Araştırma Çıktıları | TR-Dizin | WoS | Scopus | PubMed

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Citation - WoS: 2
Citation - Scopus: 1
94.8 Km-Range Direct Detection Fiber Optic Distributed Acoustic Sensor
(Optica Publishing Group (Formerly OSA), 2019) Uyar, F.; Onat, T.; Unal, C.; Kartaloǧlu, T.; Ozdur, I.; Özbay, E.; 01. Abdullah Gül University
This work demonstrates an ultra-long range direct detection fiber optic distributed acoustic sensor which can detect vibrations at a distance of 94.8 km with 10 m resolution along the sensing fiber. © 2023 Elsevier B.V., All rights reserved.
Citation - WoS: 2
Citation - Scopus: 3
94.8 Km-Range Direct Detection Fiber Optic Distributed Acoustic Sensor
(Institute of Electrical and Electronics Engineers Inc., 2019) Uyar, Faruk; Onat, Talha; Unal, Canberk; Kartaloǧlu, Tolga; Ozdur, Ibrahim T.; Özbay, Ekmel; 01. Abdullah Gül University
This work demonstrates an ultra-long range direct detection fiber optic distributed acoustic sensor which can detect vibrations at a distance of 94.8 km with 10 m resolution along the sensing fiber. © 2019 Elsevier B.V., All rights reserved.
Absolute Phase Noise Analysis of a Harmonically Modelocked Semiconductor Laser
(Optica Publishing Group (formerly OSA), 2017) Özharar, Sarper; Ozdur, Ibrahim T.; 01. Abdullah Gül University
We have designed and built a fiber coupled semiconductor laser at 1550 nm, which is harmonically mode-locked at 10 GHz by an external RF oscillator. The absolute phase noise of the laser is measured and discussed for two different cavity lengths. © 2023 Elsevier B.V., All rights reserved.
Accurate Prediction of Residual Stresses in Machining of Inconel 718 Alloy through Crystal Plasticity Modelling
(2023) Bal, Burak; Cetın, Barıs; Yılmaz, Okan Deniz; Kesriklioglu, Sinan; Kapçı, Mehmet Fazıl; Buyukcapar, Ridvan; 01. Abdullah Gül University; 02.06. Makine Mühendisliği; 02. Mühendislik Fakültesi
Artık gerilmelerin belirlenmesi ve değerlendirilmesi, savunma, havacılık ve otomotiv endüstrilerinde kullanılan bileşenlerin arızalanmasını önlemede çok önemlidir. Bu çalışmanın amacı, Inconel 718'in işlenmesi sırasında oluşan artık gerilmeleri doğru bir şekilde tahmin etmek için bir malzeme modeli sunmaktır. Ortogonal talaşlı imalat testleri, çeşitli kesme ve ilerleme hızlarında gerçekleştirilerek, Inconel 718'in işlenmesinden sonraki artık gerilmeler, X-Ray ışın kırınımı ile karakterize edildi. Bu süper alaşımın mikroyapısal girdilerini ticari olarak temin edilebilen bir sonlu eleman yazılımına (Deform 2D) aktarmak için bir viskoplastik kendi içinde tutarlı kristal plastisite modeli geliştirildi. Ayrıca simülasyonlar klasik Johnson - Cook malzeme modeli ile aynı işleme parametrelerinde yapıldı. Bu çalışmada elde edilen simülasyon ve deneysel sonuçlar, kristal plastisite tabanlı çok ölçekli ve çok ölçekli malzeme modelinin, mevcut modele kıyasla Inconel 718'in işleme kaynaklı kalıntı gerilmelerinin tahmin doğruluğunu önemli ölçüde geliştirdiğini ve yüzey kusurlarını en aza indirmek için kullanılabileceğini göstermiştir. Geliştirilen bu model, kesilmesi zor malzemelerin işlenmesinde yüzey kusurlarını ve üretim denemelerinin maliyetini en aza indirmek için kullanılabilir.
