Authors:Yavuz Ozdemir, Pelin Alcan, Huseyin Basligil, Dursun Cakrak Pages: 117 - 126 Abstract: Selection of the heating system is based on many characteristics from the customer side. Operating cost, comfort, ease of use and aesthetic of the systems are some of the most important ones of these characteristics. In this article, data is collected primarily for the implementation of quality house. With these data, customer requirements are listed and defined in terms of degree of importance from the customer side. Then, the relationship between customer requirements and technical requirements are described. Also, column weights are calculated according to the defined relations. Finally, the results obtained using a quality house is integrated with Analytic Hierarchy Process (AHP) methodology for system selection. Then results are interpreted. The main contribution of this paper is to determine the best heating system selection using the relationship between customer and technical requirements. To the authors’ knowledge, this will be the first study which uses the integrated QFD-AHP method for heating system selection. PubDate: 2018-01-10 DOI: 10.11121/ijocta.01.2018.00420 Issue No:Vol. 8, No. 1 (2018)

Authors:Mehmet Yavuz Pages: 1 - 7 Abstract: In this work, we develop a formulation for the approximate-analytical solution of fractional partial differential equations (PDEs) by using conformable fractional derivative. Firstly, we redefine the conformable fractional Adomian decomposition method (CFADM) and conformable fractional modified homotopy perturbation method (CFMHPM). Then, we solve some initial boundary value problems (IBVP) by using the proposed methods, which can analytically solve the fractional partial differential equations (FPDE). In order to show the efficiencies of these methods, we have compared the numerical and exact solutions of the IBVP. Also, we have found out that the proposed models are very efficient and powerful techniques in finding approximate solutions for the IBVP of fractional order in the conformable sense. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00540 Issue No:Vol. 8, No. 1 (2017)

Authors:Asuman Zeytinoglu, Murat Sari, Bilender P. Allahverdiev Pages: 8 - 16 Abstract: In this paper, a new hybrid approach based on sixth-order finite difference and seventh-order weighted essentially non-oscillatory finite difference scheme is proposed to capture numerical simulation of the regularized long wave-Burgers equation which represents a balance relation among dissipation, dispersion and nonlinearity. The corresponding approach is implemented to the spatial derivatives and then MacCormack method is used for the resulting system. Some test problems discussed by different researchers are considered to apply the suggested method. The produced results are compared with some earlier studies, and to validate the accuracy and efficiency of the method, some error norms are computed. The obtained solutions are in good agreement with the literature. Furthermore, the accuracy of the method is higher than some previous works when some error norms are taken into consideration. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00461 Issue No:Vol. 8, No. 1 (2017)

Authors:Ilknur Koca Pages: 17 - 25 Abstract: In this paper we investigate a possible applicability of the newly established fractional differentiation in the field of epidemiology. To do this we extend the model describing the Rubella spread by replacing the time derivative with the time fractional derivative for the inclusion of memory. Detailed analysis of existence and uniqueness of exact solution is presented using the Banach fixed point theorem. Finally some numerical simulations are showed to underpin the effectiveness of the used derivative. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00532 Issue No:Vol. 8, No. 1 (2017)

Authors:M. Hakan Akyüz Pages: 26 - 42 Abstract: The Capacitated Multi-facility Weber Problem addresses optimally locating I capacitated facilities in the plane and satisfying demand of J customers so as to minimize the total transportation cost. It assumes that facilities can be located anywhere on the plane and customers are directly connected to them. This study considers the case where there exist convex polyhedral barriers blocking passage and locating facilities inside. Then, the distances between facilities and customers have to be measured by taking into account the polyhedral barriers. The resulting problem is non-convex and difficult to solve. We propose several discretization based heuristic procedures which are especially designed for the problem. The performance of the suggested methods are tested on an extensive set of randomly generated test instances which are derived from standard test instances. Our results imply that the suggested heuristics yield very accurate and efficient solutions for this problem. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00388 Issue No:Vol. 8, No. 1 (2017)

