Tezler

Bu topluluk için Kalıcı Uri

http://hdl.handle.net/11527/3

Gözat

19. yüzyıl tarihi demiryolu binalarında yapısal malzeme ve yapım teknolojilerinin deprem performansına etkisi

(Lisansüstü Eğitim Enstitüsü, 2024-06-25) Küçükayan, Sena Merve ; Çelik, Oğuz Cem ; 502211513 ; Çevre Kontrolü ve Yapı Teknolojisi

Bu tez çalışması, Osmanlı Devleti döneminde inşa edilen tarihi demiryolu hatları ve demiryolu yapılarını, yapısal ve mimari özellikleri ile birlikte deprem performanslarını içermektedir. İlk olarak, Osmanlı'da önemli demiryolu ağları olan İzmir-Aydın, Rumeli, Anadolu, Bağdat ve Hicaz demiryolu hatları ve güzergâhları detaylıca araştırılmış ve bu güzergâhların oluşmasında göz önünde bulundurulan durumlar incelenmiştir. Demiryolu duraklarının konumu belirlenirken, stratejik önemleri, doğal kaynaklar ile ilişkisi, ekonomik katkısı, ticaretin gelişebilmesi ve şehir merkezlerine olan yakınlığı gibi durumlar etkili olmuştur. İncelenen tarihi demiryolu projeleri, devletin modernleşme ve kalkınma sürecinin bir parçası olarak başlasa da zamanla ekomomik durumlardan ötürü yabancı yatırım ve alanında uzman mimar ve mühendislerin katksısı ile gelişmiştir. İnşa edilen demiryolu hatları ile birlikte Osmanlı Devleti'nin iç ve dış ticareti gelişmiş, zamanla hatların genişlemesi ile birlikte farklı bölgeler birbirlerine bağlanmıştır. Yabancı şirketlerin katkısı ve kullanılan yapım teknikleri de demiryolu hatlarının gelişmesi sürecinde önemli bir rol oynamıştır. Demiryolu yapılarında sıkça görülen, ancak günümüzde yaygın olmayan perçin teknolojisi ile birlikte çelik yapılar strüktürel açıdan incelenmiştir. Yığma, ahşap ve çelik yapı malzemeleri ile taşıyıcı ve çatı sistemleri hakında da detaylı bir şekilde inceleme yapılmıştır. Son olarak, tarihi demiryolu garlarının ve istasyonlarının zaman içerisinde yaşanan depremler sonrasında performansları analiz edilmiş ve meydana gelen hasar boyutları ele alınmıştır. Bu kapsamda, demiryolu yapılarının ciddi oranda etkilendiği iki deprem olan 10 Temmuz 1894 İstanbul depremi (~M 7.0) ve 6 Şubat 2023 Kahramanmaraş depremleri (Mw 7.9 ve 7.8) ele alınarak farklı bölgelerde yer alan istasyon yapılarının nasıl etkilendiği detaylandırılmıştır. Yapılan analizler ile birlikte, tarihi demiryolu yapılarının gelecek kuşaklara güvenle aktarılabilmesi için kapsamlı olarak yapısal bakımdan incelenmesi gereği ortaya çıkmıştır. Demiryolu yapılarının incelenmesi, bir yandan ait olduğu dönemin teknolojisini ve mühendislik başarısı ile birlikte yapıların nasıl inşa edildiğini, kullanılan malzemeleri, uygulanan tekniklerini ve dönemin koşullarını göstermektedir. Sonuç olarak bu çalışma, demiryolu yapılarınının detaylı bir şekilde incelenerek yapısal sistemlerinin anlaşılmasını ve tarihi demiryolu yapılarının korunması ve güçlendirilmesi için önemli kararların alınmasına yönelik öneriler sunmaya yöneliktir. Tarihi demiryolu yapılarının yapısal özelliklerini ve depremlere dayanıklılığını anlamak, tarihi mirasın gelecek nesillere aktarılabilmesi için önemli bir süreçtir. Çalışmanın, tarihi demiryolu yapılarının yapısal ve mimari değerini anlamak ve korunmasını isteyen uzmanlar, tarihçiler, mimarlar ve mühendisler için yol gösteren bir kaynak olması hedeflenmektedir.
3B nokta bulutlarının derin öğrenme yöntemiyle semantik segmentasyonu

(Lisansüstü Eğitim Enstitüsü, 2022-02-11) Beşiktepe, Mert ; Güner, Caner ; 501181657 ; Geomatik Mühendisliği

Üç boyutlu (3B) kent modelleri, kentsel alanlarda yaşanabilecek değişimlerin 3B olarak izlenmesi, kent çevre ilişkisinin modellenmesi ve kentsel simülasyon uygulamaları için altyapı sağlayarak mekansal planlama çalışmaları için veri temelli karar verme süreçlerinin geliştirilmesine olanak tanımaktadır. Söz konusu modelleri geliştirilmesi için; detay düzeyi uygulama amaçlarına bağlı olarak değişen, yüksek doğruluklu, güncel ve büyük miktarda 3B mekansal bilgiye gereksinim duyulmaktadır. Lazer tarama, görüntüleme ve yer gözlem uyduları gibi veri elde etme teknikleri ile fotogrametri ve bilgisayarlı görü alanlarındaki veri değerlendirme yöntemlerine ilişkin yaşanan gelişmeler 3B mekansal bilginin nokta bulutu biçiminde doğrudan ölçme ile ya da başka veri kaynaklarından türetme yolu ile üretilmesine olanak sağlamıştır. 3B nokta bulutları günümüzde klasik kullanım alanları olan ölçme ve planlama çalışmaları haricinde robotik, otonom mobilite, 3B modelleme ve dijital ikiz oluşturma gibi yüksek teknolojili ve katma değerli uygulamalara olanak tanımaktadır. Kent ölçeğinde ve yüksek çözünürlüklü bu veri kaynağının klasik yaklaşımlarla yönetilmesi ve işlenmesi pek mümkün olamamaktadır. Öte yandan derin öğrenme yaklaşımları büyük veriden modern hesaplama donanımları kullanılarak derin yapay sinir ağlarının eğitilmesini sağlayacak bir paradigma değişimi getirmiştir. Derin öğrenme sayesinde sınıflandırma, nesne yakalama ve segmentasyon görevlerinin veri işlem süreçlerinin otomasyonu amacıyla yerine getirilmesi için geçmişe nazaran çok daha güçlü çözümler elde edilebilir hale gelmiştir. Bu çalışmada, 3B nokta bulutlarından derin öğrenme alanının gelişimi incelenmiş, bu modelleri kıyaslamada kullanılabilecek değerlendirme ölçütleri, araştırma grupları tarafından kabul görmüş açık veri setleri, 3B nokta bulutlarını işlemek için mevcut açık kaynaklı derin öğrenme yazılım kütüphanesi, performans yarışmaları tanıtılmıştır. 3B nokta bulutlarının semantik segmentasyonu için yararlanılabilecek modern bulut bilişim olanakları araştırılmıştır. Eğitim sürecini yürütmek için gereksinimler belirlenmiş ve çözüm önerileri geliştirilmiştir. Bulut bilişim imkanları kullanılarak derin öğrenme için oluşturulan bir geliştirme ortamında bir segmentasyon modelinin eğitim ve test süreci uygulama olarak gerçekleştirilmiştir. Yapılan literatür taraması ve yürütülen derin öğrenme ağının eğitimi süreci sonucunda 3B nokta bulutlarından derin öğrenme çalışmalarında 3B şehir modelleme ve diğer pek çok farklı uygulama alanının 3B uzamsal veri gereksinimini gerçek zamanlı olarak dahi karşılayabilecek çözümler geliştirildiği görülmüştür. Bu çözümlerden yararlanmak için ise yüksek performanslı hesaplama donanımlarına erişime ve açık kaynaklı derin öğrenme yazılım kütüphaneleri ile 3B nokta bulutundan derin öğrenme çalışmalarında geliştirilen yazılımlardan oluşan bir dizi teknolojiyi uyumlu biçimde bir araya getirme becerisine sahip olunması gerektiği görülmüştür.
A computable vitality: Kenzo Tange's architectural system

(Graduate School, 2024-09-12) Berber Tolunay, Cansu ; Özkar, Mine ; 502112014 ; Architectural Design

