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Acta polytechnica HungaricaVolume 10, Issue No. 6 (2013.)


  • Jih-Gau Juang ,
    Chia-Lung Yu ,
    Chih-Min Lin ,
    Rong-Guan Yeh ,
    Imre J. Rudas :

    DOI: 10.12700/APH.10.06.2013.6.1

    Abstract: This paper aims to design a wheeled mobile robot for path tracking and for automatically taking an elevator by integrating multiple technologies, including image processing using hue-saturation-value color space, pattern recognition using the adaptive resonance theory (ART), and robot control using a fuzzy cerebellar model articulation controller (FCMAC). The ART is used to recognize the button of the elevator. It is an effective competitive learning rule for figure identification. The FCMAC is used for path tracking. Experimental results demonstrate the proposed control system can drive the wheeled robot to take the elevator automatically.

    Keywords: Pattern recognition; Adaptive resonance theory; Fuzzy CMAC; Wheeled mobile robot

  • Peter Fanfara ,
    Marek Dufala ,
    Ján Radušovský :

    DOI: 10.12700/APH.10.06.2013.6.2

    Abstract: Computer security presents one of the fastest-evolving segments in the Information Technologies (IT) area. The traditional system security approach is slightly focused on defence but more attention has been drawn to aggressive forms of defence against potential attackers and intruders. The advanced decoy based technology called Honeypot is a similar form of protection against intrusion. The paper is focused mainly on the proposal of the autonomous hybrid Honeypot and its features in cooperation with the Intrusion Detection System (IDS). The weakness of the detection mechanism is a major IDS shortcoming that can be minimized by using the hybrid Honeypot technology. The proposed architecture can be used as a solution for a rapid increase a security with the autonomous behaviour model in a distributed computer system.

    Keywords: Honeypot; Hybrid Honeypot; Intrusion; Intrusion Detection System; Types of Honeypots

  • Árpád Horváth :
    The Cxnet Complex Network Analyser Software43-58en [756.93 kB - PDF]EPA-02461-00044-0030

    DOI: 10.12700/APH.10.06.2013.6.3

    Abstract: The study of complex networks has become important in several fields of science such as biology, sociology and physics. The collection of network data and the storage, analysis and visualisation of these data have become important contributors to the knowledge of programmers working in these fields. Our cxnet software connects several software packages of the Python language to make these tasks easier. One of the main goals of this development is to provide a comfortable application programming interface for students to develop their own programs. The cxnet software package is able to create the software package network of the Ubuntu Linux distribution. This network is a directed network with several types of vertices and connections. It changes quite fast and can be created easily. These properties make it an ideal object of investigation. The present paper describes some useful measures of the properties of the complex networks, the usage of the cxnet package with some examples, and our experiences in the education.

    Keywords: complex network; graph theory; education; software

  • Slobodan Aleksandrov ,
    Zoran Jovanović ,
    Dragan Antić ,
    Saša Nikolić ,
    Staniša Perić ,
    Radica Aleksandrov :

    DOI: 10.12700/APH.10.06.2013.6.4

    Abstract: The rapid development of science and technology sets high demands for schools and faculties in terms of educating students to be able to manage complex technological systems. On the other hand, the application of new technologies in modern industry requires the creation of real and virtual laboratories capable of producing the conditions for the rapid and reliable transfer of new knowledge and skills from teachers to students. Having this in mind, the main focus of this paper is the realization of a module as a combination of virtual and real learning systems. The advantage of these systems is reflected in a possibility of creating virtual laboratories using three-dimensional models that simulate real industrial systems. Research shows that the use of virtual didactic systems in modern education increases motivation for learning, reduces learning time and enables modelling and simulation of real systems. However, in order to improve professional competencies, an interaction of simulation models with real industrial systems is needed.

    Keywords: Mechatronics; education; learning systems; real and virtual laboratory; simulation

  • Attila Rétfalvi ,
    Mihály Stampfer :
    The Key Steps toward Automation of the Fixture Planning and Design77-98en [954.70 kB - PDF]EPA-02461-00044-0050

    DOI: 10.12700/APH.10.06.2013.6.5

    Abstract: In automating fixture planning and design two major directions can be distinguished – automated dedicated fixture design, and automated modular fixture design. In this paper, the main steps that are needed for automated modular fixture planning and design are presented, and an integrated process planning and fixture design system – developed following these steps – is introduced. These main steps are feature recognition, systematization of the fixturing subtasks, defining the fixturing feature determination rules, systematization of the modular elements, and systematization of the element selection rules.

