International Journal of Applied Mathematics and Informatics

E-ISSN: 2074-1278
Volume 6, 2012

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Issue 1, Volume 6, 2012 

Title of the Paper: Risk Software Application Using a Credit Scoring Model

Authors: Gabriela Mircea, Marilen Pirtea, Mihaela Neamtu, Sandra Bazavan

Pages: 1-8

Abstract: The purpose of this paper is to define a specific credit score model, based on the discriminant analysis in order to complete financial diagnoses on particular predefined classes. The model is built based on a set of observations for which the classes are known. The classes in this paper are made of companies with certain characteristics which reflect the creditworthiness of that entity.

Title of the Paper: Effects of Aircraft Preventive Maintenance on Reliability

Authors: E. Kiyak

Pages: 9-16

Abstract: Preventive maintenance can be described as maintenance of equipment or systems before fault occurs. The main goal of maintenance is to avoid or mitigate the consequences of failure of equipment. It also improves reliability, decreases cost of replacement and system downtime. Preventive maintenance helps provide high level of availability of system function and obtains great return on investments of hardware and software. However, very frequent application of preventive maintenance is not economical though. In order to obtain optimum benefit, this maintenance should be done at proper times. This study aims at explaining the importance of preventive maintenance mathematically. The mean time to failure (MTTF) or the mean time between failures (MTBF) is taken as the reliability criteria. The reliability values obtained when preventive maintenance is applied and not applied are compared to the MTTF.

Title of the Paper: A Fundamental Conception to Formulate Image Data Hiding Scheme Based on Error Diffusion from Stochastic Viewpoint

Authors: Masakazu Higuchi, Shuji Kawasaki, Jonah Gamba, Atsushi Koike, Hitomi Murakami

Pages: 17-24

Abstract: Image data hiding schemes are techniques to embed secret image data into several images. The embedded data can be extracted with some procedure. On the other hand, visual cryptographic techniques break up a secret image into several shares so that only someone with all shares can decrypt the secret image by superposing all shares together. Image data hiding schemes based on error diffusion have the feature of visual cryptography with respect to extracting of embedded data. They embed secret image data into several halftone images without affecting their perceptual qualities and the embedded data can be restored with apparently high quality when the halftone images are overlaid without any special electronic calculation. In this paper, we consider to formulate an image data hiding scheme based on error diffusion. We propose a formulation for the scheme in the view of a stochastic analysis. The idea is very basic, but theoretical studies by formulating is important trial in this field.

Title of the Paper: Trap-Decoding of Reed-Solomon Codes and Its Burst-Error-Correcting Performance Evaluation

Authors: Dunwei Xue, Liuguo Yin

Pages: 25-32

Abstract: The communication and storage systems may be corrupted by bursts of noise. These bursts may be long in duration, resulting in a significant degradation for the system performance. Reed-Solomon (RS) codes are proven to be very effective in correcting burst errors. According to the Singleton bound, the maximum length of burst errors that can be corrected by an (n, k) RS code is (n-k)/2 symbols. However, it turns out that, if correlation between erroneous symbols within bursts is considered and well used, variables for burst locations will be decreased and, accordingly, decoding capability may be enhanced with increased length of correctable bursts. As such, we propose a new trap-decoding algorithm for RS codes in this paper. It is shown that, for (n, k) RS codes, this algorithm can correct continuous burst errors with length that approaches to n-k symbols with fairly low miscorrection probability, achieving a good performance over long-burst channels. Moreover, we will further show that the complexity of the proposed algorithm is fairly lower, and the decoding delay is much less than those of existing burst-error-correcting algorithms.

Title of the Paper: Using Factor Analysis on Survey Study of Factors Affecting Students’ Learning Styles

Authors: Suriani Hassan, Norlita Ismail, Wan Yonsharlinawati Wan Jaafar, Khadizah Ghazali, Kamsia Budin, Darmesah Gabda, Asmar Shahira Abdul Samad