Kenzo Tange's methodology of vitality as a design tool is explored in depth in this study. Tange, a leading figure in the Metabolist movement, revolutionized urban design with his visionary plans, develops a design methodology by referencing information derived from city flows. Tange perceived cities as living organisms that required continuous nurturing through vital elements to thrive. His approach deeply considered the dynamics of different movement types in city, proposing architectural solutions that would not only accommodate but actively promote the growth and expansion of urban planning. Tange's approach to understanding urban dynamics involves conducting flow analyses of the existing traffic system, which define the movements within and outside the city. Tange's use of movement as a regulatory and form-giving tool is explored which draws upon original research from the Harvard University Kenzo Tange archive, especially the Skopje Project. It posits that the repetitive, cyclic nature of pedestrian and vehicle movement is not just a characteristic of urban life but a driving force behind urban design. This approach underscores the Metabolist focus on cities as dynamic, living entities that continually evolve and adapt to ensure their vitality and sustainability. In his proposals, Tange introduced innovative structures that catalyzed urban movement, thereby ensuring the development of functional spaces within the city fabric. Tange determines that the intersection of different movements will create transitional areas and generate creative forms, not through design speculation but through analysis. Archive research shows how the process serve as primary data in the design process and how the analyzed dynamics of the city and Tange's reading of the city and its dynamics play a central role in formulating these movements. Tange layers movement vertically and then relates each layer horizontally to maintain fluidity. The productivity of this concept in urban design lies in the layering of movement and transmitting it through different forms and spatializations within its flow. Kenzo Tange's use of symbols in his urban design for Skopje represents a sophisticated method of encoding the dynamic processes of urban growth and change. By employing basic geometric shapes like triangles, circles, and lines, Tange developed a visual language that mapped out not only the physical infrastructure of the city but also the flow and movement within its urban space. These shapes were thoughtfully selected, with each carrying specific meanings that contribute to a deeper understanding of the urban landscape. xxiv Tange's integration of these symbols into his urban planning diagrams provided a clear and systematic depiction of how various elements of the city interact and function together. Focusing instead on creating a urban system capable of adapting to growth and change, the diagrams function as a rule system that guides the development and transformation of the city, ensuring that each component, communication space— a road, building, or public space—plays an effective role in the overall urban fabric. This method showcases Tange's visionary approach to urban planning, where symbolism and functionality converge to foster a cohesive and adaptable urban environment. Tange's work bridges Eastern and Western thought, particularly the notion of "vitality" in architecture. Tange's approach goes beyond aesthetic considerations, involving human movement and experience. While his methods may seem abstract through today's computational lens, they were operating like a coding system despite not being recognized as such. Tange's urban analysis, relational studies, and systemic observations contributed significantly to the development of architecture and systems thinking, offering a precursor to modern computational design approaches.
A framework for the embodiment of empathy in design education: Exploring empathic perspective-taking of design teachers in design conversations

(Graduate School, 2024-07-27) Efilti, Pelin ; Gelmez, Koray ; 502182908 ; Industrial Product Design

The sophisticated and multi-layered phenomenon of empathy has become an essential aspect of design research and design practice. However, the connections of this phenomenon with design education are indirect and ambiguous as well as have not yet been clarified. Thus, the dispersed nature of empathy in design education invites us to explore and address this phenomenon with the context of both conceptual and practical research objectives. This thesis study is prepared in regard to three phases going deeper considering research objectives that are addressed under four different studies. The first phase (scanning horizon) focuses on a systematic identification and analysis of the relevant literature overlapping design education and the concept of empathy. Under this phase, two preliminary studies based on systematic literature review are conducted to map the dimensions of empathy in design education (Chapter 2) and to reveal the impacts on design learning and teaching (Chapter 3). The second phase (deep diving) based on a participant observation study addresses how empathy is embodied in the design studio, so explore the empathic indicators embedded in design conversations (Chapter 4). Lastly, the third phase (mining together) based on a pedagogical probe study centres upon the underlying motives behind empathic perspective-taking of design teachers during design conversations (Chapter 5). In the first study (Chapter 2), a systematic scoping review study is adopted as a technique to map the field of interest. The dataset is analysed via qualitative content analysis method to uncover and map the hidden dimensions of empathy in design education. The analysis reveals three dimensions of empathy, such as educational interventions, aspects and contexts of empathy. Educational interventions are the implementations applied or discussed in the articles with special attention to the learning and teaching activities, connecting with empathy. The aspects of empathy are the materialisation of empathy with specific educational purposes. Finally, the context of empathy represents the distinctive contexts in which learning takes place, induced by empathy. These interwoven dimensions help us to generate an integrative framework of the relevant literature. Based on this integrative framework, particular implications are proposed, such as research-based implications for design education researchers, pedagogical implications for design teachers and institutional implications for decision-makers. This chapter entitled "Mapping three dimensions of empathy in design education: Educational interventions, aspects and contexts" is published in the journal Art, Design & Communication in Higher Education. It is understood that empathy considerably transforms learning processes and teaching activities. Thus, aiming to explore and discuss the impacts of empathy on learning and teaching in the relevant design education literature, the systematic scoping review study is analysed thematically the second study (Chapter 3). Eight themes appear in this study, such as cognitive, affective, interactive, collaborative, operative, perceptive, formative and connective impacts. All these impacts are mostly in relation to design learning; however, the impacts of empathy on teaching activities are relatively limited. Within the context of this study, the research gaps for further studies are also addressed, as well as methodological and pedagogical implications are presented. This chapter entitled "A deep dive into the impacts of empathy on design learning and teaching" is published in the International Journal of Technology and Design Education. The first phase (scanning horizon) helps to scan the relevant literature intensively and unfold the implicit nature of empathy by uncovering the dimensions of empathy in design education and its impacts on design learning and teaching. These studies also illustrate particular research gaps in the relevant literature underlining the less-concentration on in-studio interactions between design teachers and learners as well as the development of empathic ways of teaching. In the following study (Chapter 4), empathy is addressed as an embodied happening in design studio conversations between design teachers and students. In this study, empathy embedded in design studio conversations is highly associated with perspective-taking of design teachers to ensure empathic understanding with design students. In participant observation studies conducted at two universities in Finland and Türkiye how design teachers take the perspective of other agencies and what deliveries are utilised for empathic perspective-taking are traced. The findings of the ethnographic content analysis show that design teachers take the perspectives of both human and non-human agencies during design conversations, such as design students, users, and materials. Moreover, they utilise discursive and performative deliveries, which lead to the identification of design teachers with these agencies. It is understood that design teachers' perspective-taking of design students during design conversations has particular effects on enhancing the learning experiences. Moreover, perspective-taking of design teachers towards users and materials help students to observe and understand the implications of design. This chapter entitled "Eliciting empathy embedded in design conversations: Empathic perspective-taking of design teachers towards design students, users and materials" is published in the International Journal of Art and Design Education. This second phase (deep diving), which is the core study of this thesis, dives deeply into design studio education and teaching activities, starting from the embodiment of the empathy phenomenon. Design conversations are focused, which are the backbone interactions in the design studio. This study exploring the implicit nature of design conversation is an initial step to frame the empathic approaches of design teachers. Aiming to develop an in-depth understanding specific to empathic approaches of design teachers in design conversations, in the last study (Chapter 5), empathic perspective-taking phenomenon in design teaching is addressed. To dig into the motives of design teachers behind empathic perspective-taking in design conversations, a pedagogical probe study based on self-documentation and reflection on design teaching approaches is conducted with the participation of design teachers and supporting teaching staff. A directed approach to qualitative content analysis is used for the data analysis in this study to explore the underlying motives behind perspective-taking. There appear distinctive intentions of design teachers cultivated from personal motivations that have potential impacts on learning processes. This chapter is an in-review process in an international peer-reviewed journal. The third phase (mining together) helps to expand the knowledge around empathic perspective-taking and presents it in all its aspects via a participatory approach. As an empathic approach, allocentric perspective-taking of design teachers in design conversations can serve for the designerly way of thinking and enhancement of learning activities, the motivation and inspiration of design students particularly. In conclusion, both conceptual and practical implications of this thesis are discussed. The conceptualization of design teachers' perspective-taking as an empathic action in design conversations is addressed through the synthesis of the findings. It is understood that design teachers may face multiple traps to fall on the way of taking a perspective in design conversations. Moreover, the development of practical pedagogical tools and exercises at personal, collective and institutional levels are encouraged. Via new pedagogical tools, design teachers and supporting teaching staff can raise their own awareness, ensure their well-being, reflect each other and become empowered in a pedagogical sense. This thesis can be taken as an attempt to bring a new perspective and pedagogical approach to design studio conversations in the quest of empathic design education. Raising awareness of design teachers in this context can make it possible for the development of empathic design teachers and teaching approaches. By this way, more empathic interactions in the design studio education can be established.
A hybrid deep learning metaheuristic model for diagnosis of diabetic retinopathy

(Graduate School, 2022-10-17) Gürcan, Ömer Faruk ; Beyca, Ömer Faruk ; 507142109 ; Industrial Engineering

