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Acta polytechnica HungaricaVolume 11, Issue No. 1 (2014.)


  • Heap-Yih Chong ,
    Christopher N. Preece :

    Abstract: Numerous types of construction procurement systems have been developed for project implementation. However, previous studies have not focused on subsequent managerial strategies and the project organizational forms to be adopted towards the selected procurement system. This research proposes that further managerial theories are required to enhance the project performance and effectiveness. Therefore, this paper aims to extract the principles of projectized and nonprojectized organizations and incorporate them with the selected procurement systems at the project level. A mechanism for assessing the key areas of compatibility was developed using the well established McKinsey 7 S model. The paper shows that the characteristics of the organizational principles are complementary with the procurement systems. It contributes an insight for future strategic organization and management at the project level in construction.

    Keywords: projectized; nonprojectized; construction procurement systems; organizational principles; McKinsey; compatibility

  • Tomislav ©uh ,
    Dragan Mitić ,
    Dragica Lebl-Antonić ,
    Aleksandar Lebl :
    Determination of the Necessary Number of Technicians on the Faculty21-36en [311.91 kB - PDF]EPA-02461-00047-0020

    Abstract: In this paper we present the mathematical analysis of engagement of technicians in the teaching (educational) process on the faculty. The technicians receive the requests from professors and assistants. In the case that all technicians are busy in the moment of generating a new request, some of the assistants take over processing of the request. We analyse the probability of unwanted states, i.e. the states when it was necessary to engage the assistants on processing the request, which could have been processed by the technicians, if they had been free. The number of engaged technicians is determined in such a way that the probability of these unwanted states is satisfactorily small, i.e. that these states take available assistants’ time in reasonable limits.

    Keywords: queueing systems; teaching process; unwanted states

  • Chih-Min Lin ,
    Yi-Jen Mon ,
    Ching-Hung Lee ,
    Jih-Gau Juang ,
    Imre J. Rudas :

    Abstract: In this paper, an adaptive network based fuzzy inference system (ANFIS) combining a location awareness system (LAS) is used to to develop an application of patient’s position monitoring system. The setup procedure of LAS is carried out in advanced, then the ANFIS is designed to demonstrate the performance of the proposed methodology. From experimental and simulation results, satisfactory performance of LAS for patient’s position monitoring can be achieved.

    Keywords: Wireless sensor network (WSN); Location awareness system (LAS); ZigBee; ANFIS

  • Fethi Farhani ,
    Abderrahmen Zaafouri ,
    Abdelkader Chaari :

    Abstract: This paper presents a new adaptive rotor flux observer with both speed and rotor and stator resistance identification. The proposed solution , which is based on a full-order Luenberger observer, guarantees a perfect reconstruction of state variables while reducing the drive system complexity. By using the Lyapunov's direct method, the gain-scheduled of the suggested observer can be achieved by solving four bilinear matrix inequalities using the LMI Toolbox of MATLAB. To overcome the problem of parametric variation of induction machine, a tracking-parameter mechanism is used. To validate the effectiveness and robustness of the proposed solution, some simulation results are provided.

    Keywords: Asymptotic stability; Gain-scheduled; linear matrix inequalities; Pole Placement; State estimation

  • Mohammad Hamed Samimi ,
    Moien Abedini ,
    Amir Hossein Mostajabi ,
    Davood Farokhzad ,
    Hossein Ayoubzadeh ,
    Amir Abbas Shayegani Akmal ,
    Hossein Mohseni :

    Abstract: A reactor winding has been damaged due to induction of resonance voltages on the de-energized circuit of two parallel 230 kV shunt compensated lines between Zahedan and Iranshahr. The phenomenon is modeled in PSCAD and the safe range of shunt compensation is derived. In this study the effect of various faults on the lines, the reactor saturation and corona dissipation are considered and the results are compared to the electrostatic no-loss method results. Various ways are examined for damping the resonance condition and the best solution is chosen.

