ISSN: 1998-0159



Year 2011

All papers of the journal were peer reviewed by two independent reviewers. Acceptance was granted when both reviewers' recommendations were positive.

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    Paper Title, Authors, Abstract (Issue 1, Volume 5, 2011)


Learning the Value of a Function by Using Hypercircle Inequality for Data Error
B. Novaprateep, K. Khompurngson, D. Poltem

Abstract: In this paper, we briefly review Hypercircle inequality for data error (Hide) measured with square loss. We provide it in the case that the unit ball B is replaced by δB where δ is any positive number. Moreover, we also discuss some important facts of Hide for practical computation and study the problem in learning the value of a function in reproducing kernel Hilbert space (RKHS) by using the available material from Hide with different values of δ: We compare our numerical experiment to the method of regularization, which is the standard method for learning problem.


Robot Global Path Planning Overview and a Variation of Ant Colony System Algorithm
Buniyamin N., Sariff N., Wan Ngah W.A.J., Mohamad Z.

Abstract: This paper presents the results of a research that aims to develop an algorithm to solve robot path planning (RPP) problems in static environments. The problem is to find a global optimal path that satisfies the optimization criteria of shortest path with minimum computation time. A description of a variation of Ant Colony System (ACS) algorithm utilized for Robot Path Planning (RPP) purposes is presented. A representation of heuristic and visibility equation of state transition rules is proposed to sustain the function of Ant Colony System (ACS) for solving RPP problem of finding the optimal path. This algorithm was applied within a global static map that consists of feasible free space nodes. The performance of the algorithm in terms of computation time and number of iteration required to obtain an optimal path were evaluated by using a simulation approach. Subsequently, its performance was compared to the performance of Genetic Algorithm (GA) a well known and established RPP algorithm. The results obtained indicate that the developed algorithm performed much better than the GA. In addition, an overview of robot path planning (PP) algorithms in global static environment is also offered.


An Analysis of a Problem Related to Decision-Making Applying Computational Geometry Techniques
J. Rodrigo, M. D. Lopez, S. Lantaron, R. Caro

Abstract: This paper introduces a problem related to decision-making and the shaping of political strategies in the course of one term of office. First it is assumed than one of the parties, say the one in the government, does not modify its position and then the other one, say the opposition, searches for the best proposal within a circular neighborhood of flexibility. Next it is assumed that the government and the opposition shape their proposals for action on two issues that are relevant for the citizens and a variable component is considered regarding both the relevance of the issues to be dealt with and the strategies that the parties are presumed to adopt. This component is reflected in the consideration of elliptic neighborhoods of flexibility for both parties. In addition, it is considered that the process is dynamic because the proposals are intended to be modified taking into account the other party’s foreseen action in order to get the maximum number of votes. The contribution of this article lies in this approach, as well as in its taking into account variable components. The problem is dealt with from a geometric point of view, and a search algorithm to find optimum strategies is developed.


Extended Motion Model of Autonomous Ground Vehicle
Petr Stodola

Abstract: This article deals with the design and implementation of the mathematical motion model of an autonomous unmanned ground vehicle. This model comes from the specific construction of the vehicle, which was designed in order to verify and demonstrate its autonomous motion possibilities indoors and outdoors. This article presents two different issues of the model: a) computing vehicle’s position depending on values of parameters of its motion system and b) deriving values of these parameters according to current demands for movement of the vehicle from a current position to a new position. The second issue is presented in the two versions: basic and extended.


EVA: Expressive Multipart Virtual Agent Performing Gestures and Emotions
Izidor Mlakar, Matej Rojc

Abstract: Embodied Conversational Agents (ECAs) play an important role in the development of personalized and expressive human-machine interaction, allowing users to interact with a system over several communication channels, such as: natural speech, facial expression, and different body gestures. This paper presents a novel approach to the generation of ECAs for multimodal interfaces, by using the proprietary EVA framework. EVA’s articulated 3D model is mesh-based and built on the multipart concept. Each of its 3D sub-models (body-parts) supports both bone and morph target-based animation, in order to simulate natural human movement. Each body movement’s structural characteristics can be described by the com-posite movement of one or more elementary units (bones and/or morphs), and its temporal characteristics by the durations of each of the movement’s stages (expose, present, dissipate). EVA scripts provide a means of defining and fine-tuning body motion in the form of predefined gestures, or complex behavioural events (provided by external behaviour modelling sources). Since behavioural events can also be described as a combination of tuned predefined gestures and the movements of elementary units, a small number of predefined gestures can form infinite sets of gestures that ECA can perform. ECA EVA, as presented in this paper, provides both: a personaliza¬tion of its behaviour (gesture level), and a personalization of its outlook.


Necessity of IT and SW Support for Business Process Management
Zuzana Tuckova, David Tucek

Abstract: In our researches [42], we evaluated the influence of the application of industrial engineering methods on increasing the competitive abilities of Czech industrial manufacturing enterprises, and one of the results of my research study based on a selected sample of these Czech enterprises was the following fact: that the exploitation of re-engineering and process management components was woefully inadequate – for the sample of Czech enterprises being tracked. It was for this very reason and - as a consequence of our interest in the given problems and issues in manufacturing production enterprises, that we oriented ourselves on the field of Business Process Management - BPM as well as on the problems and issues involving dramatic changes in enterprises/ processes – i.e. Business Process Reengineering – BPR.


A Combined Scheme for Computing Numerical Solutions of a Free Boundary Problem
Nuha Loling Othman, Takashi Suzuki, Takuya Tsuchiya

Abstract: Numerical schemes for free boundary problems are categorized into two groups: level-set approaches and iterative approaches. In this paper we present a combined approach for computing numerical solutions of a free boundary problem. At first, a rough numerical solution is obtained by a level-set method. Then, using the solution as an initial guess, we use an iterative scheme to obtain more precise solution. To design an iterative scheme, we calculate first variations with respect to boundary perturbation of quantities related to the free boundary problem. Such a variation with respect to domain perturbation is called Hadamard’s variation. Since our iterative scheme is designed with Hadamard’s variations, it is fast and stable. If the iteration starts with good initial guess obtained by a level-set method, iteration converges almost immediately. Numerical examples show the effectiveness and usefulness of our approach.


