INTERNATIONAL JOURNAL of MATHEMATICS AND COMPUTERS IN SIMULATION


 









 

ISSN: 1998-0159

 
 

 

Year 2009

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

Main Page

    Paper Title, Authors, Abstract (Issue 1, Volume 3, 2009)

Pages

Inversion of Complex Valued Neural Networks Using Complex Back-propagation Algorithm
Anita S. Gangal, P. K. Kalra, D. S. Chauhan

Abstract: This paper presents the inversion of complex valued neural networks. Inversion means predicting the inputs for given output. We have tried inversion of complex valued neural network using complex back-propagation algorithm. We have used split sigmoid activation function both for training and inversion of neural network to overcome the problem of singularities. Since inversion is a one to many mapping, means for a given output there are number of possible combinations of inputs. So in order to get the inputs in the desired range conditional constraints are applied to inputs. Simulation on benchmark complex valued problems support the investigation.
 

1-8

Mining Classification Rules for Liver Disorders
Humar Kahramanli, Novruz Allahverdi

Abstract: Nowadays data mining is a very popular technique and has been successfully applied in medical area. Classification is a essential approach in data mining. One of the classification methods is a Artificial Neural Networks. Artificial Neural Network (ANN) generally achieve high accuracy of classification. However, knowledge acquired by ANN is incomprehensible for humans. This fact is causing a serious problem in data mining applications. The rules that are derived from ANN are needed to be formed to solve this problem and various methods have been improved to extract these rules. Selection of the activation function is important in the performance of ANN. Networks with adaptive activation function seem to provide better fitting properties than classical architectures with fixed activation function neurons [1]. In this study, first neural network has been trained with adaptive activation function. Then for the purpose of extracting rules from adaptive ANN which has been trained for classification, OptaiNET that is an Artificial Immune Algorithm (AIS) has been used and a set of rules has been formed for liver disorder.
 

9-19

Information Amount Threshold in Self-Replicating RNA-Protospecies: Branching Processes Approach
Krzysztof A. Cyran

Abstract: The paper addresses the problem of information content threshold in the early stage of RNA-World. This terms refers to the hypothetical stage of the evolution of Life which assumes that before emergence of organisms whose genome was based on DNA molecules and enzymatic activities were performed by proteins there existed world of RNA-protospecies in which RNA molecules constituted both the genetic material and enzymes. According to this theory the RNA enzymes, called rybozymes, were required for metabolism and for self-replication. However, as it was already shown basing on information loss - selection balance approach, and as it is presented in the paper using branching processes approach, the replication error-rate is a crucial quantity for the maximum information content of the RNA-protospecies. Therefore, one hypothetical rybozyme called RNA replicase is required in the early phase of RNA-World, since it can reduce the mutation rate and thus allow for development of genomes with increasing information content. Otherwise, the information would have been lost, and the error catastrophe would have taken place. However, the information preserved in the RNA replicase itself is strongly limited, because in the phase of evolution proceeding the emergence of this rybozyme the replication could not take the advantage of the low mutation rates and yet the evolution of RNA-strands leading finally to the “invention” of replicase had to satisfy the information limiting constraints.. Therefore, RNA replicase would have never been able to evolve if its function could appear only in RNA chains containing large amounts of information. In the paper this problem is considered using model proposed by Demetrius and Kimmel. This model draws the conclusions relaying on the criticality property in branching processes. While utilizing this approach, the originality of the paper lies is the introduction into the model the parameters which can be experimentally measured in a test tube. Therefore the estimations of the maximum information content of the primordial RNA-based RNA replicase can be determined using data from biochemical experiments. Last but not least, the paper can encourage biochemists for experiments yielding results helpful in the estimation of the probability of the break of phosphodiester bonds in RNA molecules under conditions feasible on the early Earth.
 

