Atılım Academic Archive (Atılım University)
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Tripadvisor Değerlendirmelerinin Analizi: Ankara'daki Önde Gelen Otellerde Müşteri Sadakatini Artırmaya Yönelik Stratejilerin Geliştirilmesinde Müşteri Geri Bildirimlerinin
No full textBu çalışma, Ankara’daki premium otellerin, müşteri deneyimlerini geliştirmek, sadakati artırmak ve tekrar eden misafir harcamalarını yükseltmek için veri odaklı stratejileri nasıl kullanabileceğini incelemektedir. Araştırmada, Ankara'daki dört önde gelen lüks otelden (Hilton Ankara Hotel, JW Marriott Ankara Hotel, Lugal, a Luxury Collection Hotel ve Sheraton Ankara Hotel & Convention Center) alınan 186 TripAdvisor misafir yorumu üzerinde nitel içerik analizi yapılmıştır. Yorumlar, hizmet kalitesi, oda temizliği, kahvaltı sunumları ve personel etkileşimleri gibi ana temalara odaklanılarak analiz edilmiştir. Çalışmada, misafir geri bildirimlerinde tekrarlayan düzenleri ve temaları belirlemek amacıyla tematik analiz yöntemi kullanılmıştır. Örneklem, otellerin premium statüsü ve fiyatlandırmasına göre seçilerek, Ankara'nın konaklama piyasasındaki lüks segmentin temsil edilmesi sağlanmıştır. Bulgular, genel memnuniyetin yüksek olduğunu ortaya koymakla birlikte, yan hizmetlerde iyileştirme yapılması gereken alanları da vurgulamaktadır. Çalışma, misafir geri bildirimlerini analiz etmenin, kişiselleştirilmiş ve hedefe yönelik hizmet sunumları oluşturmadaki önemine dikkat çekmektedir. Otelcilere yönelik öneriler arasında, hizmet kalitesinin optimize edilmesi ve misafir tercihlerini karşılayacak deneyimlerin tasarlanması, böylelikle uzun vadeli müşteri sadakatinin güçlendirilmesi yer almaktadır
3-D Gravity Modeling of the Kars Basin as a Hidden Extension of the Caspian Petroleum System, Ne-Anatolia, Turkey
No full textThe Kars Basin in northeastern Turkey is closely related to the Caspian Petroleum System but it is hidden by a great extent of volcanic rocks. The Oligo-Miocene Komurlu Formation within the basin is the Turkish equivalent of the Maikopian Formation which is the main source rock in the Caspian region. Although the Kars Basin has considerable hydrocarbon potential it is one of the least explored basins in Turkey and there is only a limited literature on the region. This study is the first comprehensive investigation to determine the basement geometry, depth, internal structure and basin boundaries. Gravity data and power spectrum analysis were used in this study. The gravity anomalies were low-pass filtered and the average depth of the basin is found to be approximately 5 km. Boundaries of the basin are entirely confined within the Turkish territorial borders. The basin geometry is remarkably consistent with the crustal thickness geometry across the region and the maximum crustal thickness is 42 km, indicating that the basin was formed on the thickest part of the crust in the region. A 3-D model of the Kars Plateau indicates that the Kars Basin is made up of four different deep (> 6 km) depressions forming a channel-like trend from southwest to northeast from the Horasan area to the Arpacay area. There are four less deep sections (< 6 km) to the north of this trend. The depressions in the north are separated by the Allahuekber Mountains that are marked by a distinctive magnetic anomaly, from the deep SW-NE trend. High-standing regions between the depressions could be prospective areas for the oil accumulation.General Directorate of Mining Research and Exploration (MTA); Turkish Scientific Research Council (TUBITAK) [116Y369]This study has been completed using the gravity and magnetic data purchased from the General Directorate of Mining Research and Exploration (MTA) under a research project granted and supported by the Turkish Scientific Research Council (TUBITAK). Authors would like to thank TUBITAK once more, for their valuable support on our project (Project Code: 116Y369).Science Citation Index Expande
Establishing the <i>nimo<sub>6</Sub>se<sub>8< Chevrel Phase as a Promising Material Using Dft
