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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14411/19

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4D Printing of Reusable Mechanical Metamaterial Energy Absorber, Experimental and Numerical Investigation
(Iop Publishing Ltd, 2025) Fallah, Ali; Saleem, Qandeel; Scalet, Giulia; Koc, Bahattin
This study investigates the compression behavior, energy absorption, shape memory properties, and reusability of 4D-printed smart mechanical metamaterials. Four structural configurations, i.e. honeycomb, re-entrant, and two modified re-entrant designs were developed to assess microstructure effects. Samples were fabricated using Polylactic Acid (PLA), a widely used shape memory polymer (SMP) in 4D printing, and polyethylene terephthalate glycol (PETG), an emerging SMP with demonstrated shape memory performance in recent studies. Cold-programming-induced shape recovery was evaluated at room temperature, simulating real-world conditions. Finite element simulations of compression and shape memory cycles matched experimental results well. Auxetic samples with negative Poisson's ratios showed superior energy absorption. However, only PETG demonstrated sufficient reusability, while PLA proved unsuitable for reusable designs. The PETG-3 modified re-entrant structure exhibited the best performance, with high energy absorption, delayed densification onset, and shape recovery and reusability factors of 0.95 and 0.96, respectively. Findings highlight the importance of considering both shape recovery and reusability when designing smart structures to address industrial challenges.
Citation - Scopus: 3
Achieving Business Benefits From ERP Systems
(IGI Global, 2010) Mishra, Alok; Software Engineering
Enterprise resource planning (ERP) systems are becoming popular in medium and large-scale organizations all over the world. As companies have to collaborate across borders, languages, cultures, and integrate business processes, ERPs will need to take globalization into account, be based on a global architecture, and support the features required to bring all the worldwide players and processes together. Due to the high cost of implementation for these systems, organizations all over the world are interested in evaluating their benefits in the short and long terms. This chapter discusses various kinds of business benefits in a comprehensive way in order to justify the acquisition and implementation of ERP systems in organizations in the present global context. © 2025 Elsevier B.V., All rights reserved.
Afthd: Bayesian Accelerated Failure Time Model for High-Dimensional Time-To Data
(Springernature, 2025) Kumari, Pragya; Bhattacharjee, Atanu; Vishwakarma, Gajendra K.; Tank, Fatih
Analyzing high-dimensional (HD) data with time-to-event outcomes poses a formidable challenge. The accelerated failure time (AFT) model, an alternative to the Cox proportional hazard model in survival analysis, lacks sufficient R packages for HD time-to-event data under the Bayesian paradigm. To address this gap, we develop the R package afthd. This tool facilitates advanced AFT modeling, offering Bayesian analysis for univariate and multivariable scenarios. This work includes diagnostic plots and an open-source R code for working with HD data, extending the conventional AFT model to the Bayesian framework of log-normal, Weibull, and log-logistic AFT models. The methodology is rigorously validated through simulation techniques, yielding consistent results across parametric AFT models. The application part is also performed on two different real HD liver cancer datasets, which reveals the proposed method's significance by obtaining inferences for survival estimates for the disease. Our developed package afthd is competent in working with HD time-to-event data using the conventional AFT model along with the Bayesian paradigm. Other aspects, like missing values in covariates within HD data and competing risk analysis, are also covered in this article.
AI Trustworthiness and Student Pilots: Exploring Attitudes, Anxieties, and Adaptation Performance
(Elsevier B.V., 2025) Ceken, S.; Yilmaz, A.A.; Acar, A.B.
This research explores the attitudes of student pilots toward artificial intelligence (AI) applications within the aviation sector, with a focus on their adaptation processes and potential challenges. The recent release of the "EASA AI Roadmap 2.0"by the European Union Aviation Safety Agency (EASA) underscores the growing impact of AI on aviation, driving the emergence of new business models and emphasizing a human-centric approach to AI integration within the aviation industry. This study addresses a significant gap in the literature by examining student pilots' perspectives on AI, specifically focusing on AI trustworthiness, attitudes, anxieties, and adaptation performance. The study utilizes a quantitative research approach, collecting data from 150 student pilots through surveys. Preliminary results from 106 respondents indicate varied attitudes toward AI, with significant implications for AI-supported cockpit assistant systems and the broader aviation industry. The study sample consisted of 106 (Mage = 23.6, SDage= 4.64; 79% male) student pilots from of university pilot training departments and various flight school in Turkey. Collected data were analyzed on SPSS 29. The study revealed that Sociotechnical Blindness AI anxiety is a significant predictor of general attitudes toward AI among student pilots. This finding suggests that higher levels of anxiety related to the perceived complexity and potential unintended consequences of AI are associated with more positive general attitudes toward AI. The findings emphasize the need for a human-centric approach to AI integration, highlighting the importance of trust, transparency, and adaptive training in the successful adoption of AI technologies in aviation. © 2024 The Authors. Published by ELSEVIER B.V.
