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Acta polytechnica HungaricaVolume 11, Issue No. 8 (2014.)


  • Shahaboddin Shamshirband ,
    Nor Badrul Anuar ,
    Miss Laiha Mat Kiah ,
    Sanjay Misra :
    Anomaly Detection using Fuzzy Q-learning Algorithm5-28en [858.87 kB - PDF]EPA-02461-00054-0010

    Abstract: Wireless networks are increasingly overwhelmed by Distributed Denial of Service (DDoS) attacks by generating flooding packets that exhaust critical computing and communication resources of a victim’s mobile device within a very short period of time. This must be protected. Effective detection of DDoS attacks requires an adaptive learning classifier, with less computational complexity, and an accurate decision making to stunt such attacks. In this paper, we propose an intrusion detection system called Fuzzy Q-learning (FQL) algorithm to protect wireless nodes within the network and target nodes from DDoS attacks to identify the attack patterns and take appropriate countermeasures. The FQL algorithm was trained and tested to establish its performance by generating attacks from the NSL-KDD and CAIDA DDoS Attack datasets during the simulation experiments. Experimental results show that the proposed FQL IDS has higher accuracy of detection rate than Fuzzy Logic Controller and Q-learning algorithm alone.

    Keywords: Intrusion detection; Fuzzy system; Reinforcement learning; Multi Agent System

  • Optimisation of Computer-aided Screen Printing Design29-44en [918.00 kB - PDF]EPA-02461-00054-0020

    Abstract: Computer-aided screen printing is a widely used technology in several fields like the production of textiles, decorative signs and displays and in printed electronics, including circuit board printing and thick film technology. Even though there have been many developments in the technology, it is still being improved. This paper deals with the optimisation of the screen printing process. The layer deposition and the manufacturing process parameters strongly affect the quality of the prints. During this process the paste is printed by a rubber squeegee onto the surface of the substrate through a stainless steel metal screen masked by photolithographic emulsion. The off-contact screen printing method is considered in this paper because it allows better printing quality than the contact one. In our research a Finite Element Model (FEM) was created in ANSYS Multiphysics software to investigate the screen deformation and to reduce the stress in the screen in order to extend its life cycle. An individual deformation measuring setup was designed to validate the FEM model of the screen. By modification of the geometric parameters of the squeegee the maximal and the average stress in the screen can be reduced. Furthermore the tension of the screen is decreasing in its life cycle which results in worse printing quality. The compensation of this reducing tension and the modified shape of squeegee are described in this paper. Using this approach the life cycle of the screen could be extended by decreased mechanical stress and optimised off-contact.

    Keywords: screen printing; FEM; optimisation

  • Ivan Buzurovic ,
    Dragutin Lj. Debeljkovic ,
    Vladimir Misic ,
    Goran Simeunovic :

    Abstract: In this article, stability of the robotic manipulator with time delay in open kinematic chain configuration was analyzed. The dynamic equations of motions were derived for one five-degree-of-freedom (DOF) robotic system with system latency. The mathematical model includes the model of the actuators to define the parameters of the actuators that can stabilize such a system. Investigation of the system stability was performed using novel stability conditions. The system state responses and the system stability were analyzed for different time delays. The proposed control methodology was shown to be appropriate to maintain the stability of the robotic system during tracking tasks. To analyze the concept, we presented a numerical example together with an extensive system simulation. The stability analysis showed the full compliance of the system behavior with the desired system dynamics. The proposed method can be used for the stability analysis of any robotic system with state delays in the open kinematic chain configuration

    Keywords: stability; stability conditions; robotic systems; time delay

  • Manu Vardhan ,
    Dharmender Singh Kushwaha :

    Abstract: Data centers are built to provide a highly available and scalable infrastructure on which the applications run. As enterprises grow, so do their application need, along with resources required for additional application-specific services. This increase in bottom line expense heightens the overall resource requirement. This paper provides solution to mitigate the impact of these expenses by proposing a file replication and consistency maintenance mechanism that enhances the manageability, scalability, and high availability of resource in these environments. To keep files consistent, changes made at one replica of the file are reflected on other replicas in minimum possible time. File replica is updated on-demand by only propagating the required partial updates. The results show that as compared to Google File System (GFS), the proposed partial write rate shows an improvement of 38.62% while updating the stale replicas. Time required for invalidating the replicas decreases by 34.04% and the time required to update the replica on FRS reduces by 61.75%. Process algebraic approach has been used to establish the relationship between the formal aspect of the file replicating server and its architectural model