20-29

Influencing Factors of Successful Transitions towards Product-Service Systems: A Simulation Approach
Nicola P. Bianchi, Steve Evans, Roberto Revetria, Flavio Tonelli

Abstract: Product-Service Systems (PSS) are new business strategies moving and extending the product value towards its functional usage and related required services. From a theoretical point of view the PSS concept is known since a decade and many Authors reported reasonable possible success factors: higher profits over the entire life-cycle, diminished environmental burden, and localization of required services. Nevertheless the PSS promises remain quantitatively unproven relaying on a simple theory that involves a few constructs with some empirical grounding, but that is limited by weak conceptualization, few propositions, and/or rough underlying theoretical logic. A plausible interpretation to analyze the possible evolution of a PSS strategy could be considering it as a new business proposition competing on a traditional Product-Oriented (PO) market, assumed at its own equilibrium state at a given time. The analysis of the dynamics associated to a possible transition from a traditional PO to a PSS strategy allows investigating the main parameters and variables influencing an eventual successful adoption. This research is worthwhile because organizations undergoing fundamental PSS strategy are concerned about change and inertia key processes which, despite equilibrium theory and because of negative feedback loops, could undermine, economically, the return of their PSS proposition. In this paper Authors propose a qualitative System Dynamics (SD) approach by considering the PSS as a perturbation of an existing PO market featured by a set of known parameters. The proposed model incorporates several PSS factors able to influence the success of a PSS proposition under a set of given and justified assumptions, attempting to place this business strategy in a dynamic framework.
 

30-43

Rendering Human Skin using a Multi-Layer Reflection Model
Ling Li, Carmen So-ling Ng

Abstract: A key element to creating realistic images is the appearance of surfaces. In order to overcome the artificial look of synthetic humans, human skin has to be modelled in all its variety. A new physically-based skin reflection model is presented in this paper to render a diverse selection of skin complexions. The reflection model is based on steady-state light transport theory in multi-layered skin tissue. A three-layer simulation model has been developed to capture the effect of natural sebum on skin appearance. Sebum is found over most parts of the body, causing skin to look more specular, depending on the viewing conditions. Optical and geometric properties are used as control parameters to influence the surface reflection and subsurface scattering of light within the three layers. The resultant reflection consists of the specular reflection due to the Fresnel effect, as well as the diffuse reflection from subsurface scattering. The Monte Carlo method is used to simulate the propagation of light in skin tissue. Various effects like scattering, absorption, reflection and transmission have been taken into account. The bi-directional reflectance distribution function (BRDF) obtained from the simulation is used to render the appearance of human skin. Comparisons between the simulated BRDF results and experimental measurements show that the physical simulation is highly realistic.
 

44-53

    Paper Title, Authors, Abstract (Issue 2, Volume 3, 2009)

Pages

A System Dynamics Decision Cockpit For A Container Terminal: The Case Of Voltri Terminal Europe
Enrico Briano, Claudia Caballini, Marco Mosca, Roberto Revetria

Abstract: The drastic changes in market features imposed in the last decades by market globalization and production delocalization, have determined the need for ports to quickly react to market change in order to capture and manage the increasing quantity of global freight. But because of the highly dynamic and stochastic context, ports have to adjust in real time their planning of work in the most efficient way. For instance, a ship’s delay or a truck’s strike can modify the operative scenario, consequently imposing to rescheduling the container terminal activities. In this context the system dynamics paradigm can usefully help in efficiently modeling the port activities in order to take the right decisions under different scenarios. More specifically the system dynamics model can be efficiently integrated with an ERP system in order to receive real time data, and then, through a suitable decision cockpit– which allows an easy management of huge amount of dynamic data - created with the system dynamics, carry out real time what-if analysis and then make the most appropriate decisions for a particular port context.
The paper presents the case of Voltri Terminal Europe, one of the biggest container terminal in the Mediterranean area. In particular the goal of the paper is to model, through the system dynamics approach, the functioning of VTE and to helps its management through an efficient decision cockpit, connected with an ERP system.
 