Analytic Hierarchy Process in Determining Aircraft Basic Maintenance Training Durations
(Emerald Publishing, 2025) Açıkel, Gürkan; Alemdaroğlu Temel, Mine; Pilot Training; Airframe and Powerplant Maintenance
Purpose – Currently, in aircraft basic maintenance training, it is determined that various aircraft basic maintenance training organizations around the world apply different basic maintenance durations for the same modules of the same licence categories. Aircraft basic maintenance training organizations are lacking a common curriculum with standard durations for the basic maintenance training modules. To remedy the problems associated with this issue, the purpose of this study is to develop and demonstrate a quantifiable reference (i.e. theoretical training and evaluation content intensity) based scientific theoretical method to determine the durations of the basic theoretical maintenance trainings held for B1.1 and B2 licence categories in aircraft basic maintenance training organizations. Design/methodology/approach – The total basic maintenance training duration was first allocated to basic, theoretical and practical maintenance trainings. The obtained basic theoretical maintenance training duration was then allocated to related modules and submodules by using weighted theoretical training content intensity and weighted theoretical evaluation content intensity, which were obtained by applying a multi-criteria decision-making approach using the analytic hierarchy process (AHP). Findings – In this study, it was found that there is no standardization upon aircraft basic maintenance training organizations for the allocation of the basic maintenance training durations to modules. To remedy this problem, a scientific method, which relies on quantifiable reference bases rather than subjective reasoning, is needed. The reference bases of the proposed theoretical method (i.e. theoretical training and evaluation content intensity) can be tuned with the inclusion of the effect of basic knowledge requirements through multi-criteria decision-making (AHP). The theoretical method proposed in this work is robust in terms of resulting in close proximity values of the basic theoretical maintenance training durations for the common modules of B1.1 and B2 licence categories. The theoretical method is proven to yield greater basic theoretical maintenance training durations for modules having greater theoretical training and evaluation content intensity and lower basic theoretical maintenance training durations for modules having less theoretical training and evaluation content intensity. A distinct similarity in terms of basic theoretical maintenance training durations and the ranking of the modules (in terms of durations) is not present when the average of the training organizations is compared to the results of the theoretical method. A quantifiable reference (i.e. theoretical training and evaluation content intensity) based scientific theoretical method to determine basic theoretical maintenance training durations was developed and demonstrated. Practical implications – Results of this study would especially be useful in an international effort to standardize the different basic theoretical maintenance training durations applied in various aircraft basic maintenance training organizations. Originality/value – To the best of the authors’ knowledge, this study is the first in providing and demonstrating a scientific theoretical method based on a systematic, multi-criteria decision-making approach to determine the durations of the basic theoretical maintenance trainings. © 2025 Elsevier B.V., All rights reserved.
Barriers To Bim Implementation in Sustainable Building Projects in Türkiye
(East Carolina University, 2024) Aksoy, I.; Akcay, E.C.
As the construction industry is a major contributor to greenhouse gas emissions, sustainable building projects play a vital role in mitigating its harmful environmental impact. Building energy analysis is particularly important for sustainable projects. Building Information Modeling (BIM), which enables comprehensive data management and analysis throughout the building lifecycle, has emerged as an indispensable tool at every stage of sustainable building projects. This study aims to investigate the barriers hindering the implementation of BIM in sustainable building projects in Türkiye. For this purpose, potential barriers were initially identified through literature searches in databases such as Scopus and Web of Science. Following the literature review, a structured questionnaire was designed to evaluate the significance of 18 identified barriers on the use of BIM technology in green buildings. The results indicate that significant impediments include financial barriers such as high licensing costs, the high costs of BIM experts, and high training costs. The findings highlight the critical need for support mechanisms to facilitate the broader adoption of BIM in sustainable construction practices. © 2024 International Conference on Construction in the 21st Century. All rights reserved.
