Istanbul Ticaret University Institutional Repository (DSpace@Ticaret)
Not a member yet
8409 research outputs found
Sort by
Constraining and application an stock control model for products sold with e-commerce
No full textElektronik ticaret veya kısaca e-ticaret, ürün izleme, sipariş verme, tedarik ve ödeme işlemlerinin internet üzerinden gerçekleştirildiği ticaret modelidir. E-ticaret alanında faaliyet gösteren işletmeler, hızla değişen tüketici talepleri, dalgalanan tedarik zincirleri ve dinamik pazar koşullarıyla karşı karşıya kalmaktadırlar. Bu etkenler, işletmelerin stok yönetimi süreçlerini karmaşıklaştırır ve stok seviyelerini etkin bir şekilde kontrol etmelerini zorlaştırır. İşletmeler, hızlı değişen tüketici taleplerine karşı rekabet avantajı sağlamak, stok maliyetlerini minimize etmek, müşteri memnuniyetini artırmak ve operasyonel süreçleri etkin bir şekilde yönetmek için stok kontrol stratejileri uygularlar. Çalışma kapsamında, Q,R stok kontrol modeli oluşturularak optimizasyon çalışması yapılmıştır. Uygulama için belirlenen ürün üzerinden yapılan modelleme çalışması, stok kontrolünün etkin bir biçimde nasıl yönetilebileceğini ortaya koymaktadır. Model sonrası elde edilen bulgulara göre, belirlenen ürünün toplam maliyetinde %16,58'lik bir azalma gözlemlenmiştir. Sonuç olarak, çalışmada önerilen stok kontrol yönteminin, geleneksel yönteme kıyasla daha düşük maliyetli olduğu ve işletmeye kâr ve avantajlar sağlayabileceği belirlenmiştir.Electronic commerce, or e-commerce for short, is a trade model in which product tracking, ordering, supply and payment transactions are carried out over the internet. Businesses operating in the field of e-commerce face rapidly changing consumer demands, fluctuating supply chains and dynamic market conditions. These factors complicate the inventory management processes of businesses and make it difficult for them to effectively control inventory levels. At this point; businesses apply inventory control strategies to provide competitive advantage against rapidly changing consumer demands, minimise inventory costs, increase customer satisfaction and manage operational processes effectively. Within the scope of the study, a Q,R inventory control model was created and an optimisation study was carried out. The modelling study conducted on the product determined for the application reveals how inventory control can be managed effectively. According to the findings obtained after the model, a 16.58% reduction in the total cost of the specified product was observed. As a result, it has been determined that the inventory control method proposed in the study is less costly than the traditional method and can provide additional profits and advantages to the business
Looking at the communication perspectives of environmental and ecology organizations through social media: The Northern Forests Defense and Greenpeace International
No full textÇevre bilinci ve doğal kaynakların korunması, günümüzde modern toplumların önceliklerinden biri haline gelmiştir. Çevre ve ekoloji odaklı oluşumların iletişim stratejileri de sosyal medya platformlarının yükselişiyle birlikte kritik bir rol oynamaktadır. Bu araştırma, küresel çapta etkinlik sürdüren Greenpeace International ile yerel düzeyde faaliyet gösteren Kuzey Ormanları Savunması örgütlerinin sosyal medya hesaplarını analiz ederek sosyal medya kullanımlarını karşılaştırmayı hedeflemektedir. Çalışmada, içerik analizi yöntemiyle her iki örgütün Mayıs-Kasım 2023 tarihleri arasındaki X hesaplarındaki paylaşımları beğeni, tekrar paylaşım ve yorum sayılarına dayanarak etkileşim düzeyleri arasında
karşılaştırmalar yapılmıştır. Ayrıca yapılan paylaşımlarda hangi içeriklere odaklanıldığı ve hangi konuların ön plana çıkarıldığı analiz edilmiştir. İnceleme sonucunda, Kuzey Ormanları Savunması ve Greenpeace International’ın X’te yayınladıkları gönderilerde bazı benzerlikler ve farklılıklar tespit edilmiştir. Aylık gönderilere bakıldığında her iki örgütün de düzenli paylaşım yaptığı görülmektedir. Ayrıca gönderi içerikleri karşılaştırıldığında protesto gösterilerine çağrı, çevreye zarar veren uygulamalar hakkında bilgilendirme ve gönüllülük çağrısının her iki örgütün de en fazla kullandıkları içerikler olduğu tespit edilmiştir. Gönderilerde ele alınan olaylar ise birbirinden farklılık göstermektedir. Kuzey Ormanları Savunması yerel olaylara odaklanırken Greenpeace International ise uluslararası çevre sorunlarını gündeme taşımaktadır.Environmental awareness and the protection of natural resources have become one of the main priorities of modern societies. With the rise of social media platforms, the communication