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A class of nonlinear systems with new boundary conditions: existence of solutions, stability and travelling waves
Get PDFIn this work, we begin by introducing a new notion of coupled closed fractional boundary conditions to study a class of nonlinear sequential systems of Caputo fractional differential equations. The existence and uniqueness of solutions for the class of systems is proved by applying Banach contraction principle. The existence of at least one solution is then accomplished by applying Schauder fixed point theorem. The Ulam Hyers stability, with a limiting-case example, is also discussed. In a second part of our work, we use the tanh method to obtain a new travelling wave solution for the coupled system of Burgers using time and space Khalil derivatives. By bridging these two aspects, we aim to present an understanding of the system's behaviour
Düzce İli Orman Ürünleri Sanayi İşletmelerinde İş Kazalarının Analizi
Get PDFÇalışmanın amacı, Düzce ilinde orman ürünleri sektöründe faaliyet gösteren işletmelerde yaşanan iş kazalarının analiz edilmesidir. Bu amaçla Düzce ilinde orman ürünleri sektöründe faaliyet gösteren işletmelerdeki 5029 çalışan çalışmanın evrenini oluşturmuştur. Oluşturulan anket formları Eylül 2023-Temmuz 2024 döneminde toplam 30 işletmede, 405 çalışana yüz yüze anket yöntemiyle uygulanmış ve 374 anket değerlendirmeye alınmıştır. Çalışma sonucunda; katılımcıların %82,9’unun iş sağlığı ve güvenliği konusunda bilgi sahibi olduğu, %85’inin ise yapılan işle ilgili olarak kişisel koruyucu ekipman kullandıkları tespit edilmiştir
A detailed 3D volumetric magnetic resonance arthrographic analysis in a spiral ligament and anteroinferior capsuloligamentous complex of the shoulder joint
Get PDFObjectivesThis study aimed to delineate the anatomical characteristics of the spiral glenohumeral ligament (SpiGHL), middle glenohumeral ligament (MGHL), and anterior band of inferior glenohumeral ligament (AB-IGHL), as well as their potential interrelationships, using MR arthrographic images from a large patient population.MethodsAll patients underwent 3D volumetric magnetic resonance (MR) arthrography sequences in addition to conventional MR imaging. All MR arthrography images were retrospectively assessed by two radiologists with expertise in arthrography. The origins and insertions of SpiGHL, MGHL, and AB-IGHL, along with any variations and interrelationships, were carefully examined and documented. These findings were statistically analyzed according to the patient's age, gender, and laterality of the shoulder (right or left).ResultsThe study included 190 shoulder MR arthrographies, identifying SpiGHL in 15 patients (7.9%). Among the 190 patients, 20 (10.5%) had an AB-IGHL with a high insertion on the anterior glenoid margin. In 10 of 15 patients with SpiGHL (66.6%), a conjugation of SpiGHL and MGHL was observed. MGHL hypoplasia was observed in 11 MR arthrographies. Of the 11 patients, 5 (45.5%) also presented with SpiGHL. The incidence of SpiGHL was significantly higher in the group with hypoplastic MGHL. Additionally, the average age of patients with a high-origin AB-IGHL was significantly lower than that of patients without this feature.ConclusionsKnowing the anterior capsuloligamentous detailed anatomy of the shoulder joint and its possible variations is important in correctly interpreting the pathologies of this region. The spiral GHL and its possible relationship with other ligaments can be defined in detail on MR arthrography.Scientific and Technological Research Council of Turkiye (TUBITAK)Open access funding provided by the Scientific and Technological Research Council of Turkiye (TUBITAK)
Examining Open-Top Culverts Impact on Forest Road Surface Deteriorations via UAVs