Image Encryption Methods Using Intensity Transformations in Visual Cryptography
Masakazu Higuchi, Aya Emori, Shuji Kawasaki, Jonah Gamba, Atsushi Koike, Hitomi Murakami

Abstract: In a kind of visual cryptography, a secret image is encoded as other images. Then, we can reconstruct the secret image by using share images produced in secret image encoding process. In the case that share images are binary, the secret image is reconstructed by printing the share images onto transparencies and stacking them together without any special electronic calculation. Myodo’s method based on error diffusion can produce two high quality binary halftone share images from three input images, that is, two gray-scale images and a grayscale secret image, and restore the gray-scale secret image with high quality by using those share images. The method changes intensities of each pixel in input images as a pre-processing in order to restore a high quality secret image in term of visual effects. By improving the intensity transformation in Myodo’s method, authors have proposed a method to generate high quality share images with high speed from which a secret image can be reconstructed with apparently higher quality than myodo’s method. In this paper, we review the method and evaluate its performance for any input images objectively and subjectively.


Estimating Local Part Thickness in Midplane Meshes for Finite Element Analysis
Vanio Ferreira, Luis Paulo Santos, Markus Franzen, Omar O. Ghouati, Ricardo Simoes

Abstract: Within the development of motor vehicles, crash safety (e.g. occupant protection, pedestrian protection, low speed damageability), is one of the most important attributes. In order to be able to fulfill the increased requirements in the framework of shorter cycle times and rising pressure to reduce costs, car manufacturers keep intensifying the use of virtual development tools such as those in the domain of Computer Aided Engineering (CAE). For crash simulations, the explicit finite element method (FEM) is applied. The accuracy of the simulation process is highly dependent on the accuracy of the simulation model, including the midplane mesh. One of the roughest approximations typically made is the actual part thickness which, in reality, can vary locally. However, almost always a constant thickness value is defined throughout the entire part due to complexity reasons. On the other hand, for precise fracture analysis within FEM, the correct thickness consideration is one key enabler. Thus, availability of per element thickness information, which does not exist explicitly in the FEM model, can significantly contribute to an improved crash simulation quality, especially regarding fracture prediction. Even though the thickness is not explicitly available from the FEM model, it can be inferred from the original CAD geometric model through geometric calculations. This paper proposes and compares two thickness estimation algorithms based on ray tracing and nearest neighbour 3D range searches. A systematic quantitative analysis of the accuracy of both algorithms is presented, as well as a thorough identification of particular geometric arrangements under which their accuracy can be compared. These results enable the identification of each technique’s weaknesses and hint towards a new, integrated, approach to the problem that linearly combines the estimates produced by each algorithm.


    Paper Title, Authors, Abstract (Issue 2, Volume 5, 2011)


Time-Domain Simulation of Nonuniform Multiconductor Transmission Lines in Matlab
Lubomir Brancik, Bretislav Sevcik

Abstract: The paper presents a technique for the time-domain simulation of nonuniform multiconductor transmission lines (MTL) based on an implicit Wendroff method. This technique falls into a class of the finite-difference time-domain (FDTD) methods useful to solve various electromagnetic systems. Its basic version is extended to enable solving both voltage and/or current distributions along the MTL’s wires and their sensitivities w.r. to lumped and distributed parameters. An experimental error analysis is done on the Thomson cable, a single transmission line with known analytical solutions. The examples of simulation of both uniform and nonuniform MTLs are shown and compared with other methods, some results for nonlinear MTLs are also presented. All computations were performed in the Matlab language, and the computational efficiency is assessed by means of detailed CPU times evaluation.


A New Proposal for Computing Portfolio Value-at-Risk for Semi-Nonparametric Distributions
Trino-Manuel Niguez, Javier Perote

Abstract: This paper proposes a semi-nonparametric (SNP) methodology for computing portfolio value-at-risk (VaR) that is more accurate than both the traditional Gaussian-assumption-based methods implemented in the software packages used by risk analysts (RiskMetrics), and alternative heavy-tailed distributions that seem to be very rigid to incorporate jumps and asymmetries in the distribution tails (e.g. the Student’s t). The outperformance of the SNP distributions lies in the fact that Edgeworth and Gram-Charlier series represent a valid asymptotic approximation of any “regular” probability density function. In fact these expansions involve general and flexible parametric representations capable of featuring the salient empirical regularities of financial data. Furthermore these distributions can be extended to a multivariate context and may be estimated in several steps and thus we propose to estimate portfolio VaR in three steps: Firstly, estimating the conditional variance and covariance matrix of the portfolio consistently with the multivariate SNP distribution; Secondly, estimating the univariate distribution of the portfolio constrained to the portfolio variance obtained from the previous step; Thirdly, computing the corresponding quantile of the portfolio distribution by implementing straightforward recursive algorithms. We estimate the VaRs obtained with such methodology for different bivariate portfolios of stock indices and interests rates finding a clear underestimation (overestimation) of VaR measures obtained from the traditional Gaussian- (Student’s t-) based methods compared to our SNP approach.


Performance Analysis of Micro-Cantilever Beams and Sensor Data Fitting
Bai Yanping, Hao Yilong

Abstract: This paper investigates the specimen size influence on bending strength of microstructures cantilever beams. The vertical bending deflection of microfabricated polysilicon beams was evaluated. Because the original data contain noise terms, the data should be processed via wavelets analysis. The experiment results takes into account the effect of device geometry and elastic properties of the specimens, and agrees well with the results obtained by the theoretical line model for small deflection. The vertical deflection increases with increase in the beam length for a fixed beam width and thickness, decreases with increase in the beam width for a fixed beam length and thickness. And when vertical deflections of specimens are about less than 800nm, the relationship of force and deflection are linear. For larger displacements, non-linear terms will appear in the force-displacement relationship. On the other hand, we used autoregressive models and genetic ARMA model to fit a set of sensor data. Fitting results show following conclusions. In the case of fitting model to determine, the regression model gets only a fitting curve. And yet genetic ARMA model of can get different the fitting parameters by adjusting the parameters of genetic algorithm, which provides an effective method according to different accuracy fitting curve.


Synchronization Chaos using OGBM with Genetic Algorithm
Ali Reza Sahab, Mohammad Reza Modabbernia, Amir Gholami Pastaki

Abstract: This paper presents a new method to synchronize chaos in nonlinear systems. This new method is called Generalized Backstepping Method (GBM) because of its similarity to Backstepping Method (BM), but its more abilities to control nonlinear systems than it; such as wide range of controllable systems, better settling time, lower overshoot and etc. In paper chaos in Lorenz equations is selected as case study. This method has some coefficient that positively is only condition to select them. In papers this parameters are chosen optionally but optimal selection of this parameters help to receive best response of systems. In this study Genetic Algorithm (GA) is chosen to optimize these parameters. GA select best values for them by minimizing fitness function that defined to minimize error function. The results of simulations prove more abilities of GBM than many methods to decrease error.