strategies of environmental and ecological organisations also play a crucial role. This research aims to compare the communication strategies of Greenpeace International, which operates globally, and the Kuzey Ormanları Savunması, which operate locally, by analyzing their social media accounts. In the study, comparisons were made between the interaction levels of both organizations based on the number of text, photo and video contents, likes, reshares and comments posted on the X accounts of both organizations between May and November 2023, using the content analysis method. “The analysis revealed some similarities and differences in the posts published on X by the the Northern Forests Defense and Greenpeace International. Looking at the monthly posts, it was observed that both organizations share content regularly. Additionally, when comparing the content of the posts, it was found that calls for protests, information about practices harmful to the environment, and calls for volunteerism are the most frequently used content by both organizations. However, the events covered in the posts differ from each other. While the the Northern Forests Defense focuses on local events, Greenpeace International highlights international environmental issues.
Comparison of experimental thermal conductivity of water-based Al2O3–Cu hybrid nanofluid with theoretical models and artificial neural network output
No full textThe research aimed to experimentally test the thermal conductivity of five distinct Al2O3–Cu/water hybrid nanofluids. These nanofluids were generated at volumetric concentrations of 0.0125, 0.025, 0.05, 0.1, and 0.2. The measurements were conducted within a temperature range of 10–65 °C. The primary objective of this research is to tackle the insufficient empirical data on hybrid nanofluids and establish a dependable artificial neural network model for forecasting their thermal conductivity. A multilayer perceptron feed forward back propagation artificial neural network has been created using the acquired experimental thermal conductivity data. The experimental thermal conductivity data have been compared with four commonly used mathematical correlations and the outputs of an artificial neural network. The findings demonstrated that the constructed artificial neural network accurately forecasted the thermal conductivity of the Al2O3–Cu/water hybrid nanofluid, with an average deviation of just 0.4%. Nevertheless, Maxwell’s mathematical correlation proved to be the most accurate model in predicting the experimental findings, with an average error margin of just 0.08%. © Akadémiai Kiadó, Budapest, Hungary 2024
Investigation of teachers' opinions on the applicability of artificial intelligence in education in the perspective of industry 4.0
No full textBu çalışmada Endüstri 4.0 perspektifinde yapay zekanın eğitimde uygulanabilirliği ile ilgili öğretmen görüşlerinin incelenmesi amaçlanmıştır. Araştırma nitel araştırma yöntemlerinden olgubilim deseninde olup verilerin toplanması için araştırmacılar tarafından alanyazına dayalı olarak hazırlanan yarı yapılandırılmış görüşme formu kullanılmıştır. Araştırmanın çalışma grubunu lisansüstü eğitim almış veya almakta olan 15 öğretmen oluşturmaktadır. Araştırma sonucunda öğretmenlerin Endüstri 4.0 perspektifinde yapay zekanın eğitimde kullanılmasına hazırlıklı olunabilmesi için stratejik planlarda yer verilmesinin gerekli olduğunu düşündükleri ve endüstri 4.0 ve yapay zekâ ile ilgili eğitim almaya istekli oldukları görülmüştür. Öğretmenler yapay zekâ teknolojilerinin ve endüstri 4.0 araçlarının eğitime entegre edilmesinin öğrenciler için zengin öğretim materyali sağlayacağını, kişiye göre öğrenmenin önünü açacağını, öğretmenin üzerindeki öğretim faaliyetleri dışındaki iş yükünü hafifleteceğini düşünmektedirler. Ayrıca eğitimde yapay zekâ kullanımının öğrencileri tembelleştirebileceği ve veri güvenliği gibi endişeler taşımaktadırlar. Öğretmenler sosyal-duygusal öğrenme noktasında insan öğretmenlere hep ihtiyaç olacağını düşünmekte ve bu konudaki yerlerini yapay zekaya kaptırmayacaklarından emin görünmektedirler.In this study, it is aimed to examine the opinions of teachers about the applicability of artificial intelligence in education in the perspective of Industry 4.0. The research is based on one of the qualitative research methods, a phenomenological design, and a semistructured interview form prepared by the researchers based on the literature was used to collect the data. The study group of the study consists of 15 teachers who have received or are currently receiving postgraduate education. As a result of the research, it