Get PDFThe life and robustness of forest roads depend on their protection from the harmful effects of water coming into the road surface. In particular, the deterioration of the road surface affects the safe navigation of vehicles and traffic safety. This situation requires that the surface be stable on forest roads. The aim of the study is to examine whether surface deterioration (erosion and accumulation) on forest roads due to the drainage problem of water falling on the road surface can be minimized by open-top culverts and to determine their effectiveness. These are used in three separate trial blocks every 25 m (A parcels; total of 3 parcels), every 50 m (B parcels; total of 3 parcels) and control block (C). Volumetric erosion and accumulation in these blocks was compared by UAV for about 3 years and the effectiveness of the open-top culverts was examined by this method. A 500 m section of the forest road coded 001 of the Kard & uuml;z Forest Operations Directorate (D & uuml;zce/T & uuml;rkiye) was examined in the study. As a result, erosion and accumulation in all blocks have been found to have a dynamic course. It was determined that this mobility was greater in the control block than in the blocks with open-top culverts installed at intervals of 25 m and 50 m. The mean Z values for the blocks showed that the deterioration in the control block (C) was higher than in the blocks with 25 m and 50 m open culverts. The volumetric deterioration rate was 5 times higher in the control block than in the block installed at 25 m interval (A plots) and 2 times higher than in the block installed at 50 m interval (B plots). Similarly, the areal deterioration rate was 3.3 times higher in the control block than in the block installed at 25 m interval (A plots) and 1.4 times higher than in the block installed at 50 m interval (B plots). These results showed the effectiveness of open-top culverts and it was also determined that the open-top culverts installed at 25 m intervals were more effective than the open-top culverts established at 50 m intervals. In addition, according to the statistical analysis, a statistically significant difference was found between the erosion volume in the blocks. Open-top culverts should be used against forest road surface deterioration and UAV technology should be used for deterioration detection.Scientific and Technological Research Council of Turkey (TUBITAK) [118O309]This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 118O309
Unraveling landscape connectivity: The impact of mega-projects on Istanbul's Northern Forests and conservation pathways
Get PDFNatura 2000 and the Emerald Network are crucial for habitat protection across Europe. Istanbul's Northern Forests are a key part of the Pan-European Ecological Network (PEEN). The rapid expansion of large-scale infrastructure projects, such as Istanbul Airport (IA), the Northern Marmara Motorway (NMM), and Kanal Istanbul (KI), in Northern Forests, has severely weakened landscape connectivity and threatened biodiversity in this vital region. This study assesses mega-project impacts on structural and functional connectivity using directional graph analysis from 2000 to 2020, identifying 2010 as a turning point due to the initiation of these projects. Results show a significant decrease in connectivity metrics, such as a 26.8% reduction in structural corridors and substantial decreases in corridor length and node degree, particularly in the NW, N, and W directions identified as high-impact areas. These areas, located near IA, NMM, and KI, exhibit critical losses in ecological corridors and stepping stones. Potential corridors also diminished markedly in length and density, indicating reduced functional connectivity. It was observed that these declines accelerated in 2020 and might accelerate in the 2020-KI periods, especially after the construction of mega-projects started in 2013 and afterward. The study emphasizes the need to reframe landscapes as habitable spaces for ecological sustainability and outlines specific policy recommendations, including the establishment of a legal framework that defines ecological network components and connectivity types, as well as short-, medium-, and long-term ecological restoration strategies. These measures aim to mitigate the impacts of rapid infrastructure development and ensure the long-term protection of Istanbul's Northern Forests within the broader ecological network.Scientific and Technological Research Council of Turkiye (TUBITAK) under the 2214-A International Research Fellowship ProgrammeDuzce University (DU) Scientific Research Projects Coordination Office [2023.02.01.1427]TUBITAKDUThis study was supported by The Scientific and Technological Research Council of Turkiye (TUBITAK) under the 2214-A International Research Fellowship Programme for PhD Students Programme and the Duzce University (DU) Scientific Research Projects Coordination Office (Project no: 2023.02.01.1427). The authors would like to express gratitude to TUBITAK and DU for their support. The authors are also grateful to the reviewers for their invaluable feedback on this article