The Efficiency of Value at Risk Models on Central and Eastern European Stock Markets
Simona Mutu, Peter Balogh, Darie Moldovan

Abstract:  In this paper we have analyzed the performance of some Value at Risk models through the quadratic loss function backtesting approach. In order to highlight the differences among VaR models we have calculated the risk measure through Historical Simulation, EWMA, GARCH and EVT models. VaR was calculated on daily data of five Eastern and Central European main indices: BET (Romania), PX50 (Czech Republic), BUX (Hungary), SOFIX (Bulgary) and WIG20 (Poland) from 30.09.2004 to 30.09.2010. In order to highlight different behaviors in the crisis period we have divided the data into two samples and found that only advanced VaR models such as Extreme Value Theory or GARCH models can adequately measure the risk of the capital markets and satisfy the requirements of the investors in periods characterized by extreme events.


Entropy Analysis in Interacting Diffusion Systems on Complex Networks
Shaoting Tang, Xin Jiang, Zhicong Liu, Lili Ma, Zhanli Zhang, Zhiming Zheng

Abstract: Interacting diffusion systems induced by finite-capacity effect is a typical diffusion model on networks. Its complexity influenced by structure and function has hardly been studied. Aimed at filling this gap, we introduce entropy to quantify such interacting process, and exhibit its strong dependence on topology and routing capacity. The analytical expressions are derived and convinced by simulations. Also, Maximum entropy principle provides an effective measure to design an optimal diffusion process. This will play a crucial role for inference problems emerging in the field of interacting dynamics on complex networks.


Least-Squares based Technique for Identification of Thermal Characteristics of Building Materials
Jiri Vala

Abstract: The thermomechanical behavior of building materials and whole engineering structures is conditioned by their complicated non-periodic microstructure and non-deterministic influences from external environment, involving phase changes, moisture transport, etc. However, technical standards require evaluation of effective (macroscopic) material characteristics for simplified linear differen-tial or integral equations. Even if related direct mathematical and computational problems (with a priori known material characteris-tics) are rather easy, inverse problems (with missing or uncertain values of some material characteristics) may be ill-posed and non-stable, requiring artificial regularization. This article demonstrates how to avoid some difficulties of this type in the case of identifica-tion of basic thermal characteristics, namely of the thermal conduc-tivity and of the heat capacity (including the potential effect of inter-face heat transfer), using the numerical least squares technique. The corresponding laboratory equipment, supplied by the robust MATLAB-based computational tool, is presented.


Performance of the Improved Artificial Bee Colony Algorithm on Standard Engineering Constrained Problems
Ivona Brajevic, Milan Tuba, Milos Subotic

Abstract: Artificial bee colony (ABC) algorithm is successfully used for many hard, mostly continuous, optimization problems. There is a way to extend standard ABC algorithm to constrained problems. In this paper an improved version of the artificial bee colony algorithm adjusted for constrained optimization problems is presented. It uses Deb’s rule. This modified algorithm has been implemented and tested on four standard engineering constrained benchmark problems which contain discrete and continuous variables. Our results were compared to the results obtained by simple constrained particle swarm optimization algorithm (SiC-PSO) which showed a very good performance when it was applied to the same problems. Our results are of the comparable quality with faster convergence.


A Study on Moving Object Direction Control Technology in AR Video
Sungmo Jung, Yohwan So, Eunseok Lee, Seoksoo Kim

Abstract: According to Gartner Report, Augmented Reality is a desirable next generation content technology that allows of inserting 3D virtual objects into the real-world environment seen through the camera. It maximizes interest and flow experience with its interactive feature. In other words, it is a technology that can reduce the difference between the virtual world and the real world. Thus, one of important objectives of Augmented Reality is to enable users to have enhanced flow experience toward the augmented contents. However, generally virtual objects do not have physical properties, which results in reduced flow experience in simulation on virtual objects. Therefore, his research suggests a technology that gives users control over directions of moving objects in AR video.


Performance of Object-Oriented Software System for Improved Artificial Bee Colony Optimization
Nebojsa Bacanin, Milan Tuba, Ivona Brajevic

Abstract: Artificial bee colony (ABC) metaheuristic algorithm introduced by Karaboga was successfully used on many continuous optimization problems. There is also a corresponding program written in C. This article describes an object-oriented software system for improved artificial bee colony algorithm written in C with corresponding flexible graphical user interface (GUI). Since this implementation is object-oriented it is easier for maintenance and it uses threads which significantly increases execution speed on multicore processors. The application was successfully tested on standard benchmark problems.


Design a Digital Archive Value-added Model of Supporting Formal Instruction
Lung-Hsing Kuo, Jui-Chen Yu, Li-Min Chen, Hung-Jen Yang

Abstract: The purpose of this study was to identify a way for applying big 6 information skill on digital book for supporting learning in the formal education. Digital learning projects show us fruitful opportunities of promoting learning. Those abundant research products should be used in a more efficient way to support our formal education. The standard based formal education provides a well defined foundation for teachers to develop learning experience for their students. Based upon both the content of digital book and guide line of educational standard, a big 6 learning activity design procedure was identified and verified.


Multiple Incident Splines (MISs) Algorithm for Topological Reconstruction of 2D Unordered Point Clouds
R. Furferi, L. Governi, M. Palai, Y. Volpe

Abstract: An automatic 3D model retrieval from freehand conceptual sketches is a key target for both commercial software houses and academic research. Unfortunately, most of the approaches are not suitable for properly translating stylistic sketches into 3D models. In order to carry out this 3D model conversion, the first task to be dealt with is to turn raster data (3D or 2D free-form curves) into vectorial ones. Such a task represents a key issue which has been addressed by a number of authors but still far to be exhaustively worked out. To address this challenge, this work presents a new method that allows to fit 2D unordered point cloud data with Multiple Incident Splines (MISs). At the heart of the proposed approach are two main procedures: the first one is based on Euclidean Minimum Spanning Tree (EMST) and Principal Component Analysis (PCA) for detecting the main local directions of the point cloud and to order its points while preserving original topology; the second is meant to fit ordered point clouds with spline curves providing a robust intersection and vertex detection. The proposed methodology, tested on a number of case studies, proves to preserve the original topology more efficiently than alternative techniques supplied by commercial vectorization software packages.


    Paper Title, Authors, Abstract (Issue 3, Volume 5, 2011)


On a General Efficient Class of Four-Step Root-Finding Methods
F. Soleymani, M. Sharifi

Abstract: In this paper, a general class of four-step iterative methods with four points per iteration is investigated for solving onevariable nonlinear equations. The introduced approximation for the first derivative of the function in the fourth step can be applied on any optimal derivative-involved eighth-order method to attain a new fourteenth-order without memory method with 1.6952 as its efficiency index. The produced methods have better order of convergence and efficiency index in comparison with optimal eighth-order methods and in light of these strong points; they can be observed as robust and efficient multi-point iterative methods. Per cycle, they consist of four evaluations of the function and one evaluation of the first derivative. The error equation for one method of this class is obtained theoretically. And subsequently its efficacy is tested on a series of relevant numerical problems to reveal that the presented methods from the class are efficient and accurate.


