Yazarlar
- Peker, Iskender(23)
- Araz, Onur(16)
- Erol, Ismail(15)
- Ar, Ilker Murat(12)
- Bayraktar, Alemdar(10)
- Seferoğlu, Mehmet Tevfik(10)
- Aydin, Metin Mutlu(9)
- Günaydin, Murat(9)
- Adanur, Süleyman(8)
- Altunişik, Ahmet Can(8)
- Basoglu, Mustafa Engin(8)
- Akyol, Mehmet(7)
- Yanarateş, Cağfer(7)
- Akpinar, Muhammet Vefa(6)
- Altan, Aytaç(6)
- Barut, Abdulkadir(6)
- Başoğlu, Mustafa Engin(6)
- Cakmak, Recep(6)
- Searcy, Cory(6)
- Çavdar, Özlem(6)
- Baki, Birdogan(5)
- Benli, Tolga(5)
- Gergin, Ramazan Eyüp(5)
- Kahya, Volkan(5)
- Kuzulugil, Kenan(5)
- Ozden, Talat(5)
- Pala, Fahrettin(5)
- Seferoğlu, Ayşegül Güneş(5)
- Sevim, Bariş(5)
- Yilmaz, Tekin(5)
- Adanur, S.(4)
- Adanur, Suleyman(4)
- Aksüt, Yavuz Selim(4)
- Altunisik, Ahmet Can(4)
- Aydin, Musa(4)
- Cakir, Mehmet Ali(4)
- Cavusoglu, Ibrahim(4)
- Coruh, Emine(4)
- Ercikdi, Bayram(4)
- Gunaydin, M.(4)
Yayınlar
- MakaleAçık Erişim2027A hierarchical metaheuristic framework for CPT-based soil liquefaction prediction with Kolmogorov–Arnold Network variants
Günen, Mehmet Akif; Öztürk, Kaşif Furkan
Soil liquefaction is a critical geotechnical hazard that threatens the safety of civil infrastructure under seismic loading, necessitating robust and interpretable prediction models. This study proposes a hierarchical framework for CPT-based soil liquefaction prediction using meta-heuristic-optimized Kolmogorov–Arnold Network (KAN) variants. The framework follows a two-stage optimization strategy. First, six state-of-the-art meta-heuristic algorithms are statistically compared to identify the most effective optimization method. Second, the selected algorithm is employed to optimize six KAN variants, including FastKAN, EfficientKAN, FourierKAN, ChebyKAN, JacobiRKAN, and PadéRKAN. Statistical comparisons based on the Wilcoxon signed-rank test demonstrate that the Colony-Based Search algorithm (CSA) achieves lower objective-function values than the competing meta-heuristics (p<0.01) and is therefore adopted as the core optimization strategy. Performance evaluation reveals that the CSA-optimized ChebyKAN model achieves the highest predictive accuracy, with an F1 Score of 0.8875 ± 0.011 and an AUC of 0.9115 ± 0.013. Pairwise McNemar tests detected no statistically significant difference in classification decisions for any evaluated model pair (p>0.01). SHapley Additive exPlanations analysis identified qc, qc1N, and amax as the variables with the largest model-specific attributions, whereas d, c, and σv received lower attributions. A cost-sensitive error analysis further showed that ChebyKAN produced the lowest false-negative rate and the lowest asymmetric error cost under 5:1 and 10:1 false-negative-to-false-positive cost scenarios, supporting its conservative behaviour for safety-critical liquefaction screening. The results establish the proposed CSA–KAN framework as a reliable, high-accuracy, and interpretable solution for CPT-based soil liquefaction assessment in geotechnical engineering practice.
