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Tek eksenli Silindirik Titreşimli Jiroskop tasarımı ve analizi
No full textDesign parameters and mathematical modeling of the Cylindrical Vibratory
Gyroscope (CVG) are studied in this thesis. CVG is an inertial sensor that measures
angular rate utilizing the effect of Coriolis forces. CVG has a primary motion in the
form of vibration. A secondary motion is excited due to Coriolis forces when an
angular rate is applied to its sensitive axis. By comparing primary and secondary
motions, CVG can measure the angular rate. This sensor stands out with competitive
performance despite its lightness and cheapness among the other gyroscopes. The
mathematical model of the sensor has been done with the equations of motion of the
sensor and state-space estimation of the resonator. This mathematical model has been
used for the simulation of the measurement of the angular velocity. The modal
analyses of the resonator have been done by using the finite element method (FEM)
for different design parameters. Therefore, the effect of design parameters on the
natural frequencies of the modes is calculated. In conclusion, a complete
mathematical vibrational model of the CVG system is obtained which enables
performance and optimization studies for the CVG system, and a new design of the
resonator for the CVG system is obtained.Bu tezde Silindirik Titreşimli Jiroskopunun (STJ) tasarım parametreleri ve
matematiksel modellemesi incelenmiştir. STJ, Coriolis kuvvetlerinin etkisinden
yararlanarak açısal hızı ölçen bir sensördür. STJ, titreşim biçiminde birincil bir
harekete sahiptir. Hassas eksenine bir açısal hız uygulandığında Coriolis kuvvetleri
nedeniyle ikincil bir hareket uyarılır. Birincil ve ikincil hareketleri karşılaştırarak,
STJ açısal hızı ölçebilir. Bu sensör, diğer jiroskoplar arasında hafifliği ve ucuzluğuna
rağmen rekabetçi performansıyla öne çıkmaktadır. Sensörün matematiksel modeli,
sensörün hareket denklemleri ve rezonatörün durum-uzay kestirimi ile yapılmıştır.
Bu matematiksel model, açısal hız ölçümünün simülasyonu için kullanılmıştır.
Rezonatörün modal analizleri, farklı tasarım parametreleri için sonlu elemanlar
metodu (SEM) kullanılarak yapılmıştır. Bu sonuçlarla, tasarım parametrelerinin
modların doğal frekansları üzerindeki etkisi hesaplanmıştır. Sonuç olarak, STJ
sisteminin performans ve optimizasyon çalışmalarına olanak sağlayan tam bir
matematiksel titreşim modeli elde edilmiş ve STJ sistemi için yeni bir rezonatör
tasarımı elde edilmiştir.M.S. - Master of Scienc
On the reliability of a modification of the fluid model of a glow discharge incorporating the calculation of the local EEDF at each point in space
No full textAn analysis of the approach named “Space-Dependent Electron Energy Distribution Function (EEDF) Modeling” in the COMSOL Multiphysics's Plasma Module is carried out. This modeling approach allows a wide range of users to determine profiles of glow discharge parameters, including the EEDF, in the entire discharge volume. Comparison of computed results for a short (without a positive column) glow discharge, obtained from this model and from kinetic simulations, displays not only significant quantitative but also qualitative differences in the EEDFs. The analysis showed that in this model, as well as in the previous models provided by the COMSOL Multiphysics's Plasma Module, the derivation of the main equations is based on the factorization of the EEDF, which implies the use of a local approximation when solving the Boltzmann kinetic equation. However, as has been repeatedly shown in the literature, this approximation is fulfilled under rather harsh conditions, namely, when the scale of plasma inhomogeneity is small compared to the electron energy relaxation length, and the ambipolar field is small compared to the external electric field heating the electrons. These restrictions significantly limit the applicability range of the analyzed model and make it impossible to use it in the near-electrode and near-wall regions of any gas discharges. Comparison with the corresponding data from the kinetic simulation and the subsequent analysis reveals the existence of fundamental disagreement and internal contradiction within this model that cast doubt on the reliability of the results obtained using this approach, which we address to the “computational plasma community"
Fostering Corpus Literacy: Rethinking Pre-Service EFL Teacher Training for Future-Proof Classrooms
No full textSeismic Performance of RC Structures in Pazarcık and Elbistan During the 2023 Kahramanmaraş Earthquakes