Diabetes is a disease that results in an increase in blood sugar due to the pancreas not producing enough insulin, insufficient effect of the produced insulin, or ineffective use of insulin. According to the International Diabetes Federation 2021 report, approximately 537 million adults aged between 20 and 79 live with diabetes worldwide. It is estimated that the number of people with diabetes will increase to 643 million in 2030 and 783 million in 2045. Diabetic retinopathy (DR) is an eye condition that can cause vision loss, irrecoverable visual deterioration, and blindness in people with diabetes. Today, it is one of the leading diseases that cause blindness. Anyone with any diabetes can become a DR. In ophthalmology, type 2 diabetes can lead to DR if left untreated for more than five years. Diabetes-related high blood sugar leads to DR. Over time, having too much sugar in the blood damages the retina. The deterioration of this disease in the eye begins when sugar blocks the capillaries leading to the retina, causing fluid leakage or bleeding at a later stage. The eye produces new vessels to compensate for the blocked vessels, but these newly formed vessels often do not work well and can bleed or leak easily. DR can lead to other serious eye conditions. For example, about one in 15 people with diabetes develop diabetic macular edema over time. DR can lead to the formation of abnormal blood vessels in the retina and prevent fluid from leaving the eye. That causes a type of glaucoma. It is crucial for people with diabetes to have a comprehensive eye examination at least once a year. Follow-up of diabetes; factors such as staying physically active, eating a healthy diet, and using medications regularly can stop the damage to the eye and help prevent or delay vision loss. Some risk factors increase the development of DR, such as pregnancy, uncontrolled diabetes, smoking addiction, hypertension, and high cholesterol. In addition to being detected by magnifying the pupil in eye examination, DR is also diagnosed with the help of image processing techniques. It is common to use fundus images obtained by fundus fluorescent angiography to detect DR and other retinal diseases. Nowadays, with the increasing number of patients and the developments in imaging technologies, disease detection from medical images by various methods has increased. Deep learning is one of the methods whose application area has increased exponentially in recent years. Deep learning is a subfield of machine learning; both are a subfield in artificial intelligence. Deep learning methods draw attention with their versatility, high performance, high generalization capacity, and multidisciplinary use. Technological developments such as the collection of large amounts of data, graphics processing units, the development of robust computer infrastructures, and cloud computing support the building and implementation of new models.Increasing the number of images for a particular patient case and high-resolution images increases specialists' workload. Diagnosis of DR manually by an ophthalmologist is an expensive and time-consuming process. It requires experts who have remarkable experience. In addition, the complexity of medical images and the variations between specialists make it difficult for radiologists and physicians to make efficient and accurate diagnoses at any time. Deep learning is promising in providing decision support to clinicians by increasing the accuracy and efficiency of diagnosis and treatment processes of various diseases. Today, in some medical studies, the success levels of expert radiologists have been achieved or exceeded. Convolutional neural networks (CNNs) are the most widely used deep learning networks in image recognition, image/object recognition, or classification studies. A CNN model doesn't need manually designed features for training; it extracts features from data directly while network training on images. The automated feature extraction property and their success make CNNs highly preferred models in computer vision tasks. This study proposes a hybrid model for the automatic diagnosis of DR. A binary classification of DR (referable vs. non-referable DR) is made using a deep CNN model, metaheuristic algorithms, and machine learning algorithms. A public dataset, Messidor-2, is used in experiments. The proposed model has four steps: preprocessing, feature extraction, feature selection, and classification. Firstly, fundus images are pre-processed by resizing images and normalizing pixel values. The inception-v3 model is applied with the transfer learning approach for feature extraction from processed images. Then, classification is made using machine learning algorithms: Extreme Gradient Boosting (XGBoost), Random Forest, Extra Trees, Bagged Decision Trees, Logistic Regression, Support Vector Machines, and Multilayer Perceptron. XGBoost gives maximum accuracy of 91.40%. The best potential features are selected from the extracted features by three metaheuristic algorithms: Particle Swarm Optimization, Simulated Annealing, and Artificial Bee Colony. Selected features are classified with the XGBoost algorithm. The metaheuristics significantly reduced the number of features obtained from each fundus image and increased the classification accuracy. According to the results, the highest accuracy of 93.12% is obtained from the features selected with Particle Swarm Optimization. When the study results are compared with the existing studies in the literature, it has shown that this study is competitive in terms of accuracy performance and obtained low features. On the other hand, the proposed model has some advantages; it has a few pre-processing steps, training number of parameters are considerable low, and model can be trained with a small amount of data. This study is one of the first studies showing that better results can be obtained in DR classification by using deep learning and metaheuristic algorithms together. The proposed model can be used to give another idea for ophthalmologists in diagnosing DR.
A methodology for assessment of spatial performance in hospital buildings through immersive virtual reality and behavioural sequence analysis

(Graduate School, 2024-06-12) Okuyucu, Elif Bahar ; Yazıcı, Sevil ; 523201020 ; Architectural Design Computing

The spatial and wayfinding performance of a building are key elements that affect how well a building functions. They play a crucial role in buildings' overall functionality, particularly in complex buildings like hospitals that contain interconnected units. Time loss and detrimental impact on user well-being arise when a building's wayfinding performance is insufficient. Understanding and incorporating wayfinding behaviour into the design process is essential for designing human-centred buildings. This study examines wayfinding behaviour in detail to comprehend the dynamics behind wayfinding thinking and its relationship with spatial characteristics. The thesis questions (1) the effects of spatial plan configuration on wayfinding behaviour, (2) the relationship between re-occurring behaviours during the wayfinding process depending on spatial characteristics, (3) the extent and level of detail in behavioural data that can be gathered about human wayfinding through virtual reality (VR). For this purpose, this study utilises Behavioural Sequence Analysis (BSA) and Space Syntax analysis to understand the relationship between wayfinding behaviours and spatial layout in hospital buildings through Immersive Virtual Reality (iVR). BSA investigates behavioural sequences and identifies behavioural transition patterns. Space syntax analysis measures spatial features quantitatively. This study links wayfinding behaviours with spatial features and each other by employing these two analyses. An experiment was designed employing iVR since it delivers environments that are remarkably close to reality and brings together conditions that cannot be brought together in real life. The experiment aimed to observe and record user behaviour during the wayfinding process. Hospital buildings with three different plan layouts based on the centrality of the spatial configuration were selected and space syntax analysis was used to create visibility maps of these buildings, which were subsequently utilised for final assessments. Virtual environments (VE) were prepared by creating partial 3D models of the buildings with the architectural information collected for the experiment. Wayfinding tasks with various target locations were given to the participants in each hospital building during the iVR experiment to gather behavioural data. The experiment was recorded and the routes of the participants were mapped on floor plans. After analysing experimental records, the relevant data was extracted and arranged for four types of analyses: (1) BSA, (2) visibility and behavioural relationship analysis, (3) behavioural frequency analysis and (4) average speed analysis. These four analyses investigated how wayfinding behaviours varied by space, how often they occurred, which trends emerged in behavioural sequence transitions, and how quickly participants moved through each building. Following an evaluation of each analysis, a holistic approach was applied to these findings questioning the reliability of each analysis. The findings showed that each type of plan layout directs the users to engage in different behavioural groups during the wayfinding process. The recurring transitions among the behaviours revealed the wayfinding thinking of participants for each hospital building. The centralised plan layout directs the users to a fast-paced decision-making process, whereas the semi-centralised leads to a slow and efficient one. On the other hand, the findings demonstrate that there is a directly proportional relationship between visibility and wayfinding performance. Integrated analysis results show that the semi-centralised plan layout with high visibility offers the most comfortable and efficient wayfinding experience comparatively and the decentralised plan layout with low visibility offers the worst. The results can be used to create human-centred buildings by employing the spatial characteristics that provide the most effective wayfinding outcomes, particularly in the early design stages. Furthermore, the spatial-behavioural connections detailed in this research can be used as a guide depending on the building typology and the desired user experience.
Abstract meaning representation of Turkish

(Graduate School, 2022) Oral, Kadriye Elif ; Eryiğit, Gülşen ; 774853 ; Computer Engineering Programme

In this thesis, we focus on the Abstract Meaning Representation (AMR) for Turkish. The AMR is a sentence-level representation that summarises all semantic aspects of sentences. Its goal is to create representations that abstract from syntactic features. This is an attempt to group sentences with the same meaning in a semantic representation, regardless of the syntactic features of the sentences. It is also easily readable by humans, which is very convenient for researchers who want to conduct research in this area. AMR is designed for the English language, but can be adapted to adapt to other languages by taking into account language-specific issues. To accomplish this task, it is mandatory to create an AMR guideline that defines language-specific annotation rules. In this thesis, we present Turkish AMR representations by creating an AMR annotation guideline for Turkish. Turkish is a morphologically rich, pro-drop and agglutinative language, which causes it to deviate from English AMR in its representations. In creating the Turkish guideline, we meticulously examine Turkish phenomena and propose solutions to define AMR representations for these deviant points. Besides, we present the first AMR corpus for Turkish that contains 700 AMR annotated sentences. Unfortunately, the creation of such resources is not an easy task, as it requires linguistic training and a large amount of time, and also requires a systematic annotation strategy. We adapt the model-annotate-model-annotate strategy to our annotation task, i.e., instead of dealing with all phenomena at once, we follow a stepwise path. First, we follow a data-driven approach and handle Turkish specific structures that are present in the data. In the second iteration, we use knowledge bases such as Turkish dictionaries and grammar books to cover all linguistic phenomena. This strategy allows us to build a corpus simultaneously. Instead of annotating the sentences from scratch, we use a semi-automatic annotation approach where a parser first processes the sentences and outputs the AMR graphs, which are then corrected/re-annotated by annotators (two native speakers). We implement a rule-based parser by inspiring the methods used in the literature. Our rule-based parser is very similar to the transition parsers, but its actions are driven by the rule list rather than an oracle. We design this parser in this way because our goal is to develop an unsupervised parser that utilizes the available sources. We evaluate our proposed solutions and the rule-based parser using the semantic match score (Smatch). This score shows the quality of our corpus and the accuracy of our parser. The inter-annotated agreement between our annotators is 0.89 Smatch score, the rule-based parser achieves a Smatch score of 0.60, which is a strong baseline for the Turkish AMR parsing task. The final part of this paper deals with the development of a data-driven AMR parser. We formalize our parser as two steps containing a pipeline of multiple classifiers, each with different functionality. The first step of the data-driven parser is to identify concepts to be used in the AMR graphs. Nine separate classifiers are trained for this task.
Açıkdeniz yapıları çalışanlarına verilen eğitimlere yönelik sistematik bir öğretim tasarım modeli

(Lisansüstü Eğitim Enstitüsü, 2023-08-12) Kandemir, İsmail ; Çiçek, Kadir ; 512172010 ; Deniz Ulaştırma Mühendisliği