was found that teachers think that it is necessary to include artificial intelligence in strategic plans in order to be prepared for the use of artificial intelligence in education from the perspective of Industry 4.0 and are willing to receive training related to industry 4.0 and artificial intelligence. Teachers believe that the integration of artificial intelligence technologies and industry 4.0 tools into education will provide rich teaching materials for students, pave the way for learning according to the individual, and ease the workload of the teacher outside of teaching activities. In addition, they have concerns such as that the use of artificial intelligence in education may make students lazy and data security. Teachers think that there will always be a need for human teachers at the point of social-emotional learning and they seem confident that they will not lose their place to artificial intelligence in this regard
Modeling and solution of eigenvalue problems of laminated cylindrical shells consisting of nanocomposite plies in thermal environments
No full textThis work is dedicated to the modeling and solution of eigenvalue problems within shear deformation theory (SDT) of laminated cylindrical shells containing nanocomposite plies subjected to axial compressive load in thermal environments. In this study, the shear deformation theory for homogeneous laminated shells is extended to laminated shells consisting of functionally graded (FG) nanocomposite layers. The nanocomposite plies of laminated cylindrical shells (LCSs) are arranged in a piecewise FG distribution along the thickness direction. Temperature-dependent material properties of FG-nanocomposite plies are estimated through a micromechanical model, and CNT efficiency parameters are calibrated based on polymer material properties obtained from molecular dynamics simulations. After mathematical modeling, second-order time-dependent and fourth-order coordinate-dependent partial differential equations are derived within SDT, and a closed-form solution for the dimensionless frequency parameter and critical axial load is obtained for first time. After the accuracy of the applied methodology is confirmed by numerical comparisons, the unique influences of ply models, the number and sequence of plies and the temperature on the critical axial load and vibration frequency parameter within SDT and Kirchhoff–Love theory (KLT) are presented with numerical examples
Türkiye-Rusya ikili ticaret ilişkisinin analizi: Rusya-Ukrayna savaşının zorlukları ve fırsatları
No full textPurpose: This study examines Turkey's bilateral trade intercourse with Russia in order to identify potentialities and problems for Turkey caused by the Russia-Ukraine War. Method/Design/Methodology/Approach: In the course of the study, with the help of descriptive statistics and calculations of trade indices such as trade intensity and trade complementarity indices, the current state of Russian-Turkish trade was examined. Afterwards, commodity sectors in which supply is expected to fall due to international companies’ suspension of businesses were identified. Next, the revealed comparative advantage index and its dynamic form were calculated to assess Turkey's potentialities to export commodities of the identified sectors to Russia and to highlight commodities groups where export policy should be improved. Thus, the study considers Russia and Turkey not as competitors, but as partners. Findings: It has been concluded that the countries have tight-connections and, to a certain extent, are dependent on one another. Both Russia and Turkey can benefit from further intensifying bilateral trade and improving partnership in other spheres as well. Originality: There is substantial literature comparing Russia and Turkey with other countries, trade blocks or with each other, mainly these two countries are counterposed from a competition perspective. This article, on the contrary, evaluates how cooperation and bilateral trade can improve the economic situation of both Russia and Turkey.Amaç: Bu araştırma, Rusya-Ukrayna Savaşı'nın Türkiye için yarattığı potansiyelleri ve sorunları tespit etmek için Türkiye'nin Rusya ile ikili ticari ilişkilerini incelemektedir. Yöntem/Tasarım / Metodoloji / Yaklaşım: Çalışma kapsamında, tanımlayıcı istatistikler ve ticaret yoğunluğu ve ticaret tamamlayıcılık endeksleri gibi ticaret endekslerinin hesaplamaları yardımıyla, Rusya-Türkiye ticaretinin mevcut durumu analiz edilmiştir. Ardından, uluslararası şirketlerin faaliyetlerini durdurması nedeniyle arzın düşmesinin beklendiği emtia sektörleri belirlendi. Türkiye'nin