55-64

Computer Simulation and Predicting Dangerous Forest Fire Behaviour
Jan Glasa

Abstract: The paper deals with the problem of computer simulation of forest fires and predicting their behaviour to prevent large damages of property and environment and tragic human incidents caused by the fire. The well-known forest fire simulator Farsite was adapted recently for real conditions in Slovak forests and was used for the computer reconstruction of one especially tragic forest fire in the Slovak Paradise National Park (Slovakia) in 2000. The simulation results and the experience achieved during the fire reconstruction allow to predict and analyse potential fire danger and specific fire behaviour in the investigated region. Several recent interesting results on predicting dangerous tendencies of the fire spread under various meteorological, fuel and terrain conditions are presented.
 

65-72

Accurate Computation of the Trajectory of the Spin and Fin-Stabilized Projectiles
Dimitrios N. Gkritzapis, Elias E. Panagiotopoulos

Abstract: The modified projectile linear theory trajectory report here will prove useful to estimate trajectories of high spin and fin-stabilized projectiles. The model of the modified linear theory is compared with a 6-DOF trajectory model. The computational flight analysis takes into consideration all the aerodynamics variations by means of the variable aerodynamic coefficients. Static stability, also called gyroscopic stability, is examined. The developed computational method gives satisfactory agreement with published experimental data and computational codes for atmospheric projectile trajectory analysis with various initial firing flight conditions.
 

73-80

Analyze in an MC-CDMA System Combining with Linear Diversities over Small-Scale Fading Channels
Joy Iong-Zong Chen, Chieh-Wen Liou

Abstract: An error rate probability closed-form of an MC-CDMA (multi-carrier coded-division multiple-access) system combining with linear diversity, such as EGC (equal gain combining) or MRC (maximal ratio combining) diversity working in the situations of either dependent or independent branches, that are correlated or uncorrelated sub-channels, over small scale fading are investigated in this paper. There is a sum of Nakagami-m variates (envelope intensity) is adopted as the model which characterizes the fading and to derive the closed-form solution with arbitrarily correlated channels. In order to avoid the difficulty of explicitly calculating the pdf (probability density function), for example, looking for the CF (characteristic functions), for the SNR (signal-to-noise ratio) at the MRC or EGC output, the analytical results of the new derived BER (bit error rate) formulas are validated by an example of the intensive Monte Carlo computer simulation in which a dual correlated branch is considered for an MC-CDMA system with many relative system parameters.
 

81-88

IT Outsourcing Industry Practices, Models, Trends and Challenges from a Case of a Malaysian Offshore Global Service Provider
Abdul Rahman Ahlan, Yusri Arshad, Mohd Adam Suhaimi, Husnayati Hussin

Abstract: The impact of Kodak IT outsourcing contract spread across the global. The practices have also been adopted in Malaysia since 1990s but were not widely publicized until massive public sector computerization projects and automation of financial systems after Asian financial crisis in 1997. Thus, many service providers, including world-class firms, providing ITO business models can be found operating in Malaysia. They provide both IT asset and services outsourcing. ITO models evolve from traditional to innovation phase in 2010 onwards. One of the innovative models in Malaysia is the global offshore service delivery model which is based on four pillars, namely: Experienced Leadership; Global Best Practice; Human Capital; Domain Knowledge. To be able to compete globally, Malaysia has equipped its companies with higher capabilities and competencies via international certifications and continuous skills developments. Several advantages proposed by Malaysia include: economic stability, political stability, multi-lingual, world-class infrastructure, affordable lifestyle, value propositions and many others. In this paper, we present the detailed views of a senior executive management on two open-ended in-depth interviews, literature and document reviews, secondary sources and one CEO roundtable discussion held in International Islamic University Malaysia. This paper contributes to the practice as well as the IT outsourcing literature.
 

