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ANNALS OF THE UNIVERSITY OF CRAIOVA

Series: AUTOMATION, COMPUTERS, ELECTRONICS and MECHATRONICS


    ISSN: 1841-0626 CNCSIS code 11 category B+ internationally indexed, starting with 2010, (Copernicus, Inspec)
    Semiannual publication
    Occasionally, conferences dedicated special issues may be published

    Year 2012 Volume 9(36) no. 2
  1. A SOFTWARE APPLICATION FOR THE GAS TRANSPORT AND DISTRIBUTION MANAGEMENT (pp. 1-6)

    Viorel Costin Ban?a*, Dorian Cojocaru**, Razvan Tudor Tanasie***
    *PhD Student, Mechatronics Department, University of Craiova, Romania
    ** Mechatronics Department, Faculty of Automation, Computers and Electronics, University of Craiova, Romania (e-mail: bantaviorel@gmail.com, cojocaru@robotics.ucv.ro)
    ***Computers and Information Technology Department, University of Craiova, Romania


    Abstract: The paper deals with a software application of Enterprise Resource Planning type. The presented application is concerned with the gas transport and distribution management inside a large Gas Distribution Company. The application was developed in SAP (System and Applications, Products) environment, using the dedicated programming language ABAP (Advanced Business Application Programming). Details regarding the analysis, implementation and testing of the software application are presented.
    Keywords: enterprise resource planning, advanced business application, data bases, gas distribution.

  2. DATABASE TESTING - AN OVERVIEW (pp. 7-12)

    Augustin-Iulian Ionescu*
    *Department of Computers and Information Technology (e-mail:ionescu.augustin@cs.ucv.ro), University of Craiova, Decebal Blvd. No. 107


    Abstract: The differences between data and information imply different approach of data quality and information quality. Sometimes apparently correct data can generate wrong information because the information represents an interpretation of the data in a given context and the interpretation is a very subjective process. Using the PSP/IQ model, this paper emphasizes the most important metrics for data information testing and attempts to answer what database testing means. Database quality analysis raises some specific issues that require special approaches. A very well designed database can be useless if the data timeliness is not permanently supervised but also, correct data can be useless if the database structure does not allow their correct association. This paper aims to answer the question: what does "testing a database" means.
    Keywords: database, information, metrics, PSP/IQ model, quality, testing.

  3. XPC TARGET COMMUNICATION EFFICIENCY WHEN MULTIPLE TARGETS ARE INVOLVED (pp. 13-17)

    Madalin Matasaru*
    *University of Craiova, Department of Automatic Control, 200585-Craiova, Romania (Tel: +40-251-438198; e-mail: madalin@automation.ucv.ro)


    Abstract: Most studies that involve xPCTarget as a real time operating system in charge of executing a control task are focusing on the built in control and simulation capabilities. In this paper we are trying to see how accurate and how fit xPC Target is for multiple Targets control. We will try to see how the percentage of lost packages is influenced by the number of Target PCs connected to the master and also by parameter tuning (a desynchronization between master and Targets). Also we will use real experimental data to see what's the limit for the communication and response time to be reliable. Here the xPC Target is used as an operating environment for real time processing and to create a computer network system used for remote control.
    Keywords: xPC Target, Matlab, Package Loss, Target Control, Capture packages, Error rates.

  4. IMPLEMENTATION OF ADAPTIVE LEARNING DESIGNS (pp. 18-24)

    Anna Mavroudi*, Thanasis Hadzilacos**
    *Open University of Cyprus, PO Box 12794, Cyprus (e-mail: anna.mavroudi@st.ouc.ac.cy)
    ** Open University of Cyprus, PO Box 12794, Cyprus (e-mail: thh@ouc.ac.cy) & Computer Technology Institute and Press "Diophantus", PO Box 1382, Greece (email: thh@cti.gr)