Acoustic Transformation of Rock-Cut Caves Into Performance Spaces
(European Acoustics Association, EAA, 2023) Aslan, Ahmet; Şaher, Konca; Tozoğlu, Ahmet Erdem; 01. Abdullah Gül University; 05.01. Mimarlık; 05. Mimarlık Fakültesi
Cappadocia Region in Turkey is a center of attention as a tourism destination with its rock-cut caves, some of which are being used as performance spaces for concerts, festivals and local entertainment activities. However, these spaces are not fully investigated for their acoustic performance before being transformed into performance venues. This paper reports on the findings of an initial survey which presents a systematic mapping of the rock-cut caves used as performance spaces to locate, explore and document a sample of structures scattered in this historic district. A typological classification based on volume, size, type of tuff rock material and historical original use has been proposed and an acoustic analysis of some selected rock-cut caves has been carried out. The acoustic analysis included reverberation time calculations and simulations based on apparent volume, and tuff stone absorption characteristics, which were studied by other researchers in the area. © 2024 Elsevier B.V., All rights reserved.
Active Control of the Nanoparticle Self-Assembly for Photonic Applications
(META Conference, 2023) Erdem, Talha; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
Colloidal nanoparticles enable collective utilization of the inherent properties of the nanoparticles. Furthermore, their collective optical response can be fine-tuned employing DNA-driven self-assembly. Here, we present that the optical transmission of self-assembled DNA-functionalized gold nanoparticle network can be actively manipulated using an external optical excitation. We also show control of optical polarization of emitted light from semiconducting supraparticle networks hybridized with magnetic supraparticles. These results prove the potential of programmed nanoparticle self-assembly in tailoring optical features of colloidal systems. © 2023 Elsevier B.V., All rights reserved.
Adaptive Re-Use of Medieval Caravanserais in Central Anatolia
(Gangemi Editore S P A, 2019) Yoney, Nilufer Baturayolu; Asiliskender, Burak; Urfalioglu, Nur; 01. Abdullah Gül University; 05.01. Mimarlık; 05. Mimarlık Fakültesi
Kayseri, located at the junction of two major trade routes from northeast to southwest and from southeast to northwest, has been a commercial center for at least 4,000 years. The 23,500 tablets found at the Assyrian trade colony in Kanesh-Karum dating around 2,000 BCE and located 20km from the modern city provide ample proof. The great number and relevant size of Medieval caravanserais around the city as well as commercial buildings at the center indicate that this importance continued. Some of these caravanserais are already in use, albeit with inadequate architectural preservation measures while others are abandoned and/or partially destroyed. Indeed, the preservation, restoration and adaptive re-use of Medieval buildings is a major problematic, bringing out issues and interventions related to lacunae and reintegration, liberation or clearance of additions, structural strengthening with traditional/contemporary technologies, partial reconstruction, consolidation, cleaning and conservation of original building materials, and preventive maintenance. This paper aims to consider the possible presentation and adaptive re-use of Seljukid caravanserais over and inventory of accessible and at least partially preserved examples, focusing on eight case studies from the late 12th and 13th centuries: Karatay Han (1240), Tuzhisar Sultan Han (1232-1236), Eshab-i Kehf Han (before 1235), Cirgalan Han, Saruhan, Agzikarahan (1231-1240), Alayhan and Oresin Han.
