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Acta polytechnica HungaricaVolume 13, Issue No. 6. (2016.)


  • Hsin-Yi Li ,
    Yeh Rong-Guan ,
    Lin Yu-Che ,
    Lin Lo-Yi ,
    Zhao Jing ,
    Lin Chih-Min ,
    Imre J. Rudas :

    Abstract: This study designs a stable and convergent adaptive fuzzy cerebellar model articulation classifier for the identification of medical samples. Research on medical diagnosis is important and complex. Uncertainty is unavoidable in medical diagnosis. The symptoms are one of the uncertainties of an illness and may or may not occur as a result of the disease. There is an uncertain relationship between symptoms and disease. Diagnostic accuracy can be improved using data forecasting techniques. This study proposes a generalized fuzzy neural network, called a fuzzy cerebellar model articulation controller (FCMAC). It is an expansion of a fuzzy neural network and it will be shown that the traditional fuzzy neural network controller is a special case of this FCMAC. This expansion type fuzzy neural network has a greater ability to be generalized, has greater learning ability and a greater capacity to approximate than a traditional fuzzy neural network. The steepest descent method has a fast convergent characteristic, so it is used to derive the adaptive law for the adaptive fuzzy cerebellar model classifier. The optimal learning rate is also derived to achieve the fastest convergence for the FCMAC, in order to allow fast and accurate identification. The simulation results demonstrate the effectiveness of the proposed FCMAC classifier.

    Keywords: cerebellar model articulation controller; fuzzy rule; classifier; diseases diagnosis

  • Tomáš Lojka ,
    Marek Bundzel ,
    Iveta Zolotová :
    Service-oriented Architecture and Cloud Manufacturing25-44en [772.12 kB - PDF]EPA-02461-00068-0020

    Abstract: This paper deals with service oriented architecture (SOA) and cloud technologies in the industry. SOA and cloud technologies have considerable potential to improve industrial production and control. This paper analyzes those systems and proposes an architecture for device integration, data acquisition, data processing and remote control. We designed and implemented SOA for industrial technological routers, allowing device integration in the designed architecture and cloud interoperability. We used a private cloud and designed atomic and composite services. These services empower the architecture with data acquisition, processing and data analytics. The architecture offers a solution for connecting to an industrial network with a remote HMI client and a cloud MES application. We used greenhouse and assembly lines models, a PLC, an eWON, an eFive, a private cloud (Windows Azure Pack), Android, Windows tablet applications, smartphones and desktop computers. We designed and implemented a multi-tenant cloud architecture. In our experiments, we verified our architecture in two simulated plant divisions. Each of them has their own implementation. Our architecture offers better interactivity with suppliers, cooperation with internal systems and can be easily adapted to other extensions of the processes of a plant.

    Keywords: Industrial cloud; IoT; SCADA; SOA; MES, Windows Azure

  • Tamás Réti ,
    Imre felde :
    On Some Properties of Pseudo-Semiregular Graphs45-65en [678.56 kB - PDF]EPA-02461-00068-0030

    Abstract: The application of the bipartite pseudo-semiregular graphs (BPS graphs) has recently had a growing importance in mathematical chemistry, mainly for QSAR (quantitative structure-activity relations) and QSPR (quantitative structure-property relations) studies. The aim of the research presented herein, is to give a systematic survey on the fundamental characteristics of BPS graphs and summarize some novel results concerning their structural-topological properties. We propose some practical methods for the construction of BPS graphs from various parent graphs. Moreover, a simple procedure is outlined by which a finite set of BPS graphs possessing the same spectral radius or the same second Zagreb index can be generated. Additionally, as a result of our investigations, it is verified that there is a strong correspondence between BPS graphs and balanced tree graphs of diameter 4.

    Keywords: mathematical chemistry; strongly balanced tree graphs; Zagreb indices

  • Dalibor Dobrilovic ,
    Zeljko Stojanov ,
    Stefan Jäger ,
    Zoltán Rajnai :

    Abstract: An increasing number of wireless Internet users and deployed wireless access points over the past several years and have raised the importance of wireless security issues. The absolute majority of wireless users are not IT professionals, but a population unaware of wireless security types, settings and importance. Wireless security assessment and analytics can help in raising the security awareness of users and in increasing their skills, leading to improvement of the entire security situation. In this paper a short overview of wireless security assessment and history is presented. The methodology and tools for a more accurate wireless security assessment, including data acquisition, processing and analysis, are offered. The proposed methodology and tools are used for processing wireless scan results for the two capital cities, Hungary (Budapest) and Serbia (Belgrade). The possibility of access point configuration changes and security improvement has also been investigated. The research results and potential improvements of wireless security situation are discussed.

