ISSN: 1998-0140



Year 2008

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 2, 2008)


Holomorphic generic families of singular systems under feedback and derivative feedback
M. Isabel Garcia-Planas

Abstract: Following Arnold techniques, in this paper we obtain a canonical reduced form for regularizable singular systems and we describe generic holomorphic families with respect feedback and derivative feedback, that permit us, to analyze the neighborhood of a given system.


One-dimensional parabolic equation with a discontinuous nonlinearity and integral boundary conditions
Abdelkader Boucherif

Abstract: In this paper we are concerned with the existence of solutions of an initial-boundary value problem for a one-dimensional parabolic inclusion with nonlocal integral boundary conditions. Using the Green’s function we transform the problem into an equivalent integral inclusion. Our technique is based on fixed point theorems for set-valued maps and the method of lower and upper solutions. We provide sufficient conditions that guarantee the existence of at least one solution.


Simulation wetting and drying of mangrove forests due to tidal currents in Qeshm canal
S.R. Sabbagh-Yazdi, M. Zounemat-Kermani and N.E. Mastorakis

Abstract: The main aim of the present paper is devoted to simulate flow pattern in the Qeshm canal which is affected by two open boundary conditions at inlet and outlet of the canal, which are formed by tidal currents in the Persian Gulf. In this paper, hydrodynamic simulation of tidal currents in the Qeshm canal due to tidal fluctuations in Hurmoz Strait is presented. The mathematical model utilized consists of depth averaged equations of continuity and motion in two-dimensional horizontal plane which considering hydrostatic pressure distribution. The cell-vertex finite volume method is applied for converting the governing equations into discrete form for unstructured control volumes. In order to reduce the unwanted errors during model running, an artificial viscosity formulation, was used which is designed for the unstructured triangular meshes. The quality of the model results is verified by comparison between numerical results and reported data in the literature for flow in a channel with a spur dike. Finally, the performance of the computer model to simulate tidal flow in a geometrically complex domain, which is subject to wetting and drying is examined by simulation of tidal currents in the Qeshm canal in the Persian Gulf.


On Algebraic Structures of Dynamical Systems
Stanislaw P. Kasperczuk

Abstract: The paper discusses the close relation between the existence of first integrals of vector fields X : M ! TM and Poisson structures of a manifold M.


Periodic and antiperiodic eigenvalues for half-linear version of Hill’s equation
Gabriella Bognar

Abstract: The nonlinear eigenvalue problem of a differential equation with respect to periodic boundary conditions:, or to the antiperiodic boundary conditions: are considered. Various results on the set of eigenvalues concerning both problems are presented. Some estimates are given for the periodic and antiperiodic eigenvalues.


An analysis of the beam bending problem with random beam height
Mladen Mestrovic

Abstract: The standard beam bending problem has been obtained where the beam height is assumed to have spatial uncertainty. The formulation to determine the response variability of the beam due to randomness of the beam height is given. The concept of variablity response function is extended to beam bending problem where the beam height is considered to be one-dimensional, homogenous stochastic field. The randomness of the beam height has than influence not only on the flexural rigidity of the beam, but also on self-weight load of the beam. Through the proposed formulation it becomes possible for the weighted integral stochastic finite element analysis to consider complete influence of uncertain geometrical property on response variability. The coefficeint variation and variance of the response deflection was calculated as the function of the coefficeint of variation and variance of the beam height as the input quantity. Numerical example shows good agreement of the proposed weighted integral method with solution calculated by Monte Carlo simulation.


Assessing applicative performance of a hybrid machine learning model
Sung Ho Ha, Jong Sik Jin, and Seong Hyeon Joo

Abstract: Yield management in semiconductor manufacturing companies requires accurate yield prediction and continual control. However, because many factors are complexly involved in the production of semiconductors, manufacturers or engineers have a hard time managing yield precisely. Intelligent tools need to analyze multiple process variables concerned and to predict production yield effectively. This paper devises a hybrid method of incorporating machine learning techniques together to detect high and low yields in semiconductor manufacturing. The hybrid method has strong applicative advantages in these manufacturing situations, whereby control of a variety of process variables is interrelated. In the real applications, the hybrid method provides more accurate yield prediction than other methods that have been used. With this method, the company achieves a higher yield rate by preventing low-yield lots in advance.


On reduced models to approximate particle beams and plasma physics problems
Franck Assous

Abstract: This paper is devoted to the construction of models to approximate particle beams and plasma physics problems. In recent years, solving numerically problems which couple charged particle to electromagnetic fields has given rise to challenging mathematical and scientific computing developments. In the industry, a variety of examples can be thought of, such as the ion or electron injectors for particle accelerators, the free electron lasers, the hyperfrequency devices, the vulnerability of spatial devices to particle flows, etc. The mathematical model which is most relevant in describing the physics of such problems is provided by the time-dependent coupled Vlasov-Maxwell system of equations. Eventhough this model is necessary in a number of cases, it leads to very expensive computations and simpler, i.e reduced models are required. The main lines of this paper will treat about the analysis and the development of the reduced models. We present two situations in which this strategy can be applied. Numerical results illustrate the possibilites of the approach.


Predicting business failures using the rough set theory approach: The case of the Turkish banks
Nursel Selver Ruzgar, Fahri Unsal, and Bahadtin Ruzgar

Abstract: Predicting business failures before they actually take place is very important in order to be able to take necessary preventative measures. Such predictions are especially important in the banking sector that plays a key role in any economy. This paper focused on the Turkish banking sector, and after reviewing a number of quantitative tools, selected to apply the Rough Set Theory (RST) approach to analyze the failures of banks during the 1995-2007 period. The data for the financial ratio analysis for the 41 banks investigated from the publicly available sources. The results showed that early warning systems based on statistical models can effectively be used to predict bank failures. In this study, low capital ratios were found to be important variables in discriminating between failed and successful banks in Turkey. Also low and medium assets quality and profitability ratios were the leading indicators in predicting potential failures. The overall results showed that RST model is a promising alternative to the conventional methods for failure prediction.


Rough sets and logistic regression analysis for loan payment
Bahadtin Ruzgar, Nursel Selver Ruzgar

Abstract: Risk classification is an important part of the financial processes. In small business loans, there is always a risk for nonpayment or non-refunding of loans though very detailed examinations are made about the company. In this study, behaviors that increase the risk in loans or causing non-refunding are tried to be determined by using the rough Set (RS) approach and logistic regression (LR). For this purpose, 121 regularly refunded and 121 irregularly refunded loans, drawn from a bank in 2006 year, were randomly selected and their attributes were examined in 2007. Examination is made in three sections for qualitative variables, for quantitative variables and for both qualitative and quantitative variables. As a result, RS model is applicable to a wide range of practical problems pertaining to loan payment prediction, but LR does not classify refund or non-refund of loan payment as good as RS, so LR can not be used for prediction. Moreover, the results show that the RS model is a promising alternative to the conventional methods for financial prediction. In fact, RS gives the attributes that affect the results negatively or positively with their measures which are used for predictions.