Citation - Scopus: 2
Adaptive Reuse of Industrial Heritage: Resilience or Irreparable Loss
(Docomomo, 2016) Baturayoğlu Yöney, Nilüfer; Asiliskender, Burak; Özer, Aysegul; 01. Abdullah Gül University; 05.01. Mimarlık; 05. Mimarlık Fakültesi
The restoration and adaptive reuse of industrial heritage buildings and complexes, which present structurally and functionally resilient shells, provide us with an interesting dilemma in theory and practice: made of hard wearing materials to house straining functions and to last as long as possible, they are also flexible enough to adapt to almost any new purpose as a container. However, the presence of original machinery and equipment as well as designs based on machine-buildings may reduce the possibilities of adaptive reuse to a museum, where the buildings exhibit themselves, retaining the social, economic, historic and public aspects of cultural heritage as documents. Although originally built on the outskirts of urban settlements, today most industrial heritage complexes occupy central locations in the metropolitan sprawl of major cities. If disused, they are considered obsolete brownfields by local authorities and citizens despite personal and collective memories that may be attached to them. Their conversion into new uses presents major technical difficulties that require expertise in design and implementation. This paper discusses the theoretical and practical aspects of the adaptive reuse of industrial heritage and inherent problems, focusing on the case of the Sümerbank Kayseri Textile Factory (I. Nikolaev, Turkstroj, 1932-1935), which is being transformed into the campus of Abdullah GUI University. The restoration, renovation and adaptive reuse projects for different components of the complex follow similar principles of preservation and sustainability while they are modified to fit the architectural and technological characteristics of each building. Thus, although conversive and easily adaptable, the preservation of industrial architectural heritage becomes a dilemma between disruption and continuity, which the architects have to solve going beyond the possibilities of mere building stock on the one hand and that of the museum on the other. © 2017 Elsevier B.V., All rights reserved.
Advanced Physicochemical Techniques for Wastewater Treatment
(CRC Press, 2024) El Messaoudi, Noureddine; Georgin, Jordana; Cioğeroğlu, Zeynep; Şenol, Zeynep Mine; Kazan-Kaya, Emine Sena; Arslan, Dilek Şenol; Lacherai, Abdellah; 01. Abdullah Gül University; 02.07. Malzeme Bilimi ve Nanoteknoloji Mühendisliği; 02. Mühendislik Fakültesi
This chapter provides an overview of advanced physicochemical techniques (APCTs) used in wastewater treatment, highlighting their principles, applications, and recent advancements. The chapter begins by discussing the APCTs involved in wastewater treatment, including membrane techniques, electrochemical methods, sonochemical treatment, microwave-assisted processes, hybrid processes, and green chemistry approaches. It explores the mechanisms by which these processes remove suspended solids, colloidal particles, and other contaminants from wastewater. The APCTs are versatile and can be applied to treat wastewater containing diverse pollutants, including heavy metals, organic compounds, and microorganisms. This versatility makes them suitable for various industrial and municipal wastewater streams. These methods are designed to target specific contaminants, resulting in the effective treatment and purification of wastewater. These techniques can be integrated with conventional wastewater treatment processes, enhancing overall treatment efficiency. Ongoing research and development in APCTs contribute to continuous innovation, leading to the discovery of new and improved methods for wastewater treatment. The chapter presents case studies and discusses the advantages, limitations, and future prospects of APCTs. © 2024 Elsevier B.V., All rights reserved.
Advances in the Computation of NMR Parameters for Inorganic Nuclides
(Elsevier, 2023) Holmes, Sean T.; Alkan, Fahri; Dybowski, Cecil R.; 01. Abdullah Gül University
In this article, we discuss practical aspects of the computation of NMR parameters of inorganic nuclides, as well as insights afforded by such calculations into the characterization of molecular-level structure and dynamics and the validation of theoretical models. An emphasis is placed on calculation of the magnetic shielding tensors of solids using cluster-based models that account for intermolecular interactions. In particular, the use of valence modification of terminal atoms using bond valence theory (VMTA/BV), which reduces net charges on clusters through terminal pseudoatoms with nonstandard nuclear charges, is demonstrated to be a robust technique for calculations on nuclei in network solids. Cluster-based calculations, including those that employ the VMTA/BV method, afford a unique opportunity to calculate magnetic shielding tensors for nuclei in solids by using density functional theory approximations beyond the generalized gradient approximation and by incorporating relativistic effects at the spin-orbit level. These developments are spurred by use of the zeroth-order regular approximation (ZORA), which provides a robust method of accounting for relativistic effects (up to the spin-orbit level) experienced by valence electrons. Calculations of NMR parameters are discussed for fluorine, cadmium, tin, tellurium, mercury, lead, and platinum, all of which have seen significant advances in recent years. These examples highlight the importance of such factors as coordination geometry, oxidation state, relativistic effects, and density functional approximations on computed magnetic shielding tensors. © 2023 Elsevier B.V., All rights reserved.
