WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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Analysis of Power-Law Fin-Type Problems Using Physics Informed Neural Networks
(Sciendo, 2025-12-01) Gocer, M.; Coskun, S. B.; Atay, M. T.
This study aims to model the temperature distribution in a single fin subjected to steady one-dimensional heat conduction with nonlinear thermal behavior. For the modeling and solution of the problem, the Physics-Informed Neural Networks (PINNs) architecture was used. The temperature-dependent heat conduction problem and the nonlinear boundary conditions of this problem were formulated with a differential equation. With the help of the PINN architecture, the loss function was minimized in order to reduce the difference between the true value and the predicted value. During this minimization process, the PINN architecture was forced to be consistent with the physical laws. The results obtained after training the PINN architecture exhibit successful performance in terms of accuracy and reliability when compared with the results in the literature. These findings highlight the potential of PINNs as a powerful alternative to conventional methods for solving complex nonlinear heat conduction problems.
Microstrip Stub Filter Design with Enhanced Performance Inspired by SIW Structures Operating at 1.93 GHz GSMBand
(Gazi Univ, 2026-03-29) Tosun, Huseyin; Yentur, Abdulkadir; Kilic, Veli Tayfun
This paper reports a microstrip stub filter design operating at 1.93 GHz GSM band with enhanced performance inspired by SIW structures. In the designed filter additional vias are placed around the microstrip lines to enhance the encasing of the electromagnetic fields while propagating through the filter to develop the filter performance. The filter was examined with electromagnetic simulations for various numbers of vias and different via to microstrip line distances. Results show that the maximum transmission coefficient (S21 parameter) magnitude value reached in the pass band of the filter increases with the number of the vias and as the vias get closer to the lines. On the other hand, when the via number increases and the space between them and the lines narrows, the frequency at which the maximum S21 value is attained shifts to lower frequencies. The designed filters were manufactured, too. Results obtained in the measurements agree well with the simulation results. Additionally, a receiver system operating at 1.93 GHz band was constructed. System experiments were carried out with the constructed prototype for the manufactured filters. Results show that a greater signal level in the filter pass band is achieved and unwanted signals outside the filter pass band are suppressed more in the system where the filter with vias is used instead of the filter without any additional via. The findings indicate that the designed filters inspired by SIW structures are promising for applications requiring high signal quality.
Fluctuations in the European Housing Market: Forecasting the House Price Index Change with Time-Series Models
(Gazi Univ, 2026-03-15) Soylemez, Ismet; Nalici, Mehmet Eren; Unlu, Ramazan
This study presents a comparative analysis of a time series models for forecasting changes in the Housing Price Index (HPI) in 27 European countries. Accurate HPI forecasting is essential for the development of effective policies and investment strategies. The study uses quarterly data from Q4 2013 to Q3 2024. Methodologically, the stationarity of the data is tested using the Dickey-Fuller test and differencing is applied to non-stationary series. The ARIMA, Holt Linear Trend, Additive Damped Trend and Exponential Smoothing models are evaluated based on the lowest mean squared error (MSE) value for each country. The findings confirmed the heterogeneous structure of the European housing market, showing that no single model is suitable for all countries. The ARIMA model provided the most accurate results for nine countries, while the Holt Linear Trend and Additive Damped Trend models performed best in seven countries each. Forecasts for the period 2025-2026 are generated based on these results. This study highlights the importance of adopting country-specific and adaptable forecasting approaches to accommodate the varying dynamics of European housing markets.
Tracing Trajectories of Regime Support in Turkey
(Ege Univ, Fac Economics & Admin Sciences, 2022-06-09) Inan, Murat
According to the legitimacy approach of political culture research, public's approval of a particular regime as the best form of government and rejection of its alternatives provides public support for that particular regime. This research attempted to trace temporal trajectories of approval of democratic political system as well as it's three alternative forms of government among the electorates of recent three major political parties in Turkey, the Justice and Development Party (AKP), the Republican People's Party (CHP) and the Nationalist Movement Party (MHP). It also revealed the extent these parties' manifesto documents praise democratic political system across the successive eighteen general elections in the modern Turkish political history. It revealed the changes in both public and party support for four alternative regimes across years in modern Turkish history. This research analyzed the World Values Survey and the Manifesto Project data using quantitative research methods. It has achieved four main findings. First, voters are more stable than their parties across time in terms of pro-democracy. Second, democracy clearly emerges as the strongest alternative among the four alternative regimes for all the three electorates. Third, supporting democracy and rejecting its three alternatives occupy different places in the minds of the three party electorates. Fourth, changes in the three political parties' pro-democracy as identified in their manifesto documents are not always parallel with changes in those of their voters.
Tax Compliance Behaviour and Lab Experiments: A Literature Review
(Maliye Bakanligi, 2021) Demirtas, Burak Kagan
The purpose of this article is to conduct a literature review of the papers based on laboratory experiments to analyze tax evasion behaviors of individuals. Although experimental studies in economics have become more and more important day by day, there are almost no publications on experimental economics in the Turkish literature. The studies are examined especially in terms of experimental designs because this study also aims to increase awareness about laboratory experiments. This review also discusses the criticism of laboratory experiments and concludes that the results obtained from laboratory experiments are important and it would be beneficial to support them with field experiments.