Get PDFSURUCU, Gokhan/0000-0002-3910-8575; SURUCU, Ozge/0000-0002-8478-1267In this study, the NiMo6Se8 Chevrel phase is analyzed using Density Functional Theory (DFT) and the Vienna Ab-initio Simulation Package (VASP). The analysis focuses on the phase's structural, electrical, and mechanical characteristics to fill gaps in the current literature. The presence of a rhombohedral crystal structure confirms its thermodynamic stability, as indicated by a negative formation enthalpy, which suggests that it can be synthesized under favorable conditions. The electronic properties of the phase are analyzed, indicating that it exhibits semiconductor characteristics with a bandgap of 1.07 eV. This makes it appropriate for various technological applications. The estimated elastic constants provide an indication of mechanical strength and flexibility, with a noticeable presence of anisotropic elasticity. The confirmation of dynamical stability is achieved by analyzing the phonon dispersion curve, which reveals the absence of any negative frequencies. Furthermore, the material has a low thermal conductivity, increasing its suitability for thermoelectric applications. The analysis emphasizes the versatile capabilities of the NiMo6Se8 Chevrel phase, especially in thermoelectric and energy storage applications, showcasing its promising potential for future technological implementation.Turkish Scientific and Research Council (TUBITAK) [120F305]This work was supported by Grant no. 120F305 from the Turkish Scientific and Research Council (TUBITAK). TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources) and Istanbul Technical University National Center for High Performance Computing (ITU-UHEM) were the centers where the numerical calculations presented in this work were carried out
Ensemble Transfer Learning Using Maizeset: a Dataset for Weed and Maize Crop Recognition at Different Growth Stages
No full textKhan, Muhammad/0000-0002-9195-3477Maize holds significant importance as a staple food source globally. Increasing maize yield requires the effective removal of weeds from maize fields, as they pose a detrimental threat to the growth of maize plants. In recent years, there has been a drive towards Precision Agriculture (PA), involving the integration of farming methods with artificial intelligence and advanced automation techniques. In the realm of PA, deep learning techniques present a promising solution for addressing the complex challenge of classifying maize plants and weeds. In this work, a deep learning method based on transfer learning and ensemble techniques is developed. The proposed method is implementable on any number of existing CNN models irrespective of their architecture and complexity. The developed ensemble model is trained and tested on our custom-built dataset, namely MaizeSet, comprising 3330 images of maize plants and weeds under varying environmental conditions. The performance of the ensemble model is compared against individual pre-trained VGG16 and InceptionV3 models using two experiments: the identification of weeds and maize plants, and the identification of the various vegetative growth stages of maize plants. VGG16 attained an accuracy of 83% in Experiment 1 and 71% in Experiment 2, while InceptionV3 showcased improved performance, boasting an accuracy of 98% in Experiment 1 and 81% in Experiment 2. With the proposed ensemble approach, VGG16 when combined with InceptionV3, achieved an accuracy of 90% for Experiment 1 and 80% for Experiment 2. The findings demonstrate that integrating a suboptimal pre-defined classifier, specifically VGG16, with a more proficient model like InceptionV3, yields enhanced performance across various analytical metrics. This underscores the efficacy of ensemble techniques in the context of maize classification and analogous applications within the agricultural domain.Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Science Citation Index Expande
Two-Dimensional Carbon Rich Titanium Carbide (tic3) as a High-Capacity Anode for Potassium Ion Battery
No full textPark, Jongee/0000-0003-1415-6906In recent years, two-dimensional (2D) materials, particularly MXenes such as titanium carbide, have gained significant interest for energy storage applications. This study explores the use of potassium-adsorbed TiC3 nanosheets as potential anode materials for potassium ion batteries (KIBs), utilizing first-principles calculations. The investigated electronic, mechanical, and thermal properties of TiC3 demonstrate its suitability as an anode material. The incorporation of potassium into the host material enhances electronic conductivity while maintaining a stable layered structure. Our findings reveal promising adsorption behavior of potassium in TiC3, leading to a high theoretical specific capacity of 958 mAh/g, coupled with a low energy barrier of 0.19 eV for potassium migration, which is indicative of superior electrochemical performance. Moreover, despite the high potassium content, the electrode material shows limited volume expansion of 11.3 %, suggesting good cyclability. Additionally, the equilibrium distance between potassium and TiC3, measured at 3.11 & ring;A, exceeds that of lithium and TiC3 (2.56 & ring;A), potentially augmenting the material's flexibility. Consequently, TiC3 emerges as a promising candidate for KIB anode materials.Scientific and Technological Research Council of Turkey (TUBITAK) [123M723]This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK, Project no: 123M723)
