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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.Article Citation - Scopus: 2Health Monitoring of a Benchmark Structure Using Vibration Data(2012) Gunes,B.Aging and deterioration of existing structures and the need for rapid assessment and evaluation of these structures for hazard mitigation has significantly expanded the research efforts in the field of structural health monitoring (SHM). SHM involves monitoring of a structure using periodically sampled measurements, extraction of damage sensitive features from these measurements, and assessment of the current health state/integrity of the system. The approach known as the Damage Locating Vector (DLV) technique is an SHM tool that interrogates changes in the flexibilities synthesized at sensor locations using the vibration data with respect to the location of damage. This paper presents the damage identification results of the Phase II Experimental Benchmark Structure of the IASC-ASCE Task Group on Structural Health Monitoring. © RILEM 2013.Article Potential Localization Strategies and Strategic Instruments in Nuclear Power Generation(Pergamon-Elsevier Science Ltd, 2026) Ege, AhmetDeploying the right strategies is of paramount importance and plays a key role in technology transfer to achieve localization. Today, around 30 countries are considering or embarking on nuclear power programs. What are the potential strategies for nuclear power technology localization? This study attempts to identify localization strategies in nuclear technology and also to unfold tested approaches, business models, strategic legal and technical instruments. The methodology of the study treats the nuclear industry in a state as a "unit" in which a variation of PEST analysis is implemented to reveal macro-environmental factors followed by SWOT analysis to identify strengths, weaknesses, opportunities and threats of available approaches, business models, legal and technical instruments. Four principal strategies emerge: (1) learning by doing; (2) transfer, adopt, assimilate, develop and export; (3) own or operate with limited transfer; and (4) wait and see. The first two strategies are proposed for the countries willing to launch an ambitious nuclear power program. Own or operate with limited transfer strategy can be deployed in those countries prioritizing security of supply, source of reliable base load generation, general economic development, technological and qualified human resources development. Wait and see strategy is convenient for those countries awaiting progress of new technologies or phased out nuclear power but planning to reintroduce it in the future. Regardless of the strategy selected, wise guiding policies and coherent set of actions must be deployed for a successful assimilation and acquisition of the design,Article Citation - WoS: 7Citation - Scopus: 10Autonomous Navigation of Robotic Units in Mobile Sensor Network(Elsevier Sci Ltd, 2012) Nazlibilek, SedatThis work is motivated by the problem of detecting buried anti-tank and anti-personnel mines in roads or some border regions. The problem is tried to be solved by use of small mobile robotic sensors and their some abilities such as measurement of local fields, navigation around a region, communications with each other, and constituting team within a mission area. The aim of this work is to investigate the navigation problem for the team behavior of mobile sensors within a potential field available in a small-scale environment such as an indoor area or an outdoor region. The mobile sensor network here is a collection of robotic units with sensing capability of earth magnetic field anomalies. A new kind of positioning system is needed for their collective behavior. In this work, a new method of navigation is proposed as a local positioning system. It utilizes ultrasound and radio frequency information to determine the coordinates of the points inside the operational area. The method proposed here is compared with the ultra wideband ranging ping-pong method that is used widely in recent applications. A time division multiple access method is used for the communications among the mobile sensors. The results on the positioning methods together with several simulations and experimental works are given. It is shown that the positioning method utilizing ultrasound-radio frequency method can give fairly good results. (C) 2012 Elsevier Ltd. All rights reserved.Conference Object Citation - WoS: 3Citation - Scopus: 4Comparative Analysis of Tdoa-Based Localization Methods in the Presence of Sensor Position Errors(Institute of Electrical and Electronics Engineers Inc., 2017) Dalveren,Y.; Kara,A.It is widely known that localization of emitters can be efficiently achieved by time difference of arrival (TDOA) techniques in a multiple sensor system. Several studies have been proposed in the literature to improve the localization accuracy of TDOA techniques. Among these, very few of them have considered the error in the sensor positions although the accuracy of localization is very sensitive to sensor position errors. In this study, existing TDOA-based localization methods in the presence of sensor position errors are briefly discussed, and then they are comparatively analyzed for specific scenarios. To this end, simulations are performed to compare the localization accuracy of the methods, specifically, with high level of sensor positional errors. It is intended to decide an efficient and robust estimator to be used for an ongoing research on passive localization of radar emitters in dense scattering environments. © 2017 IEEE.
