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• MakaleAçık Erişim2026/r/gumushane/13706
  Real maritime measurement-driven machine learning for path loss modeling in shore-to-ship wireless links

  Sağır, Nuğman; Eyüboğlu, Ekrem; Kuzulugil, Kenan; Tuğcu, Zeynep Hasırcı; Çavdar, İsmail Hakkı

  Reliable propagation modeling remains a fundamental requirement for the design and deployment of maritime wireless communication systems, particularly in shore-to-ship scenarios characterized by highly variable environmental conditions. Unlike conventional empirical and deterministic models that rely on theoretical assumptions, the proposed approach is entirely measurement-driven, enabling more accurate and robust propagation modeling. Four regression algorithms—Gaussian Process Regression, Least Squares Boosting, Decision Tree, and Support Vector Regression—are evaluated using a feature set that includes transmission distance, sea state, weather conditions, and antenna configurations. Among the tested models, the Decision Tree achieves the best performance, with an RMSE of 1.18 dB and an R2 of 0.96, corresponding to an error reduction of approximately 45.6% compared to the best-performing empirical model. Feature importance analysis shows that transmission distance and antenna geometry dominate signal attenuation, while environmental variables have a limited influence at this frequency. Unlike most existing studies that emphasize deep learning or black-box models, this work demonstrates that lightweight and interpretable regression models can achieve comparable accuracy while enabling real-time link planning and practical deployment. The focus is on engineering applicability rather than proposing new learning architectures. Overall, the results indicate that measurement-driven machine learning provides accurate and interpretable solutions for shore-to-ship path loss modeling under real maritime conditions.

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• MakaleAçık Erişim2024/r/gumushane/20073
  Araçlar Arası (V2V) Haberleşmede Dağlık Anayollarda Yol Kaybı ve Gölgeleme Analizi

  Tuğcu, Zeynep Hasırcı; Kuzulugil, Kenan

  Araçlar arası (V2V) haberleşme, karayolu sürüş güvenliği ve kaza önleme açısından önemli bir teknoloji olarak görülmektedir. Ancak, araçlar arasına giren binalar, diğer araçlar ve ağaçlar gibi çevresel engeller V2V haberleşmeyi olumsuz yönde etkileyebilmektedir. Bu çalışmada, virajlı dağlık anayol ortamlarında, verici ve alıcı araçlar arasındaki iletişimi engelleyen dağlık alanların etkisi incelenmiş ve 5.9 GHz’de V2V ölçümleri yapılmıştır. Ölçülen veriler, engel senaryolarında yaygın kullanılan log-normal ve çift eğimli yol kaybı modelleriyle modellenmiş ve verilere uyum performansları açısından karşılaştırılmıştır. Sonuçlar, dağ engeli bulunan senaryolarda çift eğimli yol kaybı modelinin daha iyi bir uyum sağladığını göstermektedir. Ayrıca, dağ engelinin neden olduğu gölgeleme ve zayıflatma etkileri incelenmiş, dağ engeli kaynaklı ortalama zayıflamanın 19.6 dB olduğu tespit edilmiş ve literatüre ilk kez bu çalışma ile kazandırılmıştır. Bu bulgular, sistem tasarımcıları ve araştırmacılarına çevresel faktörlerin V2V iletişim performansına etkisinin detaylandırılmasında ve sistemlerin buna göre optimize edilip tasarlanmasında katkı sağlayacaktır.

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• MakaleAçık Erişim2024/r/gumushane/13932
  Measurement-based V2V propagation modeling in highway, suburban, and urban environments