- MakaleAçık Erişim2026Madencilikte Patlatma Verimliliğinin Tahmini: Boosting Tabanlı Makine Öğrenmesi Algoritmaları ile Kapsamlı Bir Değerlendirme
Bayraktar, Cihan; Demir Şahin, Demet; Eker, Hasan
Bu çalışma, yeraltı madencilik operasyonlarında patlatma verimliliğini gerçek saha verileri kullanarak tahmin etmeyi amaçlamaktadır. Beş güncel boosting algoritması (LightGBM, XGBoost, CatBoost, NGBoost ve HistGBM) karşılaştırmalı olarak değerlendirilmiş, ayrıca basit ortalama, ağırlıklı ortalama ve en iyi üç model ile ağırlıklı ortalama gibi topluluk öğrenme stratejileri uygulanmıştır. 2019–2020 yılları arasında gerçekleştirilen 652 patlatma işleminden oluşan veri kümesi üzerinde standart ön işleme yöntemleri uygulanmıştır. Modellerin performansı R², RMSE ve MAE metrikleri ile ölçülmüştür. Bulgular, en iyi üç modelin (XGBoost, CatBoost ve NGBoost) ağırlıklı ortalamasının en yüksek başarıyı sağladığını göstermektedir (R² = 0.7383, RMSE = 8.18, MAE = 5.43). Bu sonuçlar, boosting algoritmalarının topluluk öğrenme yöntemleriyle birleştirilmesinin patlatma verimliliğini daha doğru ve güvenilir biçimde tahmin ettiğini ortaya koymaktadır. Önerilen çerçeve, madencilik operasyonlarında kaynak optimizasyonu, operasyonel güvenlik ve sürdürülebilirlik hedeflerini destekleyen veriye dayalı karar destek sistemlerine katkı sunmaktadır.
- MakaleAçık Erişim2026Modeling and Performance Analysis of Continuously Variable Series Reactors (CVSR) for Congestion Management in Meshed Distribution Networks
Ciftci, Okan; Tomsovic, Kevin; Ozkan, Gokhan
Distribution systems, particularly in densely loaded urban areas, frequently experience transformer overloading during peak consumption hours. Rather than resorting to costly infrastructure reinforcement or complex Flexible AC Transmission Systems (FACTS), this paper proposes a cost-effective optimization and control approach utilizing a Continuously Variable Series Reactor (CVSR). Unlike FACTS devices that rely on expensive power electronics, the CVSR capitalizes on magnetic core saturation to regulate reactance, offering a robust solution at a fraction of the cost (~$10/kVAr). The CVSR regulates the reactance on the primary side of the transformer via magnetic core saturation to control power distribution among transformers. In this study, the steady-state framework of the CVSR is derived and integrated into power flow formulations. The proposed model is validated using a two-parallel transformer system and tested on the heavily meshed IEEE 342-Node Low Voltage Networked Test System (LVNTS). Simulation results demonstrate the CVSR effectively relieves transformer overloading by redistributing power flow, thereby enhancing system flexibility and allowing utilities to avoid or defer extensive grid upgrades.
- MakaleAçık Erişim2026Lojıstık verımlılıkten sürdürülebılır kalkınmaya: G20 ülkelerı ıçın lpı ve sdgs endekslerının entegratıf analızı
Macit, Nazife Sahin
Bu çalışma, G20 ülkelerinde lojistik performans ile sürdürülebilir kalkınma arasındaki etkileşimi, 2022 yılı Lojistik Performans Endeksi (LPI) ve seçilmiş Sürdürülebilir Kalkınma Hedefleri (SKH) göstergeleri temelinde, bütüncül bir perspektifle incelemiştir. Korelasyon analizi ile LPI genel skoru ve alt boyutları ile SKH göstergeleri arasındaki ilişkinin boyutunu ve yönünü; sonrasında çok kriterli karar verme (ÇKKV) ve Borda yöntemleri ile ülkelerin bütünleşik performans sıralamasını açığa çıkarmayı hedeflemektedir. Korelasyon analizleri, özellikle gümrük işlemleri verimliliği, lojistik hizmetlerin kalitesi ve zamanında teslimat alt boyutları ile ithal oransızlaşma arasında; gümrük işlemleri verimliliği ile temel içme suyu hizmetlerine erişim arasında, zamanında teslimat ile temel sanitasyon hizmetlerine erişim gibi SKH göstergeleri arasında anlamlı pozitif ilişkiler olduğunu göstermiştir. Diğer taraftan, yetersiz beslenme oranı ile LPI ve alt göstergeleri arasında negatif fakat anlamsız bir ilişkinin olduğu, ayrıca elektriğe erişim ile LPI göstergeleri arasında da anlamlı bir korelasyon bulunmadığı tespit edilmiştir. SITDE yöntemi ile hesaplanan kriter ağırlıkları hesaba katılarak ülkelerin performanslarının değerlendirilmesinde FANMA, SWEI ve TODIFFA yönteminden faydalanılmış ve ortaya çıkan sonuçların birleşimi ise Borda yöntemi ile gerçekleştirilmiştir. Yapılan bütünleşik değerlendirme sonucunda Almanya, Fransa ve Çin’in en yüksek entegre lojistik ve sürdürülebilir kalkınma performansına sahip olduğu; Güney Afrika, Endonezya ve Meksika’nın ise en düşük performans sergilediği ortaya çıkmıştır. Sonuçlar, gelişmiş lojistik altyapının hem ekonomik rekabet gücünü hem de sürdürülebilir kalkınmaya katkıyı desteklediğini ortaya koymakta ve politika yapıcılar için lojistik ve sürdürülebilirlik stratejilerinin entegrasyonuna yönelik önemli ipuçları sunmaktadır.