Pages: 33-40

Abstract: This study focused on the statistical technique using the factor analysis on constructing the new factors affecting students’ learning styles of the survey done among university students. In addition, comparison means using the Kruskal-Wallis test were done to analyze the demographic differences on the new factors affecting students’ learning styles. The data were collected using survey questionnaires. The number of respondents was 189 students. The methodologies used were descriptive statistics, factor analysis and non-parametric technique using the Kruskal-Wallis test. The results showed seven new factors were successfully constructed using factor analysis and assigned as the factors affecting the learning styles; which are 1) students' attitude before and after attending class, 2) strategies used to comprehend the lecture, 3) the importance of lecture, 4) class size and its condition, 5) efforts outside class, 6) classroom convenient and 7) importance on listening to lecture. The Kruskal-Wallis test results showed there was a significant mean difference between gender on students' efforts outside class (factor 5) while there was no significant mean difference between genders on the other factors of students’ learning style. As for years of study, Kruskal-Wallis test showed that students’ attitude before and after attending class influenced learning style. The result from Kruskal-Wallis test showed different in score for science and non-science stream students. Non-science students have a better comprehend strategy as their field could be practiced outside classroom and do not merely based on theory. On the other hand, science students satisfy with their class size and its condition as compared to non-science students. The result shows that CGPA is only influenced by the importance of class size and its condition and the importance of lecture. Students with CGPA 2.00-2.49 indicated that attending lecture is crucial and satisfy with classroom size and its condition as compared to students with other group of CGPA.

Title of the Paper: Complex Valued Open Recurrent Neural Network for Power Transformer Modeling

Authors: A. Minin, Yu. Chistyakov, E. Kholodova, H.-G. Zimmermann, A. Knoll

Pages: 41-48

Abstract: Application of artificial Neural Networks (NN) for power equipment modeling has been outlined in many papers, but conventional NN deal only real valued numbers. Complex Valued Open Recurrent Neural Networks (CVORNN) is significant expansion of NN application due to complex numbers usage, which is natural form of data in electrical engineering. Dealing with complex values is very useful in Wide Area Measurement Systems. Power transformer modeling using CVORNN is presented in this paper as it is one of the most common elements of power grid which has nonlinear behavior. Considering paper consists of two main parts: conventional modeling for getting transformer data and CVORNN application for studied transformer. First part of the paper describes nonlinearities which take place in transformer model: nonlinear magnetizing system, ambient temperature influence on windings and OLTC voltage stabilization. Typical day-long load curve is used for load simulation. The second part devoted to CVORNN basics and application. CVORNN is trained and tested using received in the first part data. Obtained results show that CVORNN is promising and convenient method for modeling in electrical engineering.

Title of the Paper: Application of the Multi Segment Function in Hydraulic Systems

Authors: Claude Ziad Bayeh

Pages: 49-56

Abstract: The Multi Segment function is a mathematical function developed by the author in order to describe the continuity of non derivable linear functions. The form of this function is as its name indicate, it is composed of many linear segments connected together to form a single function. The main goal of developing this function is to be applied in the hydraulic systems and in the design of pipelines for pressurized water supply distributions underground. The Multi segment function is very important in the hydraulic systems in which the pipelines can be run parallel to the earth surface in a way to minimize the depth of the path way of the pipeline under the ground. Moreover, one can get the total length of the pipeline by using a simple formula developed in this paper. This function can be simply programmed using software as Matlab, Microsoft Excel or any other software.

Title of the Paper: Rating and Ranking Criteria for Selected Islands Using Fuzzy Analytic Hierarchy Process (FAHP)

Authors: Noraida Haji Ali, Ily Amalina Ahmad Sabri, Noor Maizura Mohamad Noor, Fathilah Ismail

Pages: 57-65

Abstract: Destination choice is one of decision making problems which should carefully be investigated in order to choose the best alternative among popular alternatives. The structure in modeling decision making may influencing the decision made and different decision making models impose different objectives with the result may not be variant. Therefore island evaluation has become one of important components in the selections. Multi-criteria decision making (MCDM) is a possible evaluation scale for many characters or quantities of decision makers’ evaluation. It could be determined by advantage or ranking. This study presents fuzzy AHP as a proposed method for dealing with decision making in ten (10) social attributes. Fuzzy analytic hierarchy process (FAHP) is employed to calculate the weights of these criteria and sub-criteria, so as to build the fuzzy multi-criteria model of island evaluation. FAHP performed better than domain experts in tourism when the size of criteria and sub-criteria set increase. A detailed numerical example, illustrating the application of our approach to criteria evaluation is given.

Issue 2, Volume 6, 2012

Title of the Paper: On Complete and Size Balanced k-ary Tree Integer Sequences

Authors: Sung-Hyuk Cha

Pages: 67-75

Abstract: Discovering new integer sequences and generalizing the existing ones are important and of great interest. In this article, various balanced k-ary trees are first studied and their taxonomy is built. In particular, two systematic balanced k-ary trees, whose nth tree is determined by a certain algorithm, are identified, i.e., complete and size-balanced k-ary trees. The integer sequences from the formal one is important to analyzing algorithms involving the popular d-heap data structures. Those derived from the later one is pervasive in analyzing divide and conquer algorithms. Numerous generalized and new formulae for existing and new integer sequences generated from the complete and size-balanced k-ary trees are given.