    Abstract: Designing adaptive learning activities, i.e. activities which provide learner-dependant variant learning experiences, is an inherently demanding pedagogical task. Designing adaptive e-learning activities should not add disproportionate technical difficulties to the task. IMS-Learning Design purports to provide a pedagogically neutral and technically smooth environment for the design of educationally rich, including adaptive, learning scenarios. However, although IMS-Learning Design has been effectively used for adaptive, web-based learning, most teachers and instructional designers consider it to be technically out of their reach. Two examples of IMS-Learning Design compliant adaptive web-based learning activities are presented in this paper to show that this is not really the case. Learner profiling and personalization is achieved in adaptive courseware compliant with the IMS-Learning Design specification, including a diagnostic learning style test and an educational recommender system. These components make use of the learning style and prior knowledge respectively, in order to adapt the presentation of the learning material and the feedback given to the learner.
    Keywords: e-learning, adaptive learning, learning design, e-learning standards, IMS-LD, IMS-QTI.

  5. LIMITING BACKTRACKING IN FAST SUDOKU SOLVERS (pp. 25-32)

    Ileana-Diana V.D. Nicolae*, Anca-Iuliana P.M. Nicolae**
    *Department of Computers and Information Technology (e-mail:nicolae_ileana@software.ucv.ro), University of Craiova, Decebal Blv. No. 107
    **Department of Cybernetics and Economic Statistics (e-mail:ancaiuliana.nicolae@gmail.com), Doctoral School of Bucharest, University of Economic Studies.


    Abstract: The paper deals with the logic and implementation of an efficient Sudoku solver, successfully tested for classic grids of small and medium difficulty. It relies on an efficient 3-d array (9x9x10) containing information on grid's content and on possible candidates for its unsolved cells at every computation step. The use of auxiliary (9x9) matrices containing flags related to restrictions associated with lines, columns and zones, along with execution branches that implement strategies from gamers' world (known as "x-wing", "y-wing", "naked pairs", "box-to-line/column restrictions" etc.) and with a minimal (ideally zero) segment of backtracking code, exhibited very good runtimes (not exceeding 0,4 s for classic grids of medium difficulty and respectively 0.15 s for easy puzzles) as compared to usually runtimes of seconds reported by literature. The solver can be easily adapted to solve grids with additional restrictions (e.g. restrictions corresponding to diagonals, symmetric grids etc.).
    Keywords: Constraing satisfaction problems, Backtracking, Binary arrays, Computer programming.

  6. INTERFACE WITH SIMULTANEOUS SAMPLING OF ANALOG INPUTS FOR POWER QUALITY MEASUREMENT: TESTING PROGRAMS AND EXPERIMENTAL RESULTS (pp. 33-42)

    Dorina C. Purcaru*, Anca I. Purcaru**, Cornelia I. Gordan***
    *Department of Automation, Electronics and Mechatronics, University of Craiova,Decebal Blvd. No. 107, 200440 Craiova, Romania (e-mail: dpurcaru@electronics.ucv.ro)
    **VIG IMPEX, Craiova, Toporasi Str. No. 5, 200233 Craiova, Romania (e-mail: aipurcaru@gmail.com)
    ***Department of Electronics and Telecommunications, University of Oradea, Universitatii Str. No.1, 410087 Oradea, Romania (e-mail: cgordan@uoradea.ro)


    Abstract: The waveforms and values of monitored analog inputs are modified and the instantaneous values are important for the after-failure analysis and diagnosis when an event (fault, disturbance) appears in energetic systems. Several programmable electronic modules for power quality measurement and monitoring different specific transient events in power systems require an interface with synchronized sampling of all analog inputs and with high and settable sampling rate. The paper deals with some design aspects and characteristics of such interface entirely controlled by PC104 CPU and some software applications for testing its operation and an analysis of results obtained using this interface for data acquisition in energetic system. The programs were implemented using C programming language.
    Keywords: Data acquisition, Interface, Sampling, Analog inputs, Current, Voltage, Programs, Flowcharts, Equipment, Events.

  7. DYNAMIC ALGORITHM CONTROL OF ROBOT MANIPULATOR OPERATING IN FAULT CONDITIONS (pp. 43-47)

    Cristina Floriana Resceanu*, Ionut Cristian Resceanu*, Dana Maria Patrascu*
    *University of Craiova, Faculty of Automation, Computers and Electronics (e-mail: {cristina, resceanu, dana} @robotics.ucv.ro)


    Abstract: The problems of control of robot manipulators in fault conditions are addressed in this paper. A fault tolerant control method is proposed for robot manipulators to maintain the required performance in the presence of actuation failures. The proposed approach integrates control law and actuator fault tolerance. Theoretical analysis and simulation results have confirmed the effectiveness of the proposed method.
    Keywords: fault, dynamics, control, robot, manipulator.