Agency Theory: A Review in Finance
(2020) Polat, Ali Yavuz; Tekin, Hasan; 01. Abdullah Gül University
Temsil ve risk paylaşımı problemleri büyük firmalarda sahiplik ve kontrolün ayrılmış olmasından dolayı, müvekkil (sahipler) ve vekil (yöneticiler) arasında çıkar çatışması olduğunda ortaya çıkmaktadır. Bu problemler temel olarak bilgi asimetrisinden kaynaklanmaktadır. Bu da müvekkil için vekalet maliyeti ortaya çıkarmaktadır. Halihazırdaki önemli teorilerden biri olan Vekil Teorisi vekalet ilişkilerindeki maliyetleri minimize etmeye odaklanmaktadır. Bu çalışma müvekkil-vekil ilişkilerini daha iyi anlamak için, kurumsal finans alanındaki hissedar-yönetici ve tahvil sahibi-hissedar ilişkilerine odaklanarak, müvekkil-vekil ilişkilerini kritik bir şekilde değerlendirmektedir.
AI-Enhanced PV Power Forecasting Using Cloud Thickness and Motion in Kayseri, Türkiye
(Wiley, 2025) Yavuz, Levent; Onen, Ahmet; Awad, Ahmed; Ahshan, Razzaqul; Al-Badi, Abdullah; 01. Abdullah Gül University
The incorporation of renewable energy in photovoltaic (PV) systems has made significant progress. The inherent intermittency nature of PV generation, nevertheless poses an obstacle to accurate energy forecasting. Historical PV production plus meteorological data such as temperature, humidity, and atmospheric pressure are largely utilized in present methods of forecasting. However, cloud thickness and dynamics-integrated system, has not been investigated and tested in real-world examples yet.This research seeks to fill this gap in research through the development of a new AI-based PV forecasting model that incorporates cloud thickness, cloud motion, and solar position into the forecasting model. Cloud properties and their impact on solar radiation are computed through a deep learning-based panel-shadowing model. For cloud movement forecasting, a gated recurrent unit (GRU) is used, while multiple convolutional neural networks (CNNs) are used for estimating cloud thickness. These outcomes are then integrated with measurements from environmental sensors to improve the accuracy of the predictions.The system was implemented and tested at Abdullah G & uuml;l University and exhibited a remarkable improvement in forecasting accuracy compared to current models. The results prove that cloud motion and thickness improve the accuracy of PV predictions, which is important for energy market stability and power grid operations.
Citation - Scopus: 1
Air Gun With Water Bullet
(Eindhoven University of Technology, 2023) Bozkuş, Zafer; Dinçer, A. Ersin; Tijsseling, A. S.; van de Ven, Alphons A.F.; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
The gun is a 12 m long inclined pipe of 0.1 m diameter which is connected to a charge of compressed air contained in a 0.5 m3 vessel. The bullet is a slug of water sitting in the upstream lower end of the pipe. The trigger is a hand-operated valve. The target is an elbow at the upstream higher end of the pipe. The smoking gun effect is created by a mist of water coming out of the pipe after each shot. The apparatus is not a toy but meant for serious research. When steam lines are out of operation and/or lack thermal insulation, liquid water collects in the lower parts of the system. System restart may accelerate the water slugs to velocities as high as 50 m/s, and subsequent slug impacts on elbows and orifices may cause pressure peaks with magnitudes only encountered in water-hammer events. The experimental programme consists of water slugs fired towards an elbow with an open end, a closed end, and an orifice end. The varied parameters are air pressure, water mass, outlet condition (open, closed, orifice). Upstream driving pressure and downstream impact pressure are measured in each experimental run. Pressure peaks up to 50 bar have been observed. Experimental results are compared with preliminary predictions from basic one-dimensional models. © 2024 Elsevier B.V., All rights reserved.