Basin Evolution in the Gulf of Çandarlı Through Seismic Mapping, Aegean Sea, Offshore Türkiye
(Springer Nature, 2025) Kılıç, B.O.; Uluğ, A.; Aydemir, A.
Early Miocene lacustrine deposits possessing source rock and reservoir properties are characterised by seismic mapping in the Foça-Çandarlı Basin of the Turkish sector of the Aegean Sea. A similar petroleum system has also been recognised in the adjacent onshore Gediz and Bakırçay grabens. In this study, 800 km of seismic data acquired in 1975 and 1985 have been interpreted. Miocene and Pliocene horizons were mapped, and possible hydrocarbon traps were identified. In this context, the tectonic evolution of the Foça-Çandarlı Basin has been determined. The Foça-Çandarlı Basin opened under NE and SE extension during the Late Oligocene to Early Miocene. The tectonic regime shifted to a transpressional state due to the westward tectonic escape of Anatolia during its collision with the Aegean Block. As a consequence of this tectonic reversal, we observe a clockwise rotation in the compressional deformation along the southern margin of the basin. In contrast, the change may have involved a counterclockwise rotation in the north since the end of the Early Miocene. Faults at the basin boundaries were inverted, and the basin began to close from the west during the Mid-Late Miocene and Pliocene. The seismic mapping accurately demonstrates all these changes. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.
Boundary-Element Method in Microfluidics
(Springer Science+Business Media, 2015) Çetin, Barbaros; Baranoğlu, Besim; Manufacturing Engineering
Citation - Scopus: 5
Challenges of using software size in agile software development: A systematic literature review
(CEUR-WS, 2018) Hacaloglu,T.; Demirors,O.; Information Systems Engineering
Software size is a fundamental measure for software management. Size is used for a variety of purposes, such as benchmarking, normalization, and portfolio measurement, and it is frequently considered as the sole input of estimation. Estimations can be produced for various reasons; e.g., to predict effort, cost and duration of software development projects. There are different types of software size measures. Particularly in projects where agile methodologies are adopted, measurement becomes a significant challenge as it is perceived as a non-value-added task and records of tasks such as requirements identification are not always consistent. The difficulties of applying traditional size measurement techniques in agile contexts, however, do not diminish the need, and new methods and techniques are introduced to improve the manageability of the agile projects. In this paper, we discuss estimation and measurement approaches in relation with ―software size in agile contexts. Based on this review, we present the perceptions of software size and related challenges, such as misinterpretation of size, difficulties in implementation, and acceptability of the measurement processes. We anticipate that providing a baseline for the state of software size measures in agile contexts and presenting related challenges, particularly in terms of its acceptability by practitioners can shed light on the development of new techniques. © 2018 CEUR-WS. All rights reserved.
Clinical Development of Quinone-Based Drugs
(Elsevier, 2024) Altuner, E.E.; Issa, G.; Ozalp, V.C.; Aldemir, O.; Torlak, Y.; Dar, U.A.
This chapter provides a detailed explanation of the clinical investigations, pharmacological effects, and characteristics of quinone and quinone derivatives, along with references to pertinent sources. Although quinones have an oxygen group in their structure, they are quickly oxidized and interact with reactive oxygen species. This demonstrates how quinones work as drugs. Quinones and their derivatives are used as medications to treat a wide range of diseases, including cancer, lung, kidney, brain, and tumor disorders. Each of the following has effects on a different area of health; lapochols, anthraquinones, naphthoquinone and its derivatives, and other wide range of quinone derivatives are thoroughly explored in this chapter. © 2025 Elsevier Inc. All rights reserved.
Common Fixed Point Results for Meir-Keeler-Type Contraction Mappings
(Springer, 2025) Karapńar, Erdal; Cvetković, Marija, S.; Yeşilkaya, Seher Sultan
Meir–Keeler contraction presents an interesting and widely studied topic in the area of Metric Fixed Point Theory. We intend to present several results concerning common fixed problem and the impact of Meir-Keeler-type contractions on this type of results. We will present results on common fixed problem for a Meir–Keeler contraction mapping in various settings—metric space, b-metric space, partial metric space, Branciari metric space, etc. It is our intention to present a comprehensive study on this topic that will present a good starting point for the researchers in the Fixed Point Theory. © 2025 Elsevier B.V., All rights reserved.
