TR-Dizin İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/396
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Article Developing a Label Propagation Approach for Cancer Subtype Classification Problem(TUBITAK, 2021) Güner, P.; Bakir-Güngör, B.; Coşkun, M.; Şahan, Pınar GünerCancer is a disease in which abnormal cells grow uncontrollably and invade other tissues. Several types of cancer have various subtypes with different clinical and biological implications. Based on these differences, treatment methods need to be customized. The identification of distinct cancer subtypes is an important problem in bioinformatics, since it can guide future precision medicine applications. In order to design targeted treatments, bioinformatics methods attempt to discover common molecular pathology of different cancer subtypes. Along this line, several computational methods have been proposed to discover cancer subtypes or to stratify cancer into informative subtypes. However, existing works do not consider the sparseness of data (genes having low degrees) and result in an ill-conditioned solution. To address this shortcoming, in this paper, we propose an alternative unsupervised method to stratify cancer patients into subtypes using applied numerical algebra techniques. More specifically, we applied a label propagation-based approach to stratify somatic mutation profiles of colon, head and neck, uterine, bladder, and breast tumors. We evaluated the performance of our method by comparing it to the baseline methods. Extensive experiments demonstrate that our approach highly renders tumor classification tasks by largely outperforming the state-of-the-art unsupervised and supervised approaches. © 2022 Elsevier B.V., All rights reserved.Article Comparative Performance Analysis of Arima, Prophet and Holt-Winters Forecasting Methods on European Covid-19 Data(2022-12-31) Bakir-gungor, Burcu; Ersöz, Nur Şebnem; Şahan, Pınar Güner; Akbaş, AyhanCOVID-19 son yılların en bulaşıcı hastalığıdır ve dünyanın her yerinde salgına neden olmuştur. Daha önce yüzlerce olan ölüm oranı önce binlere, sonra milyonlara yükselmiştir. Ocak 2020'den beri birçok bilim insanı, hükümetlerin hastanelerde yeterli düzenlemeleri yapabilmesi ve ölüm oranını azaltılabilmesi için COVID-19’un yayılımını anlamaya ve tahminlemeye çalışıyor. Bu araştırma makalesi, Avrupa’daki COVID-19 hastalık epidemiyolojisi için tahminler yapmak amacıyla, ARIMA, Prophet ve Holt Winters Üstel Düzeltme yöntemlerinin performans karşılaştırmasını sunmaktadır. Veri seti olarak, Dünya Sağlık Örgütü (DSÖ)'nün toplayıp kategorize ettiği, Avrupa ülkelerinin 2020 ile 2022 yılları arasındaki COVID-19 vaka verileri kullanılmıştır. Elde edilen sonuçlar, Holt-Winters Üstel Düzeltme (RMSE: 0.20, MAE: 0.17) yönteminin, ARIMA ve Prophet tahmin yöntemlerinden daha iyi performans gösterdiğini belirtmektedir.Article Analysis of Under-Five Mortality by Diseases in Countries With Different Levels of Development: a Comparative Analysis(2023-07-03) Ersöz, Nur Şebnem; Sütçü, Muhammed; Şahan, Pınar GünerObjectives: The right to health is critical for children because they are sensitive beings who are more susceptible to disease and health problems. It would be beneficial to compare child mortality rates in countries with different levels of development and to conduct studies to address them by taking into account their causes. This study aims to analyze the situation of developed, developing and least developed countries in terms of causes under-5 child mortality (U5CM) determined by World Health Organization and to identify the similarities or differences of under-five mortality. Methods: Child mortality rates per 1,000 live births between 2000 and 2017 years in between different age groups (0-27 days and 1-59 months) by causes (disease-specific) were obtained from World Health Organization for a total 15 countries including developed, developing and least developed countries. Regression analysis was performed to identify which causes have more impact on child mortality. In addition, the relationship between diseases was calculated using Euclidean distance, and diseases were clustered using k-means clustering algorithm for each country. Results: As a result of mathematical and statistical analysis, it was seen that causes of child mortality have a significant relation with the development level of country where a child was born. Conclusions: It has been observed that the causes of child mortality in countries with different levels of development vary depending on different factors such as geographical conditions, air quality population and access to medicine.