Evaluation and Comparison of Various Calculation Zone Analysis for Dynamic Simulation Software’s
Hendrik Voll, Erkki Seinre

Abstract: Since July 2009 it is compulsory for a new or major renovation building project to meet the requirements set by Estonian Government regulation nr. 258 „The Minimum Requirements for Energy Efficiency“. Conformity of the building to the minimum requirements for energy performance shall be inspected by way of an energy calculation upon standard use of a building, utilising primary data provided for in this Regulation regarding outdoor and indoor climate, periods of use and operation of the building and its utility systems, free heat, and air-tightness of the building. Other primary data required for the calculation shall be taken from the construction design documentation of the building. Unfortunatelly the regulation does not state in how many different calculation zones exactly should the dynamic simulation calculation be accomplished. This article reports on analysis of evaluation carried out in Tallinn University of Technology how the implementation of the regulation has taken effect as well shows how the lackage of information regarding the calculation zones may influence the calculation results. As the results show there are severe problems with application of this regulation, concerning the regulation itself, as well as the shortage of information and knowledge to use complicated dynamic simulation softwares. Finally sugestions regarding how to improve the regulations have been given.


Rapid Virtual Prototyping and Operational Monitoring of PLC-Based Control System
Kwan Hee Han, Sang Hyun Choi, Jun Woo Park, Jun Woo Lee

Abstract: As business environments are rapidly changing, the manufacturing system must be reconfigured to adapt to various customer needs. In order to cope with this challenge, it is quintessential to test industrial control logic rapidly and easily in the design-time, and monitor operational behavior correctly in the run-time of automated manufacturing system. Proposed integrated model for virtual prototyping and operational monitoring of industrial control logic is to improve limitations of current ladder programming practices and general discrete event simulation method. Each plant layout model using HMI package and object-oriented control logic model is designed independently and is executed simultaneously in integrated manner to reflect design practices of automation system in the design time. Control logic is designed and executed using UML activity diagram without considering complicated control behavior to deal with current trend of reconfigurable manufacturing. After the physical installation, layout model of virtual prototype constructed in the design time is reused for operational monitoring of system behavior during run time with slight modifications.


Convergence of Iterative Schemes in Spaces with Two Metrics
Bhagwati Prasad, Ritu Sahni

Abstract: The purpose of this paper is to study the stability of the Jungck- Mann and Jungck-Ishikawa iterative schemes for mappings satisfying general contractive conditions. We obtain the stability results for the maps in complete b-metric spaces with one and two metrics. Our results generalize the recent results of Olatinwo [12], Prasad and Sahni [20] and Singh and Prasad [26]. An example is also given to justify the need of the Jungck-Ishikawa iterative scheme.


Illusions and Reality of Space Objects Caused by Measurement Standards Variability
V. O. Groppen

Abstract: Proposed approach is based on the idea of variability of measurement standards. This approach permits us to predict some features of the Universe: spontaneous growth of distance between two resting objects detected by an observer at one of these objects, velocity/distance dependence is known to meet the Hubble Law, constancy of any solid body linear dimensions in time and equality of absolute values of gravitational braking and of illusive acceleration of galaxies is believed to be caused by linear measurement standard shortening some 6-8 billion years ago, as well as by mass loss by physical objects. The latter permits us to propose simulators, describing gravity and inertia as different manifestations of reaction forces.


Calculation of all Stabilizing PI and PID Controllers
Radek Matusu

Abstract: This paper deals with calculation of all stabilizing Proportional-Integral (PI) and Proportional-Integral-Derivative (PID) controllers. The stability region, representing the area of possible placement of the controller parameters which guarantee feedback stabilization of a controlled plant, is obtained via plotting the stability boundary locus in the P-I plane or the P-I-D space by means of the Tan’s method or the Kronecker summation method. These approaches are subsequently extended in order to compute robustly stabilizing PI controllers for interval plants. Moreover, the stabilization techniques are combined with the desired model method which is used for final controller design. The applicability of the methods is demonstrated on three control examples.


Double Compartment CA Simulation of Drug Treatments Inhibiting HIV Growth and Replication at Various Stages of Life Cycle
Sompop Moonchai, Yongwimon Lenbury

Abstract: Although there is no cure for AIDS at this time, intense research efforts have yielded several treatments that may be relied upon to delay HIV progression and improve the quality of life of those who have become symptomatic. Human immunodeficiency virus (HIV) infection typically follows a three phase pattern; the primary response phase, the clinical latency phase, and the final phase of onset of acquired immunodeficiency syndrome (AIDS). In order to test the efficiency of different protocols in drug therapy for HIV patients, it is important to have a realistic model which reliably simulates the course of the infection which exhibits two drastically different time scales, days and decades. The classical ordinary or partial differential equations have been found to be inadequate in coping with such extreme spread in time scales. In this paper, we employ a two-compartment Cellular Automata (CA) model to study the dynamics of drug therapy of HIV infection. The levels of healthy an infected CD+T cells are tracked in both the lymph node and peripheral blood compartments coupled and updated simultaneously with each time step. The viral loads in the two compartments are also updated through a system of difference equations. The cell update rules in the CA model are modified to simulate the impacts of therapeutic measures where various types of antiretroviral drugs are applied to inhibit the growth and replication of HIV at various stages of its life cycle. By adjusting the rules to update the cells in the CA lattice, it becomes possible to study the efficacies of different treatment strategies or drugs of choice, as well as the repercussion of drug resistance over time.


Delay Model of RTP Flows in Accordance with M/D/1 and M/D/2 Kendall's Notation
M. Voznak, M. Halas, B. Borowik, Z. Kocur

Abstract: This article deals with the mathematical model of an end-to-end delay and a delay variation in VoIP connections going through a two priority queue' serving system. We focused on delay caused by network components and its mathematical formulations. Our mathematical computational model is able to predict an estimated delay of packets in RTP flows, especially dealy variation in routers handling RTP packets in priority queue. We applied M/D/1 and M/D/2 queuing models and we expressed a probability of RTP packets waiting in the queue and all partial delay components and mechanisms. We determined the domain of validity in performed experiments and the proposed mathematical model is suitable for the approximation of voice traffic in network with priority queuing which consists of sources with the Poisson’s probability distribution.