Scientific Research on the Pineal Gland: a Bibliometric Analysis From Its First Publication
No full textObjective: The bibliometric perspective examines publications using a quantitative way and statistics to analyze them. The purpose of the current study was to perform a comprehensive overview of the research on the pineal gland through bibliometric methods to determine the trends and rare topics related to the gland. Methods: The Web of Science database was used to identify the publications associated with the gland. The literature review exposed a total of 8719 publications. The identified publications were analyzed using the bibliometric approaches (VOSviewer Version 1.6.13). Results: The first studies on the pineal gland were in the 1970s. The most prolific country is the United States (2451). It was seen that most of the articles were published in Journal of Pineal Research. The majority of publications (97.09%) were written in English. The most prolific author is Reiter, Russel J. Moreover, the most prolific institute is the Centre National De La Recherche Scientifique (France). The most popular keywords in the articles were pineal gland, melatonin, circadian rhythm, rat, retina, photoperiod, circadian, aging, serotonin, oxidative stress, and brain. Conclusion: The results indicated the researchers’ interest in the gland and provided quantitative data about the place of the gland in the scientific area. Studies on this subject have tended to increase in recent years. As far as we know, this research is the first bibliometric study to provide a comprehensive analysis of scientific publications with an emphasis on the pineal gland since 1976
What To Consider at the Development of Educational Programs and Courses About Next-Generation Cyber-Physical Systems?
No full textErden, Zuhal/0000-0002-4860-4271We live in an age in which new things are emerging faster than their deep understanding. This statement, in particular, applies to doing research and educating university students concerning next-generation cyber-physical systems (NG-CPSs). The fast evolution of this system paradigm would have expected a rapid and comprehensive paradigmatic change in research and education concerning this family of systems. However, this has not happened yet. Seeking a sufficient explanation, this paper reviews the current literature and attempts to cast light on the most significant recent developments in the field of NG-CPSs. The main assumptions of the authors are that research and education should appear in harmony in academic knowledge acquisition and distribution processes and that the academic education of NG-CPSs should be organized and conducted according to a defendable future vision. Combining the results of a broadly based study of the literature with prognostic critical thinking and personal experiences, this review-based position paper first discusses the current socio-techno-scientific environment, the involved stakeholders, and the demands and two approaches of truly systems-oriented education. Then, it concentrates on (i) the recognized limitations of mono- and interdisciplinary research, (ii) supradisciplinary organization of research, and (iii) transdisciplinary knowledge generation for NG-CPSs. As main contributions, the paper (i) identifies and analyzes the latest theoretical, engineering, and technological developments, (ii) reveals the major trends and their presumably significant implications, and (iii) presents several thought-provoking findings and makes propositions about the desirable actions.Science Citation Index Expande
On the Image of the Lupas <i>q</I>-analogue of the Bernstein Operators