- MakaleYalnız künye2026Determination of Human Resoruces Policies Based on Regional Labour Dynamics by Cluster Analysis
Sımsek, Tugçe
Regional labour force differences create strategic and operational challenges for national service sector firms, particularly in securing comparable employee competencies and maintaining consistent service quality across regions. This study analyses regional labour force dynamics in Türkiye and examines how human resource policies can be aligned with regional labour market profiles. Using 2023 provincial data from the Turkish Statistical Institute (TurkStat), six labour market indicators for 81 provinces were analysed through K-means clustering. The results classify provinces into three clusters: metropolitan cities, characterised by higher education levels, stronger knowledge-intensive service capacity and a larger working-age population; medium-sized cities, with relatively balanced labour market structures but more limited knowledge-intensive service development; and disadvantaged regions, marked by lower labour force participation, higher unemployment and weaker human capital conditions. Cluster differences were further examined using descriptive statistics, one-way ANOVA and Tukey HSD post hoc tests. Based on these findings, the study proposes cluster-specific HR policy priorities for service sector firms, including talent attraction and retention strategies for metropolitan cities, skill development and retention-oriented practices for medium-sized cities, and training and capacity-building policies for disadvantaged regions. By linking provincial labour market profiles to cluster-specific HR priorities, the study contributes to strategic human resource management research and regional labour market studies, while offering practical guidance for policymakers and service sector managers.
- MakaleAçık Erişim2026Çevresel Faktörler ile Finansal Performans İlişkisi: BIST Sürdürülebilirlik Endeksi Üzerine Bir Araştırma
Akdeniz, Fatih
Günümüzde doğal kaynakların hızla tükenmesi, iklim değişikliği ve çevresel bozulma gibi küresel sorunlar, sürdürülebilirlik odaklı çalışmaların önemini her zamankinden daha fazla artırmaktadır. İşletmeler için sürdürülebilirlik stratejilerinin en temel unsurlarından biri çevresel sorumluluk ve bu doğrultuda gerçekleştirilen çevresel yatırımlardır. Bu çerçevede, pek çok şirket çevreye duyarlı projelere ve yatırımlara daha fazla kaynak ayırmaktadır. Ancak, çevresel yatırımların şirketlerin finansal performansı üzerindeki etkisi hâlen tartışmalı bir konudur. Bu araştırmanın amacı, 2020-2024 döneminde BIST Sürdürülebilirlik Endeksi'nde yer alan 18 sanayi ve üretim şirketinin çevresel harcamaları ve kaynak kullanımları ile finansal performansları arasındaki ilişkiyi analiz etmektir. Çalışmada, finansal performans göstergeleri olarak aktif kârlılık, özsermaye kârlılığı ve fiyat/kazanç oranı bağımlı değişken olarak kullanılırken; çevresel harcamalar, enerji tüketimi, tehlikeli atık miktarı, su tüketimi ve sera gazı emisyonu ise bağımsız değişkenler olarak ele alınmıştır. Analiz bulguları, çevresel harcamalar, enerji tüketimi ve sera gazı emisyonlarının aktif kârlılık üzerinde negatif bir etkisi olduğunu göstermektedir. Öte yandan, tehlikeli atık miktarı ile aktif kârlılık arasında pozitif yönlü ilişki tespit edilmiştir. Özsermaye kârlılığı açısından yalnızca tehlikeli atık miktarıyla pozitif yönlü bir ilişki saptanmış, diğer çevresel değişkenlerle anlamlı bir ilişki tespit edilmemiştir. Fiyat/kazanç oranında ise tehlikeli atık miktarı dışında çevresel değişkenlerle anlamlı bir ilişki bulunmamıştır. AR-GE yatırımları finansal performans üzerinde pozitif, finansal kaldıraç oranı ve şirket büyüklüğü ise genellikle negatif etki göstermiştir. Çalışma genelinde çevresel harcamaların finansal performans üzerindeki etkisinin sınırlı olduğu ve piyasa değerleme ölçütleriyle çevresel göstergeler arasındaki ilişkinin zayıf kaldığı sonucuna ulaşılmıştır.