Discovery of Multidimensional Association Rules Focusing on Instances in Specific Class
Hyontai Sug

Abstract: Conventional association rule finding algorithms as well as multidimensional association rule finding algorithms search association rules based on support, so it is not easy to find association rules of specific class with small support due to computational complexity. In order to overcome the problem of intensive computing time and to avoid the possibility of generating a lot of uninteresting rules, a method that can reduce the intensive computing time and generate smaller number of multidimensional association rules is suggested. By limiting the search for association rules to a specific class in target data set and by selecting instances that have at least one common field value with all instances in the class, the method can reduce the target data set significantly so that computing time can be saved and also smaller number of rules can be generated. Experiments with a real world data set showed a very good result.


Distributed Models in P-Systems Architectures to Reduce Computation Time
Miguel Angel Pena, Gines Bravo, Luis Fernando de Mingo

Abstract: Membrane systems are computational equivalent to Turing machines. However, their distributed and massively parallel nature obtains polynomial solutions opposite to traditional non-polynomial ones. At this point, it is very important to develop dedicated hardware and software implementations exploiting those two membrane systems features. Dealing with distributed implementations of P systems, the bottleneck communication roblem has arisen. When the number of membranes grows up, the network get congested. The purpose of distributed architectures is to reach a compromise between the massively parallel character of the system and the needed evolution step time to transit from one configuration of the system to the next one, solving the bottleneck communication problem. The goal of this paper is twofold. Firstly, to survey in a systematic and uniform way the main results regarding the way membranes can be placed on processors in order to get a software/hardware simulation of P-Systems in a distributed environment. Secondly, we improve some results about the membrane dissolution problem, prove that it is connected, and discuss the possibility of simulating this property in the distributed model. All this yields an improvement in the system parallelism implementation since it gets an increment of the parallelism of the external communication among processors. Proposed ideas improve previous architectures to tackle the communication bottleneck problem, such as reduction of the total time of an evolution step, increase of the number of membranes that could run on a processor and reduction of the number of processors.


Solving Multiclass Classification Problems using Combining Complementary Neural Networks and Error-Correcting Output Codes
Somkid Amornsamankul, Jairaj Promrak, Pawalai Kraipeerapun

Abstract: This paper presented an innovative method, combining Complementary Neural Networks (CMTNN) and Error-Correcting Output Codes (ECOC), to solve multiclass classification problem. CMTNN consist of truth neural network and falsity neural network created based on truth and falsity information, respectively. Two forms of ECOC, exhaustive code and random ECOC, are considered to deal with k-class classification problem. Exhaustive code is applied to the problem with 3 · k · 7 whereas random ECOC is used for k > 7. In the experiment, we deal with feed-forward backpropagation neural networks, trained using 10 fold cross-validation method and classified based on two decoding techniques: minimum distance and T > F. The proposed approach has been tested with six benchmark problems: balance, vehicle, nursery, Ecoli, yeast and vowel from the UCI machine learning repository. Three data sets: balance, vehicle and nursery are dealt with exhaustive code while random ECOC is applied for Ecoli, yeast and vowel. It was found that our approach provides better performance compared to the existing techniques considering on either CMTNN or ECOC.


Relationship between Taxation of Labor and Employment in the European Union: Mathematical Simulation
Michal Tvrdon

Abstract: The paper deals with a relationship between taxation of labor and employment. When taxes on labor are introduced the tax wedge between labor costs paid by employer (gross wage) and net wage received by employee appears. The paper is focused on characteristics of labor taxation and its effects on the labor market, the level of employment or unemployment especially. The paper also analyzes and compares total tax wedge in European Union countries (original EU-15 Member States and Visegrad Group countries – Czech Republic, Hungary, Poland and Slovakia). We found that EU Member States could be classified into two groups of countries – with high tax wedge or low tax wedge. The paper also tries to identify the relationship between the tax wedge and the employment rate in Visegrad countries. The main research method was a panel data regression model over the period 2000-2009. Some basic methods were applied: (i) the constant coefficient model; (ii) the fixed effects model and (iii) the random effects model. The empirical estimates have shown that an increase in the tax wedge decreases the employment rate.


Performance Algorithms in Generating Association Rules
Ioan Daniel Hunyadi

Abstract: Having its origin in market basket analysis, the eploration of association rules represents one of the main applications of data mining. In this article we present a performance comparison between Apriori and FP-Growth algorithms in generating association rules. The two algorithms are implemented in Rapid Miner and the result obtain from the data processing are analyzed in SPSS. The database used in the development of processes contains a series of transactions belonging to an online shop.


    Paper Title, Authors, Abstract (Issue 4, Volume 5, 2011)


Deep and Surface Learning of Elementary Calculus Concepts in a Blended Learning Environment
R. Haripersad

Abstract: Poor results in mathematics at South African higher education institutions have been the centre of academic debate. Mathematics forms the core for engineering and science studies at institutions of higher learning. However, analysis of student’s performance in mathematics tasks reveals that mastery of skills is not acquired. This paper focuses on students understanding of elementary calculus in a blended learning course at a University of Technology (UOT). Conventional lectures were integrated with the computer laboratory teaching environment to promote interactive and discovery learning. Projects were designed to support the development of calculus frames in conjunction with a theoretical framework that was used in analyzing students understanding of integral calculus concepts. The students in the blended learning mathematics course (experimental group) was also compared to students that were traditionally lectured (control group). Both groups were assessed by the modified Orton’s battery of tests on integral calculus. The experimental group exhibited deep learning of concepts, while the control group possessed more surface structures.


A Simulation Approach to Achieving More Efficient Production Systems
Bronislav Chramcov, Petr Beran, Ladislav Danicek, Roman Jasek

Abstract: The paper highlights the problem of the use of computer simulation for improving the effectives of operations in production systems. The main idea of this paper is to outline the possibilities afforded by the Witness simulation environment for the construction of models and the subsequent simulation of concrete manufacturing systems. The possibilities of making use of the Witness are herein presented in the form of two simulation studies that were performed within the framework of cooperative ventures between our workplace and industrial partners. The aim of these studies is to suggest and simulate experiments designed to increase productivity and to find bottlenecks in the system. Simulation experiments are proposed on the basis of the predefined requirements of the users. Results of the paper show, that computer simulation (especially Witness simulation environment) is possible to use not only for suggestions designed to increase the effectivity of existing production system, but also in the initial creation and design of production system.


Turbulent Flow and Heat Transfer Problem in the Electromagnetic Continuous Casting Process
Theeradech Mookum, Benchawan Wiwatanapataphee, Yong Hong Wu

Abstract: This paper aims to study the effect of turbulence on the flow of two fluids and the heat transfer - solidification process in electromagnetic continuous steel casting. The complete set of field equations is established. The flow pattern of the fluids, the meniscus shape and temperature field as well as solidification profiles obtained from the model with and with no turbulence effect are presented. The results show that the model with turbulence gives a large circulation zone above the jet, much larger variation of the meniscus geometry, a slow solidification rate and higher temperature in the top part of the strand region.