Title of the Paper: Performance, Value and Penetration of Real Options into the Capital Budgeting Processes of Czech Companies using AMTs

Authors: Přemysl Pálka, Adriana Knápková

Pages: 76-83

Abstract: Paper deals with topic of capital budgeting methods that are currently used by Czech companies that implemented some of advanced manufacturing technologies (AMTs). The main aim of a paper is to analyse and propose successful implementation of real options into the value creation processes where other performance measures and concepts are used in their mutual synergy. Research is based on results of analysis that strived to find out the structure of currently used capital budgeting methods, managerial concepts and other important perspectives of competitiveness within a group of Czech companies. Supporting goal is to analyse and identify the barriers in penetration of real options to capital budgeting processes of Czech companies and describe impacts of flexible investments on enterprise value.

Title of the Paper: Traffic Accidents in Kuwait: A Decision Making Analysis

Authors: Mohammed A. Hajeeh

Pages: 84-91

Abstract: Road traffic accidents are ranked ninth as a leading cause of death worldwide, and it is predicted to move to the second rank by 2020. The estimate cost of traffic crashes globally reaches to 518 billion US dollars each year and account for around 1.5% of many countries GDP. The Middle East region has the highest rate of car accidents fatalities in the world and within this region Kuwait is ranked as one of the highest number of car accidents fatalities with around 28 fatalities per 100,000 vehicles. The problem is very alarming and hence proper and immediate actions ought to be taken to resolve it. In order to contribute in solving this problem, this paper attempted to closely examine it and provide some solutions. Due to the complexity of the problem with multiple objectives, the Analytic Hierarchy process (AHP) is used. Expert opinions wither solicited in order to identify and rank the important targets and select and address the various relevant policies.

Title of the Paper: An Algebraic Approach to Project Schedule Development under Precedence Constraints

Authors: Nikolai Krivulin

Pages: 92-100

Abstract: An approach to schedule development in project management is developed within the framework of idempotent algebra. The approach offers a way to represent precedence relationships among activities in projects as linear vector equations in terms of an idempotent semiring. As a result, many issues in project scheduling reduce to solving computational problems in the idempotent algebra setting, including linear equations and eigenvalue-eigenvector problems. The solutions to the problems are given in a compact vector form that provides the basis for the development of efficient computation procedures and related software applications.

Title of the Paper: IT Governance and Information System Auditing Practice in Credit Institutions in the Republic of Croatia

Authors: Mario Spremic, Marijana Ivanov, Bozidar Jakovic

Pages: 101-108

Abstract: Main objective of this paper was to stress the necessity for measuring the level of various risks the companies are exposed to in financial sector. We particularly focused on methods and frameworks for measuring and managing the level of operational risks in credit institutions. It can be done by conducting regular information system audits (IS audits). Information system audit represents a wide range of audit, managerial, analytical and technological activities with the main objective of thoroughly reviewing the effectiveness of control procedures in various parts of IS, conducting analytical tests and collecting evidences which helps in evaluating the level of operational risks and measuring the maturity level of IS. IS auditing is conducting according to various internationally accepted methodologies (such as CobiT), industry based best practices and/or framework (such as Basel III, PCI DSS or similar) or national and transnational regulation provisions. External (CobiT methodology) and especially national regulation framework for conducting IS audits in the Republic of Croatia are explained and analyzed in further details. Also, the methodology for conducting IS auditing is presented and maturity levels explained (5 point scale system with a qualitative marks which range from completely unsatisfactory to completely satisfactory). In the paper we describe the continuous quality control system which enables national regulatory body (Croatian National Bank) to control the quality of IS audits report. The results of assessing the level of operational risks in credit institutions in the Republic of Croatia which arises from external IS auditing activities in 2010 were depicted (11 credit institutions satisfactory manage the level of operational risk, 18 partially satisfactory and 2 partially unsatisfactory). Upon the long-lasting (3 years) in-depth case study analysis, we investigate in further details if the practice of managing operational risks in a small credit institution is improving by conducting regular IS audits and obeying to regulatory framework.