    Keywords: wireless network security; Wardriving; wireless security assessment;

  • Bálint Bedzsula ,
    János Kövesi :

    Abstract: Customer oriented conduct and process-based thinking have become quasi-vital pillars of long-lasting competitiveness, for the business world today. Following this approach should result in satisfied customers, decreased costs and efficient employees. However, the leadership in higher education is just starting to learn this way of thinking. The increasing focus on quality issues and the process-related approach to this is catalyzed by several factors. For this reason, we have decided to take the analysis of a novel approach in higher education as the main topic of this study. The focus of our analysis is the organizational process of preparing the Scientific Students' Associations (SSA) conference; this conference is an indispensable element in the effective nurturing of talent. We used a questionnaire-based survey - which provided an in-depth analysis of the different elements of the SSA activities - to make proposals related to possibilities for improvement that could increase the satisfaction of university students.

    Keywords: higher education; talent nurturing; process management; university student satisfaction questionnaire; quality improvement

  • Slavica Tomić ,
    Maja Strugar Jelača ,
    Agneš Boljević :

    Abstract: The aim of this study is to establish the relationship between the degree of an organizations' innovation and external dimensions, taking into account the dynamics of fluctuations from the environment together with the characteristics of organizations, implemented incremental management innovations and realized business results. The object of the research is the analysis of a changeable contextual frame of innovation in large organization systems. While doing the research, we observed the performance of large organizational systems during 2012 and 2013, depending on the fluctuations of external and internal factors that influence innovation. A random sample of 50 large organizational systems, in the territory of the Republic of Serbia was used, which represents 5% of the base number and covers all regions and business sectors. During the testing of set hypotheses, we used the following statistical methods: ANOVA, MANOVA, and the Kruskal-Wallis tests. The research results indicate the existence of the difference in innovation degree, depending on consumers’ preferences, as external dimension and number of employees, values of operating income and operating assets as internal dimension, as well as, a statistically significant correlation between entrepreneur-oriented managerial behavior as an aspect of management innovation and organizations' innovation.

    Keywords: contextual perspective; institutional changes; entrepreneur-oriented managerial behavior; organization's innovation

  • László Muka ,
    István Derka :

    Abstract: Simulation performance prediction methods make possible the realization of performance improvement potentials of Parallel Discrete Event Simulation (PDES) methods, important in the analysis of complex systems and large-scale networks. Currently, high performance execution environments (emerging clusters and computing clouds) advance the development of quality/cost analysis capabilities of performance prediction methods. In this paper, for the evaluation and management of prediction correctness/cost, the efficacy, efficiency and effectiveness coefficients and improvement operations are defined for predictions. The performance coefficients and improvement operations are embedded in the rough-set-modeling and learning process and presented as an enhancement approach of the conventional Coupling Factor Method (CFM). A case study based on the CFM analysis of PDES of a closed queuing network model is presented. In the example, after rough-modeling and train-and-test analysis, the correctness/cost evaluation and effectiveness improvement operations are shown for series of predictions and the feedback connection to modeling refinement phase is demonstrated too.

    Keywords: Parallel Discrete Event Simulation; simulation performance prediction; quality/cost analysis; Systems Performance Criteria; Rough Set Theory; Coupling Factor Method

  • Foroozan Zare ,
    Árpád Veress :

    Abstract: The development of an improved mathematical model is reported, herein, for modeling the thermo-dynamic processes of triple spool mixed turbofan jet engines with an afterburner, at start conditions with special care for the verification. The T-s diagram and the main characteristics of the engines are determined by a concentrated parameterdistribution type method, implemented in the MATLAB environment. The governing equations are based on mass, energy balance and the real thermo-dynamic processes. A non-linear constraint optimization method is used, for identifying the unknown parameters. Temperature and component mass fraction dependent gas properties are calculated by iteration cycles in case of functional dependencies. A new and more accurate equation is derived and applied for determining the critical pressure at converging nozzle flow with consideration of the local material properties. The thermo-dynamic analyses are completed for NK-32 and NK-25 turbo jet engines. The plausibility of the method and the verification the new equation is provided.

