Person: ÜLKÜ, İLAYDA
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Dr. Öğr. Üyesi
Last Name
ÜLKÜ
First Name
İLAYDA
Name
8 results
Search Results
Now showing 1 - 8 of 8
Publication Metadata only Optimization of Multi-token circulation with master UAV method in multi-UAV systems for location information sharing(2019) Ülkü, Eyüp Emre; ÜLKÜ, İLAYDAIn order to perform smooth and coordinated flights in multi-UAV systems, UAVs (Unmanned Aerial Vehicle) need to know each other's location information. Multi-token circulation method allows UAVs to learn each other's location information in the Flying Ad Hoc Network (FANET) quickly and this information can be updated continuously. In the multi-token circulation method, it is very important to determine how many tokens are used and how these tokens circulate in the FANET depending on the number and deployment of the UAVs. In this paper, we developed a master UAV method to determine number of tokens and circulation of these tokens.Publication Metadata only Optimization of Offshore Windfarm Cable Layouts(2018-06) Alabaş Uslu, Çiğdem; ÜLKÜ, İLAYDA; 51700; 126061As renewable energy arises to be an alternative energy source around the world, installation of the wind farms increases in the areas where the wind potential is efficient. One of the design problems in the installation of wind farms is determination of cable connections between turbines and transmitter(s) to provide the flow of generated energy from each turbine to the transmitter(s) through one or more routes. While layout of turbines should minimize wake losses to provide maximum of energy production, layout of cables should provide gathering of total energy at one or more transmitters minimizing total cost of cables. The present study takes layout of a set of turbines and a single transmitter as input data and addresses the optimization of cable layout problem to minimize of total cost of cables which can be different in types and capacities. The problem is modeled as a mixed integer linear program and optimal solutions or feasible solutions are obtained to a set of test instances using the proposed model. Experiments show that the instances can be optimized up to 20 turbines and feasible solutions are available for the larger problems.Publication Metadata only A Holistic Approach For The Optimization of Offshore Wind Farm Layouts Considering Cable Layouts(2019-08) Alabaş Uslu, Çiğdem; ÜLKÜ, İLAYDA; 51700A wind farm, mainly, is composed of a set of turbines, one or more transmitters and a set of electrical cable connections between turbines and transmitters. Determination of turbine locations within the farm to maximize total power generation is called turbine location (TL) problem. Relative turbine positions affect the amount of overall energy because of wake effects. Determination of cable connections among turbines and transmitters to collect produced energy by turbines at transmitters is called cable layout (CL) problem. While TL problem is directly effective on the total energy production in the farm, CL problem indirectly affects the total energy due to the power losses. In the literature, TL and CL problems are solved sequentially where the layout found by solving of TL is used as an input of CL problem. To minimize wake effects in TL problem, distances between turbine pairs should be increased, however, as the distances are increased the cable cost increases in CL problem. A new mathematical model is developed to deal with simultaneously solving of TL and CL problems. A set of test instances are used to show the performance of the proposed model. The experiments show the practical use of the proposed holistic model.Publication Metadata only Rüzgar Türbinlerinin Yerleşim Problemi için Yeni Bir Matematiksel Model(2018-06) ÜLKÜ, İLAYDA; 51700Enerji talebindeki hızlı artışla birlikte, yenilenebilir enerji dünya çapında alternatif bir enerji kaynağı olarak görülmektedir. Rüzgâr enerji santralleri, rüzgâr potansiyelinin en verimli olduğu bölgelere yerleştirilmektedir. Bir rüzgar türbini rüzgardan elde edilen kinetik enerjiyi mekanik enerjiye ve daha sonra elektrik enerjisine çevirir. Bu süreç, aynı zamanda, türbinin arkasında hava akımının değiştiği “gölge" adı verilen bir bölge oluşturur. Bu bölgede rüzgar hızı azalır ve hava akımı girdaba dönüşür. Gölge bölgesine yerleştirilmiş başka türbinler varsa, bu türbinlerin kullandığı rüzgar hızı azaldığı için enerji üretim miktarları da azalmaktadır. Dolayısıyla, rüzgar türbinlerinin birbirlerine göre nasıl konumlandırılacağı “rüzgar türbinlerinin yerleşim CRTYJ problemi” ortaya çıkmaktadır. Gölgelenme etkisi, rüzgâr enerji santrallerinde yıllık enerji üretimini önemli ölçüde etkilemektedir. Bu çalışmada, rüzgar türbini gölgelenme etkisini en aza