    Keywords: resonance; PSCAD; shunt reactors; transmission line modeling

  • Goran ©imić ,
    Zoran Jeremić ,
    Ejub Kajan ,
    Dragan Randjelović ,
    Aaron Presnall :
    A Framework for Delivering e-Government Support79-96en [390.41 kB - PDF]EPA-02461-00047-0060

    Abstract: This paper gives a solution for improving e-Government services based on a hybrid approach: multilayered clustering of e-government documents based on fuzzy concepts and application of different text similarity measures. The goal is to reduce time between citizen’s questions and government feedback, either completely eliminating or at least minimizing the deployment of subject matter experts. After the problem description, the paper describes step by step the functionality of the proposed system. At the end, concluding remarks emphasize some important features of the given approach and potential for future research.

    Keywords: e-government; clustering; text similarity; fuzzy clustering

  • Cecília Sik-Lányi :

    Abstract: Illustrated color of known objects in Virtual Reality (VR) games for various games exhibit characteristic differences. In the first part of our analysis we studied the cartoons’ colors, with a great emphasis on whether there are any cultural differences. Coloration of well-known objects depicted in cartoons originating from different parts of the world show characteristic differences. We analyzed several soft-copy and hard-copy cartoons form all over the world and determined what colors the designer use for complexion, sky, water, soil, etc. We continued with the study of VR games’ colors. We analyzed eight game categories’ colors and determined which colors the designer used for skin, sky, water, grass, etc. These colors were compared with the prototypical memory colors and cartoon colors of these objects. The research quantifies these differences and provides advice to the VR games to be tinted, if they are intended for a specific region of the world and specific VR games. In the second phase of the research such images of films, which were the equivalent of VR games are analyzed. The staining of these films were compared to the corresponding color of VR games and memory color display object.

    Keywords: Virtual Reality; Game; Film; Color

  • Ivica Lukić ,
    Mirko Köhler ,
    Ninoslav Slavek :
    Positioning of Public Service Systems Using Uncertain Data Clustering121-133en [406.77 kB - PDF]EPA-02461-00047-0080

    Abstract: Positioning of public service system is crucial and very challenging task. Proper positioning ensures that the public service system would complete its tasks to the end users. This paper is focused on finding the best location for public service system, to improve its efficiency when using uncertain data clustering. By choosing the best location for the service system the respond time can be minimised, and the given tasks could be performed in a reasonable time. Improved bisector pruning method was proposed for clustering previous data of public service system to find the best location for its application. Presented method can be used for different Public Service Systems, like traffic services, positioning of ambulance vehicles and other mobile objects. Cluster centres are used as best locations for public service systems because, cluster centres minimized total expected distance from tasks that have been set to the service system. On this way, public service system will be improved and can fulfil more tasks during the shortest period of time.

    Keywords: clustering; data mining; expected distance; service systems; uncertain data

  • Balázs Dániel ,
    Péter Korondi ,
    Gábor Sziebig ,
    Trygve Thomessen :

    Abstract: A new approach for industrial robot user interfaces is necessary due to the fact that small and medium sized enterprises are more interested in automation. The increasing number of robot applications in small volume production requires new techniques to ease the use of these sophisticated systems. In this paper shop floor operation is in the focus. A Flexible Graphical User Interface is presented which is based on cognitive infocommunication (CogInfoCom) and implements the Service Oriented Robot Operation concept. The definition of CogInfoCom icons is extended by the introduction of identification, interaction and feedback roles. The user interface is evaluated with experiments. Results show that a significant reduction in task execution time and a lower number of required interactions is achieved because of the intuitiveness of the system with human centered design.

    Keywords: industrial robotics; human robot interaction; cognitive infocommunication; flexible robot cell; graphical user interface; usability

  • Florin Solomonesc ,
    Constantin Barbulescu ,
    Stefan Kilyeni ,
    Oana Pop ,
    Marius Cornoiu ,
    Adrian Olariu :

    Abstract: The goal of this paper is to establish the best values for evolutionary algorithm main parameters. To do this, a real coded algorithm is tested on Rosenbrock, Schwefel and Rastrigin functions. Different genetic operators' implementation ways are described. Several numbers of variables have been analyzed. An original software tool has been developed in a Matlab environment. The most complex three mathematical test functions have been implemented within the software tool; these functions are considered as ideal for studying the behaviour of the algorithm. The settings established are crucial in the optimal power flow computing and the transmission network expansion planning, by means of EA techniques.

