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Conference Object Citation - WoS: 15Citation - Scopus: 17Numerical Modeling of Hydrogen Diffusion in Metals Accounting for Large Deformations(Pergamon-elsevier Science Ltd, 2015) Aslan, OzgurWhile the deleterious effects of hydrogen on metals and alloys are well known, the precise role of hydrogen in the underlying microscopic mechanisms is still not well understood and as of yet, the modeling attempts on hydrogen embrittlement and hydrogen induced cracking have not led to a proper method for life-time prediction. This work aims at the development of a robust numerical strategy in order to solve the non-linear coupled problem presented in the work of Anand [1]. The numerical implementation is performed for finite element method and the analysis are done to address the issue of hydrogen transport and hydrogen-embrittlement-related failures in metals. Specifically, problems related to the mechanism of hydrogen enhanced localized plasticity (HELP) is studied and macroscale shear localization phenomenon resulting from hydrogen induced material softening is considered at the phenomenological level. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Conference Object Citation - Scopus: 28Improvements on Transient Signal Detection for Rf Fingerprinting(Institute of Electrical and Electronics Engineers Inc., 2017) Ali,A.M.; Uzundurukan,E.; Kara,A.The detection of the transient signal plays a significant role in RF fingerprinting for transmitter devices. This paper proposes modifications on two transient signal detection methods, namely, Bayesian change point detection and phase based detection. For initial tests, Bluetooth signals captured in the laboratory are used for performance analysis of the proposed methods. Preliminary results show that the proposed methods can be used in RF fingerprinting of wireless devices. © 2017 IEEE.Conference Object Effects of Chamber Pressure Variation on Pollutant Formation in Cryogenic Combustion(Ieee, 2021) Omair, Muhammad; Akay, Hasan U.Liquid rocket engines have played a major role in enabling the pursuit of space exploration. Cryogenic propellants have simplified the storage in liquid rocket engines with higher densities and lower pressures. One of the main driving forces in today's engine research is the reduction of pollutants while keeping the fuel consumption as low as possible. In this study cryogenic combustion has been simulated using the `Steady Laminar Flamelet' approach. Pollutant concentrations have been evaluated at different chamber pressures. It has been shown that combustion at higher chamber pressures results in less pollutant formation.Conference Object Citation - WoS: 3From Part Design To Part Production - Virtual Hot Forming Engineering Illustrated - Focus Material Modelling(verlag Wissenschaftliche Scripten, 2015) Billur, Eren; Porzner, Harald; Lorenz, D.; Holecek, Martin; Vrojlik, M.; Hoss, M.; Skrikerud, MartinIn a press hardening process, significant efforts are necessary to model material behavior and combinations of material in one part, patch work, and die spotting. In this paper, a focus will be put on accurate modeling of material and process, being able to complete the die and process design in a timely manner A new material model has been developed that allows measuring and modelling material behavior along measurable phase paths. The reward of precise material and process modelling is a realistic determination of the deviation of the formed shape from the nominal part shape, accurate quenching time determination, correct material properties and residual stresses at the end of the process, and significant time savings in the try-out period.Conference Object Citation - Scopus: 3English to Turkish example-based Machine Translation with Synchronous SSTC(Ieee Computer Soc, 2008) Alp, N. Deniz; Turhan, Cigdem; Deniz Alp, N.Example Based Machine Translation (EBMT) is a corpus-based method which is based on using previously translated text. In this project, English to Turkish EBMT system has been developed which uses the Synchronous SSTC for the representation of the sentences in the parallel corpora. This method proves to be effective especially in structurally different languages such as English and Turkish.Conference Object Segmentation of Isolated Words Into Voiced-Unvoiced Sound Components by Kurtosis(Ieee, 2015) Uslu, Baran; Tora, HakanThis study presents a new approach to the segmentation of isolated words into their voiced/unvoiced parts. It is well known that voiced/unvoiced discrimination has an important role in speech synthesis and coding applications. The offered method makes