculated covariance value diminishes despite error and does not decrease as a result of the inconsistency of the EKF Based A-SLAM structure. The necessary conditions for the consistency of the EKF Based A-SLAM structure are described and the consistency of the EKF Based A-SLAM is consequently investigated by considering these conditions for the first time by using simulation results. The analysis during this landmark observation exhibits that a jagged UAV’s trajectory indicates an inconsistency caused by the EKF Based A-SLAM structure with the provocation of error accumulation. Finally, the major reasons of the filter inconsistency can be listed as unobservable subspace and Jacobian matrices used for linearization. As a future work, the methods that can be used to provide consistency of the EKF Based A-SLAM are proposed for better UAV navigation performance.

    Keywords: A-SLAM; EKF; SLAM; Navigation

  • Árpád Horváth :

    DOI: 10.12700/APH.10.04.2013.4.8

    Abstract: Over the last decade a lot of common properties were found in complex networks in several fields such as sociology, biology and computer engineering. Recently, the multifractal network generator method has been developed, and it seems to be a promising way to generate networks with prescribed statistical properties. For educational purposes, however, it would be adequate to create an easy-to-use redevelopment framework. Therefore, a software package had been developed in Python language that can generate a network with a given degree distribution or a given average degree using the multifractal generator method. This package is a part of the cxnet framework, which itself is suitable for educational applications. The present paper discusses the reasons why this framework was developed in Python. Those parts of the program that need longer running times were identified and rewritten in C++. Running times of the generations were measured, changing several parameters, and the new version turned out to be an order of magnitude faster.

    Keywords: complex network; graph theory; multifractal; software

  • Dániel Mihályi ,
    Valerie Novitzká :
    What about Linear Logic in Computer Science?147-160en [437.12 kB - PDF]EPA-02461-00042-0090

    DOI: 10.12700/APH.10.04.2013.4.9

    Abstract: In this paper we discuss several useful features of linear logic especially from the viewpoint of computing science. We start with a short overview of linear logic with an emphasis on the special properties of linear implication and exponential operators. We present our idea of the possible fragmentation of linear logic and the usefulness of particular fragments in various areas of computing science. Finally, we consider possible extensions of linear logic and we illustrate how an extension with epistemic operators can serve for obtaining knowledge and belief about an intrusion attempt.

    Keywords: linear logic; type theory; behavioral theory; modal logics

  • Zsolt Péter Sándor ,
    Csaba Csziszár :

    DOI: 10.12700/APH.10.04.2013.4.10

    Abstract: The route planning of trucks also includes the planning of the parking. Research has already shown that parking demands often exceed capacities. This problem can be managed by appropriate information provision. It is also discussed by European strategic documents, the ITS Directive and the ITS Action Plan, as a priority assignment. Advanced intelligent parking management systems for trucks, planned and partially installed ones, provide real-time information and central (system optimum based) navigation with automatic parking place booking. In this way, the capacity utilization of parking facilities can be maximized. Nowadays such complex systems are still not available, only some part-functions, but modern information and communication technology offers new opportunities in transportation applications. The article classifies the parking information systems into five plus one (5+1) service levels according to their functions. On the highest service level, the information system offers individual route plans for every user while it takes drivers' working hours, actual traffic conditions and personal preferences into consideration. In the future, mobility and parking demands can be influenced by real-time and interactive information management.

    Keywords: intelligent truck parking; integrated information system; parking management; navigation; intelligent transport systems and services

  • Vladimir Mučenski ,
    Milan Trivunić ,
    Goran Ćirović ,
    Igor Peąko ,
    Jasmina Draľić :

    DOI: 10.12700/APH.10.04.2013.4.11

    Abstract: In recent years, we are witnessing a greater tendency towards the use of existing construction waste, in order to reduce the amount of material being disposed of on the one hand, and to limit the exploitation of natural resources necessary for the production of construction materials on the other hand. This paper provides an outline of a process for predicting the recyclable amount of concrete and reinforcement built in structures of residential buildings based on artificial neural networks (ANN). The following analyses are included in the process: an analysis of the optimal network structure, analysis of the effect of training algorithms and a network sensitivity analysis. While analyzing these, networks with one and two hidden layers trained with 5 algorithms (Gradient descent with adaptive lr backpropagation, Levenberg-Marquardt backpropagation, quasi-Newton backpropagation, Bayesian regularization and Powell-Beale conjugate gradient backpropagation) for neural network training were observed. The research was carried out with the purpose of observing ANN that will quickly and with adequate precision provide information regarding the amounts of concrete and reinforcement that can be recycled.

