2045 research outputs found
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Analyzing customer churn: A comparative study of machine learning models on Pay-TV subscribers in Turkey
No full textUnderstanding the reasons for customer churn provides added value in terms of retaining existing customers, as customer attrition leads to revenue loss for companies and incurs marketing costs for acquiring new customers. In this study, the 6-month historical data of a Pay-TV company operating in Turkey was used, and due to the imbalanced nature of the dataset on a label basis, the oversampling method was applied. During the model development phase, various artificial learning algorithms (Random Forest, Logistic Regression, KNearest Neighbors, Decision Tree, AdaBoost, XGBoost, Extra Tree Classifier) were utilized, and their performances were compared. Based on the evaluation of success criteria for each model, it was observed that the tree-based Random Forest, Extra Tree Classifier and XGBoost achieved the highest performance for this dataset.2-s2.0-85184666022Eylü
GRAFRAUD: Fraud detection using graph databases and neural networks
No full textIndex tarihi :19 Ocak 2024The issue of fraud has become a significant concern for many companies, particularly in the finance sector, but the traditional methods of detecting fraud are no longer adequate. Innovative technologies are necessary to identify complex fraudulent activities, and RedisGraph, a high-performance graph database, may offer a solution. With the assistance of neural networks, RedisGraph can accurately and efficiently detect fraudulent transactions in vast and intricate environments. Companies typically use a combination of Python and Oracle Databases to design fraud detection systems. which provide robust data management and real time AI processing capabilities. These technologies allow to create fraud detection systems that can determine fraudulent activities in real-time. But according to advancements of fraud methods only using of these systems not efficient nowadays. This article presents a proof of concept based on an essential use case of RedisGraph-powered neural networks in detecting financial fraud. It demonstrates the value of carefully employing Python and Oracle Database to construct and deploy real-time systems that can efficiently detect fraudulent activities.2-s2.0-85184668054Kası
Supporting novice mathematics teachers: The impact of an e- mentoring and video-based professional development program on teachers? noticing skills
No full textKaradeniz Technical University Scientific Research Foundation [7178]The study was supported by Karadeniz Technical University Scientific Research Foundation with the project number 7178.This paper focuses on e-mentoring of novice mathematics teachers as professional development, and reports findings of the e-mentoring practices enriched with videos to improve noticing skills of novice teachers. A single group pre- and post-test study was conducted with the participation of 17 mentees, novice middle school mathematics teachers. Participants' noticing skills were assessed through a whole-class teaching video shown to them before and after the intervention. The responses of the teachers to the video assessment were analyzed considering attending, interpreting and decision-making dimensions of noticing. The results revealed that the ementoring program improved the novice mathematics teachers' noticing skills significantly in all dimensions.WOS:000978797700007Emerging Sources Citation IndexarticleUluslararası işbirliği ile yapılmayan - HAYIRMayısYÖK - 2022-2
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No full textKH00153MEF Üniversitesi Teknik Hizmetler, Kataloglama Uzmanı İpek Yarar, 17/01/2023 tarihinde MEF Üniversitesi'nde düzenlenen HERMES Project Training Sessions'da "MEF Library's resource sharing activities during covid-19" başlıklı sunumuyla yer aldı.Oca
Comparative study of 5 countries on how libraries contribute to SDGs
No full textLibraries are essential societal stakeholders that can contribute to the implementation of the United Nations Sustainable Development Goals. As centers of information, libraries can play a critical role in the dissemination of research and knowledge. As a key resource, libraries are always at the forefront of education and awareness creation. This poster studies the involvement of academic libraries with sustainable development in different countries and explores the factors affecting the extend of this involvement. For this study, five countries namely Azerbaijan, Bosnia-Herzegovina, Greece, North Macedonia, and Türkiye were selected and academic libraries in these countries are invited to fill a survey. These countries were chosen because of their geographical proximity, similar socio-economic and cultural backgrounds, and corresponding librarianship approaches. In addition, the fact that there is no story from any of these countries in the SDGs section of the IFLA Library Map of the World has been decisive in the country selection. North Macedonia was left out of the analysis due to no response. Low response rate from other four countries reminds a further need for using tools other than survey to expend the analysis. Despite the low response rate, results are highlighting rising awareness among academic libraries and librarians.Eylü
Utilizing of Tincal Ore Wastes in Ceramic Industry