89-96

The Transmission Mechanism of Monetary Policy in Romania
S. A. Ionescu, A. R. Voicu, A. Ionescu

Abstract: As concerns the process to traverse the macroeconomics analysis reasoning of the budgetary earnings and expenses, there shall be crossed the phases whose target consists in defining and understanding the „the balanced production” term. The issue of the consequences generated by the increase of the real quantity of money on the interest rate from the transmission mechanism point of view is by means of the monetary policy management mechanism that the National Bank shall control the money stock as an independent variable, and, consequently, shall also control the interest rate and the available income as associate variables. The multiplier modelling process can make it possible to render evident a possible interaction between the central bank and the other banks as concerns the money offer. This interaction implies an adjustment mechanism that consists in re-defining the monetary base, in re-formulating the multiplier, and in studying the money – credit relationship.
 

97-106

Simulation of 20MoCr130 Steel Drilling Process and some Mathematical Models Determined
Mihaiela Iliescu, Aurelian Vlase, Doru Bardac

Abstract: Very important materials, with lot of application in automotive, aircraft, medical products, large consumer goods, etc industries, are the stainless steels. Machining is often necessary while manufacturing parts made of these steels and drilling is a widely used procedure. This paper presents new mathematical models – of drilling axial force and torque - obtained as result of simulation, experimental research and regression analysis, carried out on 20MoCr130 stainless steel samples. Graphs, as well as further application of the obtained models are, also, shown.
 

107-114

Data Mining Strategies and Methods to Develop Microfinance Market - Case Study Currency Exchange
A. Hameed Ullah Khan, B. Zahid Ullah, C. Maqsood Mahmud

Abstract: The intrinsic characteristics of data mining are being inculcated in the market of microfinance. The use case that is brought under our consideration is of Currency Exchange. The idea was conceived and perceived by the current financial crises in the world market in the year 2008-09.The financial recession in world wide compelled individuals to think and start micro businesses rather than macro businesses. In our paper we conceived and designed some algorithms by using data mining techniques to have general micro currency exchange businesses for a developing country. Our algorithm processes two years historical data of currency rates and applies data mining strategies. The "Median Method" and "Rise & Fall Method" with probabilistic approach are being presented. It can be applied to N year?s data with unless desired results are achieved. This is to give best choice to micro currency business men to take decision either to buy or to sell currency. Some previous currency rates (i.e. Ups & Down) are also recorded from a popular bank of Canada & currency open markets as a proof of concept using our algorithm. The statistical and graphical analysis are being made on the data .Our algorithm can be efficiently used by all those who wish to initialize a small business (Cottage Industries) with a profitable income with less investment. Our research will lead to a new dimension in the fields of Micro finance and Data mining.
 

115-124

    Paper Title, Authors, Abstract (Issue 3, Volume 3, 2009)

Pages

Multiplicable Discrete Operators In Finite Volume Solvers
Dragan Vidovic, Milenko Pusic, Milan Dimkic

Abstract: This paper presents a technique for implicit PDE solver implementation using multiplicable discrete analogues of first-order differential operators and constitutive relations. The technique is intended for mimetic discretizations, but may be used for other methods as well. As a model problem, Laplace equation is solved using this technique and the finite volume method. Several mimetic methods to reconstruct the flux in mesh faces have been proposed, as well as a method to reconstruct the node velocity.
 

125-132

The Proposed Hybrid Intelligent System for Path Planning of Intelligent Autonomous Systems
O. Hachour

Abstract: In this paper, , we discuss the ability to deal with a Hybrid Intelligent Systems (HIS) for Intelligent Autonomous Vehicles IAV in unknown environment. The aim of this work is to develop HIS combining Genetic Algorithms (GA), Fuzzy Logic (FL), Neural Networks (NN) and Expert Systems (ES). This project deals with a simulation program that allows a robot to identify a path to reach a specified target avoiding obstacles. The combination of (ES FL, NN, GA) offers design flexibility and robust integration and has the benefits of reduced communications overhead and improved runtime performance. This integration provides the robot the possibility to move from the initial position to the final position (target) without collisions. The robot moves within the unknown environment by sensing and avoiding the obstacles coming across its way towards the target. The algorithm permits the robot to move from the initial position to the desired position following an estimated trajectory. The proposed hybrid navigation strategy is designed in unknown environment with static unknown obstacles. This approach must make the robot able to achieve these tasks: to avoid obstacles, and to make ones way toward its target by ES_FL_GA_NN system capturing the behavior of a human expert. The integration of these technologies (FL, NN, ES, and GA) has proven to be a way to develop useful real-world applications, and hybrid systems involving robust adaptive control. The proposed approach has the advantage of being generic and can be changed at the user demand. The results are satisfactory to see the great number of environments treated. The results are satisfactory and promising. the proposed method is computationally efficient and is suitable for more integration of hybrid intelligent systems.
 