Multinomial Regression Model for In-service Training
Hsieh-Hua Yang, Hung-Jen Yang, Jui-Chen Yu, and Wen-Chen Hu

Abstract: In-service training is education for employees to help them develop their professional skills in a specific discipline or occupation. This training takes place after an individual begins work responsibilities. On-line technology is supporting our learning in many ways. Both credit and degree pursuing are formal developing program. There is a need to developing a model of in-service training for a certain professional group so can illustrate their group behavior. The purpose of this study was to present how to develop a model of in-service training by using multiple logistic regressions. Based on literature review, a theory model was first identified. An investigating was conducted to collect data to evaluate the designed model. The model consist two factors, one is the learners’ age and the other is the learning styles. Two models were establish to explore both credit training and degree training courses. The resulted model then was further discussed to reveal in-depth of in-service needs.


Mathematical and computer tools of discrete dynamic modeling and analysis of complex systems in control loop
Armen G. Bagdasaryan

Abstract: In this paper we present a method of discrete modeling and analysis of multilevel dynamics of complex large-scale hierarchical dynamic systems subject to external dynamic control mechanism. In a model each state describes parallel dynamics and simultaneous trends of changes in system parameters. The essence of the approach is in analysis of system state dynamics while it is in the control loop. Architectural model of information system supporting simulation and analysis of dynamic processes and development scenarios (strategies) of complex large-scale hierarchical systems is also proposed.


The Impact of the Long Term Performance of a Bank on Its Market Value
Begumhan Ozdincer, Cenktan Ozyildirim

Abstract: The long-term performance besides current performance is expected to play a role on the firm’s market value. By using the non-parametric data envelopment analysis the efficient frontier for long-term performance of banks is measured within a production plan to ensure long-term presence. More efficient banks in the long-term are expected to increase their market share and achieve firm value maximization. Current performance is measured by incorporating the cost and risk factors into the return analysis. Return on solvency adjusted for the cost of free capital and shortterm liquidity are contributions of this paper in measuring bank performance.


Travelling wave solutions for a generalized Benjamin-Bona-Mahony-Burgers equation
M.S. Bruz´on, M.L. Gandarias

Abstract: In this paper, we consider a generalized Benjamin- Bona-Mahony-Burgers equation. Classical symmetries of this equation are considered. The functional forms, for which the BBMB equation can be reduced to ordinary differential equations by classical Lie symmetries, are obtained. A catalogue of symmetry reductions and a catalogue of exact solutions are given. A set of new solitons, kinks, antikinks, compactons and Wadati solitons are derived.


A General Optimization Scheme of Line-Source Pattern Synthesis and Its Applications to Monopulse Tracking Array Antennas
Keum Sook Ha and Eui Joon Park

Abstract: An iterative nonlinear inversion method in the line source pattern synthesis problem is newly presented for extracting the source distribution functions corresponded to the arbitrarily prescribed sum and difference pattern sidelobe levels. In this method, the generalized Fourier transform pair is first formulated which enables the desired patterns and the distributions to be simultaneously extracted by the optimum perturbation of pattern null positions. A significant result is that the difference patterns with the individually specified sidelobe levels are optimally synthesized by appropriately updating the Taylor line source sum pattern formula. Furthermore the method can be extended to the synthesis of the discrete linear array antennas. The scheme for extracting the excitation current weights of discrete array is also based on the perturbations of pattern nulls which are represented by the complex root locations on Schelkunoff’s unit circle. Numerical examples show the flexibility and effectiveness of the proposed procedures.


The Dynamics of Persuasion
John P. Curtis and Frank T. Smith

Abstract: The act of persuading other people to adopt an acceptable opinion, and perhaps as a result, to do something we want them to, forms a huge part of our lives. Indeed this skill and the equally important one of being willing to listen to reason and be persuaded could be said to be at the core of what we term society. To what extent can we represent this social process mathematically? The concerned reader will doubtless be greatly relieved to hear that the authors believe that this goal is still very far distant. Nonetheless, some simple models discussed here may show some promising avenues to explore. Following some assumptions about propensity to be persuaded, discrete and continuous models are investigated and solved analytically for two people, and then generalised to an arbitrary number of people. The three person continuous model is then examined in some detail. Possible applications are discussed.


Portfolio Selection Problem with Maximum Downside Deviation Measure: A Stochastic Programming Approach
K. Ibrahim, A.A. Kamil, and A. Mustafa

Abstract: In this paper, single stage stochastic programming two stage stochastic programming models are proposed for portfolio selection problems. The uncertainty of the future returns is the most important character within this optimization problem. The concept of risk is used in the Markowitz Mean-Variance model that identifies risk with the volatility (variance) of the random objective. Since then, mean-risk optimization paradigm received extensive development both theoretically and computationally. We utilize probabilistic methods alongside with optimization techniques and develop the stochastic programming models for portfolio selection problem minimizing maximum downside deviation from the expected return. We develop single stage and two stage stochastic programming with recourse. The models were developed for risk averse investors and the objective of the stochastic programming models is to minimize the maximum downside deviation. We use the so-called “Here-and-Now” approach where the decision-maker makes decision ”now” before observing the actual outcome for the stochastic parameter. We compare the optimal portfolios between the single stage and two stage models with the incorporation of the deviation measure. The models are applied to the optimal selection of stocks listed in Bursa Malaysia and the return of the optimal portfolio is compared between the two stochastic models. The results show that the two stage model outperforms the single stage model in the optimal and in-sample analysis.


About an image encryption solution adapted for surveillance flying systems
Ciprian Răcuciu, Nicolae Jula, Cosmin Adomnicăi

Abstract: This paper presents an encryption system developed to be used on an Electrical Accelerated mini-helicopter. The helicopter was developed for monitoring and surveillance purposes. The hart of the encryption system is the CV700C motherboard and it’s VIA C7 microprocessor with ultra low power consumption and efficient heat dissipation. The whole system is composed from two systems and six modules: image capture, encryption, two radio link modules, decryption and display module. The first three modules are implemented on airborne system and the last three modules on the base station system. The airborne hardware platform is the CV700C motherboard and the base station is an Intel microprocessor based notebook. For encryption, Rijndael algorithm was used.