Türkiye’de Kamu Okul ve Hastane İnşaatı Projelerinde Farklı Ön Maliyet Tahmin Yöntemlerinin Performanslarının Karşılaştırılması: Güney Marmara Bölgesi Örneği
Get PDFİnşaat projelerinin tasarım aşamasında gerekli olan ön maliyet tahmini değerleri, yatırımın gerçekleştirilebilmesi ile ilgili çok önemli bir rol oynamaktadır. Bu çalışmanın amacı; gerçek inşaat maliyetleri ve hesaplanan ön maliyetler açısından sapma miktarlarının belirlenmesinde katkı sağlamak, yukarıda anılan yöntemlerin okul ve hastane yapılarındaki performanslarını karşılaştırmaktır. Bunun için Güney Marmara bölgesinde kamu tarafından yapılan ihalelerle inşa ettirilen beş adet okul ve iki adet hastane yapısının (ayrıca üç farklı bölgedeki üç hastane yapısının daha) metraj ve keşifleri çıkarılarak (2021 yılı rayiçleriyle) Birim Fiyat Yöntemine göre gerçek maliyetleri bulunmuştur. Aynı yapıların maliyetleri, bu kez anılan ön maliyet tahmin yöntemleri ile hesaplanarak gerçek maliyetlerden sapma oranları araştırılmıştır. İlgili zaman dilimi esnasında dünyada ve Türkiye’de yaşanan Covid 19 Pandemisi şartları ve yüksek enflasyonist ekonomik şartlar da ihmal edilmeden yöntemlerin hata oranları karşılaştırılmıştır. Edinilen verilere göre Alan Yöntemi, okul yapılarında %113, hastane yapılarında %97 hata ile maliyet tahmini yaparken; Hacim Yöntemi aynı sıra ile %121 ve %120 hata ile tahminde bulunmaktadır. Kat Kabuğu Yönteminin hata oranı ise yine aynı sıra ile %158 ve %203 düzeylerinde gerçekleşmiştir. Gerek yatırımcı kurumların gerekse inşaat firmalarının; yapıların ön tasarım aşamasında kullandıkları ön tahmin yöntemlerinin hata oranlarını bilerek, yaklaşık yapı maliyeti tahmini gerçekleştirmelerinin ihalelere sağlıklı teklifler verilmesi ve projelerin gerçekleştirilebilmesi konusunda katkılar sağlayacağı düşünülmektedir. Çalışmada aynı anda, farklı yöntemlerin kullanılması ile yapılacak tahminlerin farklı yapı/bina tipleri için ve daha önceki çalışmalarla birbirinden farklı sonuçlar verebileceği; bu sebeple her yapı ve yöntem için, firmaların ayrı hesaplar yaparak, farklı güvenilirlik derecelerine ulaşmaları ve alacakları kararları bu kapsamda değerlendirmeleri gerektiğinin altı da çizilmek istenmiştir
Sex estimation with parameters of the facial canal by computed tomography using machine learning algorithms and artificial neural networks
Get PDFBackgroundThe skull is highly durable and plays a significant role in sex determination as one of the most dimorphic bones. The facial canal (FC), a clinically significant canal within the temporal bone, houses the facial nerve. This study aims to estimate sex using morphometric measurements from the FC through machine learning (ML) and artificial neural networks (ANNs).Materials and methodsThe study utilized Computed Tomography (CT) images of 200 individuals (100 females, 100 males) aged 19-65 years. These images were retrospectively retrieved from the Picture Archiving and Communication Systems (PACS) at D & uuml;zce University Faculty of Medicine, Department of Radiology, covering 2021-2024. Bilateral measurements of nine temporal bone parameters were performed in axial, coronal, and sagittal planes. ML algorithms including Quadratic Discriminant Analysis (QDA), Linear Discriminant Analysis (LDA), Decision Tree (DT), Extra Tree Classifier (ETC), Random Forest (RF), Logistic Regression (LR), Gaussian Naive Bayes (GaussianNB), and k-Nearest Neighbors (k-NN) were used, alongside a multilayer perceptron classifier (MLPC) from ANN algorithms.ResultsExcept for QDA (Acc 0.93), all algorithms achieved an accuracy rate of 0.97. SHapley Additive exPlanations (SHAP) analysis revealed the five most impactful parameters: right SGAs, left SGAs, right TSWs, left TSWs and, the inner mouth width of the left FN, respectively.ConclusionsFN-centered morphometric measurements show high accuracy in sex determination and may aid in understanding FN positioning across sexes and populations. These findings may support rapid and reliable sex estimation in forensic investigations-especially in cases with fragmented craniofacial remains-and provide auxiliary diagnostic data for preoperative planning in otologic and skull base surgeries. They are thus relevant for surgeons, anthropologists, and forensic experts.Clinical trial numberNot applicable