- MakaleAçık Erişim2026Ekonomik Büyüme ve İş Kazaları Arasındaki İlişkinin Araştırılması: Türk Mobilya Sektörü Örneği
Top, Yener
Mobilya sektörü, iş sağlığı ve güvenliği açısından risk düzeyi yüksek imalat sanayi alt sektörlerinden biridir. Aynı zamanda son yıllarda ekonomik bir büyüme süreci yakalamış ve 2009-2024 yılları arasında ihracat performansını 3.2 kat artırmıştır. Bu çalışmada, Türk Mobilya Sektörü`nün 2009-2024 yılları ihracat değerleri, istihdam sayıları, işyeri sayıları ve iş kaza sayıları arasındaki ilişkiyi incelemek amaçlanmıştır. Bu sebep ile mobilya sektörü araştırma materyali olarak seçilmiştir. Çalışmada sektöre ilişkin veriler, Türkiye İstatistik Kurumu (TÜİK) ve Sosyal Güvenlik Kurumu (SGK) gibi kurumların kamuya açık kaynaklarından elde edilmiştir. Verilerin sunumu ve analizinde grafikler, korelasyon ve regresyon analizlerinden yararlanılmıştır. 2009-2024 yılları işletme-çalışan sayıları ve işletme-kaza sayıları arasında sırası ile güçlü ve orta düzeyde ilişki bulunmuştur. Kurulan regresyon modeline göre işletme sayılarındaki artış sektör kaza sayıları artışının %54`ünü açıklamaktadır. Söz konusu ilişkinin araştırılmasında başka yaklaşımlara gerek duyulduğu ulaşılan bir diğer sonuçtur.
- MakaleAçık Erişim2026Electricity Prices, Technology, Productivity, And Environmental Degradation: Implications For Financial Stability
Çakir, Mehmet Ali; Ökte, Mehmet Kutlughan Savas
The limited availability of fossil fuels and the financial pressure they create for countries that do not have the resources have led countries to search for new energy sources. In particular, renewable energy sources and therefore electrical energy obtained from these sources have been proposed in the literature as an alternative to fossil fuels. Thus, this study investigates the impact of electricity prices on financial stability in European Union countries from 2010 to 2021 using Driscoll Kraay fixed effects estimation. Financial stability is measured using the bank z-score, while productivity-intensive technology, environmental quality, and economic growth are included as control variables. The findings indicate that an increase in electricity prices negatively affects the bank z-score. In contrast, productivity-intensive technology positively impacts the bank z-score. Similarly, environmental quality contributes to an increase in the bank z-score. Additionally, economic growth enhances financial stability. Considering that rising electricity prices negatively affect financial stability, policymakers should encourage companies to produce electricity from renewable sources, such as solar panels or wind turbines. This can be supported through incentives such as tax breaks or low-cost financing for firms investing in on-site renewable energy systems. In this way, electricity price fluctuations will have less impact on companies and, in turn, help protect financial stability.
- MakaleAçık Erişim2026Financial Performance in Transportation and Warehousing Sector: A Comprehensive Study on BIST with LOPCOW, ARWEN and RAWEC Methods
Sahin Macit, Nazife
This study analyzes the financial performance of companies in the transportation and storagesector listed on BIST using LOPCOW, ARWEN, and RAWEC methods. The research focuses on 15 financial ratios and 11 companies based on 2023 data. LOPCOW was used to calculate the weights of the criteria, while ARWEN and RAWEC determined the financial performance values of the alternatives. When comparing the validity of these methods with RAPS, it was found that RAWEC produced consistent results, whereas ARWEN exhibited inconsistencies. Spearman correlation analysis indicated a correlation of -0.5455 between ARWEN and RAWEC and 0.8909 between RAWEC and RAPS.