Akciğer Tümörlü Hastaların PET ve BT Görüntülerinin Çakıştırılıp Birleştirilmesi
(IEEE, 2015) Ayyildiz, Oguzhan; Yilmaz, Bulent; Karacavus, Seyhan; Kayaalti, Omer; Icer, Semra; Eset, Kubra; Kaya, Eser; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
Image fusion attracts attention in medical field due to complementary behavior and application such as diagnosis and treatment planning. In this study, first positron emission tomography (PET) and computed tomography (CT) images coming from 8 nonsmall cell lung cancer were registered then wavelet and principal component analysis methods were applied to fuse images. According to mutual information metric and nuclear medicine expert wavelet method gave better results when compared to PCA.
Citation - Scopus: 2
Akıllı Şebeke Uygulamaları için Pille Çalışan Duyarga Düğümlerinin Yaşam Süresi Analizi
(Institute of Electrical and Electronics Engineers Inc., 2016) Eris, Cigdem; Güngör, Vehbi Çağrı; Boluk, Pinar Sarisaray; 01. Abdullah Gül University
Wireless Sensor Networks (WSNs) enable smart grids where sensor nodes monitor and control the important parameters of power grid components. However, energy-aware communication protocols should be developed to extend network lifetime of WSNs in smart grid environments. In this study, the lifetime of wireless sensor nodes has been analyzed for various smart grid environments, such as 500 kV substation, main power control room, and underground network transformer vaults. In addition, the effects of different operation modes of sensor nodes on node lifetime have been reviewed. © 2017 Elsevier B.V., All rights reserved.
Citation - Scopus: 4
Alliances to Acquisitions: A Road Map to Advance the Field of Strategic Management
(Emerald Group Publishing Ltd. Howard House Wagon Lane, Bingley BD16 1WA, 2017) Zakaria, Rimi; Genç, Omer Faruk; 01. Abdullah Gül University
Although primarily treated as two distinct research streams, strategic alliances and mergers and acquisitions together occupy much of the strategic management discourse. Alliances, in many cases, end in acquisitions as firms use alliances as intermediate strategic options to eventually acquire a partner. As the discipline of strategy matures and the frequency and the volume of inter-firm cooperation continue to rise, it is imperative to integrate these two research streams for a holistic understanding of the theory of the firm. The purpose of this conceptual piece is threefold. First, we review the extant studies that combine these two governance modes: alliance and acquisitions. Second, drawing on the dominant strategic management theories, we highlight how prior inter-firm alliances inform future acquisitions in terms of (a) pre-combination decisions, (b) post-deal integration processes, (c) alternatives and strategies, and (d) performance outcomes. Finally, in view of the emerging trends and evocative gaps, we offer a conceptual road map to encourage future theoretical development and empirical research. © 2017 Elsevier B.V., All rights reserved.
Citation - WoS: 7
Citation - Scopus: 12
Ambient Energy Harvesting for Low Powered Wireless Sensor Network Based Smart Grid Applications
(Institute of Electrical and Electronics Engineers Inc., 2019) Faheem, Muhammed Yasir; Ashraf, Muhammad Waqar; Butt, Rizwan Aslam; Raza, Basit; Ngadi, M. A.; Güngör, Vehbi Çağrı; 01. Abdullah Gül University
Limited battery lifetime is one of the most critical issues for wireless sensor networks (WSNs)-based smart grid (SG) applications. Recently, ambient energy harvesting (AEH) has been considered to significantly improve the network lifetime of the WSNs-based SG applications. However, extracting a significant amount of energy from the ambient energy resource due to time varying links quality affected by power grid environments is the main issue for WSNs-based applications in SG. In this paper, we propose a novel multi-source energy harvesting mechanisms for WSNs-based SG applications. The propose hybrid ambient energy harvesting framework through the designed circuitry successfully harvests massive power density by capturing the radial electric field (EF) and ambient radio frequency WiFi 2.4GHz band signals present in the vicinity of 500kV power grid station. The design energy harvesting schemes have been implemented on the recently developed routing protocol for SG applications. The experiments using EstiNet9.0, demonstrate that the designed framework is efficient in terms of energy harvesting capabilities to enable a long-lasting lifetime of the WSNs-based smart grid applications. © 2020 Elsevier B.V., All rights reserved.