Denizcilik sektörü, doğası gereği tehlikeli ortamlarda faaliyet gösterdiğinden, insan kaynaklarının yüksek düzeyde bilgi, beceri ve yetkinliğe sahip olması önemli bir husustur. Değişen ihtiyaçların ortaya çıktığı aynı zamanda teknik, operasyon vb. farklı gelişmelerin meydana geldiği günümüzde, denizcilik eğitimlerinin etkili, verimli, cazip ve uygun maliyetli bir şekilde tasarlanması büyük önem taşımaktadır. Bu nedenle, öğretimsel sorunların ve kaynakların sistematik bir bakış açısıyla çözümlenmesi aynı zamanda ince ayrıntılar göz önünde bulundurularak tasarlanması gerekmektedir. Bu açıdan denizcilik eğitim ve öğretimi özelinde, gerekli bilgi, beceri ve yetkinliklerin en üst düzeyde edinilmesini sağlayacak özgün bir öğretimsel tasarım ortaya konulması sektörün insan kaynağı kalitesinin sürdürülmesi açısından gereklidir. Denizcilik sektöründeki insan kaynaklarının eğitim ve öğretiminin önemi, tüm deniz kazalarının büyük çoğunluğunun insan hatasından kaynaklandığı gerçeğiyle de vurgulanmaktadır. Benzer şekilde, açık denizlerde gemileri ve platformları bulunan petrol ve gaz endüstrisi personeline standartlar, yönetmelikler, acil durum prosedürleri vb. temel eğitimlerin yanı sıra uzmanlığa uygun diğer eğitimler sağlanmış olsa da insan hatası kaynaklı kazalar meydana gelmeye devam etmektedir. Açıkdeniz petrol endüstrisi, iş sağlığı ve emniyeti gibi konularda sert kurallara sahip olduğundan, çalışanların görevlerine başlamasından önce "Temel Açık Deniz Emniyet Giriş ve Acil Durum Eğitimi (BOISET)" sertifikasına sahip olması zorunluluğu getirmiştir. Bu kuralları, 1991 yılından başlayarak işgücü emniyeti ve yetkinliğinin iyileştirilmesine yardımcı olmak amacıyla petrol ve gaz endüstrisi için standartlar belirleme konularında çalışmalar yapan ayrıca personel eğitimlerini düzenleyen ve gerçekleştiren kurum olan Açıkdeniz Petrol Endüstrisi Eğitim Örgütü (OPITO) koymuştur. Günümüzde, BOSIET birçok farklı ülkede çeşitli eğitim merkezlerinde, OPITO standartlarına uygun olarak yürütülmektedir. Standartlar incelendiğinde, eğitimin modüllerden, modüllerin ise element adı verilen alt birimlerden oluştuğu görülebilmekte ayrıca verilecek eğitimler için genel kapsam, ders sonuçları, konu başlıkları vb. bilgiler elde edilebilmektedir. Bu bilgilerden yola çıkan eğitim merkezleri kendi müfredatlarını oluşturur ve seçtikleri çerçeve ile eğitimlerine devam ederler. Bu doğrulturda, eğitmenlerin konuya hakimiyeti, materyallerin ve ders görsellerinin etkinliği gibi seçeneklerle bağlantılı olarak kurs merkezleri iyi ya da kötü sonuçlar üretebilmektedir. Açıkdeniz ortamı, karadan uzak konumu, sert hava koşulları ve kazaların meydana gelme potansiyeli nedeniyle eşi benzeri olmayan emniyet sorunlarını ortaya çıkartmaktadır. BOSIET, çalışanların açık deniz ortamlarında emniyetli ve etkili bir şekilde çalışmaya yeterince hazırlanmalarını sağladığı için kurs merkezlerinin bireysel çabaların dışında da eğitimin bir sistematik bakış açısı gözden geçirilmesinin ihtiyacını barındırmaktadır. Tez çalışmamız, açık denizde çalışmak isteyen veya halihazırda bu sektörde çalışan personelin, OPITO standartlarına uygun olarak belirtilen yetkinlikleri en üst düzeyde kazanmalarını sağlamak ve BOSIET'in etkililiğini artırmak amacıyla dört temel bakış ile derinlemesine bir inceleme sunmaktadır. İlk olarak, öğretim tasarim modellerinin prensipleri ve öğretimin geliştirilmesi sürecindeki kritik rolleri irdelemiştir. Literatürde çok sayıda IDM'in olması ve öğretimsel probleme en uygun seçimin yapılması konusundaki belirsizlikler ve zorluklar sebebiyle tez kapsamında bir IDM seçim yaklaşımı geliştirilmiştir. Bu yaklaşım ile çok kriterli bir karar verme problemine dönüşen IDM seçimi ele alınmış ve bulanık aksiyomatik tasarım (FAD) metodolojisi kullanılarak bir karar desteği sağlanması amaçlanmıştır. Bu yeni yaklaşımın etkinliği BOSIET'e odaklanan bir vaka çalışması ile vurgulanmıştır. Vaka çalışmasında teorik ve pratik kısımlar için farklı IDM alternatifleri uzmanların değerlendirmelerine göre karşılaştırılmış, sonucunda teorik kısım için Dick, Carey ve Carey, pratik kısım için ise ADDIE modeli en iyi alternatif olarak tespit edilmiştir. İkinci olarak teorik ve pratik kısımlar için tespit edilen en iyi alternatif modellerin esneklik, revizyon kabiliyeti, biçimlendirici ve özetleyici değerlendirme özellikleri gibi güçlü yönlerinden yararlanılarak BOSIET özelinde bir IDM önerilmiştir. Üçüncü olarak, önerilen IDM'e kontrol listesi (CL) ve küresel derecelendirme ölçeği (GRS) yaklaşımları bütünleştirilerek BOSIET kursiyerlerinin bilgi ve beceri kazanım seviyelerini değerlendirmek için yeni bir araç eklenmiştir. Dördüncü ve son olarak ise ortaya konulan IDM'in etkinliğini test etme amacıyla yapı ve davranışsal testleri içeren sistem dinamiği yaklaşımından yola çıkılarak öğretim tasarımında kullanılan modellerin ve stratejilerin etkileşimi incelenmiştir. Önerilen IDM ile BOSIET'in içeriği tasarlandıktan sonra uzman ve eğitmen görüşleri alınarak düzeltmeler yapılmış daha sonra deney ve kontrol grupları üzerinde uygulanarak etkinliği test edilmiştir. Sonuçlar, yeni öğretim tasarımının geleneksel yönteme kıyasla istenen öğrenme çıktılarına daha etkili bir şekilde ulaşmayı sağladığını göstermiştir. Bu tezin ana bulguları, önerilen IDM vasıtasıyla ortaya konulan öğretimsel tasarıma değerlendirme aracı da birleştirildiğinde, delegelerin bilgi ve beceri kazanımlarını önemli ölçüde geliştirdiğini göstermektedir. Bulanık aksiyomatik tasarım kullanılarak öğretim tasarımı unsurlarının karşılaştırılmasına yönelik metodolojinin, BOSIET eğitimi için en uygun IDM'in belirlenmesinde etkili olduğu ortaya konulmuştur. Ayrıca, farklı akademik çalışmaları bir araya getirerek IDM'i test etme yaklaşımı, önerilen modelin etkinliğine dair güvenilir kanıtlar sağlamıştır. Sonuç olarak, doktora tezi, BOSIET için kapsamlı bir IDM'in yanı sıra bir değerlendirme aracı, öğretim problemi için uygun IDM'yi seçmeye yönelik bir yaklaşım ve IDM'nin etkinliğini test etmek için bir metodoloji sunmuştur.
Ahşap malzemenin robot destekli eksiltmeli üretimi: Denklemden uygulamaya bir iş akışı

(Lisansüstü Eğitim Enstitüsü, 2024-06-28) Şenkal, Habibe ; Alaçam, Sema ; 523211011 ; Mimari Tasarımda Bilişim