Authors:S. S. Ravindran Pages: 43 - 62 Abstract: Thermally coupled magneto-hydrodynamics (MHD) studies the dynamics of electro-magnetically and thermally driven flows, involving MHD equations coupled with heat equation. We introduce a partitioned method that allows one to decouple the MHD equations from the heat equation at each time step and solve them separately. The extrapolated Crank-Nicolson time-stepping scheme is used for time discretization while mixed finite element method is used for spatial discretization. We derive optimal order error estimates in suitable norms without assuming any stability condition or restrictions on the time step size. We prove the unconditional stability of the scheme. Numerical experiments are used to illustrate the theoretical results. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00325 Issue No:Vol. 8, No. 1 (2017)

Authors:Ozkan Guner Pages: 63 - 72 Abstract: In this paper, solitary-wave ansatz and the (G′/G)-expansion methods have been used to obtain exact solutions of the fractional regularized long-wave (RLW) and coupled Nizhnik-Novikov-Veselov (NNV) equation. As a result, three types of exact analytical solutions such as rational function solutions, trigonometric function solutions, hyperbolic function solutions are formally derived these equations. Proposed methods are more powerful and can be applied to other fractional differential equations arising in mathematical physics. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00417 Issue No:Vol. 8, No. 1 (2017)

Authors:Halil Ibrahim Demir, Onur Canpolat Pages: 73 - 83 Abstract: Process planning, scheduling and due-date assignment are three important manufacturing functions in our life. They all try to get local optima and there can be enormous loss in overall performance value if they are handled separately. That is why they should be handled concurrently. Although integrated process planning and scheduling with due date assignment problem is not addressed much in the literature, there are numerous works on integrated process planning and scheduling and many works on scheduling with due date assignment. Most of the works in the literature assign common due date for the jobs waiting and due dates are determined without taking into account of the weights of the customers. Here process planning function is integrated with weighted shortest processing times (WSPT) scheduling and weighted slack (WSLK) due date assignment. In this study unique due dates are given to each customer and important customers gets closer due dates. Integration of these three functions is tested for different levels of integration with genetic algorithms, evolutionary strategies, hybrid genetic algorithms, hybrid evolutionary strategies and random search techniques. Best combinations are found as full integration with genetic search and hybrid genetic search. Integration of these three functions provided substantial improvements in global performance. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00412 Issue No:Vol. 8, No. 1 (2017)

Authors:Hakan Yazici, Mert Sever Pages: 84 - 91 Abstract: This paper concerns with the optimal state derivative feedback LQR controller design for vibration control of an offshore steel jacket platform having active tuned mass damper against the wave induced disturbances. Considering that the state derivative signals such as acceleration and velocity are easier to measure rather than the state variables such as displacement, state derivative feedback control strategy is proposed to obtain practically applicable and easily realizable synthesis method. On the basis of convex optimization approach, state derivative feedback LQR controller design is formulated in Linear Matrix Inequalities (LMIs) form to get an optimal feasible solution set. Finally, an offshore steel jacket platform subject to nonlinear self excited wave force is used to illustrate the effectiveness of the proposed approach through simulations. The results show that proposed state derivative LQR controller is very effective in reducing vibration amplitudes of each floor of modeled offshore steel jacket platform and achieves compitable control performance to classical LQR controller design. PubDate: 2017-12-25 DOI: 10.11121/ijocta.01.2018.00468 Issue No:Vol. 8, No. 1 (2017)

Authors:Ismail Aydogdu Pages: 92 - 101 Abstract: Inspired by the Z2Z4-additive codes, linear codes over Z_{2}^r x (Z_{2} + uZ_{2})^s have been introduced by Aydogdu et al. more recently. Although these family of codes are similar to each other, linear codes over Z_{2}^r x (Z_{2} + uZ_{2})^s have some advantages compared to Z2Z4-additive codes. A code is called constant weight(one weight) if all the codewords have the same weight. It is well known that constant weight or one weight codes have many important applications. In this paper, we study the structure of one weight Z2Z2[u]-linear and cyclic codes. We classify these type of one weight codes and also give some illustrative examples. PubDate: 2017-12-26 DOI: 10.11121/ijocta.01.2018.00512 Issue No:Vol. 8, No. 1 (2017)

Authors:Ayşegül Yıldız Ulus Pages: 102 - 116 Abstract: Optimal growth problem is an important optimization problem in the theory of economic dynamics. This paper provides an overview of the main approaches used in the existing literature in solving infinite horizon discrete time optimal growth problem and includes very recent developments. PubDate: 2017-12-28 DOI: 10.11121/ijocta.01.2018.00464 Issue No:Vol. 8, No. 1 (2017)