- MakaleAçık Erişim2026Institutional and Financial Drivers of Renewable Energy Consumption and Carbon Emissions: Evidence from Developed Economies
Oguz, Enes Cengiz; Gyasi, Evans Akwasi; Pala, Fahrettin; Pilatin, Abdulmuttalip; Barut, Abdulkadir
The study sheds light on the subtle interactions among financial development, foreign direct investment (FDI), and the quality of regulatory frameworks, with particular reference to their deep influence on renewable energy use and carbon emissions across 22 developed countries from 2002-2021. The results show an interesting tendency: Financial development and FDI will reduce reliance on renewable energy, whereas a significant increase in GDP per capita will increase reliance. Secondly, carbon emissions have a negative association with the adoption of renewable energy and financial development, though both reduce environmental quality; there is a positive relation between real gross domestic product (GDP) and energy depletion in terms of these toxic emissions. The significant role of regulatory quality as a moderator in this process is particularly striking. There is a direct correlation between financial stability and more robust regulation, resulting in reduced financial liquidity available for investing in renewable projects and restricting the free flow of clean FDI. Crucially, the paper argues that when combined with strong regulation, FDI is more likely to contribute to reductions in emissions, while FYGD, nevertheless regulated at a high level of quality, should raise emissions. Winding up, the result indicates that neither financial depth nor institutional quality, in isolation, is sufficient to deliver significant environmental improvement. Thus, it is urgent to adopt sound green finance policies and to formulate focused regulatory systems that integrate financial development and foreign direct investment with a broader sustainability agenda.
- MakaleYayıncıda açık erişim2026What is the Contribution of Green Innovation and Digitalization to Economic Growth: Analyzing the Role of Geopolitical Risks and
Agirkaya, Melahat Batu; Akyol, Hikmet
This research examines the impact of green innovation and digitalization on economic growth in Brazil, Russia, India, China, South Africa, and T & uuml;rkiye (BRICS+T) during the period 2002-2021. Within this framework, it analyzes the role of geopolitical risks and climate policy uncertainty. The relationships between variables were estimated using Pooled Bewley (CPS-BP), Dynamic Least Squares Mean Group (DOLS-MG), Fully Modified Least Squares (FMOLS), Canonical Cointegrated Regression (CCR), and Dynamic Least Squares (DOLS) estimators. Our results show that green innovation, digitalization, information technologies, infrastructure investments, life expectancy at birth, and US-originated climate policy uncertainties positively impacted economic growth. Increased geopolitical risks hindered growth in BRICS+T countries.
- MakaleAçık Erişim2026When the Human Firewall Fails: Techno-Strain as the Hidden Link Between Technostress and Information Security Policy Violations
Demirbağ, Orkun; Kaymak, Halil İbrahim; Alan, Hale; Akdeniz, Ferhan
In today’s dynamic business environment, organizations are increasingly investing in strategies to protect themselves against information system violations. While these technologies offer remarkable benefits—boosting efficiency, productivity, and overall performance—they also bring significant risks, particularly regarding information security breaches. This study delves into the critical connections between technostress, techno-strain, and the violation of information security policies. Our research aims to shed light on how technostress, which is commonly experienced by engineers working in technology-intensive environments within the IT sector, drives information security violations. Importantly, we will also explore how techno-strain mediates this relationship. By focusing on engineers who are consistently engaged with advanced technology, we seek to answer essential questions about their experiences. It is worth noting that the requirements for information security technology can widely vary based on factors such as industry type, organizational structure, departmental roles, and cultural norms. Therefore, this study examines how technostress increases the likelihood of information security policy violations and how techno-strain mediates this relationship. Looking ahead, future research should consider both the broader institutional contexts and the individual characteristics that may shape the relationship between information security violations and technostress. Furthermore, understanding the repercussions of information security violations—stemming from technostress—on a company’s financial health is vital for organizations aiming to safeguard their assets and maintain a competitive edge. Emphasizing these insights can lead to more effective strategies for managing both technology and talent in the workplace.