    Keywords: Cluster Computing; Consistency; File Replication; Process algebra

  • András Mucsi :

    Abstract: This paper deals with the metallurgical phenomena occurring in aluminium-killed low carbon steels during industrial batch annealing process. The formability of these steels is strongly influenced by the nitride precipitation – recrystallization interaction during the batch annealing stage of the production technology. The accurate precipitation kinetics of nitrides is not clearly described yet because of the difficult evaluation of precipitated fraction of nitrides in cold rolled state steels. The aim of this study is to present a methodology for measuring the precipitated nitride fraction in cold rolled state, moreover to investigate the precipitation – recrystallization sequence during batch annealing process. Another purpose of this study is to give the conditions of the development of good deep-drawable microstructure. The nitride precipitation process in cold rolled and annealed state is measured using a special thermoelectric power test based methodology. On the basis of the experimental work, it is concluded that good formable microstructure develops if the precipitated nitride fraction reaches at least ~40% at the beginning of the recrystallization. This condition can be satisfied if the heating rate is held between 30 and 45 °C/h during the industrial batch annealing process.

    Keywords: Al-killed low carbon steel; nitride precipitation; thermoelectric power

  • Ugur Bekcibasi ,
    Mahmut Tenruh :

    Abstract: Localization is a prominent application and research area in Wireless Sensor Networks. Various research studies have been carried out on localization techniques and algorithms in order to improve localization accuracy. Received signal strength indicator is a parameter, which has been widely used in localization algorithms in many research studies. There are several environmental and other factors that affect the localization accuracy and reliability. This study introduces a new technique to increase the localization accuracy by employing a dynamic distance reference anchor method. In order to investigate the performance improvement obtained with the proposed technique, simulation models have been developed, and results have been analyzed. The simulation results show that considerable improvement in localization accuracy can be achieved with the proposed model.

    Keywords: RSSI; Wireless Sensor Networks; WSN Localization

  • Viet-Cuong Nguyen ,
    Xhevi Qafmolla ,
    Karel Richta :

    Abstract: As modern distributed and cloud architecture keep gaining their popularity, web services have become the programmatic backbones of more and more systems. Developing web services requires gathering information from different aspects. Model-driven engineering promises to ease the burden of development and promote reuse of web services by focusing more on a higher level of abstraction. Current approach of modeling web services using UML is not well-suited since UML is created for multiple disciplines and is not specific for web service development. With current growing scale of distributed systems, the challenge is not only in development but also integration and maintenance of web services. Introducing a domain specific language (DSL) for modeling of web services promises to become a novel approach and could be the solution to the current problem with web service modeling and development. This article outlines the analysis as well as the current state of the problem domain and introduces an approach to model-driven development of web services by implementing a domain specific language called SWSM (Simple Web Service Modeling). This approach aims to solve problems that UML could not effectively resolve and promote efficiency with a non-complex language facility for modeling and code generation of web services. Our best practices and observation during the design of SWSM are also presented.

    Keywords: web service; model-driven development; DSL; SWSM

  • Dalai Tang ,
    Janos Botzheim ,
    Naoyuki Kubota :

    Abstract: This paper proposes a method for multi-modal perception of human-friendly robot partners based on various types of sensors built in a smart phone. The proposed method can estimate human interaction modes by fuzzy spiking neural network. The learning method of the spiking neural network based on the time series of the measured data is explained as well. Evolution strategy is used for optimizing the parameters of the fuzzy spiking neural network. Several experimental results are presented for confirming the effectiveness of the proposed technique. Finally, the future direction on this research is discussed.