Complete Blow-up for a Degenerate Semilinear Parabolic Problem in the Sense of Semigroup Theory
Panumart Sawangtong, Wannika Jumpen

Abstract: Before blow-up occurs, under certain conditions, we establish a unique blow-up solution for a degenerate semilinear parabolic problem.


SEIQR-SIS Epidemic Network Model and Its Stability
Wannika Jumpen, Somsak Orankitjaroen, Pichit Boonkrong, Benchawan Wiwatanapataphee

Abstract: In this paper, we propose an SEIQR-SIS epidemic network model to study pandemic influenza and derive the approximate threshold condition (basis reproductive number) to examine the stability of the model. The numerical imulation of the disease transmission in the adaptive social network with people nodes and hub nodes is presented. The network parameters including visiting probability, hub radius and contact radius are used to investigate their impacts on the disease transmission. Our results show that these network parameters have a significant effect on the disease spread.


Numerical Simulation of Blood Flow Through the System of Coronary Arteries with diseased Left Anterior Descending
Pearanat Chuchard, Thitikom Puapansawat, Thanongchai Siriapisith, Yong Hong Wu, Benchawan Wiwatanapataphee

Abstract: This paper aims to study the arterial stenosis effect on blood flow problem in the system of coronary arteries. Blood is assumed to be non- Newtonian incompressible fluid. The system of coronary arteries with diseased Left Anterior Descending (LAD) is considered. Governing equations are the Navier-Stokes equations and continuity equation subjected to the time-dependent pulsatile boundary conditions. Based on finite element method, the solution of the governing equations is solved numerically. Disturbances of blood flow through the diseased LAD for the restrictions of 25%, 50% and 75% are investigated. Flow characteristics, wall pressure and wall shear rate have been studied in detail. Numerical studies show that blood flow with high speed and pressure rapidly drops in the area supplied by the stenosed artery. As the degree of coronary-artery stenosis increases, the maximal coronary flow decreases.


Design and Simulation Verification of Selftuning Smith Predictors
V. Bobal, P. Chalupa, P. Dostal, M. Kubalcik

Abstract: This paper deals with a design of algorithms for selftuning digital control of processes with time-delay. The algorithms are based on the some modifications of the Smith Predictor (SP). One modification of the SP based on the digital PID controller was applied and it was compared with two new designed modifications based on polynomial approach (pole assignment and minimization of the quadratic criterion). The program system MATLAB/SIMULINK was used for simulation verification of these algorithms. Some of designed algorithms are suitable for implementation in real time conditions.


Searching Optimal Buyer Coalition Structure by Ant Colony Optimization
Anon Sukstrienwong

Abstract: In recent years, several buyer coalition schemes have been proposed by researchers in order to form effective coalitions and achieve the maximum benefit for consumers in an electronic market. However, there are few algorithms applying the ant colony optimization for forming buyer coalition. In this paper, we present the approach based on the Ant Colony Optimization (ACO). The approach called the Ant Colony Optimization for Forming of Buyer Coalition (ACO_FBC) algorithm for the formation of buyer coalition with bundles of items. The algorithm involves searching for the optimal buyer coalition structure by partitioning the whole group of buyers into smaller coalitions so that the aggregate of discount of the whole buyers is maximized. A number of artificial ants search to find the best disjoint subgroups of all buyers based on the total utility functions. The results of the ACO_FBC simulation are compared with the genetic algorithm (GAs) in the terms of the global optimal buyers' benefits. It indicates that in most situations our proposed algorithm significantly improves the utility of the buyer coalition.


The Shape Optimization of the Pneumatic Valve Diaphragms
Jakub Javorik, Michal Stanek

Abstract: Our goal was to analyze mechanical behavior of a rubber diaphragm inside a pneumatic valve and the FEM analysis appears as a very appropriate tool for this work. The hyperelastic parameters of the elastomer material of valve diaphragms were measured. Analyses of the diaphragms in working conditions were carried out. Considering the results of these analyses the new shapes of the diaphragms were designed and were verified again by the numerical analyses.


Simulation of Nonlinear Adaptive Control of a Continuous Stirred Tank Reactor
Petr Dostal, Vladimir Bobal, Frantisek Gazdos

Abstract: The paper presents design and simulation results of nonlinear adaptive control of a chemical reactor. The control strategy appear from factorization of the controller on an adaptive dynamic linear part and a static nonlinear part. The static nonlinear part is derived on the basis of simulated steady-state characteristics of the process and its subsequent inversion and approximation. The linear part consisting of two linear feedback controllers results from an approximation of nonlinear elements in the control system by an external linear model with recursively estimated parameters. The control law is derived via the polynomial approach and the pole placement method.


Design and Testing an Artificial Arm Microsystems in Virtual Environment
E. D. Franti, A. Zafiu, A. Plavitu, M. Teodorescu, P. Schiopu

Abstract: In this paper is presented a virtual environment that was designed in order to develop and test different architectures for Artificial Arms microsystems. The utility of the virtual environment is significant because testing different structures of Artificial Arms and microsystems architectures and then selecting the best option is much cheaper when it is used a virtual environment compared to the option of testing different hardware implemented microsystems. The virtual environment also allows the user to evaluate the performance/cost ratio for each microsystem correlated with the type of the Artificial Arm that was used.


Simulation and Modelling in Critical Infrastructure Protection
Lukas Ludek, Hromada Martin

Abstract: Critical Infrastructure Protection is currently considered an important aspect of solving security issues of EU countries, even given that its role is perceived in terms of maintaining functional continuity of the economic and social terms. It is therefore clear that the responsible entity will use all available approaches to ensure an acceptable level of security and protection of important elements of national as well as transnational (European) critical infrastructure. Among the useful approaches you can use appropriate forms of simulation and modelling tools. It is clear that the analysis of current approaches to protection of property points to the fact that the physical protection systems could be considered as an one aspect of a comprehensive protection system also useful in the present issue. Therefore, in this article we consider the use of modelling and simulation tools in the context of determining the optimal structure of the physical protection system of critical infrastructure elements. For the purpose of fulfilling this goal, we chose an EASI model and OTB SAF simulation tool.


    Paper Title, Authors, Abstract (Issue 5, Volume 5, 2011)


Fuzzy Multi-Objective Linear Plus Linear Fractional Programming Problem: Approximation and Goal Programming Approach
Pitam Singh, Shiv Datt Kumar, R. K. Singh

Abstract: In this article, a fuzzy goal programming (GP) and method of approximation is presented for the solution of a multiobjective linear plus linear fractional programming problem. In the proposed approach, membership functions are defined for each fuzzy goal and then a method of variable change on the under- and over- deviational variables of the membership functions associated with the fuzzy goals of the model is introduced. Then the problem is solved efficiently by using goal programming(GP) methodology and method of approximation(MAP). Three numerical examples is given for verification of the method. The examples are solved by optimization software TORA@ 2.0 version, 2006.