  8. DESIGN PROCEDURE OF SLIDING MODE OBSERVERS VIA BOND GRAPH (pp. 48-53)

    Monica Roman*
    * Department of Automatic Control, University of Craiova, Craiova, Romania, (e-mail: monica@automation.ucv.ro).


    Abstract: This work deals with a Bond Graph approach used to design sliding mode observers. The method is an extension of the Bond Graph technique designed for classical Luenberger observers. Two kind of sliding mode observers are analysed and designed by using the Bond Graph approach: the equivalent control method based sliding mode observers and the so-called modified Utkin observers.
    Keywords: Bond graphs, bioprocesses, observers.

  9. ABSOLUTE STABILITY OF A LONGITUDINAL BLENDED WING BODY AIRCRAFT MODEL WITH RATE LIMITING OF THE ACTUATOR (pp. 54-59)

    Claudia Alice State*
    *Doctoral School of Control Engineering and Computers, University of Craiova, A.I.Cuza, 13, Craiova, RO-200585, Romania (e-mail: cldstate@ yahoo.com).


    Abstract: This paper is focused on P(ilot) I(n-the-Loop) O(scillations) of Category II associated to quasi-linear models, which are induced by nonlinearities determined by the saturation of position or rate limited elements. The theoretical model of the airplane is a Blended Wing Body (BWB) con¯guration and the human operator is expressed by the Synchronous Pilot Model, represented by a simple gain. The absolute stability for the longitudinal BWB aircraft model proposed is investigated using a frequency Popov-type criterion. The mathematical model presented in this article is a pilot-aircraft coupled system used for describing the longitudinal motion of the Blended Wing aircraft and techniques from the frequency domain are applied. The transfer function obtained from open-loop analysis has a double pole at the origin. Therefore, the pilot-aircraft system is in the critical case of a double zero root and the Popov criterion, in the case of the in¯nite parameter, is applied in order to investigate the absolute stability for the longitudinal BWB aircraft model in the presence of the rate saturation of the actuator.
    Keywords: Absolute stability, Popov criterion, Nonlinear system, Blended Wing Body, Frequency domain inequality.

  10. DESIGNING THE ARCHITECTURE OF A RENDERING ENGINE (pp. 60-64)

    Razvan Tanasie*
    *University of Craiova, Faculty of Automation, Computers and Electronics, Romania (e-mail:tansie_razvan@software.ucv.ro).


    Abstract: Sometimes developers do not consider feasible the purchase of a pre-made rendering engine for creating a computer game so they prefer to create their own engine. Moreover, if the engine might be used for several games or applications that may run on different operating systems, it is desirable to be reusable and to have platform-independent functionality. This paper focuses on presenting the theoretical aspects involved by the construction of a portable and reusable rendering engine and on how they can be applied to design the architecture of the system. Although the author only intends to offer an overview of the subject, a prototype for a rendering engine is used for exemplification purposes. It has been implemented using the C++ programming language and the OpenGL API (Application Programming Interface), which confirm the claims of portability.
    Keywords: Computer graphics, Real-time rendering, Rendering engine, OpenGL.

  11. A FRAMEWORK FOR MEDICAL IMAGES DIAGNOSING (pp. 65-70)

    Anca Loredana (Ion) Udristoiu*, Stefan Udristoiu*
    *University of Craiova, Faculty of Automation, Computers and Electronics, Romania (phone: 40-251-438-198; fax: 40-251-438-198; e-mail: aion@software.ucv.ro)


    Abstract: In this paper we propose a framework for medical image diagnosing. The proposed framework includes components for the extraction of low-level features along with methods for the incorporation of semantic knowledge into the diagnosing process. The semantic information is represented by semantic rules which are used for an interactive diagnosing of the image data. The experiments through the framework were realized on collections of medical images from the digestive apparatus.
    Keywords: Content-based image retrieval, Image mining, Rough sets.