Πλοήγηση ανά Συγγραφέας "Theodoropoulos, Dimitrios"

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  • Μικρογραφία εικόνας
    Τεκμήριο
    Semantic segmentation of diabetic retinopathy lesions, using a UNET with pretrained encoder.
    (ΕΛ.ΜΕ.ΠΑ., Σχολή Μηχανικών (ΣΜΗΧ), ΠΜΣ Πληροφορική και Πολυμέσα, 2022-01-19) Theodoropoulos, Dimitrios; Θεοδωρόπουλος, Δημήτριος
    With the emergence of Deep Learning nowadays, a lot of novel architectures have been devised to perform tasks such as classification, detection, segmentation etc. In Medical Imaging and especially in Ophthalmology, the robustness of Deep Learning is exploited in many studies. Most of the state of art papers nowadays use UNets or Fully Convolutional Networks (FCN) for segmentation tasks. UNets instantiate a modified version of the acknowledged Convolutional Neural Networks. In this study we focus on the segmentation of Diabetic retinopathy lesions. In the real world, this task is very difficult because a good algorithm is based on a robust dataset. The special annotated datasets for segmentation tasks are pretty rare and comprise fewer images compared to other larger datasets. Additionally, images dedicated to segmentation are imbalanced as far as the ratio of lesions and normal pixels are concerned. Those were the main reasons we chose not to train a model from scratch and confront possible difficulties. Instead we exploited transfer learning and utilized a pretrained network (MobileNetV2) as encoder of the Unet. We segmented four kinds of Diabetic Retinopathy lesions, surpassing the existing state of art models in the case of two lesions: Hemorrhages and Soft Exudates. More specifically, Sensitivity in Hemorrhages reached 0.89 whilst in Soft Exudates reached 0.97. One of the novelties of the thesis is that the algorithm could be further easily applied on mobile phones, something that MobileNetV2 is intended to.
  • Δεν υπάρχει διαθέσιμη μικρογραφία
    Τεκμήριο
    Χρηματοοικονομική ανάλυση και σύγκριση δυο επιχειρήσεων: ΑΤΤΙΚΑΤ Α.Τ.Ε και Μηχανική Α.Ε.
    (Τ.Ε.Ι. Κρήτης, Σχολή Διοίκησης και Οικονομίας (Σ.Δ.Ο), Τμήμα Χρηματοοικονομικής και Ασφαλιστικής (Άγιος Νικόλαος), 2008-12-15T15:17:36Z) Θεοδωρόπουλος, Δημήτριος; Theodoropoulos, Dimitrios