- MakaleYalnız künye2026Optimal design of a novel enhanced inerter-based tuned mass damper in seismic-excited structures considering SSI effects
Araz, Onur; Shahraki, Mohammad Alibabaei
This paper proposed a novel enhanced inerter-based tuned mass damper (E-TMDI) for the control of damped single-degree-of-freedom structures due to ground acceleration. The apparatus represents an energy-dissipating passive absorber assembled from a pair of inerter elements, a pair of springs, a single mass, and a single damper. The present work directly integrates soil-structure interaction (SSI) effects within the optimization process, thereby yielding more accurate and dependable outcomes. For a clearer insight into the control mechanism of E-TMDI, the frequency-domain transfer function for responses is derived, while the influences of various model parameters on the displacement amplitude magnification factor of the superstructure both considering and neglecting SSI are examined. Four design parameters (i.e., f 1 first frequency ratio, f 2 secondary frequency ratio, ξ1 damping ratio, and κ inertance ratio of the second inerter to the first) of E-TMDI are obtained using particle swarm optimization (PSO) algorithm to minimize peak displacement amplitude of the structure. Results from the frequency domain analyses in this research indicate that the proposed E-TMDI has better efficiency and frequency band property both traditional TMD and TMDI configurations when equipped with same total mass (μ) and inertance ratio (β) in suppressing structural vibrations. Additionally, the stability of the proposed device is examined through simulations of the E-TMDI-equipped structure under a range earthquake record. The findings reveal that the E-TMDI maintains superior effectiveness even when the host structure experiences diverse earthquake events. This validation, conducted under real earthquake records, confirms the reliability of this design framework, filling a significant gap in determining the seismic control performance of E-TMDI under varying soil conditions.
- MakaleYalnız künye2026A comprehensive optimization framework for indoor laser-based optical wireless communication using gimbal-steered transmitters
Başer, Oğuzhan; Küçük, Mehmet Ali; Türk, Kadir
The growing demand for high-speed wireless communication, driven by data-intensive applications such as high-definition video streaming and augmented reality, has highlighted the limitations of the Radio Frequency (RF) spectrum. Optical Wireless Communication (OWC) has emerged as a promising complementary technology, offering wide bandwidth, license-free operation, high security, and immunity to electromagnetic interference. Among OWC transmitters, Laser Diodes (LDs) provide high modulation bandwidth and narrow divergence angles, enabling data rates of several tens of gigabits per second. However, the narrow beam of LDs requires precise Line-of-Sight (LoS) alignment, making beam steering essential. This study focuses on optimizing the positioning and orientation of gimbal- or galvo-based LD transmitters in indoor OWC systems to minimize outage probability under LoS constraints and physical obstructions. An outage probability model considering room geometry and device field-of-view angles is developed and analyzed for three scenarios within a 7 × 5 m room: an empty environment, a room with a 1 × 1 m column, and a user-occupancy-aware environment. The complex optimization problem is solved using multiple meta-heuristic algorithms, including Particle Swarm Optimization (PSO), L-SHADE, and Stochastic Fractal Search with Fitness-Distance Balance (FDB-SFS). The obtained results are subsequently validated through grid search approach. The proposed approach achieves significant outage reduction, demonstrating that incorporating obstacle and user-distribution information enables efficient coverage with fewer terminals, reaching outage probabilities as low as 0.4%.
- MakaleAçık Erişim2026Innovation and Competitive Characteristics in Local Forest Industry Enterprises: A Case Study; [Inovacijska i konkurentska obilježja lokalnih poduzeća drvne industrije: studija slučaja]
Komut, Osman; Karabulut, Ayşenur
The forest products industry makes significant contributions to national economies in terms of basic economic indicators such as employment, expansion into rural areas, added value, investment and exports. This study aims to measure the innovation perception, awareness and competitiveness of small and medium-sized forest products enterprises operating in local areas on the basis of different variables. Within the scope of the study, a data collection tool including on-site observation, interviews and the developed scale was used on enterprises located in a local administrative region. The data obtained were subjected to hypothesis testing and correlation analysis. The findings revealed that the perception of innovation in small and medium-sized forest products industry enterprises is affected by demographic factors related to the enterprise managers, and basic factors related to the enterprise such as the number of employees, field of activity, duration of activity, annual average income, and product distribution channels. Furthermore, it has been determined that innovation awareness decreases as the scale of the enterprises shrinks. As a result, it can be said that the innovation and competition characteristics that are valid in the global and national forest products industry market are not yet fully applicable to local-scale and low-capacity enterprises.