Issue 3, Volume 6, 2012

Title of the Paper: Analysis of the Development of Mergers in the Czech Republic in the Period 2001–2009 from the Perspective of Ownership Structure

Authors: Jaroslav Sedláček, Petr Valouch, Eva Hýblová

Pages: 109-116

Abstract: Success in business is a relative term and depends on the evaluator’s point of view. A successful entity should be beneficial both for owners and other stakeholders. Economically spoken, a company is successful if it brings higher value for its owners. An increase in company value is connected with internal and external development of the business, often in the form of acquisitions and mergers. The subject of this paper is mergers of Czech companies which took place between 2001 and 2009. The study focuses on changes in the structure of ownership in particular quarters of the monitored period and the development in ownership relationships among participating entities. The analysis uses temporal series containing numbers of mergers and volumes of assets of participating entities.
The results of the analysis have confirmed a slight increase in the number and volume of mergers implemented under foreign owners’ control in contrast to entities controlled by domestic owners. They have also identified waves of mergers within an annual cycle reflecting the timing of the decisive day and the preparation of the starting balance sheet as of the first day of a new accounting and taxation period. In the Czech conditions, mergers under foreign successor company control prevail, while mergers under domestic control have a negative trend in the monitored period. A positive development trend has been proved for mergers implemented under control by only one owner of all participating entities.

Title of the Paper: Using DEMATEL and the Smartphone as a Case Study to Investigate How Consumers Evaluate Many Features of a Product Collectively

Authors: Wee-Kheng Tan, Yi-Der Yeh, Shin-Jia Chen, Yu-Cheng Lin, Chia-Yu Kuo

Pages: 117-125

Abstract: Manufacturers and marketers often highlight the existing features of a product or introduce new features to increase the competitiveness of the product vis-à-vis other competing products. For this strategy to be workable, the targeted consumers must be willing to include these features in their consideration, assess them and buy-in to the arguments put forward by the manufacturers and marketers. However, consumer’s evaluation of product features is often a multiple criteria decision-making problem. Given the need to consider many features at the same time, consumers may mentally group related product features and evaluate them collectively to simplify their decision making process. This study investigates the above idea by using DEMATEL and the case study of consumers evaluating the product features of smartphones. Our analysis revealed that indeed this is the case. Consumers may mentally link product features. For some product features, there are even existences of bi-directional relationship between the product features. This linkage of product features with other features has implications for new technology features and their associated applications, such as the Near Field Communication (NFC) and electronic wallets. To be successful, new product features need to entrench themselves as a collective part of the product by “locking” (linking) themselves to other existing and more established product features. Other implications arising from the analysis are also discussed.

Title of the Paper: Signal Processing by a Neural System and its Application to Location of Multiple Events

Authors: Yumi Takizawa, Atsushi Fukasawa

Pages: 126-133

Abstract: This paper describes a neural system to minimize errors between observation and estimation. This scheme is different to the principle of conventional learning methods. The proposed neural system is applied to the problem of time-space analysis of multiple sound source locations on 2D plane and in 3D space. The number of sources is assumed 16 sounds with a time-frame of 15 sec, and number and size of sensors are 6 and 20 cm cubic. Sound sources are located at 20m with mutual distance 20cm cubic. The proposed scheme is confirmed with well coincidence of generation times and locations. The proposed neural system shows that the algorithm is enough to solve both of 2D and 3D time-space random data problems.

Title of the Paper: Applying Multiple Complementary Neural Networks to Solve Multiclass Classification Problem

Authors: Pawalai Kraipeerapun, Somkid Amornsamankul

Pages: 134-141

Abstract: In this paper, a multiclass classification problem is solved using multiple complementary neural networks. Two techniques are applied to multiple complementary neural networks which are one-against-all and error correcting output codes. We experiment our proposed techniques using an extremely imbalance data set named glass from the UCI machine learning repository. It is found that the combination between multiple complementary neural networks and error correcting output codes provides better performance when compared to the combination between multiple complementary neural networks and one-against-all. Its performance is also better than using a single k-class neural network, a single k-class complementary neural networks, multiple binary neural networks based on error correcting output codes, and multiple binary neural networks based on one-against-all.

Title of the Paper: On Some Technical Issues and Challenges in Development and Implementation of Autonomous Design System’s (ADS) Functionality

Authors: Dmitri Loginov

Pages: 142-151

Abstract: In this paper technical issues and challenges regarding implementation of ADS functionality on AutoCAD platform are discussed. The results of the experiments for adaptation of the synergetic computer algorithm and its basic functionality to AutoCAD environment are presented. Technical aspects of the possible implementation of this algorithm in ADS system, as well as vectors’ elements combination/permutation routine performance are analyzed. A brief philosophical outlook on the problem of modeling the engineering creativity in ADS/CAD systems was given.