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.
Comparison of Field Survey-Based Macroseismic Intensity Map and Numerical Macroseismic Intensity Maps Using Mars and Multiple Regression Methods for 6th of February 2023 Kahramanmaraş Earthquakes
(Springer Science and Business Media Deutschland GmbH, 2024) Albayrak, Kubilay; Askan, Aysegul; Yerlikaya-Ozkurt, Fatma; Industrial Engineering
Earthquakes are natural events that cause damage to built environments by the instant seismic energy release. This energy is measured by instrumental devices to obtain the peak ground motion parameters such as Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV). Additional measurements based on the questionnaires after the earthquakes are required to identify the felt or macro seismic intensity levels. These measurements are crucial to identify the total effects of earthquakes over not only an area but also for the spatial distribution of ground motion parameters. For this purpose, it is important to study the multi-variable criteria correlations between ground motion parameters and Modified Mercalli Intensity (MMI) levels based on linear relationships of predictor variable couples. In this regard, the Multivariate Adaptive Regression Splines (MARS) Method and the Multiple Linear Regression Method are used. The entire dataset is composed of 69 earthquakes between 2005 and 2022 with 2171 ground motion parameters coupled with MMI levels. For MMI-based correlations, the MARS method is used to identify the non-linearities between predictor variables by piecewise linear functions, but for the Multiple Linear Regression Method, the least correlated variables of PGA-Epicentral Distance and PGV-Epicentral Distance are used to obtain the relationship between MMI and PGM parameters. The resulting equations obtained for the entire Turkiye database are performed to identify MMI maps of the 6th of February 2023, Kahramanmaras Earthquakes, and these maps are used to check the accuracy of the results by the comparison of field survey-based MMI maps. Finally, the numerical MMI maps are found to be consistent with the field survey-based MMI maps.
A Comparison of Stream Processing Frameworks
(Institute of Electrical and Electronics Engineers Inc., 2017) Karakaya,Z.; Yazici,A.; Alayyoub,M.; Software Engineering; Computer Engineering
This study compares the performance of Big Data Stream Processing frameworks including Apache Spark, Flink, and Storm. Also, it measures the resource usage and performance scalability of the frameworks against a varying number of cluster sizes. It has been observed that, Flink outperforms both Spark and Storm under equal constraints. However, Spark can be optimized to provide the higher throughput than Flink with the cost of higher latency. © 2017 IEEE.
Complex Partial Differential Equations
(Springer, 2025) Aksoy, Ü.; Begehr, H.; Çelebi, A.; Shupeyeva, B.
The Schwarz and iterated Dirichlet boundary-value problems are reported on for the polyanalytic operator in certain plane domains having a harmonic Green function. Hybrid polyharmonic Green functions are reviewed upon which open a variety of boundary-value problems for the polyharmonic operator. This topic is far from being complete. The higher the order of the polyharmonic operator the richer is the theory of related hybrid Green functions: they are constructed by continued convoluting harmonic Green, Neumann, Robin functions also incorporating polyharmonic Green–Almansi functions. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.
Citation - Scopus: 1
A computer-controlled triaxial swelling test apparatus
(2004) Bilir,M.E.; Müftüoǧlu,Y.V.; Sari,D.
To avoid the problems encountered during and after the construction of engineering structures built within swelling rocks or soils, data related to swelling stresses and strains should be used in the design stage. For an effective design, it is important that the data used for this purpose should be derived from triaxial swelling tests. In this article, a re-designed and computer-controlled triaxial swelling test apparatus is introduced. Due to the limited amount of test equipment, the work associated with triaxial swelling tests has been rather limited and consequently a test standard has not been developed yet. The computer-controlled triaxial swelling test apparatus has made tedious swelling tests easier and thus it has provided better possibilities for the investigation of the triaxial swelling behavior of soils and rocks.
