NeuroHybridNet: Otokodlayıcı Destekli Fraktal-Dalgaçık Özelliklerle Zenginleştirilmiş Hibrit Bir EEG Sınıflandırma Modeli

Öz

Elektroensefalografi (EEG) sinyalleri, özellikle sürücü dikkatinin izlenmesi gibi dinamik ve yüksek riskli ortamlarda bilişsel durumların değerlendirilmesi açısından zengin ancak karmaşık bir bilgi kaynağı sunar. Bu çalışmada, WaveFrac-AE adı verilen, zaman-frekans analizi, fraktal dinamikler ve doğrusal olmayan betimleyicileri Otokodlayıcı (Autoencoder) tabanlı boyut indirgeme ile birleştiren hibrit bir EEG sınıflandırma modeli önerilmektedir. Dikkatli, dikkati dağılmış ve uykulu olmak üzere üç bilişsel durumu temsil eden EEG sinyalleri, hem zamansal hem de yapısal karmaşıklığı yansıtan kompakt bir gizil uzaya dönüştürülmektedir. Model, Sürekli Dalgaçık Dönüşümü (CWT) özelliklerini, fraktal ölçütlerle (Petrosian Fraktal Boyutu, Hurst Üssü, DFA) birleştirerek EEG sinyallerinin durağan olmayan doğasını sağlam bir biçimde temsil eder. Otokodlayıcı bileşeni, gürültü ve gereksiz bilgileri filtreleyerek genellenebilirliği artırır ve gerçek zamanlı nöroergonomik uygulamalar için doğru ve ölçeklenebilir sınıflandırma sağlar. Bu hibrit yaklaşım, XGBoost, LightGBM, CatBoost, Random Forest ve SVM gibi çeşitli makine öğrenmesi algoritmalarıyla test edilmiştir. Kişiye özel analizlerde SVM ortalama %97’nin üzerinde doğruluk sağlarken, tüm deneklerin birleşik veri setinde %92’nin üzerinde doğruluk elde edilmiştir. Güncel çalışmalarla yapılan karşılaştırmalar, yöntemin rekabetçi olduğunu ve birçok durumda üstün performans sergilediğini göstermektedir. Sonuç olarak, önerilen model, sürücü dikkat takibi sistemleri için yüksek performanslı bir çözüm sunmakta ve akıllı araçlara entegre erken uyarı sistemlerinin geliştirilmesi açısından önemli bir potansiyele sahiptir.

Anahtar Kelimeler

• Otokodlayıcı
• Sürekli Dalgaçık Dönüşümü (CWT)
• EEG
• Fraktal Boyut
• Makine Öğrenmesi

NeuroHybridNet: A Hybrid EEG Classification Model with Autoencoder-Enhanced Fractal-Wavelet Features

Abstract

Electroencephalography (EEG) signals offer a rich but complex source of information for assessing cognitive states, particularly in dynamic and high-stakes environments such as driver attention monitoring, where rapid and accurate detection of mental fatigue or distraction is critical for safety and performance.This study proposes WaveFrac-AE, a hybrid EEG classification model that combines time-frequency analysis, fractal dynamics, and nonlinear descriptors with Autoencoder-based dimensionality reduction. EEG signals representing three cognitive states—focused, distracted, and drowsy—are transformed into a compact latent space capturing both temporal and structural complexity. By fusing Continuous Wavelet Transform features with fractal measures (Petrosian, Hurst, DFA), the model achieves robust representation of non-stationary EEG dynamics. The Autoencoder component enhances generalizability by filtering noise and redundancy, enabling accurate and scalable mental state classification for real-time neuroergonomic applications. This hybrid approach has been tested with various machine learning algorithms—namely XGBoost, LightGBM, CatBoost, Random Forest, and Support Vector Machines (SVM). In subject-specific analyses, SVM achieved an average accuracy exceeding 97%, while the aggregated dataset—combining all subjects—yielded an accuracy surpassing 92%. Comparisons with contemporary studies suggest that this method occupies a competitive position and, in numerous cases, demonstrates higher performance. Consequently, the proposed model offers high-performance solution in driver attentiveness monitoring systems, thereby showing substantial potential for the development of early warning systems integrated into smart automobiles.

Keywords

• Autoencoder
• CWT
• EEG
• Fractal Dimension
• Machine Learning.

Kaynakça

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