Citation - WoS: 4
Strategic Sustainable Site Management in Higher Education Institutions
(deomed Publ, Istanbul, 2016-12-01) Ayten, Asim Mustafa
In retrospect, the role of scientific progress is of the utmost importance in the development and the current status of the universitites whose history is as old as the city life. The main determinants of the emergence of Enlightenment period have been the Reformation and the Renaissance movements in Europe. Thus, thoughts and ideas based on the mind instead of dogmas have made progress under the guidance of positivism and the city life has been indirectly affected from this development. The industrial revolution caused remodeling and changes in urban and spatial structure. Although educated and skilled labor force was not requested by the industry initially, that kind of force gained importance over time and the collaboration between industry and universities became inevitable. Until the years of 1940, Von Humboldt system, prevailing in Germany, changed and US system has become effective since 1945. During the years of 1960, universities became technology-based organizations and the institutions where scientific researches were conducted instead of the ones where only educational activities were carried out. Particularly, new settlements based on technology development regions attracted the attention. Within the order created by this relationship, different kinds of universities, research centers and spatial constructions were emerged either inside or outside the cities. In parallel with the growth of the cities, university buildings moved to the campuses outside the cities in accordance with the changing needs and new applications were made inside the cities and over the vast areas with different spatial typologies. In our study, campus site managements were examined in terms of environmental factors, logistics, traffic management, transportation and other criteria (population size, field size, space per person and etc.), sampled with a survey carried out on 22 universities and made an evaluation based on the responses taken by 17 universities. This study has shown that our universities have not got a large part of the criteria required to become a 3rd generation university. So as to compete with the other universities in the World, an approach with corresponding social, economic, and spatial dimensions which leaves an impression on the city, region, country and the whole World should be put into practice in the field of higher education.
Social Constructivism and Its Contributions to Explain the European Integration
(Ankara Univ European Union Research Centre, 2015) Buyuktanir, Derya
Social constructivist approach attained an important place within international relations discipline after 1980's. Constructivism focuses on social ontological elements such as inter-subjective meaning, norms, rules, institutions, discourse and communicative action. By this way it prevents these constructivist qualifications to be degraded to epistemological matter and also constitutes a starting point for the researches carried out on the European integration. Because, analyzing interaction between the subjects and social impacts shall assist to find the answers of the questions how and why European integration came to the current situation, to a great extent. Explaining this process within the scope of social constructivist approach rather than the integration theory shall provide to take many issues into consideration without getting far from the rational point of view.
Rings With Variations of Flat Covers
(Honam Mathematical Soc, 2019) Demirci, Yilmaz Mehmet; Turkmen, Ergul
We introduce flat e-covers of modules and define e-perfect rings as a generalization of perfect rings. We prove that a ring is right perfect if and only if it is semilocal and right e-perfect which generalizes a result due to N. Ding and J. Chen. Moreover, in the light of the fact that a ring R is right perfect if and only if flat covers of any R-module are projective covers, we study on the rings over which flat covers of modules are (generalized) locally projective covers, and obtain some characterizations of (semi) perfect, A-perfect and B-perfect rings.
Citation - WoS: 4
Relationship Between Neutrophil Gelatinase-Associated Lipocalin and Mortality in Acute Kidney Injury
(Galenos Yayincilik, 2018-12-03) Kayaalti, Selda; Kayaalti, Omer; Aksebzeci, Bekir Hakan
Objective: Almost half of intensive care patients are affected by acute kidney injury (AKI). The purpose of this study is to determine parameters that can be used for predicting of early (within 28 days) and late (within 90 days) mortality in patients who are followed-up with AKI in intensive care units. Materials and Methods: In this study, a dataset that contains 50 patients with AKI in intensive care units was used. This dataset contains blood urea nitrogen, creatinine, plasma and urinary neutrophil gelatinase-associated hpocalin (NGAL), lactate dehydrogenase, alkaline phosphatase and gammaglutamyl transpeptidase values of patients who were admitted to intensive care for various reasons and who developed AKI on the days 1, 3 and 7. In addition to these values, laboratory results such as serum electrolytes on day 1, blood gas; vital signs such as mean arterial pressure, central venous pressure; and demographic data were also recorded. Data mining techniques were applied to determine correlation between all of these data and mortality. Results: The threshold level of urinary NGAL on day 7 was determined to be 69 ng/mL, and strong correlation was found between this threshold level and early mortality. Similarly, the threshold level of plasma NGAL on day 7 was determined to be 150 ng/mL, and this was highly correlated with early mortality. Besides, strong correlation was also found between the difference in the urinary NGAL levels on day 1 and 7, and early mortality. Conclusion: In this study, plasma and urinary NGAL levels were found to be closely related to early mortality in patients who were followed-up with AKI in intensive care units. On the other hand, any parameter associated with late mortality was not found.
Citation - WoS: 2
Reconsidering the Changing Higher Education System from Sociocultural and Spatial Perspectives
(Deomed Publ, Istanbul, 2020-07-27) Ayten, Asim Mustafa; Gover, Ibrahim Hakan
Education and research are vital for social development and progress. The changing sociocultural structures and new needs have resulted in some important functional changes in higher education systems with a deep impact on universities serving these needs at the highest level. Besides experiencing these functional changes, the universities today have become spaces of socialization with their social, cultural and sports facilities, replacing their traditional spatial role of offering education only. The local dynamics changing with globalization have now reshaped the global and local roles of universities, highlighting the added value they provide to the society. Sociocultural changes trigger all these functional and structural changes in universities. Therefore, sociocultural factors and their importance should not be ignored in a changing higher education system. In this study, the impact of sociocultural factors with their related spatial structures on world higher education system will be analyzed within their historical contexts, and some suggestions for future universities will be offered considering the current changes. In the first part of the study, the changes in societies and universities will be presented within the historical context. In the second part, the spatial forms and structures of universities will be discussed. In the third part, the catalytic effects of the specific sociocultural factors will be highlighted and elaborated on. Finally, some suggestions will be made for the universities of the future in the light of the current situation and the data available.

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