Hacettepe University Reserach Information System
Not a member yet
118745 research outputs found
Sort by
Risk Prediction of Low Bone Density in Elderly Patients with Supervised Machine Learning Algorithms
No full textBackground: Low bone mineral density (BMD) is a common age-related condition that elevates the risk of fractures and mortality. Machine learning (ML) techniques offer a promising approach for early prediction using readily available clinical, biochemical, and demographic data. Aims: To evaluate the predictive performance of eleven ML models in identifying low BMD and to determine the most influential risk factors using the best-performing model. Study Design: Cross-sectional study. Methods: Data were obtained from National Health and Nutrition Examination Survey (2005-2010, 2013-2014, and 2017-2020), focusing on individuals aged ≥ 50 years with available femoral neck or total femur BMD data. After applying exclusion criteria, 12,108 participants were included. Supervised ML algorithms were trained using 57 clinical, biochemical, demographic, and behavioral features. Model performance was assessed using accuracy, area under the curve (AUC), recall, precision, and F1 score. SHAP analysis was employed to interpret model outputs and rank predictors. Results: The extra trees classifier outperformed other ML methods, achieving an accuracy of 76.7% and an AUC of 0.85. Recursive Feature Elimination with Cross-Validation identified 14 key predictors of low BMD in descending order of importance: sex, age, body mass index, race, family income-to-poverty ratio, serum uric acid, diabetes status, HDL cholesterol, urinary creatinine, alkaline phosphatase, mean cell volume, lymphocyte count, diastolic blood pressure, and glycohemoglobin. Conclusion: Tree-based ML models, particularly Extra Trees, can effectively predict low BMD. The identified risk factors include both established and lesser-studied predictors. These findings support the use of ML for personalized osteoporosis and osteopenia screening and highlight its ability to capture complex, multifactorial relationships in population health data
Experimental evaluation of slab reinforcement contribution to negative moment capacity in beam-column joints to prevent storey mechanism in RC frames
No full textT & uuml;rkiye, located in a high seismic risk zone, has experienced the collapse of many reinforced concrete (RC) buildings due to the strong beam-weak column problem, largely caused by neglecting the contribution of adjacent slab reinforcement in joint design. While Turkish standards and Eurocode disregard this contribution in negative moment regions, international codes such as ACI 318 partially or fully consider it. This study presents an experimental investigation on the flexural contribution of slab reinforcement placed parallel to beams in joint regions. Eighteen half-scale RC beams, including T-section beams with slabs and rectangular beams without slabs, were tested under static three-point loading. The results show that slab reinforcements significantly enhance the negative moment capacity, with their effectiveness decreasing parabolically as the distance from the beam web increases. Approximately 35 % of the reinforcement within the effective slab width was found to contribute as effectively as beam reinforcement. Based on these findings, an equation was proposed to determine the effective slab width and the contribution rate of slab reinforcement. Recognizing this effect can help maintain ductile strong column-weak beam behavior, reduce reinforcement congestion at joints, and improve seismic performance
Machine Learning for the Prediction of Automobile Insurance Claim Components: Beyond The GLM
No full textAgreement between serum creatinine and fingerstick creatinine measurements in adult patients admitted to the emergency department
No full textIntroductionCritically ill patients are frequently encountered in the emergency department (ED) and requiring rapid diagnosis and treatment. It has been shown that fingerstick tests shorten examination and treatment durations in the ED. The aim of this study was to assess the agreement between fingerstick creatinine measurements and serum creatinine values obtained by laboratory enzymatic testing.MethodsThis study was conducted as a single center, prospective, observational study. 