Stability condition for a class of linear discrete systems
Ilja Martisovits and Katarına Zakova

Abstract: The paper deals with the proof of the stability condition for a certain class of linear time-discrete systems. From the mathematical point of view it shown that all roots of the speci£ed class of the n-th order linear equation are placed inside of the unit circle.


Designing Fuzzy Based Mobile Robot Controller using VHDL
Shabiul Islam, Mukter Zaman, Bakri Madon, and Masuri Othman

Abstract: This paper presents a designing of model for an autonomous mobile robot controller (MRC) hardware with navigation concept using Fuzzy Logic Algorithm (FLA). The MRC enables with navigation for an unstructured environment to avoid any encountered obstacles without human intervention. The designed hardware architecture of autonomous mobile robot can be easily used in unstructured environments appropriately to avoid collision with obstacles by turning to the proper angle. Additionally, the FLA concept has proven a commendable intelligent solution in dealing for the certain control problems, when the situation is uncertain.


    Paper Title, Authors, Abstract (Issue 2, Volume 2, 2008)


Fuzzy based PID Controller using VHDL for Transportation Application
Md.Shabiul Islam ,Nowshad Amin , Mukter Zaman , M.S.Bhuyan

Abstract: This paper describes the designing of PID-type (Proportional-Integral-Derivative) controller based on Fuzzy algorithm using VHDL to use in transportation cruising system. The cruising system with Fuzzy concept has developed to avoid the collisions between vehicles on the road. The developed Fuzzy Logic Controller (FLC) provides a reference for controlling the vehicle speed either increase or decrease. The controlling speed depends on the distance of the preceding vehicle when it gets too close or alert the driver when necessary. The Mamdani Fuzzy Inference theory is studied, and developed in Matlab package at first for designing the PID-type FLC hardware system. The behavioral of the PID-type FLC algorithm is then simulated using VHDL language. The comparison of simulation results between Matlab and VHDL are presented for designing the PID-type hardware implementation. The synthesis tool from Quartus-II environment is chosen to synthesize the designed VHDL codes for obtaining the Register Transfer Level (RTL) hardware architecture of the PID modulus. The developed and designed Fuzzy based PID-type cruising controller is cheaper in cost compare to conventional PID controller system, and, thus we can propose this developed chip to use to the entry-level vehicles such as the national car. This can be further reduced the road accident and ensure the safety of the road users in the future.


Modeling the Market Adoption of Mobile Payment Solutions
K.B. Saji

Abstract: As mobile commerce becomes increasingly acceptable, mobile payments (m-payments) are now predicted to have a brilliant future. In order to exploit this growing opportunity, a number of innovative m-payment products have been brought to the market by many firms in recent years by taking advantage of the rapid technological progress. However, the evolution of m-payment market is subjective to scores of speculative scenarios that have led to many new product failures. The central issue of concern here is observed to be the problem of choice by the customers. Although many commentaries are available in the existing literature on the status of mobile commerce acceptance in general, there is no focused effort so far to explore the market adoption of m-payment solutions. To address this critical gap, an exploratory study has been conducted on the market adoption of m-payment solutions. With the support of two cases, the present paper reports the antecedents of market adoption of m-payment solutions.


Effects of bottom aerator and self aeration in steep chute spillways on cell center finite volume solution of depth-averaged flow
S.R. Sabbagh-Yazdi, H. Rezaei-Manizani and N.E. Mastorakis

Abstract: In this paper the effects of air concentrations on the numerical computation of spill flow parameters in chute canals are investigated. The flow parameters in terms of depth averaged velocity components parallel to the bottom surface and flow depth are computed by solution of depth average continuity and momentum equations using cell centre finite volume method. The effect of self aeration from the water surface on the flow parameters are assessed by comparison of computed results with the observations on the AVIMORE chute spillway. The best experimental relations for simulating the entrainment of air into the flow on chute spillways have been chosen. Then, the model is completed for aeration from a bottom aerator and results of air concentration distribution are compared with the reported measurements on a physical model. In order to provide better understanding of the velocity and air concentration, the vertical distribution profiles of these parameters are plotted from the multi layer treatments of depth averaged computed results.


Finite volume analysis of two-dimensional strain in a thick pipe with internal fluid pressure
S.R. Sabbagh-Yazdi, M.T. Alkhamis, M. Esmaili and N.E. Mastorakis

Abstract: Internal fluid pressure of fluids may cause nonuniform distribution of stresses in thick pipes. In this work, a novel matrix free Unstructured Finite Volume Method based on Galerkin approach is introduced for solution of weak form of two dimensional Cauchy equilibrium equations of plane strain solid state problems on linear triangular element meshes. The developed shape function free Galerkin Finite Volume structural solver explicitly computes stresses and displacements in Cartezian coordinate directions for the two dimensional solid mechanic problems under either static or dynamic loads. The accuracy of the introduced algorithm is assessed by comparison of computed results of a thick pipe under internal fluid pressure load with analytical solutions. The performance of the solver is presented in terms of stress and strain contours as well as convergence behavior of the method.


Axisymmetric motion of a generalized Rivlin-Ericksen fluids with shear-dependent normal stress coefficients
Fernando Carapau

Abstract: We analyze the unsteady flow of an incompressible generalized second-order fluid in a straight rigid tube, with circular cross-section of constant radius, where the normal stress coefficients depend on the shear rate by using a power law model. The full 3D unsteady model is simplified using a one-dimensional hierarchical approach based on the Cosserat theory related to fluid dynamics, which reduces the exact three-dimensional equations to a system depending only on time and on a single spatial variable. From this new system we obtain the relationship between mean pressure gradient and volume flow rate over a finite section of the tube. Attention is focused on some numerical simulation for unsteady/steady mean pressure gradient and on the analysis of perturbed flows.


On the exact symmetries of dynamical systems from their reduced system of equations
F.I. Arunaye

Abstract: In a recent paper we presented the computation of the exact symmetry transformations of dynamical systems from their reduced systems using the Kepler problem as vehicle. We also noted therein that this computational technique is applicable to systems that can be reduced to couple oscillator(s) and a conservation law both in two-and three-dimensions. In this paper we show in addition to the former that when the reduction variable for the radial component of the equation of motion is varied by the multiples of quadratic powers of the angular momentum, the exact symmetry transformations of the vector fields 1 1 αv ∂ and 2 2 αv ∂ are invariants in 2-dimension. We demonstrate this by using both the Kepler and the generalized Kepler problems in two dimensions. We also note that this is not necessarily the case for the dynamical system in 3-dimensions.


