Arama Sonuçları

Listeleniyor 1 - 6 / 6
  • Yayın
    Suicidal ideation detection from social media
    (Işık Üniversitesi, 2023-08-24) Ezerceli, Özay; Dehkharghani, Rahim; Işık Üniversitesi, Lisansüstü Eğitim Enstitüsü, Bilgisayar Mühendisliği Yüksek Lisans Programı
    Suicidal ideation is a global cause of life-threatening injury and, most of the time, death. Mental health issues have been rapidly increasing, and most are being avoided without adequate treatment. Due to the developments in social media platforms and the online anonymity that these platforms provide, people would like to interact more with others on social platforms. Social platforms are surveillance tools for mining social content and suicidal tendencies. The current thesis attempts to present a solution to detect depression/suicidal ideation by using state-of-the-art natural language processing (NLP) and deep learning (DL) approaches (BiLSTM, BERT Transformer). Three different novel approaches are proposed for three different datasets of textual content. The SuicideDetection dataset is a publicly available dataset which is a collection from the social platform of Reddit’s subreddits (“SuicideWatch”, ”depression”, ”bipolar”, ”offmychest”, ”anxiety”) in Kaggle and the SWMH dataset is a collection from only “SuicideWatch” subreddit. The CEASEv2.0 dataset is another used dataset which is a collection of 4932 suicide notes. The proposed models outperformed the latest models by 2% and 1% F1 scores on SuicideDetection and CEASEv2.0 datasets, respectively. The best models for each dataset have been analyzed and discussed in terms of performance, along with the characteristics of the datasets and limitations in the suicidal ideation classification. This performance can be measured by common metrics such as Accuracy, Precision, Recall, F1-Score, and ROC curve. As its application in the real world, this project can assist psychologists in the early identification of suicidal ideation before the suicidal person harms him/herself. The thesis also demonstrates the potential of employing DL algorithms such as transformers along with the latest word embedding techniques and NLP techniques that could improve the issue of suicidal ideation.
  • Yayın
    Convolutional neural network (CNN) algorithm based facial emotion recognition (FER) system for FER-2013 dataset
    (IEEE, 2022-11-18) Ezerceli, Özay; Eskil, Mustafa Taner
    Facial expression recognition (FER) is the key to understanding human emotions and feelings. It is an active area of research since human thoughts can be collected, processed, and used in customer satisfaction, politics, and medical domains. Automated FER systems had been developed and have been used to recognize humans’ emotions but it has been a quite challenging problem in machine learning due to the high intra-class variation. The first models were using known methods such as Support Vector Machines (SVM), Bayes classifier, Fuzzy Techniques, Feature Selection, Artificial Neural Networks (ANN) in their models but still, some limitations affect the accuracy critically such as subjectivity, occlusion, pose, low resolution, scale, illumination variation, etc. The ability of CNN boosts FER accuracy. Deep learning algorithms have emerged as the greatest way to produce the best results in FER in recent years. Various datasets were used to train, test, and validate the models. FER2013, CK+, JAFFE and FERG are some of the most popular datasets. To improve the accuracy of FER models, one dataset or a mix of datasets has been employed. Every dataset includes limitations and issues that have an impact on the model that is trained for it. As a solution to this problem, our state-of-the-art model based on deep learning architectures, particularly convolutional neural network architectures (CNN) with supportive techniques has been implemented. The proposed model achieved 93.7% accuracy with the combination of FER2013 and CK+ datasets for FER2013.
  • Yayın
    Web service translating content into Turkish sign language
    (Institute of Electrical and Electronics Engineers Inc., 2020-10-12) Gümüşçekiçci, Gizem; Ezerceli, Özay; Tek, Faik Boray
    The essential communication tool for people with hearing loss is sign language. It is way more efficient for their communication. Existing systems for translating the text into sign language are offline and not practical. In this study, we propose a web service-based solution for online translation of content into Turkish Sign Language. We implemented the system and tested it using 32 sentences of 189 words as inputs. The correct word translation rate was 81.74% for the media or audio inputs and the correct word translation for the text inputs was 81.09% The results show the feasibility of the solution and the potential for improvements.