    Keywords: modular fixture design; CAPP

  • András Keszthelyi :
    About Passwords99-118en [442.93 kB - PDF]EPA-02461-00044-0060

    DOI: 10.12700/APH.10.06.2013.6.6

    Abstract: In our age of cyber war and cyber crime, it is critically important to select and use “good” passwords to protect user accounts. A well-known general rule says that passwords should contain a mix of letters, numbers, and special characters. In this paper I will show mathematically that this rule is a misbelief. Instead of this, the length is the significantly important attribute. Then I will analyse the most common password structures and give an estimation on the time requirements of brute force attacks. (Un)fortunately there are a lot of password lists originating from a lot of intrusions and data thefts to analyse, and we have the incredible results of the latest brute force experiments. On the basis of these calculations we can state that passwords can give us strong protection if we apply some simple rules, unless the password encoding algorithm of the operating system is too weak. It is worth the time and energy for mathematicians to develop stronger hash functions and OS manufacturers to apply them, but this is not discussed here, and nor is how password using habits have changed.

    Keywords: password; user authentication; password cracking; brute force attack; good password

  • Balázs Németh ,
    Alfréd Csikós ,
    Péter Gáspár ,
    István Varga :

    DOI: 10.12700/APH.10.06.2013.6.7

    Abstract: The paper presents the design of cruise control systems considering road and traffic information during the design of speed trajectories. Several factors are considered such as road inclinations, traffic lights, preceding vehicles, speed limits, engine emissions and travel times. The purpose of speed design is to reduce longitudinal energy, fuel consumption and engine emissions without a significant increase in travel time. The signals obtained from the road and traffic are handled jointly with the dynamic equations of the vehicle and built into the control design of reference speed. A robust H∞ control is designed to achieve the speed of the cruise control, guaranteeing the robustness of the system against disturbances and uncertainties.

    Keywords: look-ahead control; multicriteria optimization; robust H∞ control

  • Melinda Majláth :
    Who Does Generate e-WOM and Why? – A Research Proposal135-150en [396.06 kB - PDF]EPA-02461-00044-0080

    DOI: 10.12700/APH.10.06.2013.6.8

    Abstract: E-WOM is a very popular topic among marketing researchers as it gives the chance for consumers to share their reviews almost totally freely. As more and more consumers’ purchase decisions rely on the experiences of others shared on the Web, it has become more important to know what the motivation pattern behind the review writing activity is. There are three research questions in the focus of the present research proposal: (1) What kinds of personality traits are typical for those who generate e-WOM? (2) Why e-WOM is generated? (3) Can personality traits forecast with higher probability whether positive or negative reviews will be posted? The conceptual framework has been developed on an interdisciplinary basis: it is a combination of differential psychology and marketing. The big five personality traits (neuroticism, extraversion, agreeableness, conscientiousness, and openness to experience) are included in order to explain the intention to write electronic reviews. Moreover, a new variable called perceived informational effectiveness is introduced as a potential predictor of e-WOM generation activity.

    Keywords: e-WOM; personality traits; perceived informational effectiveness; NEO-FFI

  • László Ratgeber ,
    Branko Markoski ,
    Predrag Pecev ,
    Dejan Lacmanović ,
    Zdravko Ivanković :

    DOI: 10.12700/APH.10.06.2013.6.9

    Abstract: Basketball is one of the most popular sports. During a basketball game, statisticians note a large amount of information, helping coaches and players to improve their game and to analyse opponents in order to prepare for the following games. Due to amount and complexity of the information, basketball is the ideal discipline for the application of data mining techniques, especially neural networks that enable one to extract conclusions and knowledge from these data. In this paper, we compared the First senior leagues for men and for women in Serbia during the 2011/2012 season, and from these statistics, we calculated influence of certain parameters on a game’s outcome. We concluded that the most influential parameter, in both leagues, is the offensive rebound. In men basketball then follows the three-point shot, the two-point shot and the one-point shot. In women’s basketball, after the defensive rebound, the two-point shot follows, and then turnovers.