- MakaleYalnız künye2026Electromechanical characterization and deep learning-based force prediction in 3D-printed PLA core–shell composites
Ekmekci, Dursun; Kaplan, Emrah
In this study, composite samples were produced using fused deposition modeling to contain an outer layer of red insulating polylactic acid and an inner core of black conductive polylactic acid. The mechanical properties of the samples were determined using three-point bending experiments, and their electro-mechanical impedance responses during loading were monitored using impedance experiments. To examine the effects of physical aging and crystallization, the composites were heat-treated at 50 °C for 2, 4, and 6 hours. The insulating polylactic acid exhibited brittle fracture with a sharp post-peak force drop, whereas the conductive polylactic acid showed a ductile fracture mode accompanied by substantial energy dissipation. The physically aged composites were stiffer and less ductile, which was attributed to the presence of partially crystallized and partially relaxed molecules, especially around the glass transition region. In support of the observed properties, scanning electron microscopy images confirmed that the fractured layers were smoother compared to the ductile conductive layers, which had surface roughness patterns resembling fibrillated or lamellar structures. Additionally, the impedance signals obtained during the bending experiments were linked with the corresponding mechanical properties using an advanced deep learning model that could model the electric signals to accurately provide the corresponding real-time force values.
- MakaleYalnız künye2026Energy-based wind vibration control of turbines equipped with nonlinear tuned mass damper inerter considering soil-structure interaction
Alibabaei Shahraki, Mohammad; Araz, Onur
This study evaluates the effectiveness of a Nonlinear Tuned Mass Damper Inerter (NTMDI) in mitigating wind-induced vibrations in wind turbines, with explicit consideration of soil–structure interaction (SSI). Kinetic energy is selected as the primary response metric, supported by nacelle displacement, total structural energy, soil energy absorption, acceleration reduction, and residual soil energy to provide a comprehensive assessment. A detailed numerical model is developed in OpenSees, incorporating SSI effects and subjected to turbulent wind loads generated using the Shinozuka method. NTMDI parameters are optimized using the Multi-Objective Cuckoo Search Algorithm (MOCS) to balance kinetic-energy minimization, displacement suppression, and soil-energy management. The results show that NTMDI implementation achieves approximately 45% reduction in total kinetic energy, 20% reduction in nacelle displacement, and 25% reduction in tower acceleration relative to the uncontrolled system. When SSI is considered, the NTMDI further improves performance by reducing soil energy demand by an additional 15–20%, highlighting the importance of absorber–soil coupling. Compared with traditional TMDIs, the NTMDI exhibits superior adaptability and efficiency, particularly for flexible foundations. These findings confirm NTMDIs as an effective passive control strategy for enhancing wind-turbine stability.
- MakaleYalnız künye2026Determining the effect of blockchain technology on the medical waste management process in the circular economy framework using integrated FUCOM-ARAS methods
Batar, Bilge; Peker, İskender
Background: The circular economy concept aims to reduce environmental impact by promoting resource reuse, minimizing waste through input reduction, and lowering costs. Rising costs are leading healthcare facilities and other organizations to prioritize medical waste management. Blockchain technology, introduced in 2008, functions as a database of auditable and traceable transactions built on a network of trust-based blocks. Key features such as transparency, reliability, accessibility, flexibility, and automation can significantly enhance the efficiency of medical waste management processes, thereby contributing to the circular economy. Objective: This study aims to evaluate the effectiveness of medical waste management—critical for healthcare institutions and sustainable development—within the framework of the circular economy. Multi-criteria decision-making (MCDM) techniques are used to assess the contributions of blockchain technology to this process. Methods: A literature review was conducted to identify relevant criteria and alternatives. The Full Consistency Method (FUCOM), an MCDM technique, was used to calculate the weight of each criterion. The Additive Ratio Assessment (ARAS) method was applied to rank the alternatives. Conclusion: According to the analysis's findings, transparency, traceability, and dependability are the three most important criteria, respectively. The stages of medical waste storage, disposal, and transportation have the highest priority ratings among the available options. According to these results, incorporating blockchain technology into medical waste management can significantly improve system traceability and reliability, enhancing its role in the circular economy. Notably, the storage phase is the most appropriate for implementing blockchain. However, the other phases’ comparatively high appropriateness scores attest to the technology's capacity to be used efficiently across the waste management cycle. This integration promotes traceable and transparent procedures, guaranteeing dependable waste management procedures in healthcare facilities and supporting the objectives of the circular economy and sustainability. Additionally, the sensitivity analysis shows that when the weighting of criterion is altered, the ranking of alternatives changes as well. This dynamic interaction emphasizes how blockchain technology may be successfully integrated into all phases rather than being restricted to just one because waste management is cyclical and holistic.