    Keywords: evolutionary algorithm; test function; crossover rate; mutation rate; random mutation; variable step mutation

  • Emma Lógó ,
    Ildikó Petruska :

    Abstract: This paper is investigating the latent factors affecting Industrial Design Engineer students’ everyday product use and analyse their product experiences. Different and distinct parts of product experience are frequently investigated, like usability, aesthetic judgments, or brand preferences. In this article authors examined a holistic aspect. Qmethodology is used for data collection and the sample is analyzed with a modified factor analysis. This method provides researchers a systematic and rigorously quantitative mathematical tool for examining human subjectivity. Q-set construction was the first step in order to reach the targeted aim. It was based on product experience case studies derived from students’ everyday product interactions. Focusing on the group of intelligent everyday product was the next step. Q-sorts (the data collection) concentrated on this type of humanproduct interactions with 23 products chosen by Q-sorters. After the factor analysis a combination of experience structure was shown by means of 8 different factors.

    Keywords: Q-methodology, Product experience, Industrial Design Engineer student, Intelligent product, Subjectivity

  • Sead Maąović ,
    Muzafer Saračević ,
    Predrag Stanimirović :
    Alpha-Numeric Notation for one Data Structure in Software Engineering193-204en [912.89 kB - PDF]EPA-02461-00047-0120

    Abstract: This paper presents one way to store balanced parentheses notations in shortened form in order to lower memory usage. Balanced parentheses strings are one of the most important of the many discrete structures. We propose new method in software engineering for storing strings of balanced parentheses in shortened form as Alphanumeric (AN) notation. In addition, our algorithm allows a simple reconstruction of the original strings. Another advantage of the presented method is reflected in savings of working memory when it comes to deal with combinatorial problems. The proposed method is implemented in Java environment.

    Keywords: Balanced Parentheses, Catalan number, Binary tree, Software engineering, Java programming.

  • András Farkas :

    Abstract: The problem of alternative-fuel modes of buses used for public transportation in urban areas is considered. Classification and characteristics of these vehicles are discussed in detail. A multi-criteria decision analysis (MCDA) method called MAROM is used to rank and evaluate the alternative-fuel modes of buses for an empirical study taken from the literature. Numerical results are compared to those generated from a classical MCDA method called TOPSIS. Exploring causal effects, cross-impacts between the fuel modes are formulated and trend projections are made using a dynamic simulation model. Findings for the expected changes in the characteristics of the alternative-fuel modes in the long-run are then analyzed. Finally, the formal description of the scaling method MAROM is also presented.

    Keywords: alternative-fuel modes; multi-attribute decision making; cross-impact analysis

  • Slobodan Tabaković ,
    Milan Zeljković ,
    Aleksandar ®ivković :
    General Parametric Model of The Body of The Total Hip Endoprosthesis227-246en [591.60 kB - PDF]EPA-02461-00047-0140

    Abstract: The endoprostheses of the hip joint are the most commonly used group of implants in orthopedic surgery. The success of their application in the process of replacing natural hip joint with artificial depends, besides the patient related and surgical factors, which include the selection of the type of endoprosthesis and the extent of its adaptability to the patient. Because of that, endoprostheses adapted to the patient's measures, so-called custom made endprostheses, are used. The main challenge in their design is large number of influential factors on the shape and dimensions of the endoprosthesis, the long period of development, and high prices as a consequence of these factors. One of the directions of endoprosthesis design process improvement is the introduction of generalized computational models that enable the adaptation of the endoprosthesis to a specific patient's femur, taking into consideration all influential factors of the disease. This paper describes a general parametric model of the body of the hip endoprosthesis, which was developed by combining two methods of parametric modeling with the aim to implement all existing contributing factors and, also, facilitate introduction of the new ones. The main advantages of this model of endoprosthesis are: flexibility and simplicity which makes this model easy for application in a variety of CAD software systems.

    Keywords: parametric model; endoprosthesis; Bezier curves; Computer Aided Design