Authors:Vedat Toğan, Ali Mortazavi Pages: 130 - 141 Abstract: Teaching Learning Based Optimization (TLBO) is one of the non-traditional techniques to simulate natural phenomena into a numerical algorithm. TLBO mimics teaching learning process occurring between a teacher and students in a classroom. A parameter named as teaching factor, TF, seems to be the only tuning parameter in TLBO. Although the value of the teaching factor, TF, is determined by an equation, the value of 1 or 2 has been used by the researchers for TF. This study intends to explore the effect of the variation of teaching factor TF on the performances of TLBO. This effect is demonstrated in solving structural optimization problems including truss and frame structures under the stress and displacement constraints. The results indicate that the variation of TF in the TLBO process does not change the results obtained at the end of the optimization procedure when the computational cost of TLBO is ignored. PubDate: 2017-03-31 DOI: 10.11121/ijocta.01.2017.00309 Issue No:Vol. 7, No. 2 (2017)

Authors:Yusuf Altun Pages: 142 - 148 Abstract: The main aim of this paper is to attenuate the effects of the road disturbance on the quarter-car active suspension system (ASS) for the passenger comfort by using design. Therefore, a new static disturbance compensator is proposed by using linear matrix inequality method such that the disturbance compensator and feedback controller are simultaneously designed for the disturbances in the linear time-invariant systems, which are measurable or predictable. They have static structure, and the disturbance compensator is designed on the feedforward path. The design is applied against the road disturbance affecting the quarter car ASS. The effectiveness of the design is demonstrated with the simulations. PubDate: 2017-06-13 DOI: 10.11121/ijocta.01.2017.00458 Issue No:Vol. 7, No. 2 (2017)

Authors:Okan Kon Pages: 149 - 157 Abstract: In this study, five different cities were selected from the five climatic zones according to Turkish standard TS 825, and insulation thicknesses of exterior walls of sample buildings were calculated by using optimization. Vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 were chosen within the study content. Glass wool, expanded polystyrene (XPS), extruded polystyrene (EPS) were considered as insulation materials. Additionally, natural gas, coal, fuel oil and LPG were utilized as fuel for heating process while electricity was used for cooling. Life cycle cost (LCC) analysis and degree-day method were the approaches for optimum insulation thickness calculations. As a result, in case of usage vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 resulted different values in between 0.005-0.007 m (5-7 mm) in the optimum insulation thickness calculations under different insulation materials. Minimum optimum insulation thickness was calculated in case XPS was preferred as insulation material, and the maximum one was calculated in case of using glass wool. PubDate: 2017-07-05 DOI: 10.11121/ijocta.01.2017.00462 Issue No:Vol. 7, No. 2 (2017)

Authors:Revna Acar Vural, İbrahim Demirel, Burcu Erkmen Pages: 158 - 166 Abstract: The ongoing demand for smaller and lighter power supplies is driving the motivation to increase power density while maintaining a robust design compatible with international harmonic standards. Transformer design is a major challenge for low profile and high power density TV power cards. In addition to these, for electromagnetic interference standard and for providing efficient thermal management for heat emission, it is required to minimize EMI noise. In this study, by taking these stated criteria into consideration, a TV power card has been designed, which has 220W output power and can be used in low profile televisions. Proposed power card will meet desired critical parameters such as surface area and output power of the referenced card which has 13.5mm height, the heat, and power consumption at standby mode. Moreover, it is designed with 10mm height limit without any engraving on PCB in a way that it will meet International Electrotechnical Commission (IEC) current harmonic standard to which TVs are subjected. Experimental results demonstrate that the proposed power supply with 10mm height has 34% higher power density with respect to its counterpart having 13.5 mm height. PubDate: 2017-07-05 DOI: 10.11121/ijocta.01.2017.00440 Issue No:Vol. 7, No. 2 (2017)