Teknolojideki ilerlemeler, ahşap işlemeciliğini araç ve yöntemler bakımından gelenekselden otomatiğe dönüştürmüştür. Massachusetts Teknoloji Enstitüsü (MIT)'nde servomekanizma laboratuvarının kurulmasıyla başlayan ve bir erken dönem bilgisayarın freze tezgahına bağlanmasıyla ilk kez sayısal olarak kontrol edilen bir freze tezgahının geliştirilmesiyle devam eden çalışmalar, otomatik işlemede dönüm noktası oluşturmuş ve bilgisayarlı sayısal kontrol (computer numeric control, CNC) teknolojisinin temellerinin atılmasını sağlamıştır. Bu gelişmeler sadece ahşap işlemeciliğini otomatikleştirmekle kalmamış, aynı zamanda karmaşık formların ahşap malzemeden üretimindeki sınırları belirsizleştirmiştir. Karmaşık kavramı genellikle eğrisel kavramıyla birlikte, Öklid dışı geometrilerden olan topolojik geometriler ile ilişkilendirilmektedir. Topolojik geometriler, bükme, esnetme ve dönüştürme gibi işlemlerle oluşmaktadır. Cebirsel geometriler ise denklemlerle tanımlanan geometrik nesneleri ifade etmekte olup soyut cebirsel ifadelere ve hesaplara dayanması sebebiyle karmaşık bir yapıya sahiptir. Matematiğin barındırdığı form bilgisini açığa çıkarmak konusunda karmaşıklık, matematik alanında derinlemesine bilgiye sahip olmayan mimar ve tasarımcılar için bir kısıttır. Bu bağlamda, tez kapsamında, bir hesaplamalı tasarım aracı olan Rhino-Grasshopper yazılımı için, Python yazılım dili kullanılarak, MathForm adında bir eklenti geliştirilmiştir. MathForm eklentisi, matematik denklemlerinin kural temelli yapısını kullanarak tekrarlama veya manipülasyon ile form üretimine olanak sağlamaktadır. Eklenti ile yaklaşık 20 matematik denkleminden form üretimi araştırılmıştır. Tez kapsamında, araştırılan formlar içinden topolojik ve cebirsel karmaşıklıkları sebebiyle iç-dış ayrımının yapılamadığı, yönlendirmesiz, dört Öklid dışı matematik yüzeyinden form üretimi derinlemesine bir bakış ile sunulmaktadır. Bunlar Möbius şeridi, Figür-8 Klein şişesi (çift sarmal Möbius şeridi olarak da adlandırılmaktadır), sekiz torus ve Umbilic torus yüzeyleridir. Bu tez, tasarım ile matematik arasındaki ilişkiyi bilgisayar destekli hesaplamalı tasarım ve üretim araçlarıyla geri bildirimli bir form üretim serisi kurgusu üzerinden araştırmakta ve denklemden uygulamaya bir iş akışı sunmaktadır. Bu bağlamda tez, matematik denklemleriyle tanımlanan çift eğrilikli yüzeylerin, hesaplamalı tasarım yöntemiyle modellenerek form oluşturulmasına, modellerin bilgisayar destekli üretim yazılımları aracılığıyla üretim planlaması yapılarak simüle edilmesine ve robot destekli eksiltmeli üretim yöntemiyle ahşap malzemeden üretilmesini odaklanmaktadır. Tez, dört farklı formun üretimini beş üretim uygulaması deneyi ile araştırmaktadır. Deneylerin her biri, matematik denklemleri kullanılarak, tez kapsamında geliştirilen MathForm eklentisi aracılığıyla oluşturulan formların üretim sürecini içermektedir. Üretim uygulaması deneylerinde, işleme için eksiltmeli üretim yöntemi ile CNC makinelerinin kullanımı benzerlik göstermesine rağmen kullanılan makine, makinelerin programlanması ve simüle edilmesi için kullanılan bilgisayar destekli üretim yazılımı, takım özellikleri, üretim tekniği, malzemenin montajlanması ve operasyon stratejileri bakımından farklılık göstermektedir. Deney 1'de üç eksen CNC makinesi kullanılırken, diğer dört uygulama deneyinde altı veya yedi eksen endüstriyel robot kol kullanılmıştır. Üretimlerde kontrplak ve lamine ayous malzeme, iki farklı tip ve çaptaki takımlar ile işlenmiştir. Deney 1, Figür-8 Klein Şişesi formunun üç eksen CNC makinesiyle, kontrplak malzemeden yığılmış dilimleme yöntemiyle üretimini ele almaktadır. Kullanılan üretim tekniği hızlı üretim avantajı sağlayarak araştırılan formların kavisli yüzeyleri ve yüzey açıları ile uyumlu takım çapı ve fiziksel model boyutunun belirlenmesine katkı sağlamıştır. Deney 2'de Möbius şeridi formu, endüstriyel robot kol aracılığıyla, bir destek malzemesi ile işleme tablasından yükseltilen lamine ayous bloğun XZ ekseninde çift yönlü olarak iki aşamada işlenmesi ile üretilmektedir. Deney 3 ise, bu montajlama ve üretim yönteminde nihai ürün kalitesine dolu hacim miktarı, malzeme kalınlığı ve ağırlığının etkisini araştırmaktadır. Bu amaç ile karakteristik formu itibariyle daha kalın, dolu hacmi ve ağırlığı daha fazla olan sekiz torus formu daha da büyütülerek Deney 2'de kullanılan montajlama ve işleme yöntemi ile üretilmektedir. Üretim yöntemindeki benzerliklerin yanı sıra bu deney, önceki üretimden farklı olarak, takım, işleme ekseni, formun alt parçalara ayrılarak üretimi gibi farklılaşan unsurlar içermektedir. Deney 4'te sekiz torus formu, Deney 3'teki montajlama yöntemine ilave çapraz elemanlar eklenerek yeniden üretilerek robot kol işleme hızı ve üretim süresine etkisi araştırılmıştır. Deney 5 ise montajlama ve işleme yönteminin üretim süresine ve fiziksel modele etkisi araştırılmaktadır. Bu amaçla umbilic torus formu, lamine ayous bloğunun doğrudan işleme tablasına monte edildiği ve bir yüzeyi XY ekseninde işlendikten sonra manuel olarak döndürülerek, kullanılan bir kılavuz sistemiyle, tekrar işleme tablasına montajlanarak diğer yüzeyinin işlenmesi sonucu üretilmektedir. Üretim uygulaması deneylerinin süreçleri, üretim öncesi yapılan simülasyon sonuçlarıyla karşılaştırılarak montajlama ve işleme yönteminin üretim hızı ve süresine etkisi analiz edilmiştir. Üretilen fiziki modeller, fotoğraf temelli üç boyutlu tarama yöntemi (fotogrametri) kullanılarak, dijitalleştirilmiş ve üretildikleri dijital modellerle çakıştırılarak fiziki model doğruluğu analiz edilmiştir. Çalışmanın ilave araç, farklı özelliklerdeki takım ve malzemeler ile yürütülmesinin üretim süreci ve nihai fiziksel modele etkisi öneriler üzerinden tartışılmıştır. Tez kapsamında sunulan MathForm eklentisinin, tasarımcıların matematik denklemleri aracılığıyla tasarımın erken aşamalarında form bulma, manipülasyonu ve formun analiz edilmesi süreçlerine hesaplamalı tasarım konusunda uzman bilgisine ihtiyacı azaltarak destek olacağı düşünülmektedir. Ahşap malzemenin hesaplamalı üretim yöntemleriyle işlenmesi ve endüstriyel robot kolun programlanması konularında sunulan kriterlerin yanı sıra simülasyon ve fiziksel üretim süreçlerinde deneyim ile elde edilen bilgiler, gelecek çalışmaların üretim süreçleri için bilgi kaynağı oluşturmaktadır. Geri bildirimli üretim süreci, ahşap malzemenin robot destekli eksiltmeli üretimini etkileyen parametrelerin belirlenmesi ve önerilecek iş akışı için kriterlerin oluşturulmasını sağlamıştır. Önerilen iş akışı, benzer çalışmalarda yaşanabilecek sorunlara karşı hazırlıklı olunmasına ve çözüm stratejilerinin geliştirilmesine katkı sağlamaktadır.
An action research on the integration of virtual reality into industrial design education

(Graduate School, 2021-10-13) Hamurcu, Ahmet ; Öğüt, Şebnem ; Rızvanoğlu, Kerem ; 502142901 ; Industrial Product Design