  • Yayın
    Mental disorder and suicidal ideation detection from social media using deep neural networks
    (Springer, 2024-12) Ezerceli, Özay; Dehkharghani, Rahim
    Depression and suicidal ideation are global reasons for life-threatening injury and death. Mental disorders have increased especially among young people in recent years, and early detection of those cases can prevent suicide attempts. Social media platforms provide users with an anonymous space to interact with others, making them a secure environment to discuss their mental disorders. This paper proposes a solution to detect depression/suicidal ideation using natural language processing and deep learning techniques. We used Transformers and a unique model to train the proposed model and applied it to three diferent datasets: SuicideDetection, CEASEv2.0, and SWMH. The proposed model is evaluated using the accuracy, precision, recall, and ROC curve. The proposed model outperforms the state-of-theart in the SuicideDetection and CEASEv2.0 datasets, achieving F1 scores of 0.97 and 0.75, respectively. However, in the SWMH data set, the proposed model is 4% points behind the state-of-the-art precision providing the F1 score of 0.68. In the real world, this project could help psychologists in the early detection of depression and suicidal ideation for a more efcient treatment. The proposed model achieves state-of-the-art performance in two of the three datasets, so they could be used to develop a screening tool that could be used by mental health professionals or individuals to assess their own risk of suicide. This could lead to early intervention and treatment, which could save lives.
  • Yayın
    TurkEmbed: Turkish embedding model on natural language inference & sentence text similarity tasks
    (Institute of Electrical and Electronics Engineers Inc., 2025) Ezerceli, Özay; Gümüşçekiçci, Gizem; Erkoç, Tuğba; Özenç, Berke
    This paper introduces TurkEmbed, a novel Turkish language embedding model designed to outperform existing models, particularly in Natural Language Inference (NLI) and Semantic Textual Similarity (STS) tasks. Current Turkish embedding models often rely on machine-translated datasets, potentially limiting their accuracy and semantic understanding. TurkEmbed utilizes a combination of diverse datasets and advanced training techniques, including matryoshka representation learning, to achieve more robust and accurate embeddings. This approach enables the model to adapt to various resource-constrained environments, offering faster encoding capabilities. Our evaluation on the Turkish STS-b-TR dataset, using Pearson and Spearman correlation metrics, demonstrates significant improvements in semantic similarity tasks. Furthermore, TurkEmbed surpasses the current state-of-the-art model, Emrecan, on All-NLI-TR and STS-b-TR benchmarks, achieving a 1-4% improvement. TurkEmbed promises to enhance the Turkish NLP ecosystem by providing a more nuanced understanding of language and facilitating advancements in downstream applications.
  • Yayın
    TurkEmbed4Retrieval: Türkçe için geri getirme görevine özel gömme modeli
    (Institute of Electrical and Electronics Engineers Inc., 2025-08-15) Ezerceli, Özay; Gümüşçekiçci, Gizem; Erkoç, Tuğba; Özenç, Berke
    Bu çalışmada, öncelikle Doğal Dil Çıkarımı (DDÇ) ve Anlamsal Metin Benzerliği (AMB) görevleri için geliştirilen TurkEmbed modelinin, MS-Marco-TR veri seti üzerinde ince ayar yapılarak geri getirme görevlerine uygun hale getirilmesini sağlayan TurkEmbed4Retrieval modelini tanıtıyoruz. Model, Matruşka temsili ögrenme ve özel tasarlanmış negatif çiftlerin sıralanması kayıp fonksiyonu gibi ileri seviye egitim teknikleri kullanılarak optimize edilmiştir. Yapılan kapsamlı deneyler, TurkEmbed4Retrieval’ın, geri getirme metriklerinde TurkishcolBERT modelini Scifact-TR veri kümesinde %19–26 oranında geçtiğini göstermektedir. Bu bağlamda, modelimiz, Türkçe bilgi getirme sistemleri için yeni bir çıtaya ulaşmaktadır.