A Coupled Modelling and Simulation Approach to Electromagnetic Sheet Metal Forming
(Taylor & Francis Ltd, 2025) Aslan, Ozgur; Kabakci, Gamze Cakir; Sait, Ferit; Camalan, Caner; Baranoglu, Besim; Bayraktar, Emin; Aerospace Engineering; Mechanical Engineering; Manufacturing Engineering
This study presents a coupled numerical and experimental investigation of electromagnetic forming (EMF) for aluminium sheets. A custom simulation framework is developed in ABAQUS/Standard using user-defined material (UMAT) and load (DLOAD) subroutines. The magnetic pressure exerted on the workpiece is computed through a finite difference-based solution of Maxwell's equations and applied to the mechanical solver. The mechanical response of the material is modelled using a strain-rate-sensitive plasticity law calibrated for aluminium 7075-O. Experimental forming trials are performed using a custom-built EMF setup, and the results are compared with numerical predictions to validate the model. The comparison shows strong agreement in deformation profiles, confirming the predictive capability of the proposed simulation strategy. This work offers a reliable computational tool for optimising EMF processes and provides insights into material behaviour under high strain rate electromagnetic loading.
Cultural Logics of Honor, Face, and Dignity as Moderators of the Relationship Between Group Process and Pro-Migrant Collective Action Intentions
(Elsevier, 2025) Besta, Tomasz; Thomas, Emma; Celikkol, Goksu; Olech, Michal; Jurek, Pawel; Van Zomeren, Martijn; Wlodarczyk, Anna
Although group identification, efficacy, and injustice appraisals are well-established predictors of collective action support, contextual factors are rarely examined. We address this oversight in preregistered study by testing whether country-level norms moderate the relationships identity, anger at injustice, and efficacy have with support for pro-immigrant solidarity collective action using data from 22 countries (N = 4615). Given that cultures that emphasize honor and face prioritize harmony and social cohesion over conflict, we expected that honor codes and face orientation would attenuate the links identity, injustice, and efficacy have with collective action support. Results showed that identification, efficacy, and anger at injustice were linked to collective action intentions in most countries, but honor codes attenuated the relationship between anger and collective action intentions. We further discuss the implications and limitations of these results in light of cross-cultural studies of pro-immigrant attitudes and actions. Overall, our findings complement research on predictors of collective action and the dual-chamber model of collective action by presenting potential cultural constraints.
Death-In Women in Dubliners
(Ovidius University, 2025) Serdaroğlu, Duygu; Department of English Language and Literature
This article analyses three stories “Eveline”, “Clay” and “The Dead” in James Joyce’s Dubliners by focusing on female characters and them being dead souls because of the pressures they have. In the stories, religion and marriage are two important reasons of the oppression that the Irish society creates on women who are victimized and devalued regardless of the fact that they are married or not. The study also claims that the protagonists of these stories, Eveline, Maria and Gretta also meet on the same ground in mirroring each other and showing the same end for all women in Dubliners. In that sense, the reason why these three women are chosen is the possible connection of these women, i.e., Eveline is the younger version of all these women and if she remains unmarried, her older version would be Maria and if she gets married, she would be like Gretta, underscoring the same end for all women. Thus, this article aims to scrutinise the female characters as dead souls in the stories “Eveline”, “Clay” and “The Dead” and how they are silenced to hide their disappointment, frustration and unfulfilled desires by the society which depreciates them. © 2025 Elsevier B.V., All rights reserved.
Deep Learning Based Covid-19 Detection Using Computed Tomography Images
(Prof.Dr. İskender AKKURT, 2024) Yılmaz, A.A.; Sevinç, Ö.
The infectious coronavirus disease (COVID-19), seen in Wuhan city of China in December 2019, led to a global pandemic, resulting in countless deaths. The healthcare sector has become extensively use of deep learning (DL), a method that is currently quite popular. The aim of this study is to identify the best and most successful deep learning model and optimizer approach combination for COVID-19 diagnosis. For this reason, several DL methods and optimizer techniques are tested on two comprehensive public data set to select the best DL model with optimizer technique. A variety of performance evaluation metrics, including f-score, precision, specificity, and accuracy, were used to assess the models' effectiveness. The experimental results show that the most suitable and effective architecture is DenseNet-201 in the network comparison, which achieved a 98% accuracy rate using the AdaGrad optimizer and 200 iterations. © IJCESEN.

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