Amerikan İşletme İdeolojisinin Türkiye’ye Gelişi, Yayılışı ve Ücret Tartışmaları,1960-1980
(2019) Balkılıç, Özgür; 01. Abdullah Gül University; 06. İnsan ve Toplum Bilimleri Fakültesi; 06.03. Sosyoloji
1960-1980 arasında yeni bir toplu sözleşme düzenine geçilmesiyle ve kalkınma, sosyal adalet, ücreteşitsizlikleri gibi konularda kamusal tartışmaların gittikçe yoğunlaşmasıyla birlikte sermaye sahiplerinin enönemli gündemlerinden birisi sınai karlılıklarını gizlemek/arttırmak ve bunu yaparken de emek süreçleriüzerindeki denetimlerine özellikle örgütlü emeğin rızasını almaktı. Bu anlamda, özellikle 1945 sonrası dünyayayayılan Amerikan işletme ideolojisi burjuvazinin/işletme yöneticilerinin bir yandan kapitalist karları gizlemekve diğer yandan emek üzerindeki denetimi sağlamak hususunda rızanın üretilmesinde en önemli araçlardanbirisi oldu. Bu çalışma, burjuvazinin örgütlü emeğin rızasını almak için kullandığı en önemli ideolojikmekanizmalardan birisi olan işletme ideolojisinin Türkiye’ye gelişine, yayılmasına ve özel olarak bu ideolojininönemli bir boyutu olan ücret tartışmalarına odaklanmaktadır. Makalede sermaye sahiplerinin/yöneticilerinkarlarını gizlemek-arttırmak ve emek üzerinde denetimi sağlamak için öne sürdüğü ücretler-verimlilik ilişkisive ücret sistemlerine örgütlü emeğin sendikal yapısı ve stratejileri nedeniyle rıza göstermediği öne sürülecektir.Bu bağlamda, çalışmanın temel amacı 1960-1980 arasının emek-sermaye çatışmasını incelerken emeksüreçlerini büyük oranda ihmal eden mevcut literatüre katkı koymaktır.
Citation - WoS: 1
Analysis of Battery-Powered Sensor Node Lifetime for Smart Grid Applications
(IEEE, 2016) Eris, Cigdem; Gungor, V. Cagri; Boluk, Pinar Sarisaray; 01. Abdullah Gül University
Wireless Sensor Networks (WSNs) enable smart grids where sensor nodes monitor and control the important parameters of power grid components. However, energy-aware communication protocols should be developed to extend network lifetime of WSNs in smart grid environments. In this study, the lifetime of wireless sensor nodes has been analyzed for various smart grid environments, such as 500 kV substation, main power control room, and underground network transformer vaults. In addition, the effects of different operation modes of sensor nodes on node lifetime have been reviewed.
Analysis of Under-Five Mortality by Diseases in Countries With Different Levels of Development: a Comparative Analysis
(2023) Ersöz, Nur Şebnem; Sütçü, Muhammed; Şahan, Pınar Güner; 01. Abdullah Gül University
Objectives: The right to health is critical for children because they are sensitive beings who are more susceptible to disease and health problems. It would be beneficial to compare child mortality rates in countries with different levels of development and to conduct studies to address them by taking into account their causes. This study aims to analyze the situation of developed, developing and least developed countries in terms of causes under-5 child mortality (U5CM) determined by World Health Organization and to identify the similarities or differences of under-five mortality. Methods: Child mortality rates per 1,000 live births between 2000 and 2017 years in between different age groups (0-27 days and 1-59 months) by causes (disease-specific) were obtained from World Health Organization for a total 15 countries including developed, developing and least developed countries. Regression analysis was performed to identify which causes have more impact on child mortality. In addition, the relationship between diseases was calculated using Euclidean distance, and diseases were clustered using k-means clustering algorithm for each country. Results: As a result of mathematical and statistical analysis, it was seen that causes of child mortality have a significant relation with the development level of country where a child was born. Conclusions: It has been observed that the causes of child mortality in countries with different levels of development vary depending on different factors such as geographical conditions, air quality population and access to medicine.

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