No full textDue to their support during the study, the authors are acknowledged to Kaleseramik Plants and Etimine Company.Boron mining is carried out as opencast/open pit mining in Turkey. The obtained boron ore is presented to the utilization of many industrial branches such as insulation fiberglass and ceramic glazes, after washing, distribution, and classification according to the size but most of commercial applications of borates require the use of refined borates (Briggs in Kirk–Othmer encyclopedia of chemical technology, 2001). Approximately 4.2 million tons (2 million tons based on B2O3) of boron were produced globally in 2016. In worldwide B2O3-based boron production, Eti Maden (Turkey) ranks first with a 50% share, USA with 25%, and other countries with 25% are trailing Turkey (Bor Sector Report, Eti Mine, 2009). It is known that, during the production of boron containing chemicals, some of these are spreading to environment (Karahan et al. in J Colloid Interface Sci 293:36, 2006; Sahin in Desalination 143:35, 2002). Boron-containing wastes coming out of the exploitation facilities are generally solid and in small dimensions, and also in pulp state. The studies related with the evaluation of boron waste demonstrate that the most appropriate evaluation method for the boron waste is storing the waste without harming the environment or regaining the boron within the waste and making the remaining minerals including clay suitable for the utilization of appropriate sectors (Christogerou et al. in Ceram Int 35:447, 2009). Boron containing wastes generating from production facilities are suitable raw materials for appropriate sectors when environmental impacts are being taken into consideration, too. In this study, the effect of various amounts of boron waste added to the ceramic body on forming and firing processes have been analyzed. This study has been carried out in order to provide information for bringing in this inert potential resource to the advantage of the country’s economy. © 2023, The Minerals, Metals & Materials Society.2-s2.0-8514996529
A Comprehensive Review of the Novel Weighting Methods for Multi-Criteria Decision-Making
No full textIn the realm of multi-criteria decision-making (MCDM) problems, the selection of a weighting method holds a critical role. Researchers from diverse fields have consistently employed MCDM techniques, utilizing both traditional and novel methods to enhance the discipline. Acknowledging the significance of staying abreast of such methodological developments, this study endeavors to contribute to the field through a comprehensive review of several novel weighting-based methods: CILOS, IDOCRIW, FUCOM, LBWA, SAPEVO-M, and MEREC. Each method is scrutinized in terms of its characteristics and steps while also drawing upon publications extracted from the Web of Science (WoS) and Scopus databases. Through bibliometric and content analyses, this study delves into the trend, research components (sources, authors, countries, and affiliations), application areas, fuzzy implementations, hybrid studies (use of other weighting and/or ranking methods), and application tools for these methods. The findings of this review offer an insightful portrayal of the applications of each novel weighting method, thereby contributing valuable knowledge for researchers and practitioners within the field of MCDM.WOS:0009972313000012-s2.0-85160203389Emerging Sources Citation IndexarticleUluslararası işbirliği ile yapılan - EVETHaziranYÖK - 2022-2
A new approach for measuring viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface
No full textBackground: There are several techniques to characterize the mechanical properties of soft materials, such as the indentation method and the method based on the application of a spherical object placed inside the sample. The indentation systems usually yield the elastic properties of materials and their mathematical models do not consider the inertia of the sample involved in motion and radiation damping, while placing an object inside the sample is not practical and this procedure can alter the mechanical properties of the sample for the method based on the application of a bubble/sphere placed inside the sample. Objective: A new approach for the identification of the viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface was proposed. Methods: The spherical object placed at the sample interface was pressed using an electromagnet and the dynamic response of the spherical object was tracked using a high-speed camera, while the dynamic response of the spherical object placed at the sample interface was estimated using a comprehensive analytical model. The effects of the shear modulus, viscosity, Poisson’s ratio and density of the soft sample, the radius and density of the spherical object and the damping due to radiation were considered in this mathematical model. The shear modulus and viscosity of the soft sample were determined by matching the experimentally identified and theoretically estimated responses of the spherical object. Results: The shear moduli and viscosities of the three phantoms with the gelatin mass ratios of 0.20, 0.25 and 0.29 were measured to be 3450, 4300 and 4950 Pa and 12.5, 14.0 and 15.0 Pa⋅s, respectively. The shear modulus and viscosity of the phantom increases as the gelatin mass ratio increases. The frequency of oscillations of the hemisphere placed at the phantom interface increases as the gelatin mass ratio increases due to stiffness increase. Conclusions: After matching the experimental and theoretical steady-state displacements and amplitudes of oscillations of the hemisphere at the sample interface, the comparison of the experimentally identified and theoretically predicted frequency of oscillations further confirmed the identified material properties of the samples. The approach presented here is expected to provide valuable information on material properties in biomedical and industrial applications.WOS:0010826474000032-s2.0-85174051012ArticleUluslararası işbirliği ile yapılan - EVETYÖK - 2022-23Eki