    Keywords: Recycling; concrete; reinforcement; prediction of the quantity; artificial neural network; training algorithm; sensitivity analysis

  • Sajid Ali Khna ,
    Muhammad Nazir ,
    Naveed Riaz :

    DOI: 10.12700/APH.10.04.2013.4.12

    Abstract: Gender classification is a major area of classification that has generated a lot of academic and research interest over the past decade or so. Being a recent area of interest in classification, there is still a lot of opportunity for further improvements in the existing techniques and their capabilities. In this paper, an attempt has been made to cover some of the limitations that the associated research community has faced by proposing a novel gender classification technique. In this technique, discrete wavelet transform has been used up to five levels for the purpose of feature extraction. To accommodate pose and expression variations, the energies of sub-bands are calculated and combined at the end. Only those features are used which are considered significant, and this significance is measured using Particle Swarm Optimization (PSO). The experimentation performed on real world images has shown a significant classification improvement and accuracy to the tune of 97%. The results also reveal the superiority of the proposed technique over others in its robustness, efficiency, illumination and pose change variation detection.

    Keywords: Gender Classification; Discrete Wavelet Transform; Particle Swarm Optimization; Feature Selection; Real World Face Images

  • Zoltán Imre Nagy :
    The Role of Legal Forms in Professional Football209-227en [478.32 kB - PDF]EPA-02461-00042-0130

    DOI: 10.12700/APH.10.04.2013.4.13

    Abstract: In the event of a professional football club the fundamental sports objectives can get into contradiction with the intentions of the investor, who might wish, in many cases, to take care primarily for the increase of profits instead of serving the aims of football and the most important designation of a football club. In my study you will find an analysis of legal forms for football clubs, as well as the method of the management by owner determined primarily by such forms. We keep in mind primarily the aspect how these forms influence the possibilities of financing and the acquisition of capital. A form of entrepreneurship and management which takes into account the possibilities of a football club allows for the implementation of the most important objectives of sports, even if it is necessary to involve a considerable amount of capital. Through transportation into an incorporated firm with the appropriate shaping and operation of a group of companies, the aims of capitalisation will also be pursued, while the sports objectives remain the primary ones. (Such forms are limited liability companies, limited partnerships, share companies, registered associations, etc.) On the basis of foreign experience our study intends to make findings and proposals in order to serve establishing and operating such forms of enterprises, which will create – in addition to the priority of sports objectives – also broad possibilities for capitalisation in professional football.

    Keywords: cost, football capital-company; capital; legal form of Business; Registered Association; Ltd; Share Company

  • Ali Tahri ,
    Houari Merabet Boulouiha ,
    Ahmed Allali ,
    Tahri Fatima :

    DOI: 10.12700/APH.10.04.2013.4.14

    Abstract: In this paper, an Advanced Static VAR Compensator (ASVC) based on a voltage type inverter is presented and analysed. The ASVC, which uses the Pulse Width Modulation (PWM) technique, will be modelled in the Park system. Moreover, a low pass filter is introduced at the output of the inverter in order to eliminate the high order harmonics. The proposed system may compensate inductive or capacitive reactive power. The mathematical model thus obtained will be used for the design of a linear quadratic Gaussian (LQG) multivariable (MIMO: Multiple Input Multiple Output) control strategy. The simulation results obtained with MATLAB software are included and will be thoroughly discussed in this paper.

    Keywords: LQG controller; multi-variable control; VAR; Programmed PWM; Low pass filter; ASVC; Matlab; Simulink; SimPowerSystems toolbox