No full textOn Monday, February 6th, 2023, at 04:17 and 13:24 local time, two very severe shallow earthquakes with magnitudes Mw = 7.7 and 7.6 occurred, with epicenters in Kahramanmaraş-Pazarcık and Kahramanmaraş-Elbistan. Due to the strong ground motion effect during these earthquakes, many people lost their lives and great economic losses occurred due to the destruction and damage to buildings in eleven different provinces and surrounding regions. In this study, the seismic performances of structures with various structural systems located in the Pazarcık and Elbistan districts of Kahramanmaraş city, which are the epicenters of these earthquakes, were evaluated as a result of field observations. Structural failures in the earthquake epicenters’ urban and rural building stocks directly affected the damage's extent. Structural damages occurring in both district centers and rural areas of the districts were investigated within the scope of earthquake and civil engineering. The main causes of damaged concrete structures are irregularities and insufficient reinforced concrete. The significance of earthquake-resistant structure design principles and irregularity-free structures has again become clear
Deep plug-and-play HIO approach for phase retrieval
Get PDFIn the phase retrieval problem, the aim is the recovery of an unknown image from intensity-only measurements such as Fourier intensity. Although there are several solution approaches, solving this problem is challenging due to its nonlinear and ill-posed nature. Recently, learning-based approaches have emerged as powerful alternatives to the analytical methods for several inverse problems. In the context of phase retrieval, a novel plug-and-play approach, to our knowledge, that exploits learning-based prior and efficient update steps has been presented at the Computational Optical Sensing and Imaging topical meeting, with demonstrated state-of-the-art performance. The key idea was to incorporate learning-based prior to the Gerchberg-Saxton type algorithms through plug-and-play regularization. In this paper, we present the mathematical development of the method including the derivation of its analytical update steps based on half-quadratic splitting and comparatively evaluate its performance through extensive simulations on a large test dataset. The results show the effectiveness of the method in terms of image quality, computational efficiency, and robustness to initialization and noise
AB YÜKSEKÖĞRETİM PROGRAMLARININ TRANSFERİ: ÜÇÜNCÜ ÜLKELERDEKİ ULUSLARARASI OFİS PROFESYONELLERİNİN ROLÜ
No full textThe European Union (EU) has become a major player in higher education over the years, although it does not have direct competence in this policy area. In time, the primary aim of encouraging cooperation between the Member States in the field of education has expanded beyond its members, particularly through an increasing number of initiatives such as the Bologna Process and the Erasmus Program. In the literature, the impact of the EU on the non-EU countries has been highlighted by various factors such as the growing geographic reach, funding, and participation rates. To identify such impacts, this study examines the perception, interpretation, and implementation of EU higher education programs within their internationalization practices by higher education institutions in selected three countries namely Bosnia and Herzegovina, Republic of Kazakhstan, and People’s Republic of China. To investigate this objective, this study uses qualitative research methods, in which qualitative data were collected through semi-structured interviews conducted with the International Office Professional (IOPs) from 13 institutions in these countries.
The thesis combines policy transfer literature with bottom-up Europeanization. The IOPs are the main unit of analysis in this study. By highlighting the significance of institutional filters and domestic contexts, the findings draw attention to the complexities in implementing the EU initiatives in non-EU countries. This study demonstrates that institutionalization and implementation of EU programs are also shaped by the institutional and national internationalization strategies and the nature of country’s relations with the EU.Avrupa Birliği (AB), Avrupa para birliği gibi alanlarda sahip olduğu doğrudan yetkiye sahip olmasa da yıllar içinde yükseköğretim alanında da önemli bir aktör haline gelmiştir. Artan sayıda girişim ve program aracılığıyla AB, yükseköğretim alanındaki etkisini üye ülkelerinin ötesine taşımıştır. Coğrafi kapsama alanının, bütçelerin ve katılım oranlarının genişlemesi, AB’nin üye olmayan ülkeler üzerindeki etkisini vurgulamaktadır. Bu bağlamda, bu çalışma, Bosna-Hersek, Kazakistan Cumhuriyeti ve Çin Halk Cumhuriyeti’ndeki yükseköğretim kurumlarında görevli Uluslararası Ofis Profesyonellerinin, uluslararasılaşma pratikleri içinde AB yükseköğretim programlarını ve girişimlerini kurumsal ve ulusal bağlamlarında nasıl algıladığını, yorumladığını ve uyguladığını incelemektedir. Bu amacı araştırmak için, çalışmada nitel bir yöntem benimsenmiş ve bu ülkelerdeki 13 kurumun Uluslararası Ofis Profesyonelleri ile yarı yapılandırılmış mülakatlar gerçekleştirilmiştir.
