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  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 6
    A Reinforcement Learning Algorithm for Data Collection in Uav-Aided Iot Networks With Uncertain Time Windows
    (Ieee, 2021) Cicek, Cihan Tugrul
    Unmanned aerial vehicles (UAVs) have been considered as an efficient solution to collect data from ground sensor nodes in Internet-of-Things (IoT) networks due to their several advantages such as flexibility, quick deployment and maneuverability. Studies on this subject have been mainly focused on problems where limited UAV battery is introduced as a tight constraint that shortens the mission time in the models, which significantly undervalues the UAV potential. Moreover, the sensors in the network are typically assumed to have deterministic working times during which the data is uploaded. In this study, we revisit the UAV trajectory planning problem with a different approach and revise the battery constraint by allowing UAVs to swap their batteries at fixed stations and continue their data collection task, hence, the planning horizon can be extended. In particular, we develop a discrete time Markov process (DTMP) in which the UAV trajectory and battery swapping times are jointly determined to minimize the total data loss in the network, where the sensors have uncertain time windows for uploading. Due to the so-called curse-of-dimensionality, we propose a reinforcement learning (RL) algorithm in which the UAV is trained as an agent to explore the network. The computational study shows that our proposed algorithm outperforms two benchmark approaches and achieves significant reduction in data loss.
  • Conference Object
    Citation - Scopus: 4
    Convolution Neural Network (cnn) Based Automatic Sorting of Cherries
    (Institute of Electrical and Electronics Engineers Inc., 2021) Park,H.; Khan,M.U.
    Cherries are spring fruits enriched with nutrients, and are easily available in food markets around the world. Due to their excess demand, many enterprises solely focused on their processing. Cherries are especially susceptible to pathological-, physiological-diseases and structural degradation due to their soft outer skin. The post-harvest life of the fruit is limited by various characteristics. The agricultural industry has also been at the forefront to get benefits from the advanced machine learning tools. This study presents an image processing-based system for sorting cherries using the convolutional neural network (CNN). For this study, Prunus avium L cherries of export quality, available in Turkey, tagged as ‘0900 Ziraat’, are used. Surprisingly, there exists no dataset for these cherries; hence, we developed our dataset. Through the proposed approach based upon U-Net, the binary classification accuracy of 99% is achieved. Clear identification is demonstrated by the test results of varying mixture ratios of good and bad cherries. It can therefore be said that for cherry sorting and grading, U-Net can be applied as a reliable and promising machine learning tool. ©2021 IEEE
  • Conference Object
    Analysis of Force-Indentation Measurements on Anisotropic Metals
    (Edizioni libreria progetto, 2005) Koray,E.; Topcu,N.; Tekkaya,A.E.
    Indentation tests are widely used with simultaneous measurements of indentation depth and force especially for determining material properties. In this study, findings on parameters affecting the force-displacement curves obtained from indentations on anisotropic metals using special not self-similar indenters will be presented. Parameters such as specimen dimensions, friction, surface roughness, specimen clamping and indentation spacing have been investigated by finite element analysis and by experiments. Optimum values of these parameters to achieve higher repeatability and accuracy are determined.
  • Conference Object
    Citation - WoS: 6
    Personality and Individual Differences: Literature in Psychology-Psychology in Literature
    (Elsevier Science Bv, 2015) Aras, Goksen
    Literature, which intertwines within such fields as history, philosophy, sociology, psychology and so on, is a discipline wherein language is used as a medium of expression so as to interpret man, existence and culture. The objective of this paper is to discuss literature in terms of its interdisciplinary structure, psychology, in particular, considering man and existence, personality and individual differences which have always been studied by writers, philosophers, artists, psychologists and psychiatrists. Several complex notions, unfathomable personalities and ambiguous motives have been associated with characters in literary genres: For example the term Bovarism is explained by means of Flaubert's Madame Bovary. Similar examples in literary works could be multiplied. Man and existence have been fundamental themes in literature, which has existed even before psychology. Works of literature and art enable individuals to be aware of their personalities and individual differences and to question life and existence, the main data in the field of psychology as well. It is overtly seen that there is a very strong correlation between literature and psychology since both of them deal with human beings and their reactions, miseries, desires, and their individual and social concerns by means of different concepts, methods, and approaches. (C) 2015 The Authors. Published by Elsevier Ltd.
  • Conference Object
    Citation - Scopus: 3
    A hybrid intuitionistic MCDM model for supplier selection
    (2013) Rouyendegh,B.D.
