International Journal of Applied Mathematics and Informatics
E-ISSN: 2074-1278
Volume 14, 2020
Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.
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Volume 14, 2020
Title of the Paper: Comparison of Discrete Fourier Transform and Fast Fourier Transform with Reduced Number of Multiplication and Addition Operations
Authors: Bimal Pal, Pijush Kanti Bhattacharjee
Pages: 90-94
http://doi.org/10.46300/91014.2020.14.16
Abstract: Fast Fourier Transform is an advanced algorithm for computing Discrete Fourier Transform efficiently. Although the results available from the operation of Discrete Fourier Transform (DFT) and Fast Fourier Transform (FFT) are same, but exploiting the periodicity and symmetry property of phase factor Fast Fourier Transform computes the Discrete Fourier Transform using reduced number of multiplication and addition operations. The basic structure used in the operations of Fast Fourier Transform is the Butterfly structure. For the implementation of Fast Fourier Transform the two methods are used such as decimation in time (DIT) and decimation in frequency (DIF). Both the methods give same result but for decimation in time of Fast Fourier Transform bit reversed inputs are applied and for decimation in frequency of Fast Fourier Transform normal order inputs are applied, and the result is reversed again. In this paper, operations for DFT and FFT have been discussed and shown with examples. It is found that generalized formula for FFT have been described same in the books, but the expressions in the intermediate computations for the first decimation and second decimation are different in the various books of Digital Signal Processing. The expressions in the intermediate computation of FFT described in different books are broadly compared in this paper
Title of the Paper: Determination of Heat Exchange Law Using Mean Isotherm
Authors: Ilmars Iltins, Marija Iltina
Pages: 87-89
http://doi.org/10.46300/91014.2020.14.15
Abstract: Determination of heat exchange between a solid and the environment is a significant inverse thermal physical problem. This heat exchange law irrespective of its nature can be defined easier if mean temperature of such solid is known. When mean temperature of the solid and speed of its change are known, it becomes possible to determine heat flow on the boundary of the solid. In its turn, when heat flow on the boundary, temperature on the boundary and ambient temperature are defined, heat exchange coefficient can be established. Therefore, the main attention is paid to a manner how mean temperature of a solid can be determined in the article. Examining inverse heat transfer problems, input data consist of measurements taken in temperature field as simple as possible mathematically in laboratory conditions. Hence, a symmetrical one-dimensional temperature field is discussed in the article
Title of the Paper: An Exact Method for the Multi-objective Winner Determination Problem of Combinatorial Auctions
Authors: Chahrazad Adiche, Meziane Aıder
Pages: 82-86
http://doi.org/10.46300/91014.2020.14.14
Abstract: We are interested by the problem of combinatorial auctions in which multiple items are sold and bidders submit bids on packages. First, we present a multi-objective formulation for a combinatorial auctions problem extending the existing single-objective models. Indeed, the bids may concern several specifications of the item, involving not only its price, but also its quality, delivery conditions, delivery deadlines, the risk of not being paid after a bid has been accepted and so on. The seller expresses his preferences upon the suggested items and the buyers are in competition with all the specified attributes done by the seller. Second, we develop and implement an exact algorithm based on a multi-objective branch-and-bound method.
Title of the Paper: Weighted Multi-scale Local Binary Pattern Histograms for Face Recognition
Authors: Olegs Nikisins
Pages: 76-81
http://doi.org/10.46300/91014.2020.14.13
Abstract: This paper proposes a novel face recognition methodology, which is based on the combination of the texture operator, namely Multi-scale Local Binary Pattern (MSLBP), face image filtering and discriminative feature weighting algorithms. Presented MSLBP principle enhances the discriminative power of the original Local Binary Pattern operator. The combination of the MSLBP and low-pass filtering improves the stability of the feature vector for different scales of the input face. Proposed mini-batch discriminative feature weighting methodologies are applied to the feature space in the feature and block levels in order to enhance the components more relevant to the recognition process. The observed PCA based data compression algorithm significantly reduced the dimensionality of the feature vector with a minimal loss in the precision of the recognition process. The identification precision exceeded the threshold of 99% for the frontal subsets of a color FERET database.
Title of the Paper: Collaborative Dialogue Information Model
Authors: Tomáš Nestorovič, Václav Matoušek
Pages: 70-75
http://doi.org/10.46300/91014.2020.14.12
Abstract: This paper concerns a task-oriented dialogue information management. Below we cover its main features – knowledge combining and intention detection. The approach is demonstrated in a step by step manner on one of sessions with a spoken timetable application.
