The volume 2000

Table of Contents

Ion BIVOL, Cristian VASILACHE: The Application of Euler-Lagrange Method of Optimization for Electromechanical Motion Control
Abstract  Full Text

Mihai CULEA, Dorel AIORDACHIOAIE, Marian GAICEANU: On The Harmonics Reduction Using Wavelet Based Signal Processing
Abstract  Full Text

Dorel Aiordachioaie, Atsushi AOYAMA, Ranajit Chatterjee and Yuji NAKA: On Phenomena Based Metamodelling - A Process System Engineering Point Of View
Abstract  Full Text

Dorel Aiordachioaie, Rustem Popa and Mihai Culea: On Process Modelling Using Physical Oriented And Phenomena Based Principles
Abstract  Full Text

Viorel NICOLAU, Gheorghe PUSCASU and Rustem POPA: Properties Of Potential Function- Based Clustering Algorithms
Abstract  Full Text

Ioan FILIP, Daniel CURIAC, Octavian PROŞTEAN, Iosif SZEIDERT: A Comparative Study Above Two Self-Tuning Controllers With Aplication To The Control Of Synchronous Generator Excitation System
Abstract  Full Text

Viorel MÎNZU and Antoneta BRATCU: Some Results On The Modelling Of TSS Manufacturing Lines
Abstract  Full Text

Daniel CURIAC, Ioan FILIP, Florin DRĂGAN: Secure Analog Data Transmission Based on Rössler Chaotic System Behavior
Abstract  Full Text

Ciprian-Daniel NEAGU: Modular Neuro-Fuzzy Networks: Sollutions For Explicit And Implicit Knowledge Integration
Abstract  Full Text

Emilia PECHEANU, Diana STEFANESCU, Luminita DUMITRIU, Adrian ISTRATE: Architecture of a Computer Based Instructional System
Abstract  Full Text

Luminita DUMITRIU: Finding Exception For Association Rules Via SQL Queries
Abstract  Full Text

Diana STEFANESCU, Emilia PECHEANU, Luminita DUMITRIU: A hybrid approach to dynamic course generation on the WWW
Abstract  Full Text

Cosmin Dănut BOCĂNIALĂ: The textual idea and its relationship to discourse structure
Abstract  Full Text

Daniela NEAGU, Ciprian-Daniel NEAGU: GIS Components: an overview of the software format approaches
Abstract  Full Text

Ion BIVOL, Cristian VASILACHE: The Application of Euler-Lagrange Method of Optimization for Electromechanical Motion Control

Abstract: Industrial and non-industrial processes such as production plans, robots, pumps, compressors, home applications, transportation of people and goods etc., require some kinds of motion control. The main functions of electromechanical drives are to adjust these processes by controlling the torque, speed or position. The objective of this paper is to perform the control of motion while minimizing power losses, that is ∫Ri2dt, in process conversion of electrical energy to mechanical energy. The optimal control laws for our problem is find using the Euler - Lagrange principle. We consider three types of controlled drives: torque, speed and position. Each of them has different control laws. By implementation of these controls with Borland C++ and Matlab environment, substantial energy savings are obtained.
Keywords: Motion control, sensor less, energy saving, ac drives system

 



Mihai CULEA, Dorel AIORDACHIOAIE, Marian GAICEANU: On The Harmonics Reduction Using Wavelet Based Signal Processing
Abstract: This paper presents a method for calculating the reference currents needed for the command of an active filter. By using the Discrete Wavelet Transform (DWT) the high-frequency components of the currents are eliminated. Also, a reference is delivered to the control block of the active filter and a comparison is made between the DWT and the classical Fourier transform.
Keywords: harmonic reduction, wavelet analysis, active filter, signal processing.

 



Dorel Aiordachioaie, Atsushi AOYAMA, Ranajit Chatterjee and Yuji NAKA: On Phenomena Based Metamodelling - A Process System Engineering Point Of View

Abstract: This work is looking to methodological aspects of process modelling. The point of view is more from Process System Engineering (PSE) in order to develop formal and generic techniques for process modelling, and to use representation formalisms matched to computer based modelling environments. A metamodelling approach based on phenomena is presented and discussed. The framework is easy to understand, easy to implement from computational point of view, and can be used as departure point in developing a new generation of modelling languages: languages based on phenomena. The phenomena based metamodelling approach makes the modelling process more efficient for collaboration in heterogeneous modelling environments composed from different and difficult actors: modellers, users and computers.

