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Acta polytechnica HungaricaVolume 13, Issue No. 3. (2016.)


  • József Abaffy :
    Reprojection of the Conjugate Directions in the ABS Class. Part I7-24en [166.62 kB - PDF]EPA-02461-00065-0010

    Abstract. In the paper we introduce a modification of the Kahan-Parlett ”twice is enough” [20] algorithm for conjugate direction algorithms. We apply the developed algorithm for the computation of conjugate directions in three subclasses of the ABS methods. In this part of the paper we give theoretical results and a preliminary test result as well. In the second part of our paper we test some elements of Subclass S2, while in the third part Subclass S6 and S7 will be examined. In this last part we give the conclusions regarding the reprojection of conjugate directions in the ABS classes.

    Keywords: twice is enough, reprojection of conjugate direction methods, ABS methods

  • Razvan-Mihai Aciu ,
    Horia Ciocarlie :

    Abstract: Modern GPUs provide considerable computation power, often in the range of teraflops. By using open standards such as OpenCL, which provide an abstraction layer over the GPUs physical characteristics, these can be employed to solve general computation tasks. Massively parallel algorithms used in domains such as simulation, graphics, artificial intelligence can greatly expand their application range. It is of great importance for an application to run parts of itself on GPUs and in this respect a number of issues such as OpenCL code generation, data serialization and synchronization between application and GPU must be observed. At the same time, the GPU limitations impose some limits on their applicability to general computation tasks, so an application must carefully assess what parts are suitable for this kind of execution. The computing resources must be abstracted and when possible these should be interchangeable without modifying the source code. We present a new algorithm and library which dynamically generates OpenCL code at runtime for parts of its application in order to run these parts on GPU. Our library automatically handles tasks such as data serialization and synchronization. The practical results are significant and we succeeded in obtaining important speedups using only a straightforward Java implementation of the test algorithm, without any platform specific constructs.

    Keywords: Java; OpenCL; GPU; code generation

  • Nafissa Yussupova ,
    George Kovács ,
    Maxim Boyko ,
    Diana Bogdanova :

    Abstract: This paper proposes a conceptual approach to the research into customer satisfaction based on a detailed analysis of consumer reviews written in natural languages using Artificial Intelligence (AI) techniques such as Text Mining, Aspect Sentiment Analysis, Data Mining and Machine Learning. Special Internet resources for accumulating customer reviews, such as yelp.com, tripadviser.com and tophotels.ru, are used as data sources. To evaluate the efficacy of the proposed approach, we have carried out an experiment on qualitative and quantitative research of hotel client satisfaction. Even “Big data” applications were taken into account as a possibility to evaluate quality of services. The obtained results prove the effectiveness of the proposed approach to decision support in product quality management and argues for using it instead of classical methods of qualitative and quantitative research into customer satisfaction.

    Keywords: quality management services; analysis of customer feedback; CPM; sentiment analysis

  • José Alfonso Aguilar ,
    Irene Garrigós ,
    Jose-Norberto Mazón :

    Abstract: Requirements Engineering (RE) is the first phase in the software development process during which designers attempt to fully satisfy users’ needs. Web Engineering (WE) methods should consider adapting RE to the Web’s large and diverse user groups. The objective of this work is to classify the literature with regard to the RE applied in WE in order to obtain the current “state-of-the-art”. The present work is based on the Systematic Literature Review (SLR) method proposed by Kitchenham; we have reviewed publications from ACM, IEEE, Science Direct, DBLP and World Wide Web. From a population of 3059 papers, we identified 14 primary studies, which provide information concerning RE when used in WE methods.

    Keywords: Web Engineering; Systematic Literature Review; Requirements Engineering; Model-Driven Engineering

  • Ivan Pinćjer ,
    Dragoljub Novaković ,
    Uroš Nedeljković ,
    Nemanja Kašiković ,
    Gojko Vladić :

    Abstract: This paper presents a study related to image reproduction quality assessment. The experiment was designed to determine the impact of halftone image dimensions on the perception of image fidelity and grain structure, these two, being important quality attributes. Subjective quality assessment experiments were designed to complement recently published findings obtained by objective image metric methods for quality assessment. Image fidelity and grain structure are understandable to the observers that are not familiar with the methods used to determine image quality. These attributes are directly dependent on the chosen halftoning method. In this research, the samples were halftoned using two different types of screening methods: frequency modulation (FM) and amplitude modulation (AM) method. The experiment produced around 4000 data samples, which were analyzed by standard statistical methods. Results indicate a significant influence of the image size and halftoning method on the subjective quality assessment.