Title of the Paper: Elliptic Curve Over Spir of Characteristic Two
Authors: Abdelhamid Tadmori, Abdelhakim Chillali, Mhamed Ziane
Pages: 66-69
http://doi.org/10.46300/91014.2020.14.11
Abstract: In [1] and [4] we defined the elliptic curve over the ring F3d [ε], ε2 = 0. In this work, we will study the elliptic curve over the ring A = F2d [ε], where d is a positive integer and ε2= 0. More precisely we will establish a group homomorphism between the abulia group (Ea,b,c(F2d ), +) and (F2d, +).
Title of the Paper: A Tabu Search Method for the Multi-objective Winner Determination Problem of Combinatorial Auctions
Authors: Chahrazad Adiche, Meziane Aıder
Pages: 62-65
http://doi.org/10.46300/91014.2020.14.10
Abstract: We are interested by the problem of combinatorial auctions in which multiple items are sold and bidders submit bids on packages. First, we present a multi-objective formulation for a combinatorial auctions problem extending the existing single-objective models. Indeed, the bids may concern several specifications of the item, involving not only its price, but also its quality, delivery conditions, delivery deadlines, the risk of not being paid after a bid has been accepted and so on. The seller expresses his preferences upon the suggested items and the buyers are in competition with all the specified attributes done by the seller. Second, we develop and implement a metaheuristic algorithm based on a tabu search method.
Title of the Paper: Monotonicity of a Quadratic Lienard Equation
Authors: Khalil I.T. Al-Dosary
Pages: 58-61
http://doi.org/10.46300/91014.2020.14.9
Abstract: we study the period function of the quadratic Lienard equation of a certain type in order to give necessary and sufficient conditions for monotonicity and isochronicty of the period function. We apply this result to identify the region of monotonicity of the period function of particular cases.
Title of the Paper: Double Reduction Analysis of Benjamin, DGH and Generalized DGH Equations
Authors: Muhammad Danish Khan
Pages: 51-57
http://doi.org/10.46300/91014.2020.14.8
Abstract: The exact solutions of non-linear evolution equation, Benjamin equation, Dullin-Gottwald-Holm (DGH) equation and generalized Dullin-Gottwald-Holm equation are established using the conserved vectors. The multiplier approach is applied to construct the conserved vectors for equations under consideration. For non-linear evolution equation three conserved vectors and for Benjamin equation four conserved vectors are obtained. The conserved vectors for DGH and generalized DGH equations were reported in [1]. The higher order multiplier is considered for DGH equation and a new conserved vector is found. The double reduction theory is utilized to obtain various exact solutions for Benjamin equation, DGH equation and generalized DGH equation.
Title of the Paper: Several Inverse Problems in Thermal Physics
Authors: Ilmars Iltins
Pages: 46-50
http://doi.org/10.46300/91014.2020.14.7
Abstract: There are solution approaches for several thermalphysical inverse problems discussed in the paper that are based on extension of non-stationery temperature field in the series. An applied method for separation of variables differs from the conventional method for separation of variables. Effect thereof differs as well and is especially convenient for solving inverse thermal-physical problems. Abraham Temkin (1919–2007) created this method for separation of variables. He also offered several methods for solving inverse problems. Those methods are not studied enough and are not known among a wider range of experts. Those methods have been created between 1956 and 1973 and have been published in various journals in Samara, Moscow, Minsk, and Riga. All those publications are in Russian and not available in electronic format.
Title of the Paper: Increasing Efficiency of IoT-enabled Waste Collectionwith Controlled Mobility of Robotic Bins
Authors: Theodoros Anagnostopoulos, Klimis Ntalianis, Arkady Zaslavsky, Nikolaos Mastorakis
Pages: 40-45
http://doi.org/10.46300/91014.2020.14.6
Abstract: Smart Cities cater for ever increasing population, which needs sustainable solutions for efficient wellbeing. Waste collection is significant for providing a green ecosystem in such cities. IoT-enabled waste collection solutions assist such a green ecosystem. Waste collection used to be performed by humans or via human intervention.However, contemporary research incorporates robots to perform waste collection. In this paper we describethe real case of a line following robot bin that assists waste collection in the Smart City of Saint Petersburg, Russia. Evaluation is performed through a model combining the distance covered by the actor, the time passed for the collection and the bins emptied. The results show the superiority of robot bins, compared to human workers, highlighting the impact of IoT-enabled robot assisted waste collection as part of a green ecosystem.