Keystone in the fight against nuclear terrorism: Tackling nuclear material trafficking
No full textBu çalışma, ulus-altı grupların uluslararası karaborsada gerçekleştirdikleri yasa dışı nükleer madde kaçakçılığı olaylarının sonucunda oluşabilecek nükleer terörizm olaylarını önleme noktasında uluslararası işbirliğinin önemini vurgulama hedefi ile kaleme alınmıştır. Motivasyonları gereği nükleer terör saldırısı gerçekleştirmekten geri durmayacak terör gruplarının, uluslararası karaborsadan elde edebilecekleri nükleer maddeler ile, basit bir nükleer silah yapmaları ve bu nükleer silahı gerçekleştirecekleri bir eylemde kullanma hedefleri, özellikle son yıllarda terör gruplarının gerçekleştirdiği kitlesel kayıplı eylemler göz önüne alındığında, söz konusudur. Terör gruplarının nükleer maddelere erişim imkân kabiliyetlerinin artması, olası nükleer terör saldırısı anının her an daha da yaklaştığı fikri ile doğru orantılıdır. Olası bir nükleer terör saldırısının önüne geçmek için gerçekleştirilecek ilk eylem ise, terör gruplarının nükleer maddelere erişimini minimum düzeye indirmek ve bu olayı ortadan kaldırmaktır. Bu çerçevede, ulus devletlerin, aralarında yaşanan diğer dış politika ilişkilerini bir tarafa bırakarak ve uluslararası kuruluşlar ve örgütlerin de destekleri ile nükleer karaborsa ağını ortadan kaldırmak ve dolayısı ile oluşabilecek bir nükleer terör saldırısını engellemek için birlikte mücadele etmeleri gerekmektedir. Bu tez çalışmasında, terör gruplarının nükleer maddeleri edinme hedefleri ve gerçekleştirebilecekleri olası bir nükleer terör saldırısının tüm boyutları analiz edilmiş ve nükleer terörizmin önüne geçmek için gerçekleştirilecek ilk eylem olan, yasa dışı nükleer madde ticaretinin önüne geçilmesi ve uluslararası nükleer karaborsa ağının ortadan kaldırılması için ulusal ve uluslararası düzeyde atılan ve atılması gereken ii adımları inceleme hedeflenmiştir. Ayrıca, yasa dışı nükleer madde kaçakçılığı olaylarında, Türkiye perspektifi de çalışma içerisinde yer almıştır.This study has been written with the aim of emphasizing the importance of international cooperation in preventing nuclear terrorism that may occur as a result of illegal nuclear material smuggling by sub-national groups on the international black market. Terrorist groups due to their motivation, will not hesitate to carry out a nuclear terrorist attack, to make a nuclear weapon with nuclear materials that they can obtain from the international black market and to use this nuclear weapon in an action they will carry out, especially when the mass casualties carried out by terrorist groups in recent years are taken into consideration. The increase in terrorist groups' ability to access nuclear materials is directly proportional to the idea that the moment of a possible nuclear terrorist attack is getting closer every moment. The first action to be taken to prevent a possible nuclear terrorist attack is to minimize the access of terrorist groups to nuclear materials and to eliminate this event. In this context, nation states should put aside other foreign policy relations between them and fight together with the support of international organizations and organizations to eliminate the nuclear black market network and thus to prevent a nuclear terrorist attack that may occur. In this thesis, the objectives of terrorist groups to acquire nuclear materials and all dimensions of a possible nuclear terrorist attack that they may carry out were analyzed and the first action to be taken to prevent nuclear terrorism, to prevent illegal nuclear material trade and to eliminate the international nuclear black market network, at national and international levels. It is aimed to examine the steps taken and to be taken. In addition, the perspective of Türkiye in cases of illegal nuclear material smuggling is also included in the study
Institutional quality and geography of discontent in the EU
No full textThere has been a significant rise in anti-establishment votes in the European Union (EU). The decline in socio-economic outcomes and migration played an important role in understanding the rising discontent. However, none of the existing studies analysed the effect of socio-economic factors in different institutional settings. Our findings confirm that institutional quality is of paramount importance in explaining the recent rise in populism in the EU, as institutionally developed EU regions are less opposed to EU integration. Remarkably, the effects of socio-economic factors on populist votes vary in different institutional settings. The findings highlight that institutional improvements are vital for the EU perception of less developed and socio-economically isolated EU regions.WOS:0011226064000012-s2.0-85179360980Social Sciences Citation IndexArticle; Early AccessUluslararası işbirliği ile yapılmayan - HAYIRAralıkYÖK - 2022-23Eki