Keywords: Methodology, Modelling, Models, Object modelling techniques, Behaviour, Physical models, Concurrent Engineering, Information systems, Information models.

 


Dorel Aiordachioaie, Rustem Popa and Mihai Culea: On Process Modelling Using Physical Oriented And Phenomena Based Principles
Abstract: This work presents a modelling framework based on phenomena description of the process. The approach is taken to easy understand and construct process model in heterogeneous possible distributed modelling and simulation environments. A simplified case study of a heat exchanger is considered and Modelica modelling language to check the proposed concept. The partial results are promising and the research effort will be extended in a computer aided modelling environment based on phenomena.

Keywords: Modelling, Models, Behaviour, Object Modelling Techniques, Methodology, Simulation, Physical model.

 


Viorel NICOLAU, Gheorghe PUSCASU and Rustem POPA: Properties Of Potential Function- Based Clustering Algorithms
Abstract: The clustering algorithms based on potential functions are capable of clustering a set of data, making no implicit assumptions on the cluster shapes and without knowing in advance the number of clusters. They are similarity-based type clustering algorithms and do not use any prototype vectors of the clusters. In this paper, some properties of these algorithms are studied: points arrangement tendency, constant potential surface, cluster shapes and robustness to noise.

Keywords: potential function, clustering algorithm, measure of similarity

 


Ioan FILIP, Daniel CURIAC, Octavian PROŞTEAN, Iosif SZEIDERT: A Comparative Study Above Two Self-Tuning Controllers With Aplication To The Control Of Synchronous Generator Excitation System

Abstract: This paper presents two self-tuning control structures synthesized through the minimization of two criterion functions. It is described the computation methodology of the control laws, both being particularized for the case of the synchronous generator's excitation control. The parameters estimator is considered the recursive least square error (RLSE) algorithm. In order to validate the considered control structures, two comparative study cases by computer simulation are presented.
Keywords: self-tuning control, synchronous generator, adaptive control, active load

 


Viorel MÎNZU and Antoneta BRATCU: Some Results On The Modelling Of TSS Manufacturing Lines

Abstract: This paper deals with the modelling of a particular class of manufacturing lines, governed by a decentralised control strategy so that they balance themselves. Such lines are known as “bucket brigades” and also as “TSS lines”, after their first implementation, at Toyota, in the 70’s. A first study of their behaviour was based upon modelling as stochastic dynamic systems, which emphasised, in the frame of the so-called “Normative Model”, a sufficient condition for self-balancing, that means for autonomous functioning at a steady production rate (stationary behaviour). Under some particular conditions, a simulation analysis of TSS lines could be made on non-linear block diagrams, showing that the state trajectories are piecewise continuous in between occurrences of certain discrete events, which determine their discontinuity. TSS lines may therefore be modelled as hybrid dynamic systems, more specific, with autonomous switching and autonomous impulses (jumps). A stability analysis of such manufacturing lines is allowed by modelling them as hybrid dynamic systems with discontinuous motions.

Keywords: production systems, self-organising systems, hybrid dynamic systems, convergence analysis.

 


Daniel CURIAC, Ioan FILIP, Florin DRĂGAN: Secure Analog Data Transmission Based on Rössler Chaotic System Behavior

Abstract: This paper describes a new methodology for increasing the security of analog data transmission based on a mixture of the original analog signal with one of the state variables of Rössler chaotic system. The method is described emphasizing on the practical implementation aspects.
Keywords: data transmission, encryption, chaotic system, fuzzy synchronizer.