133-145

Using Hybrid Genetic and Nelder-Mead Algorithm for Decoupling of MIMO Systems with Application on Two Coupled Distillation Columns Process
Atef A. Lasheen, Ahmed M. El-Garhy, Elsayed M. Saad, Saad M. Eid

Abstract: Multiple Input Multiple Output (MIMO) systems are characterized by significant interactions (i.e.: coupling) between their inputs and their different outputs. The control of MIMO systems is usually implemented using sets of Single Input Single Output (SISO) loop controllers, which requires proper input output pairing and development of decoupling compensation unit. In this paper, a generalized decoupling technique is proposed. The proposed technique uses relative gain array (RGA) to select proper pairing and hybrid genetic and Nelder-Mead algorithm (HGNMA) to estimate the optimal elements’ values of the steady state decoupling compensator unit that minimize internal couplings of MIMO system. HGNMA utilizes the concept of minimizing the summation of the integral square outputs (ISOs) of non-proper paired outputs with respect to specific input. One HGNMA is assigned to each input with its own fitness function. Each HGNMA services to minimize its fitness function. The proposed technique is applied on 4 input/4 output two coupled distillation columns process, it proves remarkable success in minimizing the interaction between every input and all outputs except that output has been proper paired with.
 

146-157

    Paper Title, Authors, Abstract (Issue 4, Volume 3, 2009)

Pages

A Family of Hyperbolic and Exponential–Type Controllers
Francisco Terneus, Fernando Reyes, Eduardo Lebano

Abstract: This paper addresses the problem of position control for robot manipulators. A new family of controllers with gravity compensation for the global position is presented. This new family called Hyperbolic controller has its structure composed by exponential hyperbolic functions, that force the position error to move to zero position. This paper offers enough conditions that are sufficient in order to prove directly global asymptotic stability of the closed-loop system composed by the nonlinear robot dynamics for n degrees of freedom and the proposed scheme. In addition to the theoretical results, real-time experiments are presented to compare the performance of the proposed family with other well-known control algorithms such as the PD on a three degrees of freedom direct-drive robot arm.
 

159-169

PAAN: Partial Agreement Negotiation Network based on Intelligent Agents in Crisis Situation
Ayda Kaddouci, Hayfa Zgaya, Slim Hammadi, Francis Bretaudeau

Abstract: The aim of this paper is to present a multi-agent based approach for negotiation in crisis management. We propose to harness the potential of the multi-agent system (MAS) technology for constructing a framework of cooperation agents that are capable of delivering an optimal solution for crisis.
Supply Chain study is adopted more and more for the companies’ competitiveness development. Our industrial partner EADS (European Aeronautic Defence and Space Company) handles a logistic flows demonstrator for crisis management, developed by our research team. A Multi-Agent architecture is planned to design a distributed supply chain. In this paper, we propose to adopt an advanced interaction between the autonomous entities. Therefore, we propose a multi agent based architecture for crisis management supply chain. A new form of negotiation is presented to avoid, in a crisis situation, the stock-out by balancing the resources provisions throughout the system.
 

170-178

Optimal Flow Control of a Three Tank System
Marius-Constantin Popescu, Nikos E. Mastorakis

Abstract: The 3TS system has two PI regulators with identical parameters of the intended adjustment of the level in two tanks. This paper is intended to determine the optimal parameters for the automated flow system between two open containers of a laboratory equipment "Three tank system". In doing so, a multidisciplinary paper is achieved that includes the hardware and software knowledge and adjustment.
 

179-186

   

 

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