belirlenen sektörlere ait malları Rusya'ya ihraç etme potansiyelini değerlendirmek ve ihracat politikasının iyileştirilmesi gereken mal gruplarını vurgulamak için açıklanmış karşılaştırmalı üstünlük endeksi ve onun dinamik formu hesaplandı. Bu nedenle çalışma, Rusya ve Türkiye'yi artık rakip, ancak ortak olarak görmektedir. Bulgular: Ülkelerin sıkı bağlara sahip olduğu ve bir ölçüde de birbirine bağımlı olduğu sonucuna varılmıştır. Hem Rusya hem de Türkiye, ikili ticaretin daha da yoğunlaştırılmasından ve diğer alanlarda da ortaklığın geliştirilmesinden yararlanabilir. Özgünlük: Rusya ve Türkiye'yi diğer ülkelerle, ticaret bloklarıyla veya birbirleriyle karşılaştıran önemli bir literatür vardır, esas olarak bu iki ülke rekabet perspektifinden karşı karşıya getiriliyor. Bu makale, aksine, işbirliğinin ve ikili ticaretin hem Rusya hem de Türkiye'nin ekonomik durumunu nasıl iyileştirebileceğini değerlendiriyor
Natural language text to programming language code generation studies: a review
No full textSon yıllarda Doğal Dil İşleme (DDİ) alanındaki gelişmelerin hız kazanması, araştırmacıların ve programcıların bu alana olan ilgisini büyük ölçüde artırmıştır. Bilgisayar programlarını doğal dil komutlarıyla yazma konsepti, birçok araştırmacının odak noktası haline gelmiştir. Literatür incelendiğinde, doğal dil ile programlama üzerine yapılan araştırmaların uzun bir geçmişe sahip olduğu açıkça görülmektedir. Bu uzun soluklu araştırmalar, çeşitli çözüm önerilerini beraberinde getirmiş ve kural tabanlı yöntemlerden, olasılık tabanlı yöntemlere, makine öğrenmesi yöntemlerinden derin öğrenme yöntemlerine kadar bir dizi çözüm yaklaşımının ortaya çıkmasına neden olmuştur. Literatürdeki çalışmalar tarihsel olarak kategorize edildiğinde geçmiş tarihli çalışmalarda kural tabanlı ya da istatistik tabanlı modeller üzerine yoğunlaştığı görülürken günümüze yaklaşıldıkça makine öğrenmesi ve derin öğrenme temelli çalışmaların arttığı görülmektedir. Kural tabanlı yöntemler, olasılık tabanlı yöntemler, makine öğrenmesi yöntemleri, derin öğrenme yöntemleri gibi çeşitli yaklaşımların geliştirildiği literatürde, bu çeşitlilik yeni araştırmacıların bu alana giriş yaparken karşılaşabileceği karmaşıklığı artırabilmektedir. Bu çalışma, doğal dil girdileriyle programlama dili kodu oluşturma çalışmalarına yönelik literatürde geliştirilen 32 yöntemin detaylı bir incelenmesini sunmaktadır. Çalışmanın amacı, literatürde tespit edilen çeşitli yöntemlerin zaman içerisindeki değişimlerinin gözden geçirilmesi, çalışmaların geniş bir perspektiften incelenerek genel bir çerçeve içinde toplanması ve bu alanda çalışacak olan araştırmacılara rehberlik edebilmesidir.The recent surge in advancements in Natural Language Processing (NLP) has significantly heightened the interest of researchers and programmers in this field. The concept of writing computer programs using natural language commands has become a focal point for many researchers. Upon reviewing the literature, it is evident that research on natural language programming has a long history. These extensive studies have led to the proposal of various solutions, ranging from rule-based methods to probability-based approaches, machine learning methods, and deep learning techniques. When the studies in the literature are categorized historically, it is seen that the past studies focused on rule-based or statistical-based models, while machine learning and deep learningbased studies have increased as we approach the present. The diversity of approaches, including Rule-based methods, probabilitybased methods, machine learning methods, deep learning methods, and others, as found in the literature, can potentially confuse newcomers entering this field. This paper presents a detailed review of 32 methods developed in the literature for generating programming language code with natural language input. The goal of this study is to review the changes in various methods identified in the literature over time, to collect the studies in a general framework by examining them from a broad perspective and provide guidance to researchers intending to work in this area
Energetic and exergetic metrics of a cargo aircraft turboprop propulsion system by using regression method for dynamic flight