Bu araştırma politika transferi teorisi ile aşağıdan yukarıya Avrupalılaşma (Europeanization) perspektifini birleştiren teorik bir çerçeve kullanmaktadır. Çalışmanın temel analiz birimi ve ana aktörleri olarak ele alınan Uluslararası Ofis Profesyonelleri, politika transferinin dinamikleri, karşılaşılan zorluklar ve AB programlarının kurumsallaştırılmasında kullanılan stratejiler üzerine ışık tutmaktadır. Bulgular, kurumsal filtrelerin ve yerel bağlamların önemine vurgu yaparak, AB girişimlerinin AB üyesi olmayan ülkelerde uygulanmasındaki karmaşıklıkları da ortaya koymaktadır. Bu çalışma, kurumsal ve ulusal (uluslararasılaşma) stratejileri ve ülkenin AB ile ilişkilerinin doğasının AB programlarının kurumsallaşması ve uygulanması sürecinde etkili olduğunu göstermektedir.Ph.D. - Doctoral Progra
Aerodynamic Investigation of Hover using Vortex Ring Wake Model and Free Vortex Wake Model
No full textModeling rotor inflow and wake dynamics is fundamental to understanding and improving rotorcraft performance. Especially, hover modeling plays an important role in aircraft design, aerodynamic assessments, and the development of control systems for helicopters and eVTOLs. To investigate the complexity of rotor aerodynamics, various methodologies with different levels of fidelity can be utilized, ranging from Blade Element Momentum Theory (BEMT) to high-fidelity Computational Fluid Dynamics (CFD). In this study, AeroROTOR, a fast in-house C code developed for rotor aerodynamics, is used to investigate the hover condition. AeroROTOR consists of two rotor wake analysis models: the Vortex Ring Wake (VRW) model and the Free Vortex Wake (FVW) model, coupled with the Blade Element Theory (BET). Rotor simulations with these wake models provide detailed investigations of the wake dynamics and blade aerodynamic forces. The HVAB rotor is used as a validation case and the free wake analyses are performed to investigate the hover condition and assess the capabilities of the wake analysis models by comparing the results for the rotor aerodynamic loads and wake characteristics with the experimental data
Tacikistan'ın Türkiye'ye yönelik dış politikası: 1992-2022 (rol teorisi ve ver setleri analizi)
No full textThis study analyzes Tajikistan's foreign policy towards Türkiye from 1992 to 2022 through a dataset analysis and role theory framework. Unlike general studies, it is based on local Tajik sources and provides insights into the diversity and depth of the relationship. The study employs qualitative analysis, using role theory to interpret foreign policy discourse, supported by a quantitative dataset analysis of key diplomatic agreements and events. The findings reveal that Tajikistan’s foreign policy towards Türkiye has been largely shaped by economic and security concerns, with a notable emphasis on bilateral trade agreements and regional security cooperation. Furthermore, the study identifies a consistent alignment between discourse and practice in their diplomatic relations. This research contributes to a deeper understanding of Central Asian foreign policy, demonstrating how small states like Tajikistan navigate complex international relationships. It highlights the importance of economic and security considerations in shaping diplomatic ties with larger powers like Türkiye.Bu çalışma, 1992-2022 yılları arasında Tacikistan'ın Türkiye'ye yönelik dış politikasını, veri seti analizi ve rol teorisi çerçevesinde incelemektedir. Genel çalışmalardan farklı olarak, yerel Tacik kaynaklarına dayanmaktadır ve ilişkiyi çeşitliliği ve derinliği açısından analiz etmektedir. Çalışma, rol teorisini kullanarak dış politika söylemini yorumlamakta ve anahtar diplomatik anlaşmalar ve olayların yer aldığı niceliksel bir veri seti analiziyle desteklenmektedir. Bulgular, Tacikistan'ın Türkiye'ye yönelik dış politikasının büyük ölçüde ekonomik ve güvenlik endişeleriyle şekillendiğini, özellikle ikili ticaret anlaşmaları ve bölgesel güvenlik işbirliğine odaklanıldığını ortaya koymaktadır. Ayrıca, çalışma, diplomatik ilişkilerde söylem ile uygulama arasında tutarlı bir uyum olduğunu belirlemektedir. Bu araştırma, Orta Asya dış politikasına dair daha derin bir anlayışa katkıda bulunmakta ve küçük devletlerin, Tacikistan gibi, karmaşık uluslararası ilişkilerde nasıl hareket ettiğini göstermektedir. Çalışma, ekonomik ve güvenlik unsurlarının, Türkiye gibi büyük güçlerle diplomatik ilişkilerin şekillenmesindeki önemini vurgulamaktadır.M.S. - Master of Scienc
Prognostic and therapeutic insights into LTBP1 in Hepatocellular Carcinoma: pathway enrichment, immune profiling, and drug repurposing
No full textEnhanced catalytic performance through precise structural modification of Au-Ag nanoworms using controlled etching process
No full textPolycrystalline nanomaterials inherently possess a high concentration of defects, owing to the presence of grain boundaries. These defects, while abundant in smaller nanoparticles (NPs), can become embedded within the bulk of larger particles, making them inaccessible to reactants during catalytic reactions. While deliberately arresting growth at the initial stage can reveal defect sites resulting in particles with significantly high surface energy, the precise control required to halt the growth of nanomaterials at the specific moment of optimal catalytic potential poses a formidable challenge. Herein, we introduce an alternative approach that involves the oxidative etching of fully developed polycrystalline Au-Ag alloy nanoworms (NWs). This process generates high-energy surfaces rich in defects, thereby substantially enhancing their catalytic activity. The NWs were synthesized by a seedless, single-step method and they were subsequently etched by using HAuCl4 solution. The elaborate process underlying the transformation of NWs’ structures upon exposure to HAuCl4 solution was elucidated. The Transmission Electron Microscopy (TEM) images showed a gradual decrease in the length and width of NWs and an increase in the defect density with etching. Remarkably, small alterations in the NWs’ morphology led to marked enhancement in their catalytic activity. To demonstrate this, NWs were employed for catalyzing the conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The optimized etching of NWs provided an approximately 24-fold enhancement in the activity compared to the unmodified NWs. The implications drawn from our results strongly imply that the structural modifications introduced by the etching process can be an effective technique for enhancing the catalytic activity of polycrystalline NPs