    Keywords: halftoning; size of the reproduction; psychophysical experiment; print quality; image quality

  • Nándor Vincze ,
    Zsolt Ercsey ,
    Tamás Kovács ,
    József Tick ,
    Zoltán Kovács :
    Process Network Solution of Extended CPM Problems with Alternatives101-117en [549.43 kB - PDF]EPA-02461-00065-0060

    Abstract: In this paper a novel method to extend the problem range of CPM problems is given. First, the CPM problem is transformed into a process network problem. It is shown how the directed bipartite process network has to be generated, and the corresponding mathematical programming model should be formulated. Time optimal, cost optimal, time optimal with additional cost constraints and cost optimal with additional time constraints mathematical programming models are given. Moreover, it is illustrated how alternative cases may appear in the structure. An example illustrates the efficiency of the present work.

    Abstract: In this paper a novel method to extend the problem range of CPM problems is given. First, the CPM problem is transformed into a process network problem. It is shown how the directed bipartite process network has to be generated, and the corresponding mathematical programming model should be formulated. Time optimal, cost optimal, time optimal with additional cost constraints and cost optimal with additional time constraints mathematical programming models are given. Moreover, it is illustrated how alternative cases may appear in the structure. An example illustrates the efficiency of the present work.

  • Valentin Kónya ,
    Dejan Matić ,
    Jasmina Pavlović :

    Abstract: How individuals behave in organizations became an emerging topic among both the scientific and business world during the past decade. Commitment of employees to their work and the organization is considered an important indicator of successful organizational behavior. Previous research on the demographic and individual characteristics of employees, as well as, job and characteristics of organizations has shown that they have significant influence on organizational commitment. This paper intends to reveal some crucial information on how these characteristics influence organizational commitment in Central European organizations. Our analysis resulted in several important findings, revealing some interesting differences and when compared to other studies conducted in mostly western developed environments:

    1) Gender does not have any influence on organizational commitment

    2) Characteristics of organizations and most demographic characteristics have little effect on organizational commitment

    3) Job characteristics have strong impact on organizational commitment in Central European Organizations

    The research, in this paper, is part of a broader study, investigating the mutual influence of several leadership and organizational behavior related variables. Additional, partial results of this study, published in papers and conference proceedings from 2014, with the overall results scheduled for publishing in 2015.

    Keywords: organizational commitment; demographic characteristics of employees; job characteristics; characteristics of organizations

  • Sándor Szalai ,
    János Nagy ,
    István Horváth ,
    Bálint Sódor ,
    Gábor Tróznai ,
    Kálmán Balajthy ,
    János Sulyán :
    An Overview of Low-Cost EGSE Architectures Improvement139-158en [1.06 MB - PDF]EPA-02461-00065-0080

    Abstract: this article presents EGSE architecture improvement from the 1980s until nowadays following hardware development. In EGSE development we looked for cost-effective solutions by applying available industrial products. We started EGSE development for VEGA-Halley mission in the 1980s, based on a microprocessor standalone system. The next stages of EGSE architecture were based on IBM compatible PCs with dedicated interface cards. The subsequent generation of EGSE consisted of two physical units, one was a commercial computer and the other one was an embedded processor card for signal level simulation. There was a serial communication line between the units. The fourth generation of EGSE contains high speed bus for internal communication and the use of embedded processor made simulation and data acquisition possible in real-time. The software was developed in assembly in the first generation of EGSE. The further operating software runs on a distributed intelligence system containing Windows and real-time Linux platforms.