Modeling The Store Retailing Performance Outcome
K.B. Saji

Abstract: In a fast changing global business scenario, the technological advancements are bringing in significant changes in traditional retailing operations. A revolution is under way at present in the store-dominated world of retailing both in developing as well as developed economies. Marketers have increasingly started realizing the fact that the purchasing power of customers, consumer preferences, latent need fulfillment, and convenient buying are the most important reasons for improving the retailing effectiveness. Of all these reasons, it is experienced to be the convenient buying that demands a unique approach in retailing. An effective retailing operation should facilitate placement of order for products and services from home, an in-home delivery in the shortest possible time, and payment flexibility. For these to happen, the retailing firms may have to seek appropriate technologies for bringing in operational efficiency in order to gain competitive advantage. This necessitates technology assimilation based on appropriateness, availability, accessibility, cost, and timeliness. Through this paper, it is attempted here to study these factors in the context of convenient buying for assessing their criticality in deciding the effectiveness of retailing operation. The paper successfully reports a predictive model developed for assessing the retailing performance outcome.


Multinomial Regression Model for In-service Training
Hsieh-Hua Yang, Hung-Jen Yang, Jui-Chen Yu, and Wen-Jen Hu

Abstract: In-service training is education for employees to help them develop their professional skills in a specific discipline or occupation. This training takes place after an individual begins work responsibilities. On-line technology is supporting our learning in many ways. Both credit and degree pursuing are formal developing program. There is a need to developing a model of in-service training for a certain professional group so can illustrate their group behavior. The purpose of this study was to present how to develop a model of in-service training by using multiple logistic regressions. Based on literature review, a theory model was first identified. An investigating was conducted to collect data to evaluate the designed model. The model consist two factors, one is the learners’ age and the other is the learning styles. Two models were establish to explore both credit training and degree training courses. The resulted model then was further discussed to reveal in-depth of in-service needs.


Modeling and Solution for Assignment Problem
Liying Yang, Minghong Nie, Zhenwei Wu, and Yiyong Nie

Abstract: In this paper, the mixed-integer linear programming (MILP) of minimax assignment is formed, and a solution called Operations on Matrix is presented and compared with the solutions of exhaustion and MILP. Theoretical analyses and numerical tests show that the operations on matrix are efficient well-implied enumeration for both minimax and global-minimum assignment problems.


Control of Thermal-Visual Comfort and Air Quality in Indoor Environments Through a Fuzzy Inference-Based Approach
Jean J. Saade and Ali H. Ramadan

Abstract: This study presents a control approach for the adjustment and maintenance of air quality, thermal and visual comfort for buildings’ occupants while minimizing energy consumption. The approach accounts for users’ preferences and is mainly based on the use of fuzzy inference, which lends itself to intelligent system design methods. The control objectives and criteria are described and their models are provided. Then, the fuzzy inference-based controller is designed and made to work in conjunction with the criteria models to satisfy the control objectives. The designed fuzzy controller and criteria models are also simulated using MatLab/Simulink. The simulation results, which are depicted for each control criterion, show that the presented approach is highly efficient in the sense that it is capable of responding in a minimal amount of time to fixed and variable users’ preferences. It is also capable of eliminating overshoots and oscillations in these responses and this has been achieved without the need for any adaptive procedure.


Application for conversion of types of cut XpYm and angles in a fishing net
Javier Bilbao, Eugenio Bravo, Olatz García, Concepción Varela, Miguel Rodríguez, and Alexander Odriozola

Abstract: The trawling fishing system is nowadays the most important and more used among all the caught systems in the fishing industry. Its most significant feature relies on the capability of capturing very different fish species. The modern technology seems to be the way to reach major improvements in such an environment, where there's not enough data available for research. When looking for new solutions, simulation and optimization of new models will surely reduce manufacturing costs.


ANFIS Modeling and Feedforward Control of Shape Memory Alloy Actuators
Ayyoub Rezaeeian, Aghil Yousefi-Koma, Behrouz Shasti, and Alireza Doosthoseini

Abstract: This paper focuses on the application of ANFIS in the modeling of nonlinear behavior of the shape memory alloy actuators. Although, SMA actuators have attracted much attention for applications in several areas such as miniature robots they have not been widely employed for motion control applications due to their nonlinear behaviors and control difficulties. Because of their ability in the nonlinear learning and adaptation, ANFIS architectures are suitable tools in modeling and control of nonlinear systems. The experimental test bed includes a SMA wire, a force sensor, data acquisition system and a power amplifier. Results demonstrate the ability of ANFIS in modeling of shape memory alloy behavior and successful force control of the SMA wire.


Optimal Design of an Impact Damper for a Nonlinear Friction-Driven Oscillator
E. Ehsan Maani Miandoab, A. Yousefi-Koma, D.Ehyaei

Abstract: In the present study a Friction-Driven oscillator is investigated analytically using perturbation method and numerically with Runge–Kutta’s integration procedure. The analytical method is also used to investigate damping performance of a single-particleimpact damper on amplitude and frequency of system over a wide range of particle-to-structure mass ratios, clearance, and coefficients of restitution. Considering sensitivity of the system to variation of mass ratio and coefficient of restitution, optimal values are obtained for these parameters. These optimal values are plotted as a function of the other two parameters. The frequency of the system has low sensitivity to the variation of coefficient of restitution but varies with clearance and mass ratio changes.


Modelling and Solution for Assignment Problem
Liying Yang, Minghong Nie, Zhenwei Wu, and Yiyong Nie

Abstract: In this paper, the mixed-integer linear programming (MILP) of minimax assignment is formed, and a solution called Operations on Matrix is presented and compared with the solutions of exhaustion and MILP. Theoretical analyses and numerical tests show that the operations on matrix are efficient well-implied enumeration for both minimax and global-minimum assignment problems.


Analysis of model parameters in equations on the HIV/AIDS virus
Nabendra Parumasur and Robert Willie

Abstract: A simple HIV/AIDs finite dimensional mathematical model on interactions of the blood cells, the HIV/AIDs virus and the immune system is studied for consistence of the equations to the real biomedical situation that they model. Definitions to model parameters indicate either that the system of equations is derived from one in infinite dimensions or can be naturally extended to cover this situation. A better understanding to the illness modelled by the finite dimensional equations is furnished. Various case studies, extracted from the current literature, are considered and numerical results show that mathematical analysis is very powerful for understanding such systems. In particular, by examining the effect of parameters in the model leads one to infer important properties on the variables of the system, such as blow up of solutions.


Evolutionary Processes Solved with Lie Series and by Picard Iteration Approach
Steri S., Quartieri J., Volzone G., Guarnaccia C.