250 patients aged 18 years and over who applied to the adult emergency department between 12.12.2023 and 30.12.2023 and underwent the necessary serum biochemistry examination were included in the study. In addition to the blood biochemistry tests were requested by the patients' doctors, blood samples taken from the patients' fingertips were scanned using the i-STAT device and a creatinine cartridge. Intraclass correlation coefficient (ICC) was used to examine the consistency between serum creatinine values measured in the laboratory and fingerstick creatinine values, and the type 1 error level was set as 0.05. A graphical approach, the Bland-Altman plot was used to examine the agreement between measurements. A significance level of 0.05 was used for all comparisons.ResultsIn this study, after exclusion of 4 patients due to kit problems, 133 patients (54.16%) were female and 113 patients (45.94%) were male. The median age was found to be 55.5. A strong agreement was found between the measured values (ICC: 0.996). Patients when analyzed among themselves in terms of admission complaints, existing diseases, age, gender, admission vital signs and glomerular filtration rates, a strong agreement was observed between fingertip creatinine and serum creatinine in each group.ConclusionIn conclusion, the fingerstick creatinine test may be considered for early use in patients presenting to the ED, as it is easily applicable in examination and treatment management and has strong agreement rates with laboratory values
A comparison of migration policies of the George W. Bush and Donald J. Trump administrations from the perspective of securitization theory
No full textPioneering Graph Attention Networks for Mineral Resource Estimation: A Case Study on a Copper Deposit
No full textSERAMİK FORMLARDA DEĞERLENDİRİLEN DİSTOPİK VE KIYAMET SONRASI SENARYO KAVRAMLARI*
No full textBu derleme makalesi, “kıyamet sonrası senaryolar” ve “distopya” temalarının seramik sanatındaki yansımalarını inceleyerek, bu kavramların estetik ve kavramsal uygulamalara etkilerini ortaya koymaktadır. Farklı kültürlerden on seramik sanatçısının – Bouke de Vries, Barnaby Barford, Jenny Orchard, Shary Boyle, Virgil Ortiz, Walter McConnell, Kim Simonsson, Johnson Tsang, Stephanie Kilgast ve Ronit Baranga – eserlerini temel alan çalışma, bu temaları ekolojik, teknolojik, sosyal, kültürel, ekonomik, estetik, biyolojik, etik, tarihi ve varoluşsal boyutlarda ele almaktadır. Nitel araştırma metodolojisiyle gerçekleştirilen görsel-biçimsel analizler, seramik sanatçılarının bu temaları yenilikçi biçimlerde işlerken çağdaş toplumdaki sorunlara dikkat çektiklerini göstermektedir. Bulgular, seramik sanatının benzersiz malzeme özellikleri ve teknik esnekliğiyle toplumsal ve sanatsal sorumluluklara hitap ettiğini ortaya koymaktadır. İncelenen sanatçılar, seramik formları kullanarak alternatif dünyalar inşa etmekte ve yerleşik normları sorgulayan süreçleri tasvir etmektedirler. Bu sanatçıların vurguladığı zorlukların incelenmesi, toplumsal farkındalık ve eleştirel düşüncenin gelişimine katkı sağlamaktadır. Sonuç olarak, çalışma seramik sanatı ile distopik edebiyat arasındaki etkileşimi vurgulayarak, sanatsal ifade ve toplumsal anlatıların yorumlanması için yeni yollar açmaktadır.This review article examines the incorporation of "post-apocalyptic scenarios" and "dystopian" themes in ceramic art, elucidating their impact on aesthetic and conceptual practices. The study analyzes works by ten ceramic artists from diverse cultural backgrounds, Bouke de Vries, Barnaby Barford, Jenny Orchard, Shary Boyle, Virgil Ortiz, Walter McConnell, Kim Simonsson, Johnson Tsang, Stephanie Kilgast, and Ronit Baranga, who address these themes across ecological, technological, social, cultural, economic, aesthetic, biological, ethical, historical, and existential dimensions. Visual and formal analyses conducted through qualitative research methodologies demonstrate that ceramic artists not only employ these themes in innovative ways but also draw attention to multifaceted issues in contemporary society. Findings indicate that ceramic art, with its unique material properties and technical versatility, addresses both societal and artistic responsibilities in representing dystopian and post-apocalyptic scenarios. The examined artists utilize ceramic forms to construct alternative worlds and depict processes that challenge established norms. The investigation of challenges highlighted by these artists contributes to the development of social awareness and critical thinking. Consequently, this study emphasizes the dynamic interaction between ceramic art and dystopian literature, establishing new pathways for interpreting both artistic expression and societal narratives