  Hasırcı Tuğcu, Zeynep; Kuzulugil, Kenan; Çavdar, İsmail Hakkı

  Vehicle-to-vehicle (V2V) communication is one of the promising communication applications designed to optimize traffic conditions and has played a crucial role in the improvement of intelligent transportation technologies. Since there is still some uncertainty regarding generalized models that provide a more accurate representation of propagation environments, the existing literature emphasizes the need for additional experimental studies in various countries and propagation environments. This study aims to investigate the low-density and high-density characteristics of V2V channels for highway, suburban, and urban propagation environments in Türkiye. Thus, first, channel measurements were conducted for all propagation scenarios. Then, after the estimation of path loss parameters, the best-fitted path loss model was determined for each propagation scenario by comparing log-distance, two-ray, and log-ray models. It was observed that the log-ray model offered remarkably better performance than the two-ray model, especially in the majority of scenarios with two-ray characteristics. In addition, small-scale modeling and shadowing were also examined, and the outcomes were compared to relevant literature. Last, generalized path loss models were developed for six propagation scenarios and compared with previous studies. Providing additional experimental data on the impact of traffic and road environments that vary across countries on the V2V channel, this study not only validated and compared existing propagation models but also improved the representing accuracy and generalizability of the newly proposed propagation models. Here, all findings were presented in detail to support the motivation of the research.

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• MakaleAçık Erişim2024/r/gumushane/12399
  Modified REL-Based Piecewise Path Loss Modeling Approach for Shore-to-Ship Communication at 5.6 GHz

  Eyuboglu, Ekrem; Hasirci Tugcu, Zeynep; Kuzulugil, Kenan; Cavdar, Ismail Hakki

  The need for reliable and uninterrupted communication systems in the marine environment has become critically important with increasing maritime activities, environmental monitoring, and the spread of autonomous systems. However, the complex structure of electromagnetic wave propagation in a sea environment limits the accuracy of the existing propagation models. Thus, the Modified Round Earth Loss (REL) model was first developed in this study to estimate the path loss more accurately in shore-to-ship communication. Subsequently, a piecewise modeling approach based on the principle of two-segment data modeling was proposed. In the Modified REL model, unlike the traditional REL model, the paths and gains of the direct and reflected waves were not considered equal in the calculations. Moreover, unlike in the classical approach, the receiver height was not taken as a fixed value; the estimated best receiver height value for each measurement was included in the calculations as a representation of the effect of roughness in the sea environment. Thus, the model is better adapted to various environmental conditions. In addition, the proposed piecewise model divides the propagation medium into two regions using a break point calculated by Fresnel zone theory. The Modified REL model was used for the first region and the log-distance model was used for the second region. This method allows for more accurate modeling of signal behaviors, especially at different distances. Experimental measurements and performance evaluations conducted using four different shore-to-ship communication scenarios show that the Modified REL model shows an average improvement of up to 3% in Root Mean Square Error (RMSE) values compared to the classical REL model. Additionally, the proposed piecewise model improves the fitting error of the Modified REL model, which models the data as a single whole, by an average of 22.25%. These findings emphasize the necessity of propagation models that are sensitive and adaptable to environmental changes for maritime communication.

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• MakaleYalnız künye2023/r/gumushane/14375
  A Proposed V2V Path Loss Model: Log-Ray

  Kuzulugil, Kenan; Tugcu, Zeynep Hasirci; Cavdar, Ismail Hakki

  Vehicle-to-vehicle (V2V) communication that has prominent involvement in the design of innovative communication solutions for the intelligent transportation system. Therefore, to develop V2V channel models, the knowledge of the propagation channel on which comprehensive research efforts have been carried is vital. In this study, we focused on the analysis and modeling of path loss characteristics for V2V communications and proposed a log-ray path loss model with the motivation of overcoming remarkable fitting errors between the two-ray model and measured data where the path loss exponent corresponds to different from 2. First, channel measurements were performed at 5.9 GHz with commercially available DSRC OBU devices for five different scenarios in typical highway and suburban environments in Gümüşhane, Turkey. Then, the large-scale characteristics of different propagation scenarios were analyzed and the proposed log-ray model performance was compared with commonly used log-distance and two-ray path loss models qualitatively and quantitatively. On the other hand, analysis of small-scale modeling and shadowing were also conducted for all scenarios and presented in the results. The findings clearly demonstrate that the proposed log-ray path loss model fits the measured data with a smaller RMSE value (2.54 dB) than the results of the log-distance (3.07 dB) and two-ray (3.72 dB) path loss models in the literature. In other words, the proposed model has approximately 17.5% and 32% increase in fitting performance according to the log-distance and the two-ray path loss models, respectively. The study results will be helpful for better performance analysis and system design of V2V communication.

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