Abstract: The solution of evolutionary Cauchy problems by means of Lie series expansion and its linkage to Picard iteration method, is presented. Thanks to a Taylor transform and to the introduction of a differential Lie-Groebner operator D, the initial generally non-linear and non-autonomous problem can be reduced to a linear one, whose solution is given in terms of the Lie operator exp(tD). The Picard procedure applied to the Volterra integral equation that turns out from the initial problem, can rigorously introduce generalized Lie series since its steps are the partial sums of those series.


Identification of Systems with Friction via Distributions using the simplified Dahl model
Radu Zglimbea, Virginia Finca, Constantin Marin

Abstract: This paper extends the identification procedures based on distributions theory to continuous time systems with friction. There are defined the so called generalized friction dynamic systems (GFDS) as a closed loop structure around a smooth system with discontinuous feedback loops representing friction reaction vectors. Both GFDS with static friction models (SFM) and dynamic friction models (DFM), also simplified Dahl model are analyzed. The identification problem is formulated as a condition of vanishing the existence relation of the system. Then, this relation is represented by functionals using techniques from distribution theory based on testing function from a finite dimensional fundamental space. The advantage es of representing information by distributions are pointed out when special evolutions as sliding mode, or limit cycle can appear. The proposed method does not require the derivatives of measured signals for its implementation. Some experimental results are presented to illuminate further its advantages and practical use.


The performance analysis of industrial robot under loaded conditions and various distance
Ahmad Rasdan Ismail, Azmi Hassan , Syamimi Shamsuddin, Mohd Zaki Nuawi, Mohd Nizam Ab Rahman

Abstract: The increasing usage of robots in manufacturing operations is due to its flexibility and its ability to be reprogrammed easily when the old task changes. The main obstacle in the robotics applications is to minimize the positional errors when it is under real working conditions. This implies that robots have to perform accurately under loaded conditions at any location within the working envelope. The aim of this research is to evaluate the performance of industrial robot under payload and various distances within the working envelope. Relationship between the location and payload versus accuracy and repeatability are to be obtained. The experimental work and statistical analysis was performed in order to achieve the desired objective of the research. The study of linear performance has been carried out and the results show that the FANUC Robot Arc Mate 100i under the study has the linear accuracy and repeatability of 2.125 mm. The accuracy and repeatability value obtained was not the same compare to the manufacturer specification due to various factors that cannot be avoided. Statistical analysis shows that the distance from robot center has significantly affects the accuracy and repeatability performance of the robot.


Some proposal for the improvement of the simulations of the acoustic noise propagation
Petru Cardei

Abstract: This paper tries to compare the theoretic results in the acoustic noise propagation with the experimental data and with the simulation techniques, using by the very useful software programs. In the paper are formulated some suggestions for improve the experimental formulae using for the noise propagation simulation.


An Operatorial Approach to Sturm-Liouville Theory with Application to the Problem of a Spherical Conductor Embedded in a Uniform Field
J. Quartieri, L. Sirignano, A. Troisi, C. Guarnaccia, S. D’Ambrosio

Abstract: This paper tries to compare the theoretic results in the acoustic noise propagation with the experimental data and with the simulation techniques, using by the very useful software programs. In the paper are formulated some suggestions for improve the experimental formulae using for the noise propagation simulation.


A Heuristic Method in Monitoring Environmental Parameters using a Floating Input Approach in Wireless Sensor Networks
M. Babazadeh, R. Jedermann, W. Lang

Abstract: This work is part of a research activity aiming to improve and to optimize environmental parameters monitoring system. It is essential in order to preserve the quality, safety and shelf life of perishable products. The present study reports on the investigation a way to both plausibility check and energy management in a wireless sensor network established in a closed space container. It introduces a new technique to decrease the total power consumption due to measuring and transmitting data in a few desired sensor nodes (DSNs). They are either failed or inactive (Sleeping) sensor nodes. They can be deactivated by some of surrounding key sensor nodes (KSNs) due to reduce battery-consumption. A new technique of the model making to estimate temperature, relative humidity, and air flow as important environmental parameters (EPs) instead of the direct measurement and then assessment the validity of the proposed model using some experiments will be investigated. Introduced estimators use linear models between the KSNs and a DSN. These models can be extended for possible use in different applications such as EP-controllers in air conditioning systems as well as the estimator in fault recognition procedures. .


Topological Properties of the Italian Airport Network studied via Multiple Addendials and Graph Theory
J. Quartieri, M. Guida, C. Guarnaccia, S. D’Ambrosio and D. Guadagnuolo

Abstract: The Italian Airport Network (IAN) is considered. The description in term of a mathematical graph is given and its topological properties are approached by means of a new mathematical tool: the multiple addendials. The connection degree and the betweenness centrality distributions in the IAN follow a power-law behaviour, well known in literature like a Double Pareto Law. This leads to the definition of the IAN as a scale-free network. Furthermore these distributions show the existence of some “hubs” in the network, i.e. nodes with a very large number of links. Since the mean distance between reachable pairs of airports grows at most as the logarithm if the number of airports, the IAN can be considered a candidate to represent a small-world network.


    Paper Title, Authors, Abstract (Issue 3, Volume 2, 2008)


Formulas for the Fourier Series of Orthogonal Polynomials in Terms of Special Functions
Nataniel Greene

Abstract: An explicit formula for the Fourier coefcients of the Legendre polynomials can be found in the Bateman Manuscript Project. However, formulas for more general classes of orthogonal polynomials do not appear to have been worked out. Here we derive explicit formulas for the Fourier series of Gegenbauer, Jacobi, Laguerre and Hermite polynomials. The methods described here apply in principle to an class of polynomials, including non-orthogonal polynomials.


Modelling the brazed assembly by the coupling of the eXtended Finite Element and the matched asymptotic development methods
Nguyen D.H., Lazard M.D, Bilteryst F, Lamesle P, Dour G.

Abstract: Modelling of the brazed assembly taking account the presence of a brazed joint which is considered as a singularity is proposed. The model is based on the eXtended Finite Element Method (X-FEM) coupled with the matching asymptotic development method (DAR). We consider the behavior of the brazed assembly in two problems separately: mechanical and transient thermal problems. The approach proposed by the DAR method is based on to construct the enriched functions in the X-FEM framework. The fundamental formulation of our coupling is given and illustrated in the 1D case of the brazed assembly. The accuracy of the results obtained by the coupling is evaluated by comparison with the analytical solutions (in the mechanical problem) and with the solutions of the quadrupole method and of the commercial FEM code (ABAQUS) (in the thermal problem)..