    Keywords: data mining; neural networks; statistics; basketball

  • Ágnes Bogárdi-Mészöly ,
    András Rövid ,
    Hiroshi Ishikawa ,
    Shohei Yokoyama ,
    Zoltán Vámossy :
    Tag and Topic Recommendation Systems171-191en [709.63 kB - PDF]EPA-02461-00044-0100

    DOI: 10.12700/APH.10.06.2013.6.10

    Abstract: The spread of Web 2.0 has caused user-generated content explosion. Users can tag resources in order to describe and organize them. A tag cloud provides rough impression of relative importance of each tag within the overall cloud in order to facilitate browsing among numerous tags and resources. The size of its vocabulary may be huge, moreover, it is incomplete and inconsistent. Thus, the goal of our paper is to establish tag and topic recommendation systems. Firstly, for tag recommendation system novel algorithms have been proposed to refine vocabulary, enhance reference counts, and improve font distribution for enriched visualization. Secondly, for topic recommendation system novel algorithms have been provided to construct a special graph from tags and evaluate reference counts for topic identification. The proposed recommendation systems have been validated and verified on the tag cloud of a real-world thesis portal.

    Keywords: social network; tag cloud; tag analysis; vocabulary; reference count; font distribution algorithm; topic recommendation

  • József Tick ,
    Imre Csanád ,
    Zoltán Kovács :
    Business Process Modeling and the Robust PNS Problem193-204en [375.65 kB - PDF]EPA-02461-00044-0110

    DOI: 10.12700/APH.10.06.2013.6.11

    Abstract: In this paper we define and investigate a new direction of the P-graph-based Business Process Modeling which we call the robust PNS problem. We consider the model where for each operating unit two costs are given, it has a nominal cost and an extended cost, and we know that at most b operating units have the extended cost, the others will have the nominal cost. We present a branch and bound based exact solution algorithm for the general problem, and a faster, polynomial time dynamic programming algorithm for the case of the hierarchycal problems.

    Keywords: Business Process Modeling; PNS problem; robust problems; P-graphs

  • George L. Kovács :

    DOI: 10.12700/APH.10.06.2013.6.12

    Abstract: The goal of this work is the technical, ecological, environmental and social examination of the life-cycle (LC) of any product (consumable, service, production) using the TYPUS metrics and the KILT model. The life-cycle starts when the idea of a product is born and lasts until complete dismissal through design, implementation and operation, etc. In the first phases requirements’ specification, analysis, several design steps (global plan, detailed design, assembly design, etc.) are followed by part manufacturing, assembly, testing, diagnostics and operation, advertisement, service, maintenance, etc. Then finally disassembly and dismissal are coming, but dismissal can be substituted by re-cycling (e.g. melting the metals) or re-use (used parts applications). Qualitative and quantitative evaluations of enterprise results are supported by the new models and metrics.

    Keywords: enterprise delivery; environment; life-cycle management; energy; sustainability

  • Laslo Gogolak ,
    Szilveszter Pletl ,
    Dragan Kukolj :
    Neural Network-based Indoor Localization in WSN Environments221-235en [908.00 kB - PDF]EPA-02461-00044-0130

    DOI: 10.12700/APH.10.06.2013.6.13

    Abstract: With the advancement of wireless technology even more wireless sensor network (WSN) applications are gaining ground. Their field of application is increasingly widening. This paper examines the WSN application which allows indoor localization based on the Fingerprint (FP) method. The communication between the modules was monitored during the experiment whereby the received radio signal strength indicator (RSSI) values from 5 modules were recorded by a mobile sensor. The received data was used for training of the feed-forward type of neural network. Through use of the trained neural network and the measured RSSI values an indoor localization was realized in a real environment. The neural network-based localization method is analyzed applying the cumulative distribution function (CDF). For the reference model the well-known weighted k-nearest neighbour (WkNN) method was used.

    Keywords: Fingerprint localization; WSN; Received Signal Strength; Neural Network; Mobile sensor

  • S. Rukmani Devi ,
    P. Rangarajan ,
    J. Raja Paul Perinbam :

    DOI: 10.12700/APH.10.06.2013.6.14

    Abstract: This study presents a fast search algorithm and its Very Large Scale Integration (VLSI) design to implement an Enhanced Diamond Search (EDS) of Block-based Motion estimation for video compression systems. The proposed algorithm reduces the number of search points with a slight increase in average Sum-of-Absolute Difference (SAD) per pixel and significant reduction in Peak Signal-to-Noise Ratio (PSNR) than the Full search (FS). The speed improvement ratio is 11.26%. A novel Motion Estimation (ME) algorithm is proposed in this study that exhibits some properties with potential to facilitate optimized VLSI implementation and to achieve high performance for real video sequences. The main characteristic of this proposed architecture is possessing of only five processing elements (PE) that are used to calculate minimum SAD by using efficient comparators and compressors. Simulation results indicate that our proposed architecture employs low power and processes the video data with high speed than existing architectures without significant change in the video quality.

    Keywords: Motion Estimation; VLSI; Diamond search; video compression; PSNR; SAD