Title of the Paper: Optimal Maintenance of a Production-inventory System With Continuous Repair Times and Idle Periods
Authors: T. D. Dimitrakos, E. G. Kyriakidis, C. C. Karamatsoukis
Pages: 32-39
http://doi.org/10.46300/91014.2020.14.5
Abstract: In this paper two similar models for the maintenance of a production-inventory system are considered. In both models, an input generating installation supplies a buffer with a raw material and a production unit pulls the raw material from the buffer. The installation in the first model and the production unit in the second model deteriorate stochastically over time and the problem of their optimal preventive maintenance is considered. In the first model, it is assumed that the installation, after the completion of its maintenance, remains idle until the buffer is evacuated, while in the second model, it is assumed that the production unit, after the completion of its maintenance, remains idle until the buffer is filled up. The preventive and corrective repair times of the installation in the first model and the preventive and corrective repair times of the production unit in the second model are continuous random variables with known probability density functions. Under a suitable cost structure, semi-Markov decision processes are considered for both models in order to find a policy that minimizes the long-run expected average cost per unit time. A great number of numerical examples provide strong evidence that, for each fixed buffer content, the average-cost optimal policy is of control-limit type in both models, i.e. it prescribes a preventive maintenance of the installation in the first model and a preventive maintenance of the production unit in the second model if and only if their degree of deterioration is greater than or equal to a critical level. Using the usual regenerative argument, the average cost of the optimal control-limit policy is computed exactly in both models. Four numerical examples are also presented in which the preventive and corrective repair times follow the Exponential, the Weibull, the Gamma and the Log-Normal distribution, respectively.
Title of the Paper: New Solutions of the Heat Equation and Application to Thin Plate Heat Conduction
Authors: Jacob Manale
Pages: 18-31
http://doi.org/10.46300/91014.2020.14.4
Abstract: Using a Lie symmetry group generator and a generalised form of Euler’s formula for solving second order ordinary differential equations, we determine new symmetries for the heat equation, leading to new solutions. As an application, we test a formula resulting from this approach on thin plate heat conduction
Title of the Paper: A New Inexact Line Search Method for Convex Optimization Problems
Authors: Aliyu Usman Moyi, Wah June Leong
Pages: 15-17
http://doi.org/10.46300/91014.2020.14.3
Abstract: In general one can say that line search procedure for the steplength and search direction are two important elements of a line search algorithm. The line search procedure requires much attention because of its far implications on the robustness and efficiency of the algorithm. The purpose of this paper is to propose a simple yet effective line search strategy in solving unconstrained convex optimization problems. This line search procedure does not require the evaluation of the objective function. Instead, it forces reduction in gradient norm on each direction. Hence it is suitable for problems when function evaluation is very costly. To illustrate the effectiveness of our line search procedure, we employ this procedure together with the symmetric rank one quasi-Newton update and test it against the same quasi-Newton method with the well-known Armijo line search. Numerical results on a set of standard unconstrained optimization problems showed that the proposed procedure is superior to the Armijo line search.
Title of the Paper: Delay Differential Equations in Biosciences: Parameter Estimation and Sensitivity Analysis
Authors: Fathalla A. Rihan
Pages: 6-14
http://doi.org/10.46300/91014.2020.14.2
Abstract: This is a review article to show that delay differential models have a richer mathematical framework (compared with models without memory or after-effects) and a better consistency with biological phenomena such dynamical diseases and cell growth dynamics. The article provides a general computational technique to treat numerically the emerging delay differential models. It introduces the numerical algorithms for parameter estimations, using least squares approach. The article introduces a variational method to evaluate sensitivity of the state variables to small perturbations in the initial conditions and parameters appear in the model. An application to show the consistency of DDE models with cell growth dynamics is also considered.
Title of the Paper: Modified Explicit Decoupled Group Scheme On Helmholtz Equation
Authors: Norhashidah Hj. Mohd Ali, Farhana Aziz
Pages: 1-5
http://doi.org/10.46300/91014.2020.14.1
Abstract: In this paper, the formulation of a new group iterative method called the Modified Explicit Decoupled Group method in solving the two dimensional Helmholtz equation is described. The method is derived using a combination of the five-point finite difference approximation on the rotated grid stencil together with the five-point centred difference approximation on the standard grid stencils. Numerical experimentations of this new formulation shows significant improvement in computational complexity and execution timings over the original Explicit Decoupled Group method [2].
