Sivas Cumhuriyet Üniversitesi Kurumsal Akademik Arşivi
DSpace@Cumhuriyet, Sivas Cumhuriyet Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
A novel target item-based similarity function in privacy-preserving collaborative filtering
(Springer, 27.05.2024) Bilge, Alper
Memory-based collaborative filtering schemes are among the most effective recommendation technologies in terms of prediction quality, despite commonly facing issues related to accuracy, scalability, and privacy. A prominent approach suggests an intuitively reasonable modification to the similarity function, which has been proven to provide more accurate recommendations than those generated by state-of-the-art memory-based collaborative filtering methods. However, this scheme exacerbates the scalability problem due to additional computational costs and fails to protect individual privacy. In this study, we recommend using a preprocessing method to eliminate relatively dissimilar items from the prediction estimation process, thereby enhancing the scalability of the proposed approach. We explore how to provide recommendations based on the previously proposed similarity function while preserving privacy and propose privacy-preserving schemes to accomplish this task. Additionally, we apply our preprocessing approach to our proposed privacy-preserving schemes to improve both scalability and accuracy. After analyzing our schemes with respect to privacy and additional costs, we conduct experiments with real data to examine the impact of our schemes on scalability and accuracy. The empirical outcomes indicate that our preprocessing scheme significantly alleviates scalability issues in both conventional and privacy-preserving environments and enhances accuracy within privacy-preserving frameworks.
Empowered chaotic local search-based differential evolution algorithm with entropy-based hybrid objective function for brain tumor segmentation
(Elsevier, Kasım, 2024) Aydemir, Salih Berkan
In neuro-oncology, the precise segmentation of brain tumors from Magnetic Resonance Images is crucial for diagnosis, treatment planning, and monitoring disease progression. Accurate segmentation helps determine the tumor’s size, location, and growth potential, which is essential for formulating effective treatment strategies. In response to this challenge, we developed a novel approach using Chaotic Local Search-Enhanced Differential Evolution (CJADE). CJADE, particularly its variant CJADE-M, which employs chaotic maps selected through a probability-based approach, has proven effective in optimizing brain tumor segmentation. Our study shows that CJADE-M outperforms traditional metaheuristic algorithms on various evaluation metrics. We further enhanced CJADE-M with an entropy-based hybrid objective function, which improved accuracy and reduced computational time in tumor segmentation compared to conventional methods like Minimum Cross-Entropy and Kapur. This makes our method suitable for real-time medical imaging analysis. Our findings indicate that CJADE-M, equipped with the hybrid objective function, achieves superior segmentation performance for both benign lobulated and malignant irregular tumors across metrics such as PSNR, FSIM, QILV, and HPSI. By providing a more accurate and efficient tool, our approach can significantly enhance the outcomes of brain tumor diagnosis and treatment, improving patient care in neuro-oncology.
ITEC’24 International Congress Tourism, Economy and Culture 8-10 MAY 2024 SKOPJE, NORTH MACEDONIA
(Sivas Cumhuriyet Üniversitesi, 2024) KOÇ, Hakan; Suleymani, Liza Alili
In the last 20 years, tourism has become one of the sectors that many countries prioritize and
develop policies around. This growing sector has a significant impact on the economy and
culture. A review of the literature reveals that scientific events (conferences, panels,
symposiums, etc.) investigating this impact are quite limited. To examine this effect, the
"Tourism, Economy, and Culture Congress" was organized in collaboration with Sivas
Cumhuriyet University and International Balkan University, hosted by International Balkan
University from May 8-10, 2024. Through this congress, it was aimed to conduct studies on
the relationship between tourism, which holds an important place for the economies of
countries, and economy and culture, thereby producing ideas that will lead to development in
this field. During the congress, it is planned to create a platform to bring together academics
and researchers from the fields of tourism, economy, and culture. This congress is
abbreviated as ITEC 2024, meaning the International Tourism Economy Congress. It is
planned to continue in the following years as ITEC 2025 and 2026. In its first year, the
congress attracted great interest with 189 papers and 301 participants from 23 countries.