    Keywords: EGSE; VEGA-Halley; Spectrum-X-Ray-Gamma; Rosetta; Comet; Churyumov-Gerasimenko; lander

  • Milinko Mandić ,
    Zora Konjović ,
    Mirjana Ivanović :
    Platform for Computer-aided Harmonization of Informatics Curricula159-179en [932.74 kB - PDF]EPA-02461-00065-0090

    Abstract: This paper presents a new platform aimed at improving informatics teaching by computer-aided harmonization of the standardized secondary school informatics curriculum and curricula by which teachers of informatics are educated. The platform relies on competency based curricula ontologies and the harmonization method based on ontology alignment. The secondary school informatics curriculum ontology was built to comply with the ACM K12 standard, while the teachers’ curriculum ontology was built based on selected existing curricula, due to the lack of explicit standardization in the field. A task-specific method for curricula harmonization was developed that relies on standard ontology alignment algorithms. The prototype software tool was implemented and used by independent experts to verify the proposed method, by investigating compliance of the standardized secondary school informatics curriculum and the domain (informatics) segment of the teachers’ curriculum.

    Keywords: Informatics education; curriculum; ontology alignment; ACM K12

  • N. Muthukumar ,
    Seshadhri Srinivasan ,
    K. Ramkumar ,
    K. Kannan ,
    Valentina Emilia Balas :
    Adaptive Model Predictive Controller for Web Transport Systems181-194en [558.07 kB - PDF]EPA-02461-00065-0100

    Abstract: In web transport systems (WTS), parameter variations in transported material affects the product quality and integrity of the processed material. This investigation presents an adaptive model predictive controller for WTS in process industries considering the variations of the web radius with respect to time. The proposed controller uses a radius approximation algorithm for estimating the changes in web radius. The controller then updates the WTS model with the estimated changes in web radius that enters as the disturbance in the system. Then, the controller uses the model with disturbance estimation algorithm and an optimization routine to compute the future control moves that guarantee product quality, while simultaneously satisfying the physical and operating constraints of WTS. Furthermore, it assures product quality with web radius variations. The main advantage of the proposed controller is, it combines the predictive and optimality features of MPC with adaptation provided by an adaptive controller. Simulations on WTS used in paper industries illustrates the performance and advantages derived by employing the adaptive MPC against conventional MPC. Our results show a reduction in the peak overshoot, integral absolute error, and integral time square error by using the adaptive MPC.

    Keywords: Process industries; Adaptive model predictive controller (AMPC); Web Transport Systems (WTS); Web Transport Controllers (WTC); parametric variations

  • Judith Pálfi ,
    Peter Holcsik :
    Emergency Situations Management with the Support of Smart Metering195-206en [622.88 kB - PDF]EPA-02461-00065-0110

    Today’s extreme weather conditions cause more and more emergency situations every year. These emergencies represent a big challenge for today’s power supply companies. The task to be solved in these critical situations is the processing of the huge volume of incoming data and their transmission by one-line messages (tolerant protection signals) to the operation controllers. In addition to this, high-tech equipment is to be provided in order to handle the large quantity of internal and external data and information.

    According to the opinion of the Research Group of Applied Disciplines and Technologies in Energetics (AD&TE), the optimal solution to deal with the above challenges is the use of Smart Metering devices. The implementation of these devices will result in two directional communication which reduces troubleshooting time and simultaneously supplies the required quantity of information.

    Keywords: management of emergency events; Smart Metering

  • Nemanja Berber ,
    Agneš Slavić :

    Abstract: The purpose of this paper is to explore the practice of outsourcing in Human Resource Management (HRM) in countries of Europe-EU and Serbia. An analytical exploration of available literature in the area of outsourcing was made, as well as a statistical analysis of the CRANET research data to determine the actual level of outsourcing in HRM in companies around the world, and to make comparison between Serbian compensation outsourcing practice and countries of 20 EU countries. Results of the analysis pointed out that outsourcing of payroll and benefits is used lesser than outsourcing in the field of pensions. Serbian companies use outsourcing at a new low level. There are statistically significant positive correlations between outsourcing of payroll, pension and benefits among each other, and with the number of employees in HR department. A multiple regression model was used to explore the predictors of HR outsourcing. The differences between EU countries in the area of compensation outsourcing have been discussed.

    Keywords: HR; Human Resource; outsourcing; compensation; EU; Serbia; Cranet