    Keywords: Robot Partners; Multi-modal Perception; Computational Intelligence; Human Robot Interaction

  • László Szívós ,
    István Orosz :

    Abstract: Fairly presented financial statements are factual, free from bias and any material misstatements, and reflect the commercial substance of the financial transactions at a company. These statements have a standardized format and should be prepared in accordance with the applicable financial reporting framework. External audits provide reasonable assurance to the owners of the business’s on to what extent financial statements are free of material misstatement whether due to error or fraud. There is always a risk (control risk) that the business’s internal control system cannot prevent, detect or correct misstatements. The necessary sources of the financial data are handled nowadays by ERP (Enterprise Resource Planning) systems, triggered out the manual handwork. The applied ERP systems are different in companies according to the size and the business flows of the company. When it comes to a small or middle sized company, many of them use one generic system, which operates both the OLAP (analysis) and the OLTP (transaction processing) functions. There is a common risk to overwrite the master data, which can influence the reliability of financial statements. Lot of control procedures assure that the contained data are valid and show the true and fair state of the business. In this paper, we review how control procedures in an ERP system can influence the level of control risk and thus the scope and quantity of the audit procedures performed by the financial auditor.

    Keywords: financial audit; control risk; ERP; master data management; data migration; data consistency check

  • Predrag Ralevic ,
    Momčilo Dobrodolac ,
    Dejan Markovic ,
    Matthias Finger :

    Abstract: A significant theme in data envelopment analysis (DEA) is the stability of returns to scale (RTS) classification of specific decision making unit (DMU) which is under observed production possibility set. In this study the observed DMUs are public postal operators (PPOs) in European Union member states and Serbia as a candidate country. We demonstrated a sensitivity analysis of the inefficient PPOs by DEA-based approach. The development of this analytical process is performed based on real world data set. The estimations and implications are derived from the empirical study by using the CCR RTS method and the most productive scale size concept (MPSS). First, we estimated the RTS classification of all observed PPOs. After that, we determined stability intervals for preserving the RTS classification for each CCR inefficient PPO under evaluation. Finally, scale efficient inputs and output targets for these PPOs are designated

    Keywords: data envelopment analysis; returns to scale; stability; scale efficient targets; public postal operators

  • László Elek ,
    Zsolt Kovács :

    Abstract: As a consequence of an increasing need for energy-efficiency, there is a growing interest on buildings with reduced energy consumption all over the world. Windows generally account for much higher proportion of the transmission losses through the building envelope, than their area fraction. Therefore, more attention is to be paid to the enhancement of the thermal insulation of fenestration products. In this article, the authors investigate the effect of the thermal performance of the glazing on the frame and edge-of glazing behaviour in a wooden-frame window commonly used in Central Europe. Windows’ inside surface temperature with respect to condensation risk, as well as components of the total product U-factor according to both the European standard (ISO EN 10077-1 and -2) and the National Fenestration Rating Council (NFRC) were assessed by using THERM and WINDOW software packages to simulate respective U-factor and temperature distribution throughout the structure.

    Keywords: U- factor; heat mirror; modelling; finite element model

  • Shahin G. Hasanov ,
    Vagif M. Mirsalimov :
    Modeling of Stress-Strain State of Road Covering with Cracks215-234en [450.34 kB - PDF]EPA-02461-00054-0120

    Abstract: The stress-strain state of road covering in the course of operation is considered. It is assumed that the cross section of the covering has arbitrary number of rectilinear cracks. Force interaction of the wheel (roller) and road covering with rough upper surface is investigated. Using the perturbation method and the method of singular integral equations the contact problem of the pressing of the wheel (roller) in the road surface was solved. The stress intensity factors for the vicinity of the cracks vertices are found.

    Keywords: road covering; elastic base; rectilinear cracks; stress intensity factors; rough surface

  • Vikram Chopra ,
    Sunil K. Singla ,
    Lillie Dewan :

    Abstract: A proportional integral derivative (PID) controller is the most commonly used controller in controlling industrial loops due to its simple structure, robust nature and easy implementation. Tuning a PID controller is an important task. The conventional methods for tuning a PID controller have certain limitations. These limitations can be taken care by tuning the PID controller using intelligent techniques. This paper presents the intelligent methods based on fuzzy logic, artificial neural network (ANN), adaptive neuro fuzzy inference system (ANFIS) and genetic algorithms (GA) for tuning a PID controller. The controller tuned by the given methods has been used for concentration control of a continuous stirred tank reactor (CSTR). Simulation results reveals that intelligent methods provide better performance than the conventional Zeigler Nichols (ZN) method in terms of various performance specifications.

    Keywords: PID controller; Fuzzy logic controller (FLC); ANN; ANFIS; GA; CSTR