No full textNowadays, the development of aviation in line with sustainability goals is one of the current challenges. Being a source of environmental impact, aero-engines have been the main research and design object for achieving these aims. In this study, thermodynamic analysis involving exergy and sustainability computations is performed at different flight conditions where Mach varies between 0 and 0.7 and altitude changes between 0 and 7.7 km. Based on this analysis, modeling exergy parameters for each component are carried out with multiple regression approach. The exergy efficiency of turboprop engine at dynamic flight conditions varies between 15% and 25.9% whereas it is measured between 76 and 77% for the combustor and between 93 and 99% for gas turbine. Moreover, exergy destruction of the turboprop engine changes between 2.15 MW and 7.55 MW. Exergetic improvement potential rate (IPR) of the combustor resides between 0.4 MW and 1.21 MW throughout flight conditions whereas it is found at orders of 0.1 MW or less for other components. On the other hand, linear and quadratic modelings are performed for several parameters of turboprop engine components including exergy efficiency, exergy destruction and IPR under dynamic flight conditions. The determination coefficient (R2) of the models changes between 0.69 and 0.98 in linear modeling, whereas R2 in quadratic modeling improves to 0.97 and 0.99 ranges. It is thought that component-based modeling by considering different flight conditions could contribute to determining points where component efficiency is the highest
Artificial neural network-based cooling capacity estimation of various radiator configurations for power transformers operated in ONAN mode
No full textPower transformers submerged in oil are universally acknowledged as very useful elements in electrical power networks. A fraction of the electrical energy involved in the conversion from high to low voltages is lost as thermal energy, which is produced inside the transformer's windings and core. The effective dissipation of heat is of paramount significance and can be accomplished through the strategic installation of radiators on the tank. This study aims to examine the total cooling capacity of a radiator employed for cooling a power transformer operating in oil, natural air, and natural mode. The investigation is conducted by varying the design parameters, specifically the number of fins per radiator and the radiator length. The study also utilizes computational fluid dynamics results to achieve a substantial convergence with experimental findings. In the context of the verification study conducted for a specific study point, it was found that the simulation outcomes at a mass flow rate of 0.15 kg/s corresponded to about 7.4 % of the experimental results. Additionally, the cooling capacity value obtained was 7.2 %. In the context of machine learning, the performance of the numerical approach was assessed by employing the Bayesian regularization method. The evaluation revealed that the margin of deviation, mean squared error, and coefficient of determination (R2) metrics yielded values of ?0.001 %, 1.32E-02, and 0.99930, respectively
Do Fiscal Policy Outcomes Promote Ethno-Religious Stability in African States?
No full textThis paper studies the conditions under which the use of expansionary fiscal policy may mitigate the risk of initiation, escalation, and repeated cycles of conflict on the African continent. To date, empirical evidence highlighting the effectiveness of expansionary fiscal policy as a means of mitigating conflict in Africa is still limited. This article is an attempt to fill this gap as it addresses this important empirical question in conflict-plagued Africa. The study further expands on previous studies by examining the efficacy of increased government expenditure on conflict in general, as well as on the ethnic and religious dimensions of conflict in Africa. The most encountered forms of conflict in recent times are those that cannot be neatly classified as war, peace, criminal violence or political violence. Ethnic and religious conflicts often fall into this class. This study finds that overall, non-military government expenditures across African states have played a significant role in minimizing general internal conflict, as well as ethnic and religious conflicts. Using data for 32 African nations for the period 1990–2016, the empirical analyses show that raising overall government expenditure can induce reductions in overall internal, ethnic and religious conflicts. The results suggest that total government expenditure has a stronger impact on the reduction of ethnic conflict on the continent. Empirical outcomes also show that causality varies across countries on the continent, an indication that the relationship between conflict and government expenditure is heterogeneous in nature across the continent. The causal effect of government expenditure is however most widespread for ethnic conflict