indirerek enerji üretim miktarını en yüksek seviyeye çıkaracak şekilde RTY problemi ele alınmaktadır. Bu problemde, yerleştirilecek türbin sayısının önceden belirlendiği kabul edilmekte ve gölge etkilerinin hesaplanmasında Jensen modeli kullanılmaktadır. Sunulan çalışmada yeni bir doğrusal olmayan matematiksel model geliştirilmiş ve literatürde raporlanmış olan yöntemlerle bir karşılaştırma yapılmıştır. Karşılaştırma amacıyla, rüzgarın sabit olduğu ve 36 farklı yönden estiği rüzgar senaryosu ve rüzgarın farklı hızlarda ve farklı yönlerden esme olasılıklarının söz konusu olduğu rüzgar senaryosu dikkate alınmıştır.Publication Metadata only Wind farm layout optimization to maximize total power production(2018-05) Alabaş Uslu, Çiğdem; ÜLKÜ, İLAYDA; 51700; 126061With the rapid increase in energy demand, renewable energy has been considered as an alternative energy resource around the world. A new nonlinear mathematical model is developed in the presented study and a comparison is obtained with a mathematical modelling study from the literature. The results superior according to power generation under a single wind direction. Jensen’s wake decay model is used to state multiple wake effect among the turbines. The power production is maximized in terms of the minimization of wake effects. Mathematical formulations are represented and compared with the model from the literature. The generated layouts are presented and expected power among the Introduction turbines are significantly improved.Publication Metadata only A new mathematicalpProgramming aapproach to wind farm layout problem under multiple wake effects(2019) Alabaş Uslu, Çiğdem; ÜLKÜ, İLAYDA; 51700; 126061Wind farm layout optimization is one of the challenging problems in thefield of renewable energy. In thepresent study, a new nonlinear mathematical model for layout of wind turbines under multiple wakeeffects is proposed considering two objective functions separately: maximization of total power pro-duction and minimization of cost per power. To incorporate multiple wake effects into the proposedmodel, Jensen's wake decay model is employed. It was proven that the proposed model has totallyunimodularity property and according to this property, relaxation of binary decision variables relatedwith the wind turbine locations makes the model relatively simple to solve. Computational study revealsthat results of total power production and cost of power obtained from the proposed model outperformthat of the previous studies in the literature on a set of example cases and therefore, can be used to layoutmore productive wind farms.Publication Embargo An Analytical Approach to Automotive Industry(2015) Bulkan, Serol; YÜKSEKTEPE, FADİME ÜNEY; ÜLKÜ, İLAYDA; 51700; 172541; 108243Inventory control helps to manage or locate materials and any information through the processes in the company. The aim of the inventory management in the companies is to optimize inventory control. Especially, for the manufacturing companies, inventory control has an important goal which satisfies the product to the customer on time. Therefore, the system in the production processes should not have any trouble during the production. This study aims to optimize the production system of a two stage production processes where the bumpers are produced for different type of cars and different colors due to the model of the car. In the first stage there are three injection machines which are parallel, and in the second stage, there is a dying station. A mixedinteger linear programming model is proposed to optimize the production process. With the proposed model, the production of the injection processes is optimized and the lot sizes for each stage are determined. Also, front and back bumpers for each same model is dyed concurrently which prevents the color difference for the same model of each type of car.Publication Embargo Wind Farm Layout Optimization to Maximize Total Power Production(E3S Web of Conferences, 2018) Alabaş Uslu, Çiğdem; ÜLKÜ, İLAYDA; 51700; 126061With the rapid increase in energy demand, renewable energy has been considered as an alternative energy resource around the world. A new nonlinear mathematical model is developed in the presented study and a comparison is obtained with a mathematical modelling study from the literature. The results superior according to power generation under a single wind direction. Jensen’s wake decay model is used to state multiple wake effect among the turbines. The power production is maximized in terms of the minimization of wake effects. Mathematical formulations are represented and compared with the model from the literature. The generated layouts are presented and expected power among the Introduction turbines are significantly improved.