Identification of Continuous Time Systems with Direct and Feedback Nonlinearities
Constantin Marin, Dan Selisteanu, Dorin Sendrescu, Virginia Finca, Dan Mancas

Abstract: This paper presents a procedure for the identification of two types of a continuous-time linear system interconnected by direct and feedback memoryless nonlinearities. The first case is the continuous time Hammesrstein system and the second is a specific case of the continuous time Wiener system. The direct and feedback nonlinear elements, described by bounded unknown functions, are expressed as a linear combination of some base functions. Both the parameters of the linear system and of the nonlinear elements representation are identified. To improve the representation of the nonlinear functions, the set of basis functions is iteratively refined. It is possible to identify the dominant nonlinearities, applying the singular value decomposition to the input matrix. In our approach, the linear dynamic subsystem is described by a transfer function of a given order and the distribution based identification method is applied. The DCHI (Distribution based Continuous time Hammerstein system Identification equations (DCHI) and the DCNFI (Distribution based of Continuous time Nonlinear Feedback Identification) equation are obtained. The consistency of the identification is analyzed and experimental results are presented.


Numerical Analysis of Sliding Dynamics in Three-Dimensional Filippov Systems using SPT Method
Ivan Arango, John Alexander Taborda

Abstract: We present the numerical analysis of sliding dynamics on the discontinuity boundary (DB) of threedimensional (3D) Filippov systems using an integration-free method denominated Singular Point Tracking (SPT). Many physical applications in engineering can be modelled as Filippov systems. Sliding dynamics due to nonsmooth phenomena such as friction, hysteresis or switching are inherent to Filippov systems. The analysis of sliding dynamics have many mathematical and numerical difficulties. Several well-known numerical problems can be avoid using integration-free methods. Three-dimensional Filippov systems are being studied extensively because these systems still have many open problems. In this paper, we present a first attempt to extend the SPT method to 3D Filippov systems. The discontinuity boundary (DB) is characterized using geometric criterions based on angular evaluations. Eighteen basic points on DB are distinguished and eight basic scenarios on DB are defined. Finally, local and global bifurcation scenarios are conceptualized with the SPT method and some illustrative examples are given.


Selective Predictors of Environmental Parameters in Wireless Sensor Networks
M. Babazadeh, H.-J. Kreowski, W. Lang

Abstract: This paper investigates multiple alternatives to predict environmental parameters (temperature and relative humidity) inside an intelligent container with the aim of the supervision of cool chains. A wireless sensor network will help us to measure those parameters in some distributed points of the closed space.
To achieve the aim of fault detection and also total energy saving in the sensor network, there will be several possibilities. This research deals with prediction of future values of the environment in a few specific sensor nodes by using some of active sensor nodes. It inspects several requirements of the predictors to pick out the most applicable identification styles among ARX, ARMAX, OE, BJ and SS. It employs some key-sensor nodes (KSNs) as predictors of the parameters in a few desired sensor nodes (DSNs). The DSNs either have already been turned to sleeping mode to reduce battery-consumption or deactivated due to energy depletion.


Seismic Vulnerability of Columns of RC Framed Buildings with Soft Ground Floor
Sharany Haque, Khan Mahmud Amanat

Abstract: Though multistoried buildings with open (soft) ground floor are inherently vulnerable to collapse due to earthquake load, their construction is still widespread in the developing nations. Social and functional need to provide car parking space at ground level far out-weighs the warning against such buildings from engineering community. In the present paper, an investigation has been performed to study the behavior of the columns at ground level of multistoried buildings with soft ground floor subjected to dynamic earthquake loading. The structural action of masonry infill panels of upper floors has been taken into account by modeling them as diagonal struts. Finite element models of six, nine and twelve storied buildings are subjected to earthquake load in accordance with equivalent static force method as well as response spectrum method. It has been found that when infill is incorporated in the FE model, modal analysis shows different mode shapes indicating that dynamic behavior of buildings changes when infill is incorporated in the model. Natural period of the buildings obtained from modal analysis are close to values obtained from code equations when infill is present in the model. This indicates that for better dynamic analysis of RC frame buildings with masonry walls, infill should be present in the model as well. Equivalent static force method produces same magnitude of earthquake force regardless of the infill present in the model. However, when the same buildings are subjected to response spectrum method, significant increase in column shear and moment as well as total base shear has been observed in presence of infill. In general, a two fold increase in base shear has been observed when infill is present on upper floors with ground floor open when compared to the base shear given by equivalent static force method. The study suggests that the design of the columns of the open ground floor would be safer if these are design for shear and moment twice the magnitude obtained from conventional equivalent static force method. Study of the sway characteristics also reveals significantly high demand for ductility for columns at ground floor level. Presence of infilled wall on upper floors demands significant enhancement of column capacity or ductility to cope up with increased sway or drift.


Self-Assembly Urethane Architecture: Free Volume, Connolly Surface and Diffusion Coefficients Investigation
Tarek M. Madkour, Rasha Azzam

Abstract: The efficiency of polyurethane foams as thermal insulators depends to a great deal on the permeability of various gas molecules through the urethane polymer with higher temperatures enhancing the diffusion of gas molecules through the polymer. In order to increase the efficiency of these insulators, the design of new urethane polymers with low affinity for diffusing gas molecules such as oxygen, nitrogen and carbon dioxide is necessary. Through maximizing the hydrogen bonding network between the hard blocks and the soft segments in the interface region of the polymeric material, new designs of molecularly organized polyurethanes were achieved in this study and evaluated in terms of their capacity to hinder the permeation of the various gas molecules through the polymer.


Kernels for the Remainder Term of Gauss Quadrature Formulae Type
Daniel Vladislav

Abstract: We study the kernels in the contour integral representation of the remainder term of Gauss-Lobatto quadratures, in particular the location of their maxim on circular and elliptic contours. Quadrature rules with Chebyshev weight functions of all four kinds receive special attention. We also study a general Gauss Chebyshev-Stancu quadrature with double fixed nodes.


Energetic Optimization with Arbitrary Terminal Moment of Electric Drives Systems
Niculae Boteanu, Marius-Constantin Popescu, Florin Ravigan

Abstract: In the paper we consider an electric drive having static load torque with a constant component and a speed proportional component, in the hypothesis of constant inertia moment and of proportionality between the electromagnetic torque and the load current. Using variational calculus, optimally condition and expression of optimal control and extremal trajectory are determined, which ensures the minimum of energy losses caused by the load current through a Joule effect in the acceleration processes. Using numerical computer we can obtain graphical representation of these variables as time functions.


