WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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Now showing 1 - 10 of 168
  • Conference Object
    Security Through Digital Twin-Based Intrusion Detection: A Swat Dataset Analysis
    (IEEE, 2023-10-18) Bozdal, Mehmet
    Digital twin, as a virtual replica of physical entity, offer valuable insights into Industrial Control System (ICS) behavior and characteristics. Leveraging the convergence of digital twins and cybersecurity, this research explores its role in securing critical infrastructure, using the Secure Water Treatment (SWaT) system as a case study. Existing intrusion detection systems (IDS) for SWaT encounter challenges related to requiring huge amounts of a dataset for training, being unable to adopt high data dimensionality, and adaptability to emerging threats. To address these issues, a hybrid digital twin model is proposed, combining physics-based models and data-driven approaches. This model facilitates precise attack localization and explainable IDS outcomes. The method exhibits promising capabilities for enhancing critical infrastructure security and adapting to evolving cyber threats. Experimental results demonstrate the ability to detect eight out of nine attack types.
  • Book Part
    Citation - WoS: 5
    Citation - Scopus: 5
    Wireless MEMS for Smart Grids
    (Woodhead Publ Ltd, 2017) Tuna, G.; Gungor, V. C.; Dursun, B.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    Using Students' Performance to Improve Ontologies for Intelligent E-Learning System
    (Edam, 2015) Icoz, Kutay; Sanalan, Vehbi A.; Cakar, Mehmet Akif; Ozdemir, Esra Benli; Kaya, Sukru
    Ontologies have often been recommended for E-learning systems, but few efforts have successfully incorporated student data to represent knowledge conceptualizations. Defining key concepts and their relations between each other establishes the backbone of our E-learning system. The system guides an individual student through his/her course by evaluating their progress and suggesting instructional material to review based upon their answers. Three main tasks are performed within this framework: building ontologies for the course, measuring a student's understanding level for the concepts, and making personal suggestions to create an individualized learning environment. This paper presents: the integration of ontologies, assisted with student data, together with an intelligent Recommendation Module for the development of an E-learning system; the comparison and correction adaption of ontology from students' mind maps; and the assessment of students' actual weaknesses in comparison to what Recommendation Module suggests. The sample of 127 students, five classrooms, was conveniently selected among seventh grade students of a demographically average school in a major city in Turkey. The students' achievement was assessed and the scores for different questions were investigated for associations with concepts made in the students' minds. The results provided significant correlations among scores, and a fit model for the concepts represented by questions. The student suggested model slightly differed from the ontology map from the experts. Based on the data-supported model, the Recommendation Module more accurately determined the students' learning deficiencies and suggested concepts to be reviewed.
  • Book Part
    Citation - WoS: 1
    Citation - Scopus: 4
    Understanding Communication via Diffusion: Simulation Design and Intricacies
    (Springer International Publishing AG, 2017) Acar, Bilal; Akkaya, Ali; Genc, Gaye; Yilmaz, H. Birkan; Kuran, M. Sukru; Tugcu, Tuna; Şükrü Kuran, M.
    Understanding Communication via Diffusion (CvD) is key to molecular communications research since it dominates the movement at the nano-scale. The researcher needs to properly understand the random diffusion of the molecules for the analysis of a molecular communication system. This chapter aims explaining the dynamics of diffusion from a communication engineer's perspective as well as providing useful hints for an effective simulation design by discussing some key intricacies. The chapter starts with a brief survey of simulators for molecular communications, followed by the basics of the simulation of Brownian motion and CvD. Several intricacies are addressed to help the researcher in simulation design, such as the number of replications required in terms of movement and bit sequence. We utilize this information further by discussing the design of more complex CvD systems such as tunnel-based approach that utilizes destroyer molecules and distributed simulator design based on HLA. Introduction of more complex CvD systems provides significant improvements in data rate and communications in general, bridging the gap between human-scale and nano-scale systems and enabling nanonetworking as a viable technology.
  • Conference Object
    Twist-Bend Instability of a Cantilever Beam Subjected to an End Load via Homotopy Perturbation Method
    (Amer Inst Physics, 2018) Yucesoy, Ahmet; Coskun, Safa Bozkurt; Atay, Mehmet Tarik; Cesoy, Ahmet
    In this article, twist-bend buckling analysis of a cantilever beam subjected to a concentrated end load is conducted using Homotopy Perturbation Method (HPM). Even in the linear stability analysis, obtaining an exact solution for some cases is not an easy task. However, by the use of HPM this difficulty can be overcome easily. This issue is presented with a case study and the results show that HPM can be used successfully in the analysis of twist-bend buckling of beams.
  • Conference Object
    Turkish English Teachers' Professional Teacher Self as One of the Possible Selves
    (Elsevier Science Bv, 2016-10) Demirezen, Mehmet; Ozonder, Ozgul
    This study reports the results of a study exploring Turkish English teachers' professional self in relation to teacher education. The study also examines the relationship between the participants' educational background, teaching experience and their professional self The study was carried out in Ankara, Turkey. The participants of the study were English language instructors of Hacettepe University, School of Foreign Languages. A total of 43 English instructors (females: 36 and males: 7) voluntarily participated in the study, responding to a questionnaire composed of 40 items regarding teacher professional self. The results of the Professional Self Questionnaire revealed that the rate of Turkish English teachers' professional self was very high (81%, M=4.09). Also, there was a significant difference in participants' professional self depending on their educational background. The results indicated that the participants' professional self did not differ significantly in relation to their teaching experience. (C) 2016 Published by Elsevier Ltd.
