Browsing by Author "Akin, A."

Now showing 1 - 4 of 4

Discrete Design Optimization of Space Steel Frames Using the Adaptive Firefly Algorithm
(Civil-Comp Press, 2012) Aydoǧdu, I̊.; Akin, A.; Saka, M.P.
Optimum design of steel frames is a complicated process because the designer has to consider a large number of nonlinear constraints which are imposed by steel design codes while also dealing with discrete design variables. Obtaining the optimum solution to discrete programming problems was never easy until the emergence of metaheuristic techniques. The firefly algorithm, one of the recent metaheuristic techniques that is based on the idealized behaviour of the flashing characteristics of fireflies. In this paper, the optimum design problem of steel space frames is formulated according to the provisions of LRFD-AISC (Load and Resistance Factor Design) [1]. The firefly optimization technique is used to obtain the solution to the design problem. A number of space frames is designed using the firefly algorithm developed in order to test the performance of the firefly algorithm for structural design problem. © Civil-Comp Press, 2012.
Land Use/Cover Change Modelling in a Mediterranean Rural Landscape Using Multi-Layer Perceptron and Markov Chain (mlp-Mc)
(Aloki Applied Ecological Research and Forensic inst Ltd, 2018) Mirici, M. E.; Berberoglu, S.; Akin, A.; Satir, O.
Mediterranean land use and land cover (LULC) have a very dynamic structure as a result of continuous transformation process due to anthropogenic effects and environmental gradients. LULC dynamics are important indicator of environmental condition in temporal and spatial scales. The aim of this paper was to simulate the future LULC of a Mediterranean type watershed located at the Eastern Mediterranean Region of Turkey by incorporating multi-layer perceptron (MLP), artificial neural network (ANN) and Markov chain (MC) approaches. Landsat TM/OLI images in 1990, 2003 and 2014 over the study area were classified using hybrid classification approach. The Kappa statistics of the hybrid classification that combines K-means, decision tree and object based classification method for these three images were 0.81, 0.85 and 0.87 respectively. The LULC map of 2014 was simulated using LULC maps of 1990 and 2003 for calibration and validation. The simulation results were compared with the actual 2014 LULC map to assess the accuracy of the simulation, and the rate of overlap was found as 89%. LULC map of 2025 was estimated using LULC maps of 2003 and 2014. These results indicated that, the area of bareground will reduce 13.31% whereas the rate of forest and agricultural area will increase 8.70% and 6.51% respectively.
The Mutagenic Effects of Sodium Nitrite and Monosodium Glutamate Used as Food Additives Demonstrated by the Salmonella Microsome Test System
(1991) Akin, A.; Sümer, S.
In this study, the mutagenicity of sodium nitrite (an antimicrobial agent) and monosodium glutamate (a flavoring agent), which are widely used as food additives, have been evaluated. They were tested for mutagenicity in the Salmonella/microsome test system by employing plate-incorporation test in the absence and presence of rat-liver fraction, S 9. No mutagenic activity was seen for monosodium glutamate in the Salmonella/microsome test system by using the tester strains Salmonella typhimurium TA98, TA100, TA1535 and TA1538. Sodium nitrite was found mutagenic on S. typhimurium TA1535, whereas it was found weakly mutagenic on S. typhimurium TA100, in the presence and absence of rat-liver fraction, S 9.
Optimum Detailing Design of Reinforced Concrete Plane Frames To Aci 318-05 Using the Harmony Search Algorithm
(Civil-Comp Press, 2012) Akin, A.; Saka, M.P.
This paper presents the application of the harmony search based algorithm to the optimum detailed design of special seismic moment reinforced concrete (RC) frames under earthquake loads based on American Standard specifications. The objective function is selected as the total cost of the frame which includes the cost of concrete, formwork and reinforcing steel for individual members of the frame. The modular sizes of members, standard reinforcement bar diameters, spacing requirements of reinforcing bars, architectural requirements and other practical requirements in addition to relevant provisions are considered to obtain directly constructible designs without any further modifications. For the RC columns, predetermined section database is constructed and arranged in the order of resisting capacity. The produced optimum design satisfies the strength, ductility, serviceability and other constraints related to good design and stated in the relevant specifications. The lateral seismic forces are calculated according to ASCE 7-05 and it is updated in each iteration. Number of design examples is considered to demonstrate the efficiency of the optimum design algorithm proposed. It is concluded that the developed optimum design model can be used in design offices for practical designs and this study is the first application of the harmony search method to the optimization of RC frames and also the optimization of special seismic moment RC frames to date. © Civil-Comp Press, 2012.