Authors:Ömer Öztürkoğlu Pages: 167 - 176 Abstract: This study focuses on identical parallel machine scheduling of jobs with deteriorating processing times and rate-modifying activities. We consider non linearly increasing processing times of jobs based on their position assignment. Rate modifying activities are also considered to recover the increase in processing times of jobs due to deterioration. We also propose heuristics algorithms that rely on ant colony optimization and simulated annealing algorithms to solve the problem with multiple RMAs in a reasonable amount of time. Finally, we show that ant colony optimization algorithm generates close optimal solutions and superior results than simulated annealing algorithm. PubDate: 2017-07-15 DOI: 10.11121/ijocta.01.2017.00328 Issue No:Vol. 7, No. 2 (2017)

Authors:Pro Kaelo, Sindhu Narayanan, M.V. Thuto Pages: 177 - 185 Abstract: This article presents a modified quadratic hybridization of the Polak–Ribiere–Polyak and Fletcher–Reeves conjugate gradient method for solving unconstrained optimization problems. Global convergence, with the strong Wolfe line search conditions, of the proposed quadratic hybrid conjugate gradient method is established. We also report some numerical results to show the competitiveness of the new hybrid method. PubDate: 2017-07-15 DOI: 10.11121/ijocta.01.2017.00339 Issue No:Vol. 7, No. 2 (2017)

Authors:Mehmet Giyas Sakar Pages: 186 - 194 Abstract: In this paper, homotopy analysis method is improved with optimal determination of auxiliary parameter by use of residual error function for solving neutral functional-differential equations (NFDEs) with proportional delays. Convergence analysis and error estimate of method are given. Some numerical examples are solved and comparisons are made with the existing results. The numerical results show that the homotopy analysis method with residual error function is very effective and simple. PubDate: 2017-07-15 DOI: 10.11121/ijocta.01.2017.00360 Issue No:Vol. 7, No. 2 (2017)

Authors:Ömer Oruç, Fatih Bulut, Alaattin Esen Pages: 195 - 204 Abstract: In this paper, numerical solutions of one dimensional coupled KdV equation has been investigated by Haar Wavelet method. Time derivatives given in this equation are discretized by finite differences and nonlinear terms appearing in the equations are linearized by some linearization techniques and space derivatives are discretized by Haar wavelets. For examining the performance of the proposed method, single soliton solution and conserved quantities of some test problems are used. Also, error analysis of numerical scheme is investigated and numerical results are compared with some results already existing in the literature. PubDate: 2017-07-15 DOI: 10.11121/ijocta.01.2017.00396 Issue No:Vol. 7, No. 2 (2017)

Authors:Hatice Yaldız, Mehmet Zeki Sarıkaya, Zoubir Dahmani Pages: 205 - 215 Abstract: In this paper, using Riemann-Liouville integral operators, we establish new fractional in- tegral inequalities of Hermite-Hadamard-Fejer type for co-ordinated convex functions on a rectangle of R^2. The results presented here would provide extensions of those given in earlier works. PubDate: 2017-07-17 DOI: 10.11121/ijocta.01.2017.00405 Issue No:Vol. 7, No. 2 (2017)

Authors:Sümeyra Uçar Pages: 216 - 224 Abstract: In this paper we investigate some properties of generalized Fibonacci and Lucas polynomials. We give some new identities using matrices and Laplace expansion for the generalized Fibonacci and Lucas polynomials. Also, we introduce new families of tridiagonal matrices whose successive determinants generate any subsequence of these polynomials. PubDate: 2017-07-17 DOI: 10.11121/ijocta.01.2017.00398 Issue No:Vol. 7, No. 2 (2017)

Authors:Ali Akgül Pages: 225 - 233 Abstract: Many known methods fail in the attempt to get analytic solutions of Blasius-type equations. In this work, we apply the reproducing kernel method for ivestigating Blasius equations with two different boundary conditions in semi-infinite domains. Convergence analysis of the reproducing kernel method is given. The numerical approximations are presented and compared with some other techniques, Howarth's numerical solution and Runge-Kutta Fehlberg method. PubDate: 2017-07-17 DOI: 10.11121/ijocta.01.2017.00363 Issue No:Vol. 7, No. 2 (2017)