Title of the Paper: Differentiated Access based on Cryptographic Methods

Authors: Gheorghe Grigoraş, Dana Dănciulescu, Nicolae Constantinescu

Pages: 152-159

Abstract: Starting from the basic identity-encryption, were proposed by the other authors. The models were assumed in the random oracle model with a variant of the computational Diffie-Hellman problem. In our paper we propose a new variant of Identity-Based Encryption (IBE), using elliptic curves schemes and prove his security completeness. Also, we are doing a complete description of the necessary system used in present scheme in order to secure a communication. The performance of our system is comparable to the performance of ElGamal encryption in F*p and the security of the system is based on the elliptic curve calculus intractability.

Issue 4, Volume 6, 2012

Title of the Paper: Random Processes with Separable Covariance Functions: Construction of Dynamical Model and its Application for Simulation and Estimation

Authors: Hong Son Hoang, Remy Baraille

Pages: 161-172

Abstract: This paper demonstrates that for a given randomprocess, having a canonical form, there exists a dynamicalsystem equivalent in the sense that its output has the samecovariance function. It is shown that the dynamical approach ismore effective for simulating a Markovian and non-Markovianrandom processes, computationally is less demanding, especiallywith increasing of the dimension of simulated processes. Somenumerical examples and experiments are presented to showthe advantages of the proposed method for simulating randomprocesses as well as for solving the filtering problems.

Title of the Paper: LIRA Neural Network Application for Microcomponent Measurement

Authors: Tatiana Baidyk, Ernst Kussul, Miguel Hernandez Acosta

Pages: 173-180

Abstract: An automation of the production and assembly processes is one of the important tasks in micromechanics. To create totally automated micro factory it is necessary to develop a computer vision system that can replace an operator. Computer vision system may have several functions, for example, recognition of objects on the image of working area, recognition of mutual position of several components on the image, and measurement of component size, etc. We select one task, which is connected with the micromechanics area, - size measurement. The object of measurement is a micro piston. The micro pistons are the components of thermal micro motors that transform the heat energy from solar concentrator to electrical energy. The goal of this work is the development and research of the LIRA (Limited Receptive Area) neural classifier and its application to measure the micro piston size. To obtain the micro piston sizes it is necessary to recognize its boundaries in the image. We propose to use LIRA neural network to extract and classify piston boundaries. In this article we describe and analyze the preliminary results of LIRA application to micro piston boundaries recognition.

Title of the Paper: Heat Load Modelling for District Heating Plants Using an OpenCL-based Algorithm

Authors: Erik Kral, Petr Capek, Lubomir Vasek

Pages: 181-188

Abstract: This research paper explores an OpenCL-based algorithm to aid heat load modelling for district heating plants. Previous studies have proven that heat loads mostly depend on the external temperatures (temperature dependency component) and the time of the day (time dependency component). In this research we have used the sum of two truncated exponential functions to model the time dependency component and a generalised logistic function to model the temperature dependency component. The parameters of these functions are estimated using the traditional particle swarm optimisation (TPSO). The estimation of the parameters can be time consuming so to accelerate the process we have developed an OpenCL-based version of the algorithm. The critical part of the implementation of the algorithm in OpenCL is the use of different types of memories, especially the local memory and also the coalesced or broadcast read Access to Global Memory.

Title of the Paper: An Efficient Signcryption Method using Fractal Image Coding Scheme

Authors: Nadia M. G. Al-Saidi

Pages: 189-197

Abstract: The major aim of the computer and the commutation security research is to achieve secure and authenticated message delivery/storage. This can be satisfied using digital signature followed by encryption. The functionality combining of an encryption scheme with that of a signature scheme is called signcryption. An efficient signcryption scheme using the compression capability of fractal encoding and decoding scheme is proposed in this paper. In the proposed scheme the message is encrypted using an efficient encrypted method, and a secure digital signature is constructed using hash function. Using the advantages of fractal image coding (FIC), the fractal codes of a digital signature are added to the encrypted message to be transmitted. At the receiver side, the hash function is constructed for the received encrypted message, after decryption. By comparing the received hash with the calculated one the verification process is performed to identify the integrity of the message. The message is accepted only if the verification process is success, otherwise the message is ignored. The proposed scheme is analyzed and discussed from the attacker viewpoint to prove that the scheme provides essential security requirements. The properties and the software implementation for the proposed scheme are discussed in details.

Title of the Paper: Codification of Information with Hebbian Ensemble Structures in Neural Networks

Authors: Ernst Kussul, Tatiana Baidyk, Enrique Cabello Pardos, Cristina Conde Vilda

Pages: 198-205

Abstract: An ensemble of neurons can correspond to a property, a characteristic, or any information identity. The ensembles can be intersected and can have common neurons that can be used in future as an evaluation level of association between the information identities. On the base of this type of information presentation it is possible to create a new model of associative memory. So, it is very important to investigate the problem of information capacity of neural network (NN) with neural ensembles.