Practical Application of the Heat Distribution and Consumption Model
Vasek L., Dolinay V.

Abstract: This article focused on the practical experiments made by designed and implemented computer model of the distribution system of heat consumption in the urban agglomeration (SHDC - System of Heat Distribution and Consumption). This model is designed as a simulation model connected to prediction mechanism. The simulation is one of the methods, which can be effectively used for the analysis of large and complex dynamic systems properties, which the distribution system and heat consumption in the municipal heating networks is. The model was implemented in the form of computer applications to provides interfaces to adapt it into a real heating system. To provide necessary functionality, the model takes basic information from the system to be modeled, such as the lengths and diameters of the real pipe system along with operational data. The model and its subsequent links are designed for heat supply prediction, which can be used in system regulation. Depending on the structure of the particular real system, the temperature of heating water is usually required to predict and the other variables such as mass flow and the water temperature in the return line.


Optimization of Injection Molding Process
M. Stanek, D. Manas, M. Manas, O. Suba

Abstract: Optimization of injection molding process serves for finding ideal conditions during production of plastic parts and observing their dimensions, shapes and properties. It is possible to determine the appropriate injection pressure, velocity, value and time of packing pressure, etc. by optimization. The paper is dealing with description of Moldflow Plastics Xpert (MPX) system and its usage in optimization of injection molding process on real part during its production.


Simulation of Injection Molding Process by Cadmould Rubber
M. Stanek, D. Manas, M. Manas, J. Javorik

Abstract: Simulation analyses of plastics injection molding are a tool for increasing the quality of plastic products and tools, equipment used for shortening the time necessary for preparation of new products for the market and hence leading to lowering production costs. The simulation analyses are nowadays commonly used for production of thermoplastic parts. This article stresses on the fact that injection molding of rubber compounds could be from the calculation purposes analysed already in the constructive phase during the preparation of the production to achieve positive assets, till now related only to the thermoplastic parts.


Topological Structure Analysis in Directed Network
E. Klimkova, R. Senkerik, I. Zelinka

Abstract: This paper is focused on the description, as to how to represent the network topology. It is very important to know the network topology and to understand its properties. This work describes how to find all the Giant Connected Component in directed network. The growing complex networks with preferential linking were used for experimental testing within this research. Roulette-wheel selection method was used as a preferential selection algorithm in the task of generation of complex networks.


Embedded System Inputs and Outputs Disturbing Sources and the Linear Optocoupler Behavior Mathematical Description
Otahal Jiri, Michal Brazdil, Hruska Frantisek

Abstract: The paper reveals the possible sources of interference that can disrupt the function of inputs and outputs of embedded systems or interfere with correct interpretation of the input signals or the possibility of complete destruction of input and output circuits by these interferences. The issue of capping limits for analog signals with linear optocoupler and also use of designed limit voltage limiters are solved as well. In the last part the measured static and dynamic limiters characteristics are measured and linear optocoupler is described mathematically.


Simulation and Design of Voltage Controlled Amplifier for Dynamic Expanders
Martin Pospisilik, Milan Adamek

Abstract: A design of an advanced voltage controlled amplifier made with the aid of electrical circuit simulator Multisim and mathematical computation engine Maple is discussed in this paper. This amplifier is supposed to be used in audio signal processing systems like dynamics expanders and so on. In addition, a block diagram of a complex dynamic volume expander is proposed here.


VU Meter Driver Simulation and Design
Martin Pospisilik, Milan Adamek

Abstract: This paper deals with a design, construction and practical testing of a VU meter driver that includes an accurate rectifier and logarithmical driver of a pointer-type gauge. The logarithm is taken from the rectified signal by employing a capacitor discharge voltage curve. Several software simulations were made in order to proof the circuit design. Then a simple rectifier and logarithmiser was designed and built in order these simulations were proved and afterwards, based on the gained experience, the more complex design of the VU meter driver was created. The paper incorporates mathematical description of the circuit, simulation results and results gained when the simple driver circuit underwent several physical tests as well as further propositions for practical extensions of the designed circuit.


Experiments on the Gentry-Halevi Somewhat Homomorphic Scheme
M. Mikus

Abstract: We have implemented the somewhat homomorphic scheme from [16]. We examined this scheme in the same way as mentioned in [16] and extend the results for a wider set of parameters and also increased the number of repetitions for each test. We focused on the dependencies between the largest supported degree and various parameters of the cryptosystem, specially also the encryption parameter q. We show that the probability q significantly influences the overall effectiveness of the scheme and that the growth of the supported degree doesn’t grow linearly with the parameter t (strictly) and we give an explanation for this fact.


Simulation of Municipal Heating Network Based on Days with Similar Temperature
Dolinay V., Vasek L.

Abstract: This article describes preparation and verification of particular part of the model for heat distribution. Presented improvement focuses on heat supplies proposal which is based on seeking and identification of days with similar outdoor temperature behavior. The model of distribution system for heat consumption was prepared but the main questions, for real system management as well as for simulation, still remain: When, how much and in what heat condition to deliver into the urban agglomeration? The first and simplest answer could be the similar conditions as we used yesterday or better, day alike the one we want to control now. The main task of heat supply systems is to maintain all needs associated with heat consumption. From the information we had got from previous (similar) day, the new control could starts. The idea is to make the model more precise and offer resources to improve existing control, for more accurate function.


    Paper Title, Authors, Abstract (Issue 6, Volume 5, 2011)


Computerized Mechanical Movement Control System for Two Dimensional Ultrasound Breast Scanning
Lai Khin Wee, Lee Siew Wen, Eko Supriyanto

Abstract: Ultrasound scanning system is a non-ionizing technique for breast mammography. Unfortunately, ultrasound has not approved by FDA as a screening tool yet due to the lack of spatial resolution and high operator dependent. Therefore, the quality of imaging depends on the operator technique and experience. The purpose of this project is to develop an automated 2D motion system for ultrasound scanning designed for breast cancer patient. The scanning was performed by automated movement of a transducer during image acquisition. Therefore, the automated motion system needs a very high precision of position control system which integrated with a microcontroller and two appropriate distance sensors on each axis. Besides, graphical user interface has been designed to interface between the microcontroller and personal computer. The control method for the automated motion system can achieve a resolution of 2mm. This is used to replace the conventional handholding ultrasound probe and to increase the spatial resolution of ultrasound.