Analysis of a Nonlinear Integral Equation with Modified Argument from Physics
Maria Dobritoiu

Abstract: Using the Contraction Principle, Perov’s theorem and the General data dependence theorem, some results of existence and uniqueness and data dependence of the solution of the integral equation with modified argument



A Hierarchical Clustering Method Aimed at Document Layout Understanding and Analysis
Costin-Anton Boiangiu, Dan-Cristian Cananau, Bogdan Raducanu, Ion Bucur

Abstract: This paper presents a new approach towards creating a type of hierarchy for document image page using the information given by the Delaunay triangulation. The steps of the algorithm are presented under the form of a cluster tree containing the information of the page in structures such as collections of pixels and using the distance between them as a binding measurement. The final result provides the page segmentation into clusters containing pictures, titles and paragraphs.


Montazer-Ghaem Gas Unit Synchronous Generator's Parameters Identification Using SSFR Tests
M. Pourgholi, V. J. Majd, M. R. Aghamohammadi

Abstract: Accurate generator modeling allows for more precise calculation of power system control and stability limits. In this paper a procedure using a set of measured data from Standstill Frequency Response (SSFR) test on Montazer-Ghaem gas power plant’s synchronous generator is used to obtain synchronous machine parameters. A novel approach is used to find d-axis which is different from standard SSFR scheme which can save the time in doing SSFR tests. Hook-Jeeves method is used for optimization purpose. The test procedure and identification results are reported.


Critical Marangoni Numbers and their Effect on the Dopant Distribution in Silicon Fibers
L. Braescu, T. F. George

Abstract: The dependence of the Marangoni flow and impurity distribution on the vertical temperature gradient is analyzed in the framework of a stationary model including the incompressible Navier-Stokes equation in the Boussinesq approximation and the convection-conduction, and conservative convection-diffusion equations. The computations are carried out in a 2D axisymmetric model by the finite-element numerical technique, for aluminum-doped silicon fibers grown from the melt by the edge-defined film-fed growth technique, and reveal existence of the three critical Marangoni numbers due to thermal gradients. The homogeneity of the dopant distribution in the crystal is computed for different Marangoni numbers situated in the ranges determined by the obtained critical Marangoni numbers Mac1, Mac2, Mac3.


Cluster Analysis using I-kaz Coefficient to Assist Machining Monitoring Process
M. Z. Nuawi, F. Lamin, S. Abdullah, M. J. M. Nor, A. Arifin

Abstract: Dynamic state recognition and event-prediction are fundamental tasks in signal processing. This paper presents a novel identification method which could form the basis for forecasting a generalized machining condition. The method relies on the value of I-kaz coefficient, which is an extractable unique feature that can be gained for every signal acquired during the cutting process. The method is useful for classifying the acquired signal in the machining process to a set of cluster which may represent the specific cutting condition of the machining process. The classification method was succeeded in identifying the cutting parameter that being used to generate the signal, which was the combination of the cutting speed, feed rate and depth of cut. This kind of clustering is very useful in the analysis of machining signal processing such as signal conformation, fault identification and etc.


Inference in the Progressive Three-State Model
Luis Meira-Machado, Carmen Cadarso-Suarez, Jacobo de Una-Alvarez

Abstract: In longitudinal studies of disease, patients can experience several events through a follow-up period. In these studies, the sequentially ordered events (gap times) are often of interest. The events of concern may be of the same nature (e.g. cancer patients may experience recurrent disease episodes) or represent different states in the disease process (e.g. alive and disease-free, alive with recurrence and dead). If the events are of the same nature this are usually referred as recurrent event, whereas if they represent different states (i.e. multi-state models) they are usually modeled thought their intensity functions. In this paper we present nonparametric estimators for several quantities in a progressive threestate model. We present a simple estimator for the bivariate distribution function for censored gap times and estimators for the transition probabilities. The proposed methods can be easily extended for the progressive k-state model (with a vector of k gap times). Another major goal is to study the relationship between the different covariates and disease evolution. The proposed methods were applied to a database on breast cancer from Galicia, Spain. Software (in R) implementing the methods proposed in this paper were developed by the authors.


    Paper Title, Authors, Abstract (Issue 4, Volume 2, 2008)


Integrated Model of Double-Diffusive Convection: Numerical Stability
P. Miidla, K. Rannat

Abstract: The double-diffusion effect is a known phenomenon in oceanography. In this paper a model of thermohaline field turbulent energy evolution caused by double-diffusion effects, is under consideration. The mathematical model itself is a system of three nonlinear partial differential equations for environment’s temperature, salinity and turbulence kinetic energy, where unknown functions depend on time and on one only space variable. The discretisation and numerical implementation of the model is given, which bases on implicit difference method, on the uniform rectangular time-space grid and Newton iteration method. As the main result of paper the computational stability condition is obtained. The numerical stability criterion of the numerical algorithm for finding approximate solution is estimated by the maximum values of the solutions of system components and main parameters of the model.


The Investigation of Marble Cutting Parameters for Energy Consumption
Hasan Cimen, Said Mahmut Cinar, Mustafa Nartkaya

Abstract: Marble cutting process has very complexity structure with lots of machining and stone parameters. In this paper, a marble test machine fully controlled by PC is presented. The PC based marble test machine is designed for experimental tasks such as determining suitable cutting parameters, developing saw blade performance and marble cutting with optimum electric energy. PC based systems have lots of advantages such as rapid, functional, low cost, adaptable, attractive. PC based systems can also be used industrial environments for improving productivity. Presented PC based marble test machine whereby an experimental test machine was carried out to obtain precise results.


Method to Protect from no Pulse for a Three-Phase Rectifier Bridge
Ilie Borcosi, Onisifor Olaru, Marius-Constantin Popescu, Nicolae Antonie, Alina Dinca, Marian Ionescu

Abstract: In this paper we will propose a way to detect if the electronic valves aren’t working (diodes, thyristors and transistors) of the commanded or not three-phase rectifiers with resistive load or resistive-inductive load.


Device with Analogical Circuits for Protection to the Lack of the Pulse for the Three-Phase Rectifiers in Electrical Drive
Borcosi Ilie, Olaru Onisifor, Popescu Marius-Constantin, Dinca Alina, Antonie Nicolae, Ionescu Marian

Abstract: In this paper is proposed a device for protection at the lack of pulse for the three-phase rectifiers in bridge with load inductive resistive (dc motors).