No full textThe Lupas q-analogue, R-n,R-q, is historically the first known q-version of the Bernstein operator. It has been studied extensively in different aspects by a number of authors during the last decades. In this work, the following issues related to the image of the Lupas q-analogue are discussed: A new explicit formula for the moments has been derived, independence of the image R-n,R-q from the parameter q has been examined, the diagonalizability of operator R-n,R-q has been proved, and the fact that R-n,R-q does not preserve modulus of continuity has been established.Recep Tayyip Erdogan UniversityThe authors express their sincere gratitude to Professor Heping Wang (Capital Normal University, Beijing, China) for providing them with a copy of his unpublished work which drawn their attention to the problem considered in Sect. 5. The first-named author gratefully acknowledges the support of Recep Tayyip Erdogan University as this work was completed while she was on post-doctoral leave at Atilim University. Last but not least the authors extend their appreciations to the anonymous referees for their thorough reading of the manuscript and beneficial comments
Skull base surgery for malignant tumors: The 2nd international collaborative study (1995-2015)
Get PDFValero, Cristina/0000-0003-3397-2888; Sanchez Aniceto, Gregorio/0000-0002-9667-336X; PIAZZA, Cesare/0000-0002-2391-9357; Rennie, Catherine/0000-0002-1580-5296; Shah, Jatin/0000-0002-6444-6592; Levyn, Helena/0009-0005-4402-6186BackgroundThe current study presents the effort of a global collaborative group to review the management and outcomes of malignant tumors of the skull base worldwide.Patients and methodsA total of 28 institutions contributed data on 3061 patients. Analysis evaluated clinical variables, survival outcomes, and multivariable factors associated with outcomes.ResultsThe median age was 56 years (IQR 44-67). The open surgical approach was used in 55% (n = 1680) of cases, endoscopic resection was performed in 36% (n = 1087), and the combined approach in 9.6% (n = 294). With a median follow-up of 7.1 years, the 5-year OS DSS and RFS were 65%, 71.7% and 53%, respectively. On multivariable analysis, older age, comorbidities, histology, dural/intracranial involvement, positive margins, advanced stage, and primary site were independent prognostic factors for OS, DSS, and RFS. Adjuvant RT was a protective prognostic factor.ConclusionThe progress across various disciplines may have contributed to improved OS and DSS in this study compared to previous reports.National Institutes of Health [P30 CA008748]; NIH/NCI Cancer Center Support GrantThis grant was supported in part by the NIH/NCI Cancer Center Support Grant P30 CA008748. The authors wish to thank Jasmine Kwityn for her editorial assistance
Integrating Theoretical and Experimental Approaches To Unveil the Mechanical Properties of Cusbse<sub>2</Sub> Thin Films
Get PDFAn exhaustive investigation of the mechanical characteristics of CuSbSe2 thin films is conducted in this study by combining experimental nanoindentation methods with theoretical simulations. The Ab-initio Molecular Dynamics (AIMD) calculations are performed with the machine learning (ML) force fields. By employing the Vienna Ab-initio Simulation Package (VASP) based on Density Functional Theory (DFT), theoretical inquiries are carried out to identify crucial parameters, such as bonding characteristics, elastic constants, hardness, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio. Experimental validation is conducted using nanoindentation to investigate load-dependent hardness and Young's modulus in a manner that closely matches the theorized predictions. The anomalies between experimental and theoretical outcomes are ascribed to anisotropic behavior and grain boundaries. Furthermore, an investigation is conducted into the directional dependence of sound wave velocities in the CuSbSe2 films, leading to the revelation of intricate elastic property details. By employing an integrated theoretical-experimental approach, the present attempt not only increases the knowledge concerning CuSbSe2 films but also fortifies the relationship between theory and experiment, thereby bolstering the dependability of our results. The insights provided as a result of this paper facilitate the development of CuSbSe2 film applications in a variety of technological fields in the future.Trkiye Bilimsel ve Teknolojik Arastirma Kurumu https://doi.org/10.13039/501100004410 [120F286]; Turkish Scientific and Research Council (TUBITAK)This work was supported by Turkish Scientific and Research Council (TUBITAK) under Grant no 120F286. The numerical calculations reported in this paper were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources) and Istanbul Technical University National Center for High Performance Computing (ITU-UHEM).Science Citation Index Expande