this discrimination using the kurtosis values of the words. The performance of the proposed approach was tested on Turkish digit recordings from zero to nine. It has been observed that this approach segments the parts successfully in not only clean speech but also in noisy speech.Conference Object Citation - Scopus: 9Attitude Control of Quad-Copter Using Deterministic Policy Gradient Algorithms (dpga)(Institute of Electrical and Electronics Engineers Inc., 2019) Ghouri,U.H.; Zafar,M.U.; Bari,S.; Khan,H.; Khan,M.U.In aerial robotics, intelligent control has been a buzz for the past few years. Extensive research efforts can be witnessed to produce control algorithms for stable flight operation of aerial robots using machine learning. Supervised learning has the tendency but training an agent using supervised learning can be a tedious task. Moreover, the data gathering could be expensive and always prone to inaccuracies due to parametric variations and system dynamics. An alternative approach is to ensure the stability of the aerial robots with the help of Deep Re-inforcement Learning (DRL). This paper deals with the intelligent control of quad-copter using deterministic policy gradient algorithms. In this research, state of the art Deep Deterministic Policy Gradient (DDPG) and Distributed Distributional Deep Deterministic Policy Gradient (D4PG) algorithms are employed for attitude control of quad-copter. An open source simulation environment GymFC is used for training of quad-copter. The results for comparative analysis of DDPG D4PG algorithms are also presented, highlighting the attitude control performance. © 2019 IEEE.Conference Object Securing the Internet of Things: Challenges and Complementary Overview of Machine Learning-Based Intrusion Detection(Institute of Electrical and Electronics Engineers Inc., 2024) Isin, L.I.; Dalveren, Y.; Leka, E.; Kara, A.The significant increase in the number of IoT devices has also brought with it various security concerns. The ability of these devices to collect a lot of data, including personal information, is one of the important reasons for these concerns. The integration of machine learning into systems that can detect security vulnerabilities has been presented as an effective solution in the face of these concerns. In this review, it is aimed to examine the machine learning algorithms used in the current studies in the literature for IoT network security. Based on the authors' previous research in physical layer security, this research also aims to investigate the intersecting lines between upper layers of security and physical layer security. To achieve this, the current state of the area is presented. Then, relevant studies are examined to identify the key challenges and research directions as an initial overview within the authors' ongoing project. © 2024 IEEE.Conference Object Citation - Scopus: 1Production of Highly Efficient Photocatalytic Tio2 Powders by Mechanical Ball Milling(ICT Press, 2013) Oztas,T.; Park,J.; Ozturk,A.; Corapci, E.; Aysin, B.Highly efficient photocatalytic TiO2 powders were prepared using a conventional ball mill with various milling times of 0, 12, 24 and 48 h. The photocatalytic activity of the prepared TiO2 powders was evaluated using the decomposition rate obtained by methylene blue (MB) solution and acetic acid gas under UV light irritation. After 24 h milling, the particle size decreased from 555 nm to 122 nm without changing any of the crystal structure. The photocatalytic TiO2 powders prepared by 24 h milling decomposed 94% of the methylene blue solution while the nonmilled TiO2 powders provided only 61% decomposition. After the removal of acetic acid gas, it took 1.5 h for the 24h-milled powders to decompose 100%, while the non-milled TiO2 showed 73% decomposition with same UV illumination duration. © (2013) Trans Tech Publications, Switzerland.Conference Object Design of Low-Cost Modular Rf Front End for Rf Fingerprinting of Bluetooth Signals(Ieee, 2017) Uzundurukan, Emre; Ali, Aysha M.; Kara, AliFor RF fingerprinting of wireless devices, data acquisition has a critical role. Because of this, highly sophisticated devices arc used for data capturing or acquisition. In this paper, design of a RF receiver front end with modular components is presented. This design contains filtering and down conversion processing of Bluetooth signals for cellular phones. Moreover, AWR VSS and MATLAB have been used for simulating the down converter circuit. With this simulation, effects of components that used in the design on recorded signal have been observed. In this work in progress paper, only high SNR conditions are considered.