Scientists have made academic contributions to the literature with their specific and in depth studies on the effects of tourism on the economy and culture. These studies have
provided a portfolio from the field to entrepreneurial business people and politicians. We
extend our gratitude to the institutions supporting the congress financially and morally (TİKA,
Sivas Cumhuriyet University, International Balkan University, Kilis 7 Aralık University) and the
scientists. We look forward to seeing you again at ITEC 2025 and greet you all with respect.
Stroke and Mortality Risk in Patients With Various Patterns of Atrial Fibrillation Results From the ENGAGE AF-TIMI 48 Trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48)
(Lippincott Williams & Wilkins, 2017) Link, Mark S.; Giugliano, Robert P.; Ruff, Christian T.; Scirica, Benjamin M.; Huikuri, Heikke; Oto, Ali; Crompton, Andrea E.
Background-Whether the pattern of atrial fibrillation (AF) modifies the risk/benefit of anticoagulation is controversial. In ENGAGE AF-TIMI 48 trial (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48), the factor Xa inhibitor edoxaban was noninferior to warfarin in preventing stroke or systemic embolic events and significantly reduced bleeding and cardiovascular mortality. However, detailed analyses by AF pattern have not been reported. Methods and Results-The 21 105 patients were categorized as having paroxysmal (<7 days duration), persistent (>= 7 days but <1 year), or permanent (>= 1 year or failed cardioversion) AF patterns at randomization. Efficacy and safety outcomes were evaluated during the 2.8 years median follow-up and compared by AF pattern. The primary end point of stroke/systemic embolic event was lower in those patients with paroxysmal AF (1.49%/year), compared with persistent (1.83%/year; P-adj =0.015) and permanent AF (1.95%/year; P-adj =0.004). Overall, all-cause mortality also was lower with paroxysmal (3.0%/year) compared with persistent (4.4%/year; P-adj <0.001) and permanent AF (4.4%/year; P-adj <0.001). Annualized major bleeding rates were similar across AF patterns (2.86% versus 2.65% versus 2.73%). There was no effect modification by treatment assignment. Conclusions-In ENGAGE AF-TIMI 48 trial, patients with paroxysmal AF suffered fewer thromboembolic events and deaths compared with those with persistent and permanent AF. The efficacy and safety profile of edoxaban as compared with warfarin was consistent across the 3 patterns of AF.
Impact of Spontaneous Extracranial Bleeding Events on Health State Utility in Patients with Atrial Fibrillation: Results from the ENGAGE AF-TIMI 48 Trial
(Wiley, 2017) Wang, Kaijun; Li, Haiyan; Kwong, Winghan J.; Antman, Elliott M.; Ruff, Christian T.; Giugliano, Robert P.; Cohen, David J.
Background-The impact of different types of extracranial bleeding events on health-related quality of life and health-state utility among patients with atrial fibrillation is not well understood. Methods and Results-The ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) Trial compared edoxaban with warfarin with respect to the prevention of stroke or systemic embolism in atrial fibrillation. Data from the EuroQol-5D (EQ-5D-3L) questionnaire, prospectively collected at 3-month intervals for up to 48 months, were used to estimate the impact of different categories of bleeding events on health-state utility over 12 months following the event. Longitudinal mixed-effect models revealed that major gastrointestinal bleeds and major nongastrointestinal bleeds were associated with significant immediate decreases in utility scores (-0.029 [-0.044 to -0.014; P<0.001] and -0.029 [-0.046 to -0.012; P=0.001], respectively). These effects decreased in magnitude over time, and were no longer significant for major nongastrointestinal bleeds at 9 months, but remained borderline significant for major gastrointestinal bleeds at 12 months. Clinically relevant nonmajor and minor bleeds were associated with smaller but measurable immediate impacts on utility (-0.010 [-0.016 to -0.005] and -0.016 [-0.024 to -0.008]; P<0.001 for both), which remained relatively constant and statistically significant over the 12 months following the bleeding event. Conclusions-All categories of bleeding events were associated with negative impacts on health-state utility in patients with atrial fibrillation. Major bleeds were associated with relatively large immediate decreases in utility scores that gradually diminished over 12 months; clinically relevant nonmajor and minor bleeds were associated with smaller immediate decreases in utility that persisted over 12 months.