    This paper gives an overview of the Analytic Hierarchy Process (AHP) and Intuitionistic Fuzzy TOPSIS (IFT) methods. This study deals an evaluation methodology based on the AHP-IFT where the uncertainty is handeled with linguistic values. First, the supplier selection problem is formulated by AHP is used to determine weights of the criteria. In the second stage, IFT used to obtain full ranking among alternatives based on opinion of the Decision Makers (DMs). The present model provides an accurate and easy classification in supplier attributes by that have been prioritized in the hybrid model. A numerical example is given to clarify the main developed result in this paper.
  • Conference Object
    Design and Optimization of a Notional Scramjet by Means of Stream Thrust Analysis and Design of Experiments
    (American Institute of Aeronautics and Astronautics Inc., 2014) Akpolat,M.T.; Toker,K.A.; Genç,M.S.
    Within the scope of this study, a 0-dimensional code is developed by using Stream Thrust Analysis in order to evaluate scramjet cycle performance with respect to selected performance parameters (specific impulse, overall efficiency) and combustion chamber exit temperature. By using the results of this code an analysis employing "Design of Experiments" (DoE) is performed to determine the most effective input parameters and/or interactions on the scramjet performance. The results showed that most effective input parameter for all of the selected parameters is fuel/air ratio. Selected parameters are evaluated first individually then simultaneously. The purpose of evaluating the performance parameters simultaneously is to determine the input parameter set which gives the highest values of specific impulse and overall efficiency while giving the lowest value of combustion chamber exit temperature. As a result the input parameter sets for different cases are determined.
  • Conference Object
    Citation - WoS: 1
    A Cognitive Evaluation for Meetings in Software Development Process
    (Springer-verlag Berlin, 2009) Misra, Sanjay; Akman, Ibrahim
    Software development; includes number of different type of meetings in the whole development process. The cognitive activities also play an important role in decision making activities in these meetings since they are carried out, by human being. In this paper, we evaluated the relevance of meetings in different phases of the software development process with reference to cognitive aspects.
  • Conference Object
    Microstrip Antennas For WiMAX Applications
    (Ieee, 2015) Demirci, Tugkan; Caliskan, Fatma; Aydin, Elif
    In this paper, four different antenna types have been designed to be used for WiMAX applications. These antennas have been designed using HFSS simulation software. This paper has included the return loss and the radiation pattern of the designed antennas. Using the simulation results, it is shown that these four antennas are working on Wi-Fi and WiMAX frequency ranges.
  • Conference Object
    Comparative Analysis Of Patch Antennas With Rectangular Slots For Laminate And Wearable Materials At 5g Networks
    (Institute of Electrical and Electronics Engineers Inc., 2024) Hakanoglu, B.G.; Agaya, E.; Gulmez, G.; Yalinsu, S.
    In this study, new multi-band patch antenna design models are proposed for use in 5G networks. The purpose of the designs is to open rectangular slots on rectangular shaped patch antennas and bring them to the desired operating conditions with parametric analyzes. The designs were carried out by following the same procedure steps using five different dielectric laminate substrate materials, such as RO3003, RT6006, FR4, RO3203, RO6010, and one denim fabric base material. The antennas were compared in terms of return loss, gain and radiation characteristics. Except for the antenna designed with RO3203 at certain values of rectangular slots, radiation at multiple frequencies was obtained at 5G frequencies. With the proposed method, improvement was observed for return loss and bandwidth characteristics in the RO3203 based antenna. This study will be a resource for antenna researchers by revealing the responses of different substrate materials to the same design method for 5G bands in patch antennas. © 2024 IEEE.
  • Conference Object
    Citation - Scopus: 2
    Miniaturized 2.4 Ghz Antenna Design for Uav Communication Link;
    (Institute of Electrical and Electronics Engineers Inc., 2020) Yilmaz,V.S.; Kara,A.; Aydin,E.
    In many communications applications, unlike conventional antennas, lightweight, flexible, small antennas that can adapt to mechanical and industrial constraints are required. In this study, the results of antenna design operating at 2.4 GHz are presented for use in Unmanned Aerial Vehicle (UAV) tele command links. In the parametric and optimization studies carried out on the antenna, it is aimed to increase the gain while keeping the size as small as possible. The requirements of the industry, such as light, aesthetics, miniature and high gain aspects of the antenna were targeted in the design process. Finally, an antenna of 55.2x88 mm size and 7dB gain was achieved using commercial electromagnetic design tools. The designed antenna become satisfying industrial requirements with these features. © 2020 IEEE.