  • Conference Object
    Citation - Scopus: 1
    Three-Dimensional Imaging in Degraded Visual Field
    (IOP Publishing Ltd, 2016-04) Oran, A.; Ozharar, S.; Ozdur, I.
    Imaging at degraded visual environments is one of the biggest challenges in today's imaging technologies. Especially military and commercial rotary wing aviation is suffering from impaired visual field in sandy, dusty, marine and snowy environments. For example during landing the rotor churns up the particles and creates dense clouds of highly scattering medium, which limits the vision of the pilot and may result in an uncontrolled landing. The vision in such environments is limited because of the high ratio of scattered photons over the ballistic photons which have the image information. We propose to use optical spatial filtering (OSF) method in order to eliminate the scattered photons and only collect the ballistic photons at the receiver. OSF is widely used in microscopy, to the best of our knowledge this will be the first application of OSF for macroscopic imaging. Our experimental results show that most of the scattered photons are eliminated using the spatial filtering in a highly scattering impaired visual field. The results are compared with a standard broad area photo detector which shows the effectiveness of spatial filtering.
  • Article
    Citation - WoS: 174
    Citation - Scopus: 193
    The Significance of Renewable Energy Use for Economic Output and Environmental Protection: Evidence From the Next 11 Developing Economies
    (Springer Heidelberg, 2017-04-08) Paramati, Sudharshan Reddy; Sinha, Avik; Dogan, Eyup
    Increasing economic activities in developing economies raise demand for energy mainly sourced from conventional sources. The consumption of more conventional energy will have a significant negative impact on the environment. Therefore, attention of policy makers has recently shifted towards the promotion of renewable energy generation and uses across economic activities to ensure low carbon economy. Given the recent scenario, in this paper, we aim to examine the role of renewable energy consumption on the economic output and CO2 emissions of the next fastest developing economies of the world. The study employs several robust panel econometric models by using annual data from 1990 to 2012. Empirical findings confirm the significant long-run association among the variables. Similarly, results show that renewable energy consumption positively contributes to economic output and has an adverse effect on CO2 emissions. Given our findings, we suggest policy makers of those economies to initiate further effective policies to promote more renewable energy generation and uses across economic activities to ensure sustainable economic development.
  • Conference Object
    Citation - WoS: 9
    Citation - Scopus: 10
    The Relationship of Surface Roughness and Wettability of 316L Stainless Steel Implants With Plastic Deformation Mechanisms
    (Elsevier Science Bv, 2019) Cicek, S.; Karaca, A.; Torun, I.; Onses, M. S.; Uzer, B.
    The wettability of the implant plays significant role in successful tissue-implant integration and shows strong dependence on the surface topography of the material. Recent studies showed that the plastic deformation mechanisms can improve cell response, and increase surface roughness and energy. In order to understand the effect of these mechanisms on wettability, 316L stainless steel samples were subjected to tensile test and deformed up to 15% to 35% of strain levels. Atomic force microscopy (AFM) presented approximately 22-fold greater average surface roughness on the 35% deformed sample compared to undeformed one. On the other hand, sessile drop test showed contact angle decrease from 82 degrees to 52 degrees as the deformation increased. This finding is significant since much higher contact angle value at similar surface roughness was presented in the literature. This demonstrates that the plastic deformation mechanisms can play significant role in enhancing the surface wettability without a need for a surface treatment technique. Hence, through the activation of these mechanisms, wettability and surface energy of the implant materials could be further increased which would result with enhanced cell response and lessened post-surgical complications. (C) 2018 Elsevier Ltd. All rights reserved.
  • Article
    Citation - Scopus: 1
    The Restitution Process in Conservation: Discovering the History of Sehit Ali Pasa Library
    (Middle East Technical Univ, 2019-12-31) Gumuslu Akgun, Seda Nehir; Sonmez Pulat, Ece; Bilgili, Bilal; Akgün, Seda Nehir Gümüşlü; Pulat, Ece Sönmez
    Conservation of cultural heritage sites is a multi-phased process including the architectural survey, restitution and restoration. Survey phase begins with the preliminary research and in situ analysis, which are crucial for comprehending the specifications, potentials and architectural characteristic of the site. After architectural survey, restitution is carried out to understand the situation in the first period of the site and how it has undergone a change in the historical process. During the restitution studies, alternatives are prepared for various periods by using the traces on the building and archival documents. At the last stage of the conservation process, which is restoration, the interventions for deterioration, repair proposals and spatial organization are determined according to the new/current use. This study focuses on restitution process of Sehit Ali Pasa Library, which is currently located in the garden of Vefa High School in Kalenderhane Neighbourhood, and consists of four main parts. The first part focuses on general information of the conservation process. In the second part, the historical background, location, spatial organization, construction technique and materials of the building are examined. The restitution or historical analysis process is the main theme of the third part, and all the findings and considerations are evaluated and interpreted in the final part. In this study, all characteristic features and the layers of the cultural heritage are discussed and documented to indicate the importance of architectural survey and restitution interpretation of the conservation process through the Sehit Ali Pasa Library as a multi-layered example. Unfortunately, the findings in the archives or the libraries are limited to propose certain restitution alternatives or precise historical description for this 18th century library, but it is crucial to underline the importance of detailed research process and methodology, architectural survey to prepare a scientific, reasonable, and consistent historical analyses of cultural heritage such as Sehit Ali Pasa Library as a multi-layered and complex building.