- MakaleAçık Erişim2026Enhanced Sensorless Current Control in Boost Converters for EV Fast Charging: Equilibrium Optimization-Tuned Cascaded ANN-Fuzzy Logic Control
Altan, Aytac; Yanarates, Cagfer; Alzaidi, Mohammed S.
Efficient current control in boost converters is critical for electric vehicle (EV) battery charging applications, where dynamic operating conditions challenge conventional control strategies. This paper presents a novel cascaded artificial neural network (ANN) and fuzzy logic (ANFIS) controller designed to enhance current regulation in boost converters. The performance of the proposed approach is validated through comparison with single PI, cascaded PI, and single ANFIS control schemes. To improve system performance, a sensorless current estimation technique is implemented, reducing hardware dependency and enhancing robustness, while lowering system cost. Experimental evaluations demonstrate that the proposed cascaded ANFIS controller maintains consistent current levels under rapid load changes, providing improved transient response and steady-state accuracy. Specifically, the proposed method achieves a settling time of 23 ms, compared to 185 ms for single PI and 66 ms for single ANFIS control, corresponding to an 87.6% improvement over PI. In addition, overshoot is reduced from 37.25% (PI) and approximately 20% (ANFIS) to negligible levels, while a fast rise time of 3.62 ms is obtained. These improvements reduce current deviation and transient stress, contributing to more stable and reliable charging operation. Although charging time, efficiency, and battery lifetime are not directly measured, the results indicate strong potential for improved practical charging performance. The proposed approach provides valuable insights into the integration of intelligent control methods in power electronics and supports the development of high-performance EV charging systems.
- MakaleYalnız künye2026Effects of earthquake frequency content and isolation thickness on seismic behavior of a structure system resting on geotechnical seismic isolation layer
Ozturk, Kasif Furkan; Cakir, Tufan; Araz, Onur
Geotechnical seismic isolation (GSI) systems aim to partially dissipate the energy before it reaches the foundation of the structure system and are therefore regarded as an important alternative to structural seismic isolation systems. In addition, the use of petroleum-derived waste materials in the GSI systems fills a significant gap in the field of waste recovery. The present study investigates the changes in the dynamic responses of a 5-story building system with and without GSI, using a set of earthquakes classified according to their frequency content. For this purpose, parametric analyses were performed using analytical methods, considering three different earthquake frequency contents and six different GSI thicknesses. Furthermore, an approach for selecting the GSI thickness was suggested. The results generally show that, for structures founded on both natural soil (NS) and GSI systems, the earthquakes with low frequency content produce responses greater than the average responses calculated for all the investigated earthquakes. Although increasing the GSI thickness has a significant effect on attenuating structural responses, increasing this thickness beyond 3 m does not lead to a relatively significant reduction in the dynamic responses of the investigated structural system. Therefore, considering the structural system, NS, rubber-soil mixtures and earthquakes examined in this study, selecting a GSI thickness in the range of 2–3 m (inclusive) may be regarded as a practical approach for mitigating the dynamic responses of the structure since further increments in thickness beyond this range provide only progressively limited improvements in structural responses. Consequently, this research may provide meaningful data for the development of vibration control strategies to improve seismic resilience of structures, and the results are expected to be useful for better understanding of the GSI applications.