Underlying Structure of the System Using Dynamic Clustering and Penrose Inverse
Hernando Castaneda Marin, Eliezer Colina Morles, Jesus Rodriguez Millan

Abstract: We propose a new perspective on the identification of linear dynamic system using structural similarity. The proposal consists in the meaningful exploration of each model, specifically behavior of the state variable.
The decomposition of the behavior of a state variable in different modes of behavior of a system, each one has a different set of weights and shows different patterns of behavior. These weights are more significant than eigenvalue to develop a new technique for identifying linear system and invariants over time.
We use two methods based on different areas of knowledge such as linear algebra and statistics. This paper is a conceptual proof that enriches the implementation and validity not only from point of view algorithmic likewise physic mathematical.


A System Dynamics Model For The Simulation Of A Non Multi Echelon Supply Chain: Analysis and Optimization Utilizing The Berkeley Madonna Software
C. Caballini, R. Revetria

Abstract: In today’s global market, managing the entire supply chain becomes a key factor for a successful business. World-class organizations realize that non-integrated manufacturing and distribution processes together with poor relationships with suppliers and customers are a huge limit for their success.
One of the most important aspect affecting the performance of a supply chain is the management of inventories. Inventory management in the supply chain system is quite a complex issue because demand at the upstream stage is dependent on orders from the downstream stage, and the final downstream stage receives orders from the market in uncertain conditions. Uncertainty is one of the major obstacle which limits the creation of an effective supply chain inventory model, able to optimize times and costs.
Being the management of a complex inventory model too difficult to analyze with traditional analytical mathematical methods, computer simulation is widely used to study this kind of problems. This paper has the goal of modeling a single echelon supply chain and optimizing its inventories levels so to reduce the bullwhip effect and consequently minimize the supply chain costs. The supply chain here proposed consists of five stages – customer, retailer, wholesaler, distributor and factory – and its modeling is carried out through a system dynamics approach, utilizing the Berkeley Madonna software.


Boundary Stabilization of a String with Two Rigid Loads: Calculation of Optimal Feedback Gain Based on a Finite Difference Approximation
Hideki Sano

Abstract: This paper is concerned with the boundary stabilization problem of a string with two rigid loads which is described by two kinds of hyperbolic equations. In our previous work, a control law that made an energy function of the system non-increasing was derived, and the asymptotic stability of the closed-loop system with the controller was proved by using the LaSalle’s invariance principle. Moreover, a simplified lumped parameter model was considered in connection with the string with two rigid loads, and the design method to determine an optimal feedback gain for the model was proposed. In this paper, it is shown that the controller with an optimal gain based on a finite differnce approximation works more effectively than the one based on our previous method for the original system through numerical simulations.


The Symmetry-Diagram as a Tool of the Pattern Recognition
Z. Szakal, I. Zsoldos

Abstract: The base of this paper was a new method for the detection of exact and approximate reflective symmetries. The algorithm was based on the definition of the so called symmetry-parameter which is a rate of the symmetry, a number between 0 and 1 without a dimension and its value does not depend on geometrical measures. A so called symmetry-diagram in other name a shape-diagram was determined from the symmetry-parameters computed for various lines crossing the gravity centre and for points surrounding it. Beside the possibility of the symmetry recognition, the shape-diagram shows an individual shape property of the 2D figures, independently from geometrical measures. In this paper we show a process in which similar and approximately similar 2D figures are sorted out from a multitude of different figures independently from geometrical measures using the definition of the symmetry-diagram.


On Construction of Optimised Rough Set-based Classifier
Urszula Stanczyk

Abstract: One of popularly used forms of definition for a classifier is a decision algorithm constructed from conditional clauses of "IF. . . THEN. . . " type. Extraction of decision rules that comprise such a decision algorithm constitutes one of crucial steps within the rough set approach to the problem of classification. The first step of the process is to find all relative raducts of conditional attributes and to select one, if several exist, for the computations that follow. The second phase is taken by the procedure of establishing all valid relative value reducts. From the variety of possible solutions there is required the one with the highest accuracy of classification as well as simplicity of implementation which is reflected by the lowest number of conditional clauses within the decision algorithm. In the paper there is described such optimising methodology employed to the rough set-based approach to the stylometric problem of authorship attribution.


Functional Quality and Performance Metric for some Image Processing Applications
Chang Yun Fah, Omar Mohd Rijal, Syed Abdul Rahman Abu Bakar

Abstract: One common approach to image quality and performance evaluation is to evaluate if the reference image and the processed image still remain a high level of similarity However, existing image quality metrics regarded one of the reference and processed image or both as perfect. In reality, it is not easy to obtain a perfect reference image because pre-processing procedures always generated noise into these images. In this paper, the reference and processed images are considered as imperfect and we propose a functional metric using the coefficient of determination for unreplicated linear functional relationship model as a measure of the similarity, which in turn may be used as a definition for image quality and performance indicator for some image processing applications. The sensitivity of the proposed metric is also studied and it provides a consistent interpretation for the distortion area of a processed image. Our experimental results showed that the proposed functional metric is a good quality measure for JPEG compressed image and it is sensitive in differentiating the performance or low-pass and high-pass filtered image.


Double-Spool Single Jet Engine for Aircraft as Controlled Object
Romulus Lungu, Alexandru Nicolae Tudosie, Liviu Dinca

Abstract: The paper deals with an aircraft double-spool single-jet engine identified as possible controlled object. The authors have identified the main parameters and the engine’s non-linear equation system (the motion equation and the gas-dynamic characteristics), then they have established the linear non-dimensional model, useful for further studies, and the block diagram with transfer functions. Engine’s stability domains were also established, and some simulation were performed, concerning the engine’s time behavior (step response), for two different cases of control schemes.


Limit Cycle and Chaotic Behaviors for the Transmission Model of Plasmodium Vivax Malaria
P. Pongsumpun, I. M. Tang

Abstract: Malaria is an infectious disease caused by the bite of female Anopheles mosquitoes. There are four species, namely, Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale and Plasmodium malariae causing human malaria. The difference between P.vivax malaria and P. falciparum malaria is that a person suffering from P. vivax infection can suffer relapses of the disease. The effect of a time delay on the transmission of this disease is studied. The time delay is the period in which the P.vivax parasite develops inside the mosquito (vector) before the vector becomes infectious (i.e., pass on the infection). The model is analyzed by using standard dynamic modeling method. Two stable equilibrium states are found to be possible. It is found that the disease free equilibrium state is stable when a newly defined basic reproduction number L is less than one. If L is greater than one, the endemic equilibrium state is stable. The conditions for the endemic equilibrium state to be a stable spiral node are found. For realistic values of the parameters in the model, it is found that solutions in phase space are trajectories spiraling into the endemic equilibrium state. The bifurcation diagrams of our model are discussed. It is shown that the limit cycle and chaotic behaviors can occur with only unrealistic situations.


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