 


Ciprian-Daniel NEAGU: Modular Neuro-Fuzzy Networks: Sollutions For Explicit And Implicit Knowledge Integration

Abstract: In this paper we propose a unified approach for integrating implicit and explicit knowledge in neurosymbolic systems as a combination of neural and neuro-fuzzy modules. In the developed hybrid system, training data set is used for building neuro-fuzzy modules, and represents implicit domain knowledge. The explicit domain knowledge on the other hand is represented by fuzzy rules, which are directly mapped into equivalent neural structures. The aim of this approach is to improve the abilities of modular neural structures, which are based on incomplete learning data sets, since the knowledge acquired from human experts is taken into account for adapting the general neural architecture. Three methods to combine the explicit and implicit knowledge modules are proposed.
Keywords: neural and neuro-fuzzy integration, modular structure.

 


Emilia PECHEANU, Diana STEFANESCU, Luminita DUMITRIU, Adrian ISTRATE: Architecture of a Computer Based Instructional System


Abstract: The paper describes the architecture of a tutorial system that can be used at various engineering graduate and postgraduate courses. The tutorial is using Internet-style WWW services to provide access to the teaching information and the evaluation exercises maintained with a RDMS. The tutorial will consist of server-side applications that process and present teaching material and assessing exercises to the student using the well-known Web interface. All information in the system will be stored in a relational database. By closely sticking to the ANSI SQL specifications, the system can take advantage of a free database managing system running on Linux, the mini-SQL. The tutorial can be used to on-line deliver any courses, creating new, continuing education opportunities. Taking advantage of the modern deployment techniques, the instructional/assessing tutorial offer high degrees of accessibility.
Keywords: Tutoring System, Assessment Component, Instructional Environment, Educational Server, RDBMS, miniSQL, Linux.

 


Luminita DUMITRIU: Finding Exception For Association Rules Via SQL Queries

Abstract: Finding association rules is mainly based on generating larger and larger frequent set candidates, starting from frequent attributes in the database. The frequent sets can be organised as a part of a lattice of concepts according to the Formal Concept Analysis approach. Since the lattice construction is database contents-dependent, the pseudo-intents (see Formal Concept Analysis) are avoided. Association rules between concept intents (closed sets) A=>B are partial implication rules, meaning that there is some data supporting A and (not B); fully explaining the data requires finding exceptions for the association rules. The approach applies to Oracle databases, via SQL queries.
Keywords: data mining, association rules, exceptions, SQL.


 

Diana STEFANESCU, Emilia PECHEANU, Luminita DUMITRIU: A hybrid approach to dynamic course generation on the WWW

Abstract: In recent years, hypermedia has been grown in interest in advanced research on teaching and learning. Futhermore, the extension of hypermedia toward intelligent hypermedia comes more than obviously to meet specific requirements of learning, such as the student modeling, diagnosis and guiding the learner in his investigation.
In this paper, we present an architecture for a system based on integrating hypermedia system and intelligent knowledge based system. The object formalism is chosen to represent static and predefined knowledge, whereas the rule formalism is chosen for dynamic knowledge and reasoning processes modeling. The knowledge base can be described by three models of expertise: the domain model, the student model and the didactic model (including the communication model). This architecture allows automatic generation of dynamically individualized courses according to the learner's goal, his or her previous knowledge and the learner's success in acquiring knowlede.
Keywords: Intelligent Tutoring Systems (ITS), hypermedia system, object formalism, rule formalism, WWW, dynamic course generation.


 

Cosmin Dănut BOCĂNIALĂ: The textual idea and its relationship to discourse structure

Abstract: The textual idea could be characterized through a series of either detailing the current form of idea or continuing a previous form of it. Every element of the series has associated a span of the given text that carries it. If we are to relate different spans of text according to relationship between corresponding elements of the series, we will obtain a possible representation of discourse structure. In this paper we take a set of texts and represent their structure in the above manner. The purpose is to give researchers the possibility to asset our manner to represent discourse structure.
Keywords: discourse structure, textual idea, text summarization.


 

Daniela NEAGU, Ciprian-Daniel NEAGU: GIS Components: an overview of the software format approaches
Abstract: The paper proposes a software/ multimedia point of view of the resources and file formats used in GIS applications. An overview of the most known software approaches for GIS data management and components is proposed in order to familiarize and focus to the one of the most dynamic multimedia tools. A syntesis of the characteristics of specific file formats for geographic knowledge representation is made.
Keywords: GIS software, file format, GIS databases, geographic data representation.

 

 

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