Evaluation of Conditions Affecting Women's Preference and Intention to Use Postpartum Contraceptives According to the Interaction Model of Client Health Behavior
Get PDFBackgroundTo assess women's preference and intention to use postpartum contraceptives according to the Interaction Model of Client Health Behavior (IMCHB).MethodThe study was cross-sectional and conducted in the outpatient clinics of a university hospital between March and June 2023. The sample consisted of 951 women between the ages of 15 and 49, who had given birth at least once, and had no history of menopause. Descriptive Information Form, Family Planning Attitude Scale, Contraceptive Knowledge Assessment Scale, and Contraceptive Intent Questionnaire were used as data collection tools. Moreover, Cox's IMCHB constitutes the study's theoretical framework.ResultsIn the present study, it was determined that the contraceptive method used before pregnancy, emergency contraceptive experience, access and provision of contraceptive methods, and continuation of contraceptive method had a significant effect on contraceptive method preferences in the postpartum period. It was determined that each unit increase in the continuation of the contraceptive method used before pregnancy in the postpartum period increased the intention to use by 0.244 points, each unit increase in contraceptive knowledge level increased by 0.202 points, and each unit increase in positive attitude toward family planning increased by 0.102 points. Each unit increase in the desire to become pregnant again decreased the intention to contraceptive use by 0.230 points.ConclusionTo increase the use of modern and effective contraceptives in the postpartum period and prevent unwanted pregnancies, it is necessary to evaluate the factors affecting contraceptive method use, preferences, and intentions of women and their husbands together
A detailed investigation into the curing kinetics of zinc borate-epoxy composites
Get PDFEpoxy resins (E) are widely used in composite applications due to their superior properties such as lightweight, manufacturing flexibility, and compatibility with numerous reinforcement elements. To enhance these properties and mitigate drawbacks like low toughness, curing agents that improve chain linkages and nanofillers are employed. Nano-sized zinc borates (ZB), commercially available materials, are frequently studied for improving the thermal stability, mechanical strength, and fire resistance of polymeric structures. ZB, with the formula 2ZnO.3B2O3.3.5H2O, is a white crystalline nanomaterial that possesses low toxicity, anti-corrosive properties, low density, and compatibility with various polymers. Although many studies focus on improving the thermal stability and mechanical properties of ZB-epoxy composites (ZB-E), research on curing processes remains limited. However, selecting parameters like temperature and curing duration under system transformations is crucial for composite production. Curing kinetic parameters are essential for accurately analyzing these processes. This study evaluates the curing process of epoxy systems containing different mass fractions of ZB (2-4-6-8-10 %) through dynamic differential scanning calorimetry (DSC) tests. DSC analyses were conducted at various heating rates (3-6-9 degrees C/min) with a final curing temperature of 120 degrees C. The obtained data were analyzed using different phenomenological kinetic equation models (Kissinger, Flynn-Wall-Ozawa, Boswell, and Moynihan) in Matlab-R2019b, and the curing kinetic parameters were calculated. At the same time, the reaction order was calculated using the Crane method. In the final stage, Arrhenius equations were applied to determine the activation