Industrial designers have always tended to use computers and computer-based technologies that they believe will help them do their works better and easier, and thereby, they quickly adopted them. Also, these technologies adopted by professionals have usually been used by industrial design students and/or educators and they were integrated into industrial design education shortly after their adoptions because it is conducted as a simulation of professional life. However, although Virtual Reality (VR) technology that is one of the computer-based technologies has become economically available for designers with the release of VR headsets such as HTC Vive and Oculus Rift in 2016, and has already been adopted by professionals, how it can be integrated into industrial design education is still unclear. Moving from this point of view, this thesis explores how VR technology can be integrated into industrial design education. For this purpose, an action research was conducted by trying to use it under the real conditions of an industrial design studio course. In the first step of the research, a systematic literature review on related works in addition to the general literature review and a preliminary study with prospective users (industrial design students and instructors) were carried out to reveal (i) what the former studies regarding the use of VR technology in industrial design education are; (ii) what these studies say about this issue; and (iii) what the opinions of potential users, who are industrial design students and instructors, about the use of VR technology in industrial design education are. The systematic literature review showed that VR technology was tried to be used before in the professional practices of industrial design as: a usability evaluation tool; an ergonomic evaluation tool; a visualization tool; a product demonstration tool; a presentation tool; an interactive prototyping tool; an immersive mood board; a sketching tool; and a collaboration tool. However, none of these types of use was tried to be employed before under the real conditions of the educational setting of an industrial design studio course. The preliminary study was conducted with industrial design students and instructors who came from 10 universities in Turkey. In this preliminary study, first, VR technology was introduced to the participants. Then, it was experienced by the participants. And then, both quantitative and qualitative data based on their opinions were collected and analyzed. The results of the preliminary study revealed that: (i) potential users are eager to use VR technology; (ii) however, they have reservations as well as their positive opinions about using it in industrial design studio courses; and (iii) almost all these reservations are related to its usability. In the second step, an in-studio study was planned based on the findings of these studies, and with a focus on getting started by eliminating or by minimizing these reservations as much as possible. In the third step, in line with this planning, VR technology was tried to be used in the studio-based practices of an industrial design studio course. This in-studio study was carried out in the course "EUT 320E Industrial Product Design III" with the project issue "Smart Electric Minibus Design for Anadolu Isuzu". This course was the 3rd year industrial design studio course of Istanbul Technical University (ITU) Department of Industrial Design, which was conducted in the 2017-2018 spring semester. In this process where the course process and the research process merged, the researcher worked: as one of the instructors of the course; as an operator who is responsible for installing and running the VR system properly, and responsible for its being used easily and hygienically; as an educator who will meet the learning need for VR. In the in-studio study, (i) how VR technology can be integrated into the jury practices of industrial design education was questioned by making the use of it mandatory by students for design representation and presentation purposes, and then, by trying to use it in the jury sessions; and (ii) how it can be integrated into other studio-based practices of industrial design education was questioned by making it available for use during the studio hours of the course, and then, by observing whether it will be used for/in other studio-based practices. Throughout the project process of the course, it was attempted three times to integrate VR technology into the jury practices of the course. In the last attempt, this was achieved. Each attempt was scrutinized with the observations recorded during the jury sessions and the interviews with the user groups after the jury sessions. The interviews with the students were held as group interviews, whereas the interviews with the instructor-jurors were held one-to-one. Since it was not possible to hold face-to-face interviews with the invited jury members, their opinions were tried to be gotten via e-mail. These attempts and examinations show step-by-step how VR technology can be integrated into the jury practice of industrial design education by developing solutions in line with the needs and demands of students and instructors. On the other hand, it was observed that (i) making VR available for use during the studio hours and giving a short training on how to use its hardware and software opened the way of using it as a design evaluation tool by students; and (ii) neither students nor instructors demanded or attempted to use VR in other practices and activities where students and instructors got involved together. In the last step, considering the results of the in-studio study, (i) the usability level of the proposed way for using VR technology in the final jury session was measured with the help of the System Usability Scale (SUS); (ii) the final assessments of students and instructors on the VR technology they used during the project process and its use in the educational practice of industrial design were revealed with the help of the interviews with students and instructors and the questionnaire items adapted from the scale items of the Extended Unified Theory of Acceptance and Use of Technology (UTAUT2) and the Net Promoter Score (NPS); and (iii) the reasons why VR technology was not used in other practices and activities where students and instructors got involved together were questioned with the help of interviews with students and instructors. The SUS score was calculated as 71.3. This score indicates that the usability of the last proposal for using VR technology in the jury practices of industrial design education is OK but can be improved. Besides, the final assessments of students and instructors on the VR technology they used during the project process and its use in the educational practice of industrial design revealed that although they found VR technology useful in various aspects and easy to use at various degrees, they still had some reservations in their minds. However, this time, these reservations were based upon (i) whether the facilitating conditions about the frequent or the continuous use of VR technology were sufficiently present; and (ii) the thought that using it for evaluating designs of small products will not be so useful. On the other hand, it was seen that the reasons why VR technology was not used in other practices and activities where students and instructors got involved together were related to (i) not having yet sufficient familiarity and mastery of its use in such activities and practices; (ii) perceiving VR as a technology that would only enable to evaluate and/or present the whole – not the parts – of a design over a finished model; and (iii) not being its set-up ready for use when needed. In addition to all these, participants stated that for the use of VR technology in industrial design education to be sustainable, (i) it should be easily accessible and usable for both students and instructors with a permanent installation in the studio environment; (ii) it should be led/managed by at least one instructor/executive; and (iii) the requirements of the technology such as installation/setup, learning, operating, and maintenance requirements should be met by at least one technical person/expert/operator. As a result, this thesis study contributes to the relevant literature (i) by showing, step-by-step, one of the ways of integrating VR technology into the jury practice of industrial design education; (ii) by revealing the clues of how it can be integrated into other studio-based practices of industrial design education; and (iii) by outlining what might be the possible attitudes of industrial design students and instructors towards the use of VR technology in industrial design studio courses before and after the actual use of it in those courses. This thesis study is one of the first attempts in the literature to integrate VR technology into industrial design education by trying to use it under the real conditions of an industrial design studio course. Hence, its outcomes need to be verified and/or improved with similar studies. Besides, how it can be integrated into other studio-based practices of industrial design education is still not clear enough because the relevant part of the study has been conducted with an unstructured intervention. Therefore, it should be noted that there is also need for further studies to be carried out with structured interventions on this issue.
An architectural design method using rank-based interactive evolutionary algorithm

(Graduate School, 2023-04-27) Dedeler, Elif Gamze ; Bittermann, Michael Stefan ; 523191007 ; Architectural Design Computing

Evolutionary algorithms are a stochastic search methodology that has been widely researched and used in engineering design and has recently found applications in other design fields. In each context, their aim is to maximize the satisfaction of one or more goals, based on calculated satısfaction of the goals. There are tasks, such as architectural design, where calculating satisfaction is problematic, because goals involve experiential qualities, such pleasure, comfort, meaning, etc. Although this creates a bottleneck for computational treatment, a person can evaluate experiential qualities by aesthetic judgment or some reasoning. Interactive evolutionary algorithm (IEA) is a form of evolutionary computation designed to utilize information provided through human subjective assessments. Aesthetic judgment is subjective measurement of pleasure resulting from a perception. In this respect, aesthetic judgment takes place in real-time and without conceptual abstraction. Because there is no abstraction in this type of judgment, the knowledge a designer can exercise when he/she faces multiple alternative designs, is determining which design is more pleasant to perceive compared to another one. Determining the exact score of each design on some absolute scale is problematic due to the subjective nature of judgment, ı.e. the absence of a consensus about such a scale. Therefore, this study proposes a design method based on an interactive evolutionary algorithm using a non-dominated sorting method that is well-known in the context of multi-objective evolutionary algorithm. In this method, the fitness value is assigned based on people's subjective preferences, allowing to gradually approach to the best design solution based on one's aesthetic judgment. The method developed is applied to the case of a theater named Schauspielhaus designed by Jorn Utzon (1918-2008) in Zurich, Switzerland. The ceiling module, one of the conspicuous of Utzon's design, was modeled and parameterized in Grasshopper. The convergence behavior of the proposed algorithm during the design process was examined throughout 364 design generations by 25 participants. The results indicate that the proposed algorithm is able to integrate the aesthetic preferences of the designers. The study also yields hints about the richness of the resulting information produced by the interactivity, by applying non-parametric statistical tests as well as unsupervised machine learning for design knowledge elicitation.
An artificial intelligence based methodology in architectural design process: Integrated diffusion model-aided design (DMAD)

(Graduate School, 2024-10-15) Müezzinoğlu, Can ; Yazıcı, Sevil ; 523211007 ; Architectural Design Computing

The thesis focuses on the integration of Diffusion Models (DMs) that synthesize text, images, or videos based on written or visual prompts into architectural design and how architectural design process can shift. The thesis aims to develop a methodology that integrates traditional design and computational design with DMs. The design process in this thesis is separated into three distinct phases: (1) preliminary design, (2) design development, and (3) presentation of finalized design. Each phase utilizes different capabilities of DMs. The designer can use Ideative DMs in the Preliminary Design Phase to generate new ideas to contribute to concept generation. Variative DMs can be used in the Design Development Phase to generate image alternatives to the design produced by the designer in the preliminary design phase. These alternatives can be related to mass model decisions, solid-void experiments, material selection and facade decisions. In the Presentation of Finalized Design phase, the designer works with Post Productive DMs to edit the visuals which were produced with Variative DMs, for presentation. The integrated DM-aided design framework was first tested through a preliminary study, followed by a case study involving two experts who were architects undertaking their PhD degrees in architecture. In the case study, data was obtained through questionnaires and through the collection of inputs used in the design process and outputs produced. The data was analyzed under two main categories: (1) phase-based evaluation of each DM separately and (2) the overall evaluation of the design process. In phase-based evaluation, the study examines the use of various DMs across three design phases. During the preliminary design phase, DM can enhance exploration and evaluation of alternatives, providing valuable new ideas for designers. In the later phases, DMs facilitate the generation of alternatives and the creation of visuals for presentations. The effectiveness of different detection methods for image analysis is assessed using image difference method. As seen in the case study, the outputs from the various environments used throughout the design process are used as inputs in the next design environment, allowing reflection in the process. Integrating DMs into architectural design creates a dialogue between the designer and the tool, especially in the early stages. As the design process advances, the designer becomes a decision-maker. The integration of multimedia and multiscale approaches enriches the design process by expanding the search space and addressing specific design challenges efficiently. Additionally, DMs expand the design search space by generating alternative outputs throughout the process. The framework also allows for transitions between different design stages and scales. The proposed methodology has the potential to develop new strategies for architectural design.
Analysis of visual design principles in art and architecture by computer vision and learning based model

(Graduate School, 2022-09-20) Demir, Gözdenur ; Kanan, Aslı ; 523142002 ; Architectural Design Computing

Visual design is associated with different uses and organizations of design elements and principles. They are explained in numerous books in art and design disciplines as the bases of visual communication. Those are applied subjectively by the designers in various disciplines for aesthetics and presentation of information. For the constitution of a perceptual framework for visual processing, the logical procedures that use the design elements are called visual design principles (VDP) ; three are selected as the main principles for this study: emphasis, balance, and rhythm. As the examples of these principles were inspected, it was established that the use of the design elements differed and led to sub-visual similarities existing in their compositions, despite following the main organizational rationale. So nine sub-VDP are defined, which have similar visual patterns: color, isolation, shape, symmetric, asymmetric, crystallographic, regular, progressive and flowing. Although numerical analysis of design visuals is considered as hard, it has become possible with emerging artificial intelligence (AI) technologies. Due to the advances in computer vision applications, a deep learning model can identify these underlying common visual patterns in the data. This Ph.D. thesis develops an approach to detect and classify the VDP in a visual composition over different domains, including photography, art (paintings, prints and graphic art) and architecture (building facade visuals) by a neural network model. The AI applications in art, design, and architecture conducted by the disciplines of computer science and design have been found, analyzed and the models, methods, numbers, and types of data used in the studies have been extracted. Next to the compiled knowledge in AI studies in art and architecture, the manual and computational analyzes of the building facade in architecture have been researched. As there was no existing dataset for this problem, three genuine datasets have been created in the given domains for this study. The majority of the examples showing the VDP directly belong to the contemporary era, so the data search has been oriented toward this period. Various websites and online museum databases are used for collecting the data. The amount of data found for the labels of VDP in each domain has been kept as high as possible to achieve high performance from the deep learning model. Multiple experiments are structured for testing the model. Classification results within the domains are evaluated by considering the clarity and the amount of the data. The effect of the labeling procedure in the preparation of the initial datasets is discussed by analyzing multi-class and multi-label classification results. Also, domain adaptation is investigated with instances tested in models trained in other domains. The knowledge of myriads of original designs, captured by the underlying computational patterns, can be used to consolidate the design process by providing an objective evaluation of the visual compositions.
Application of a novel energy dissipation beam-column connector in precast structures