    Keywords: triple spool turbojet engine, thermodynamics, mathematical model, verification

  • Gergely Bojtár ,
    Béla M. Csizmadia ,
    János Égert :

    Abstract: Knowledge of the material properties is important at machine design from composite materials. This information cannot be found in related literature and is not standard, therefore, it was necessary to determine, by measurements and by basic experiments of the mechanics of materials. This paper presents a new 3D finite element (FE) model-cell for the modeling of the material properties of a roving. By this numerical modeling method, one can determine the orthotropic and macroscopic material properties of a roving. This model-cell, models numerically, a roving, which consists of multiples of thousands of fibers that are embedded in a matrix material, as a homogenized orthotropic material. The numerical results of the material properties of the roving, can be applied to the definition of the macroscopic material properties of fiber reinforced composite laminates.

    Keywords: roving; orthotropic material properties; fiber reinforced composite; finite element method; model-cell

  • José António Tenreiro Machado ,
    Afshin Babaei ,
    Behrouz Parsa Moghaddam :

    Abstract: In this paper, a weighted algorithm, based on the reduced differential transform method, is introduced. The new approach is adopted in the approximate analytical solution of the Cauchy problem for the Burgers-Huxley equation. The proposed scheme considers the initial and boundary conditions simultaneously for obtaining a solution of the equation. Several examples are discussed demonstrating the performance of the algorithm.

    Keywords: Weighted reduced differential transform method; Burgers-Huxley equation; Cauchy problem.

  • László Zsidai ,
    László Kátai :

    Abstract: Abrasion wear is one of the most common failure mechanisms of moving machine elements. Because of their mechanical and tribological ability, engineering polymer composites can be chosen to replace metal parts in certain applications (e.g. bearings). Increasingly newer polymer composites are appearing and data on their tribological behaviours are incomplete, it is not so easy to choose from this wide wide selection of choices (mechanical properties, price, etc.). In the present study two groups of polymer composites (PA 6 and PEEK with different mechanical properties and prices) are experimentally investigated by a unique small-scale abrasion tribotesting. The main objectives of our study were to compare the tribological properties of composites and to investigate the effect of different additives and mechanical properties. The tests were prepared using the pin on plane (band) model system and tested on different loads (11.5 N and 23 N), where the abrasion mating surface was emery cloth. We found among other things that the fillings have a favourable effect on PA opposite to PEEK. The short carbon fibres proved better for improving wear resistance as compared to short glass fibres. Our present work is connected to a research project, which aims to map the tribological features of different polymer composites.

    Keywords: abrasion; PA 6; PEEK; friction; tribology

  • Attila Nemes :

    Abstract: Multi-rotors are popular unmanned aerial vehicles (UAVs) of versatile applicability. This paper presents a novel grey-box fuzzy-system identification method for multi-rotor UAV dynamic modelling by continuous, periodic, fuzzy-partitions based systems. The method is initiated by a linear, continuous, periodical transformation of fuzzysystem input data and a special parameterization of the antecedent part of fuzzy-systems that result in circularly connected fuzzy-partitions for antecedents. Fuzzy-rule consequents are designed so that the system output is continuous for the full input space of the naturally periodic angular orientation over the complete [0, 2π) interval, including the 2π-0 transition at complete rotations. The antecedent parameter representation method of fuzzyrules ensures upholding of predefined linguistic value ordering and ensures that fuzzypartitions remain intact throughout an unconstrained hybrid evolutionary and gradient descent based optimization process. The dynamic model is based on the Euler-Lagrange equations structure. State variables and their derivatives remain explicit, while their nonlinear inertia multipliers are identified with fuzzy-systems. Christoffel symbols, partial derivatives of fuzzy-systems are used for Coriolis effects, gyroscopic and centrifugal terms modelling. Linear parameters of the model are evaluated by SVD-based least squares method. Non-linear parameters are subjected to a global multi-objective evolutionary optimization scheme and fine-tuned by gradient descent based local search. The training data is collected along specially designed trajectory of smooth high order derivatives.

    Keywords: multi-rotor UAV; grey-box dynamic model; continuous periodic fuzzy-partition system; optimal smooth trajectory; hybrid multi-objective genetic algorithm