A Mathematical Model of Bone Remodeling Process: Effect of Vitamin D
Sahattaya Rattanamongkonkul, Wannapa Kunpasuruang, Sittipong Ruktamatakul, Chontita Rattanakul

Abstract: We propose a system of differential equations in order to investigate bone remodeling process based on the effect of vitamin D. The model is then analyzed by using singular perturbation technique in order to identify different dynamic behaviors exhibited by the model. Numerical simulations are also carried out to support our theoretical predictions. Both of theoretical and numerical results show that the model can exhibit a periodic behavior corresponds to the pulsatile serum level of vitamin D observed in the clinical evidence.


The Development of Discrete Decision Tree Induction for Categorical Data
Nittaya Kerdprasop, Kittisak Kerdprasop

Abstract: In decision analysis, decision trees are commonly used as a visual support tool for identifying the best strategy that is most likely to reach a desired goal. A decision tree is a hierarchical structure normally represented as a tree-like graph model. The tree consists of decision nodes, splitting paths based on the values of a decision node, and sink nodes representing final decisions. In data mining and machine learning, decision tree induction is one of the most popular classification algorithms. The popularity of decision tree induction over other data mining techniques are its simple structure, ease of comprehension, and the ability to handle both numerical and categorical data. For numerical data with continuous values, the tree building algorithm simply compares the values to some constant. If the attribute has value smaller than or equal to the constant, then proceeds to the left branch; otherwise, takes the right branch. Tree branching process is much more complex on categorical data. The algorithm has to calculate the optimal branching decision based on the proportion of each individual value of categorical attribute to the target attribute. A categorical attribute with a lot of distinct values can lead to the overfitting problem. Overfitting occurs when a model is overly complex from the attempt to describe too many small samples which are the results categorical attributes with large quantities. A model that overfits the training data has poor predictive performance on unseen test data. We thus propose novel techniques based on data grouping and heuristic-based selection to deal with overfitting problem on categorical data. Our intuition is on the basis of appropriate selection of data samples to remove random error or noise before building the model. Heuristics play their role on pruning strategy during the model building phase. The implementation of our proposed method is based on the logic programming paradigm and some major functions are presented in the paper. We observe from the experimental results that our techniques work well on high dimensional categorical data in which attributes contain distinct values less than ten. For large quantities of categorical values, discretization technique is necessary.


Effects of Parathyroid Hormone and Calcitonin on Bone Formation and Resorption: Mathematical Modeling Approach
Inthira Chaiya, Chontita Rattanakul, Sahattaya Rattanamongkonkul, Wannapa Kunpasuruang, Sittipong Ruktamatakul

Abstract: A system of nonlinear differential equations is proposed here to describe the mechanism of bone formation and resorption based on the effects of parathyroid hormone and calcitonin. Singular perturbation technique is then applied to the model in order to obtain the conditions on the system parameters for which the various kinds of dynamics behavior can be occurred. Computer Simulations are also carried out to support our theoretical predictions. Both of theoretical result and numerical result show that a periodic solution of the model can be expected for a certain set of parametric values corresponding to the pulsatile secretions of parathyroid hormone and calcitonin reported in clinical evidences.


The Methodology. Meta-Synthetic Integrated Environment and Data Accessing Service of Stratagem Research
Wei Jicai, Ren Tingguang, Zhang Jing

Abstract: The stratagem-research (SR) methodology was brought forward and constructed in this paper, under the guidance of the combination of qualitative and quantitative methods, the meta-synthetic integrated environment of SR was designed. and then, the data accessing service is designed to meet the needs of searching and utilizing various data in the meta-synthetic integrated environment of stratagem research (SR) and meanwhile data fuzzy mining engine is supposed to refine the collected data to make them useful for the stratagem research. Also, for accessing and utilizing database, data accessing API is designed, which provides a uniform interface for all data accessing requests and with mapping function gets all data address and accessing transparent.


Use of MATLAB Environment for Simulation and Control of CSTR
Jiri Vojtesek, Petr Dostal

Abstract: This contribution presents the usability of the mathematical software MATLAB ® (MATrix LABoratory) in the field of simulation of the steady-state, dynamic behaviour and adaptive control of the Continuous Stirred Tank Reactor (CSTR). These types of chemical reactors belong to the class of nonlinear lumped-parameters systems mathematical model of which is described by one or more Ordinary Differential Equations (ODEs). The simple iteration method was used for steady-state analysis of the system while the Runge-Kutta’s method was employed for the numerical solution of the set of ODE. Both methods are simple, provides sufficient results and they are easily programmable which was important in our case. The presented adaptive approach used for controlling of the system provides sufficient results although the system has negative properties from the control point of view. The benefit of this paper can be found in the simulation program made in MATLAB with the use of Graphical User Interface (GUI) that provides user possibilities to examine simulations without changing of the program code.


Effect of Time Delay on Bone Remodeling Process
Suchanan Thongmak, Chontita Rattanakul, Sahattaya Rattanamongkonkul, Wannapa Kunpasuruang, Sittipong Ruktamatakul

Abstract: We modify a mathematical model of bone remodeling process to study the effect of time delay observed clinically in the process. We then utilize the Hopf bifurcation theorem to investigate the possibility of the occurrence of periodic behavior exhibited by our model. Numerical simulation is also carried out to support our theoretical results. Theoretical and numerical results indicate that the periodic behavior observed clinically in the pulsatile secretion of parathyroid hormone can be expected in our model.


Design of SVC Controller for Oscillations Damping Using Self-Learning Fuzzy Approach
N. Magaji, M. W. Mustafa

Abstract: Application of fuzzy PD controller based on self learning algorithm for SVC device has been investigated in this paper. This approach used sensitivity model for learning Self Learning Fuzzy Logic parameters. This has been improved by adding up an integral term whose gain coefficient is also synthesized by learning that is actuated after completion of the main learning algorithm. The paper considers the conventional PID controller and compares its performance with respect to the proposed SLFLC controller. Several fault and load disturbance simulation results are presented to emphasize the efficiency of the proposed SVC controller in a TNB 25- bus of south Malaysian power system and New England 39 Bus system.


Development of Process Control Systems with the Use of Emulation Models
Victor Okolnishnikov

Abstract: This paper describes the use of emulation models to provide feedback for industrial process control systems in order to test their logical operation prior to commissioning. The new visual interactive discrete simulation environment intended for the development and execution of simulation and emulation models is presented. Main possibilities that are provided by the environment are: the rapid building of models from libraries elements, 3D representation, and the interaction of models with real control systems. The paper presents three cases of successful development and use of emulation models for process control systems in various industrial fields created with the help of this environment. The use of emulation models reduces the time and the cost of testing and optimization control systems. Emulation models were also used for training of operating personnel.




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