(Graduate School, 2024-08-12) Bozan, Ali Berk ; Oyguç, Reşat Atalay ; 802221204 ; Earthquake Engineering

In this study, which is prepared as a master thesis, seismic performance and cyclic loading behavior of four type precast reinforced concrete frames with two different type of moment resisting beam to column connection is investigated comparatively. The first one is the widely used moment resisting connection that is defined as wet connection in TBDY. The second connection type is known as ACPH (Artificial Controllable Plastic Hinge) that is taken as reference study about repleaceable plastic hinge concept. The goal of this connection, known as an replaceable plastic hinge, is to defend reinforced concrete components from earthquake related plastic deformations by keeping them in a specialized connecting section. It will be possible to repair the broken connections after the earthquake so the building can keep on operating normally. Another advantage of the developed method is that it is disassemblable and removable, allowing a completed structure to be dismantled, transported and reassembled when desired. The study is consist of five major sections. In the first section, precast reinforced concrete structures are introduced briefly and most used moment resisting beam to column connections is explained with mentioning advantages and disadvantages of them. Then the precast structure connection types included in the Turkish seismic design code are introduced. Within the scope of the thesis, MAB1 type connection, which is mentioned in Turkish Seismic Code, is used for analytical study. After that, the aim and scope of this thesis and literature review on replaceable hinge conncections are explained. At the end of first section, the paper which is named as "Performance coordination design method applied to replaceable artificial controllable plastic hinge for precast concrete beam-column joints" by Yuan (2022) are explained in more detail. Within the scope of thesis, this paper are chosen as reference for analytical study. An idea of strong joint/weak component structural design is covered by this design philosophy. It is recommended that the ACPH have a lower bending capacity than the end beam to ensure that the damage mechanism and failure mode are stable, regular, and controllable. Moment design of the connection was performed according to the equations given in the reference article. According to the reference article, it is recommended to keep λ below 0.9. When λ value were less than 0.9, This indicated that the ACPH performance was weaker than that of the concrete components, and the structural deformation was mainly concentrated at the ACPH. When λ were about 1, the area of the ACPH hysteresis loop gradually grew. The ACPH and concrete components subjected to loading participated in the structural deformation, and the Z-shape of the hysteresis loops gradually changed to spindle-shaped. The concrete components became a vulnerable section as λ increases. In the second section, first of all, details of ABAQUS software and information about Concrete Damaged Plasticity (CDP) are given. Then, modeling of reference article is performed in ABAQUS software by considering parameters such as model geometries, materials, interactions, loading, boundary conditions and mesh. Then the results are compared with article to show that the model works correctly. In this section details about modeling are as follows; reinforced concrete elements and steel joint elements are modeled within the ABAQUS software. ABAQUS software uses the Concrete Damaged Plasticity (CDP) model, which allows us to take into account nonlinear effects of materials and degradation effects. The geometric shapes for concrete and steel hinge elements are modeled as three-dimensional (3D), deformable, solid and extrusion. Reinforcement Steels are selected as 3D, wire and planar. For the material properties, the concrete model used is the Popovics compressive stress-strain model for concrete by Popovics (1973) and a modified tensile reinforcement model by Nayal and Rasheed (2006) is chosen to represent the tensile stress behavior of concrete. Reinforcement steel and steel hinge elements have inputted to software as a stress-plastic strain. Another important parameter to get the right result is the mesh, C3D8R was selected for concrete materials and ACPH. With this selection, concrete is defined as a 3D element with 8 nodes. For steel reinforcements, T3D2 is selected as a linear 3D material with 2 nodes. In the test setup of the reference article, a design was made for λ=0.3 and an experimental study was performed. Accordingly, in order to calibrate the ABAQUS model, the model was calibrated using this λ value and the hysteresis curves compared. In the third section, frame designs are made to evaluate the characteristics of the ACPH type connection that stand out from other connection types. The frames consist of 4 different type that depends on number of storeys and bays. These are one bay-one storey, one bay-two storeys, two bays-one storey and two bays-two storeys. The column and beam elements to be used in the design are dimensioned. 1.8m column height and 3m beam length were taken because the same dimensions were used in the reference article. However, the frame dimensions are smaller in height and length than the actual field application. The reason is that it is not feasible to analyze with real applications due to reasons such as data storage and analysis time in the analysis performed in ABAQUS software. Therefore, the results obtained should be evaluated accordingly. Beam and column are dimensioned for a total of 4 types of frames. The selected column and beam reinforcement is common for all of them. A force of 15% of the axial load capacity of the column is applied to the top of the column. It is checked that the column is stronger than the beam. After deciding on the properties of the column and beam, moment and shear design for ACPH was performed. The λ value for the design of the frames was 0.45, while the reference article calibration had an λ value of 0.3. In this direction, it is possible that the hysteresis curve behavior may change as the λ value increases. As a result, 8 frames including 4 ACPH and 4 wet connection type frames were modeled in ABAQUS software. As ABAQUS element geometry and material model creation parts are discussed in section 2, the same method is used in this section. In the Step module, 3 different procedures will be applied for each frame analysis. Within the scope of this thesis, these procedures are "frequency" for period calculation, "dynamic implicit" for nonlinear dynamic analysis and "static general" for cyclic displacement loading. After the solution steps are determined, the desired data is selected from the "Edit Field Output" section to select which data will be in the solution outputs. The outputs for frequency analyses is frequency of frames. The outputs for dynamic analyses are base shear, DAMAGEC, DAMAGET, SDEG, PE and S. The outputs for cyclic analyses are base shear and roof displacement. After that, it is selected how the elements that we combine in the assembly section will establish a connection on the surfaces they come into contact with each other. In the other section, loading states and boundary conditions of the models are defined. For frequency analysis, all column bottom surfaces should be defined as fixed. In case of earthquake, the direction in which the acceleration is applied should be left free. Earthquake accelerations are applied to the column bottom surfaces and the nonlinear dynamic analysis steps are completed by applying gravity loading to the whole model. To complete modeling of frame, mesh system is created in the elements. C3D8R was selected for concrete materials and ACPH. With this selection, concrete and ACPH are defined as a 3D element with 8 nodes. For Steel Reinforcements, T3D2 is selected as a linear 3D material with 2 nodes. Another issue mentioned in this section is the selection of the earthquake record to be applied to the frames. The selected earthquake record belongs to the Maraş Earthquake. However, in order to save analysis time, accelerations between 70th and 80th seconds, which is the region where the acceleration reaches peak value in the earthquake record, are selected for analysis. The selected earthquake record exceeded the value of the spectrum used in the design of the frames. This made it possible to see the frame damages more clearly in the seismic analysis. For the cyclic load analysis, a loading reaching a drift rate of 5.6% is applied to the frames. In the fourth section which is the dicussion section, the frames mentioned in section 3 were subjected to earthquake recording and cyclic displacement loading. Then their seismic performances were examined and discussed. As a result of frequency analyses, period changes of the frames are calculated. It is seen that an increase in period was observed in all frames thanks to ACPH. Among the frame types, it is observed that increase in the storey number affected the period change more than increase in the bay number. As a result of dynamic implicit analyses, base shear vs time, compressive damage, tension damage, SDEG (scalar stiffness degredation), PE (plastic strain) and S (von mises stress) are evaluated. When base shear results is investigated, a decrease was observed in all frames thanks to ACPH. As in the period change, the highest effect was observed in the increase in the number of storeys. Another outcome for base shear is the use of ACPH reduces the base shear carried by the middle column proportionally and provides a more balanced distribution with the other columns. For other analysis results, the following can be said that damage occurred at the column base of both RC and ACPH frames during the earthquake. Plastic hinges were formed on the column bottom surfaces of all frames due to damage. Therefore, plastic hinges at the bottom of the columns should be investigated as a separate study subject. Regarding the damage to the beams, in RC frames, damage occurred in the region of the beams close to the column face. In the two bays case, damages also occurred in the beam-column joint region in the middle of the frames. In ACPH frames, the damage to the beams was concentrated on the energy dissipation plate region of the ACPH, which significantly reduced the damage to the reinforced concrete elements. The use of ACPH will contribute to achieving undamaged middle beams, which is one of the philosophies of the use of the replaceable connection. Lastly, ductility and structural system behavior coefficient were evaluated by looking at the cyclic analysis results. Within the scope of this thesis,the yield displacement was obtained by balancing the assumed bilinear shape. For the ultimate displacement, the ultimate displacement can be obtained from the point where the maximum base shear capacity usually decreases by 10% or 20%, assuming that it corresponds to the point where the compressive stress in concrete or the fracture or buckling of the transverse reinforcement in any structural element occurs. However, for ultimate displacement in this thesis, the maximum base shear capacity was not reduced, and the ultimate displacement is matched with the maximum base shear capacity. It is recommended to evaluate the results to be obtained in this direction. Because it was preferred to stay on the safe side regarding the semi-rigid or rigidity of the connection.According to the results the effect of ACPH on ductility in frame 1B2S is 47.5% on average and in frame 2B2S it is 57.3% on average. it was concluded that a value between 3.90 and 4.52 should be used for the behavioral coefficient (R) of the structural system for this type of joint. As a result of this analytical study, the use of replaceable joints in precast structures are investigated in different types of frames and comparative data are presented. Based on the data, the use of replaceable joints in precast structures minimized the damage to the structural members after the earthquake. It is shown that it will increase the ductility of the structure and a suggestion is made for the behavior coefficient of the structural system.
Artificial intelligence based and digital twin enabled aeronautical AD-HOC network management