energies of the systems. This study assesses the influence of ZB addition on epoxy curing kinetics and the activation energies of ZB-E structures. The activation energy (Ea) values calculated from different models (Kissinger, FWO, Moynihan, and Boswell) show some variation, but the overall trend is consistent: as the ZB content increases, the activation energy generally decreases. The Ea value calculated using the Kissinger, FWO, Moynihan, and Boswell methods decreases by approximately 35.48 %, 33.27 %, 33.27 %, and 34.63 % respectively, when the ZB content increases from 0 % to 10 %. It also provides a new perspective for pre-production optimization and characterization of composite curing systems, aiming to reduce manufacturing costs and production times.Turkish Energy, Nuclear and Mineral Research Agency-Boron Research InstituteThis work was supported by Turkish Energy, Nuclear and Mineral Research Agency-Boron Research Institute. We would also like to express their gratitude to the staff and facilities of Turkish Energy, Nuclear and Mineral Research Agency-Boron Research Institute and Duezce University for their invaluable assistance with the characterization studies
Technical analysis review using fuzzy logic method in investment instruments
Get PDFBu çalışma, finansal piyasalarda yatırım kararlarının daha etkin bir şekilde alınabilmesi için teknik analiz yöntemleri ile Bulanık Mantık Yöntemi'nin entegrasyonunu incelemeyi amaçlamaktadır. Finansal piyasalarda belirsizliklerin ve risklerin azaltılmasına yönelik bir çerçeve sunmayı hedefleyen bu araştırma, yatırımcıların karar alma süreçlerine hem teorik hem de pratik anlamda katkılar sağlamayı amaçlamaktadır. Çalışma kapsamında, Borsa İstanbul'un (BIST50) endeksine dahil hisse senetleri, 2015-2024 dönemindeki fiyat hareketleri ve teknik analiz göstergeleri temel alınarak analiz edilmiştir. Araştırmada, hisse senetlerinin geçmiş fiyat hareketlerini inceleyen teknik analiz yöntemi, Bulanık Mantık'ın esnek ve yorumlamaya dayalı analitik yaklaşımıyla birleştirilmiştir. Teknik analiz göstergeleri arasında hareketli ortalamalar (HO), Göreceli Güç Endeksi (RSI), Bollinger Bantları, Stokastik RSI ve Emtia Kanal Endeksi (CCI) kullanılmıştır. Bu göstergeler, hisse senetlerinin trendlerini ve fiyat hareketlerindeki dönüş noktalarını belirlemek için üyelik fonksiyonları ve bulanık kurallar çerçevesinde değerlendirilmiştir. Çalışmanın bulguları, Bulanık Mantık ve teknik analiz yöntemlerinin entegrasyonunun, yatırım kararlarının doğruluğunu artırdığını ve risk-getiri analizlerine farklı bir bakış açısı kazandırdığını göstermektedir. Bu araştırma, yalnızca finansal analiz yöntemleriyle ilgili literatürdeki bir boşluğu doldurmakla kalmamış, aynı zamanda yatırımcılara sektörel düzeyde daha bilinçli kararlar alabilmeleri için bir rehber sunmuştur.This study aims to examine the integration of technical analysis methods with the Fuzzy Logic Method to enhance the effectiveness of investment decision-making in financial markets. By offering a framework to mitigate uncertainties and risks in financial markets, this research seeks to contribute to the decision-making processes of investors both theoretically and practically. The study focuses on the analysis of stocks included in the Borsa Istanbul (BIST50) index, utilizing price movements and technical analysis indicators from the 2015–2024 period. In the research, technical analysis, which evaluates the historical price movements of stocks, is combined with the flexible and interpretation-based analytical approach of Fuzzy Logic. Technical indicators such as Moving Averages (MA), Relative Strength Index (RSI), Bollinger Bands, Stochastic RSI, and Commodity Channel Index (CCI) were utilized. These indicators were evaluated using membership functions and fuzzy rules to identify stock trends and turning points in price movements. The findings reveal that the integration of Fuzzy Logic with technical analysis improves the accuracy of investment decisions and provides a new perspective on risk-return analyses. This research not only addresses a gap in the literature regarding financial analysis methods but also offers a practical guide for investors to make more informed decisions on a sectoral level