(Graduate School, 2022-12-20) Bilen, Tuğçe ; Canberk, Berk ; 504172508 ; Computer Engineering

The number of passengers using aircraft has been increasing gradually over the following years. With the increase in the number of passengers, significant changes in their needs have been made. In-flight connectivity (IFC) has become a crucial necessity for passengers with the evolving aeronautical technology. The passengers want to connect to the Internet without interruption regardless of their location and time. The aeronautical networks attract the attention of both industry and academia due to these reasons. Currently, satellite connectivity and air-to-ground (A2G) networks dominate existing IFC solutions. However, the high installation/equipment cost and latency of the satellites reduce their efficiency. Also, the terrestrial deployment of A2G stations reduces the coverage area, especially for remote flights over the ocean. One of the novel solutions is the Aeronautical Ad-hoc Networks (AANETs) to satisfy the IFC's huge demand by also solving the defects of satellite and A2G connectivities. The AANETs are based on creating air-to-air (A2A) links between airplanes and transmitting packets over these connections to enable IFC. The AANETs dramatically increase the Internet access rates of airplanes by widening the coverage area thanks to these established A2A links. However, the mobility and atmospheric effects on AANETs increase the A2A link breakages by leading to frequent aircraft replacement and reducing link quality. Accordingly, the mobility and atmospheric effects create the specific characteristics for AANETs. More specifically, the ultra-dynamic link characteristics of high-density airplanes create an unstructured and unstable topology in three-dimensional space for AANETs. To handle these specific characteristics, we first form a more stable, organized, and structured AANET topology. Then, we should continuously enable the sustainability and mapping of this created AANET topology by considering broken A2A links. Finally, we can route the packets over this formed, sustained, and mapped AANET topology. However, the above-explained AANET-specific characteristics restrict the applicability of conventional topology and routing management algorithms to AANET by increasing its complexity. More clearly, the AANET specific characteristics make its management challenging by reducing the packet delivery success of AANET with higher transfer delay. At that point, artificial intelligence (AI)-based solutions have been adapted to AANET to cope with the high management complexity by providing intelligent frameworks and architectures. Although AI-based management approaches are widely used in terrestrial networks, there is a lack of a comprehensive study that supports AI-based solutions for AANETs. Here, the AI-based AANET can take topology formation, sustainability, and routing management decisions in an automated fashion by considering its specific characteristics thanks to learning operations. Therefore, AI-based methodologies have an essential role in handling the management complexity of this hard-to-follow AANET environment as they support intelligent management architectures by also overcoming the drawbacks of conventional methodologies. On the other hand, these methodologies can increase the computational complexity of AANETs. At that point, we propose the utilization of the Digital Twin (DT) technology to handle computational complexity issues of AI-based methodologies. Based on these, in this thesis, we aim to propose an AI-based and DT-enabled management for AANETs. This system mainly consists of four main models as AANET Topology Formation Management, AANET Topology Sustainability Management, AANET Topology Mapping Management, and AANET Routing Management. Here, our first aim is to form a stable, organized, and structured AANET topology. Then, we will enable the sustainability of this formed topology. We also continuously map the formed and sustained AANET topology to airplanes. Finally, the packets of airplanes are routed on this formed, sustained, and mapped AANET topology. We will create these four models with different AI-based methodologies and combine all of them under the DT technology in the final step. In the Topology Formation Management, we will propose a three-phased topology formation model for AANETs based on unsupervised learning. The main reason for proposing an unsupervised learning-based algorithm is that we have independently located airplanes with unstructured characteristics in AANETs before forming the topology. They could be considered as the unlabeled training data for unsupervised learning. This management model utilizes the spatio-temporal locations of aircraft to create a more stable, organized, and structured AANET topology in the form of clusters. More clearly, the first phase corresponds to the aircraft clustering formation, and here, we aim to increase the AANET stability by creating spatially correlated clusters. The second phase consists of the A2A link determination for reducing the packet transfer delay. Finally, the cluster head selection increases the packet delivery ratio in AANET. In the Topology Sustainability Management, we will propose a learning vector quantization (LVQ) based topology sustainability model for AANETs based on supervised learning. The main reason for proposing a supervised learning-based algorithm is that we already have an AANET topology before the A2A link breakage, and we can use it in supervised learning for training. Accordingly, we can consider the clusters in AANET topology as a pattern; then, we can find the best matching cluster of an aircraft observing A2A link breakages through pattern classification instead of creating topology continuously. This management model works in three phases: winning cluster selection, intra-cluster link determination, and attribute update to increase the packet delivery ratio with reduced end-to-end latency. In the Topology Mapping Management, we will propose a gated recurrent unit (GRU) based topology mapping model for AANETs. In topology formation, we create AANET topology in the form of clusters by collecting airplanes having similar features under the same set. In topology sustainability, we sustain the formed clustered-AANET topology with supervised learning. However, these formed and sustained AANET topologies must be continuously mapped to the clustered airplanes to notify them about the current situation. This procedure could be considered a part of sustainability management. Here, we continuously notify the airplanes with GRU at each timestamp about topological changes. This management model works in two main parts ad forget and update gates. In Routing Management, we propose a q-learning (QLR) based routing management model for AANETs. For this aim, we map the AANET environment to reinforcement learning. Here, the QLR-based management model aims to let the airplanes find their routing path through exploration and exploitation. Accordingly, the routing algorithm can adapt to the dynamic conditions of AANETs. In this management model, we adapt the Bellman Equation to the AANET environment by proposing different methodologies for its related QLR components. Accordingly, this model mainly consists of two main parts current state & maximum state-action determination and dynamic reward determination. Therefore, we execute the topology formation, sustainability, and routing management modules through unsupervised, supervised, and reinforcement learning-based algorithms. Additionally, we take advantage of neural networks in topology mapping management. After managing the topology and routing of AANETs with AI-based models, in the DT-enabled AANET management, we will support them with the DT technology. The DT can virtually replicate the physical AANET components through closed-loop feedback in real-time to solve the computational challenges of AI-based methodologies. Therefore, we will introduce the utilization of DT technology for the AANET orchestration and propose a DT-enabled AANET (DT-AANET) management model. This model consists of the Physical AANET Twin and Controller, including the Digital AANET Twin with Operational Module. Here, the Digital AANET Twin virtually represents the physical environment. Also, the operational module executes the implemented AI-based models. Therefore, in this thesis, we aim to propose an AI-based and DT-enabled management for AANETs. In this management system, we will first aim to propose AI-based methodologies for AANET topology formation, topology sustainability, topology mapping, and routing issues. Then, we will support these AI-based methodologies with DT technology. This proposed complete management model increased the packet delivery success of AANETs with reduced end-to-end latency.
Ayakları farklı yerel zemin sınıflarında bulunan köprülerin sismik analizi

(Lisansüstü Eğitim Enstitüsü, 2024-06-27) Öztürk, Mustafa Enes ; Fahjan, Yasin ; 501221022 ; Yapı Mühendisliği

Köprüler tarihin uzun dönemleri boyunca kullanılmış olan ve genellikle nehir, vadi veya diğer engelleri geçmek için kullanılan yapılardır. Köprüler uzun açıklıkları birbirlerine bağladığından ve ulaşımı kolaylaştırdıklarından uzun yıllar maruz kaldıkları dış etkenlere karşı dayanmaları amaçlanır. Deprem dayanımları bakımından incelendiğinde köprü analiz yöntemleri , binalar için kullanılan yöntemlerle her zaman aynı değildir. Binaların deprem analizleri incelenirken kullanılan Türkiye Bina Deprem Yönetmeliği (TBDY) ile köprülerin deprem analizlerinin incelenmesinde kullanılan Türkiye Köprü Deprem Yönetmeliği (TKDY) arasında farklılıklar bu konuda beklenebilir. Köprüler binaların aksine, yatay açıklıklıkları oldukça büyük değerlere ulaşabilen ve analizlerinin buna göre yapılması gereken yapılardır. Bu hususta köprülerde görülebilen olası bir durum, yapı boyunca zemin koşullarının değişebileceğidir. Düşey doğrultuda büyük yükseklik değerlerine sahip olan binalarda bu durum genellikle görülmezken, köprülerde farklı analiz methodlarını gerektirebilir. Yerel zemin koşulunun değişmesine bağlı olarak köprü ayaklarında oluşan deprem ivmelerinin farklı büyüklüklere sahip olmasına değişken zemin etkisi (DZE) adı verilir. Bu durum AASHTO LRFD kaynağında Spatial Variation due to Local Soil Condition olarak geçmektedir. Tez kapsamında bu etkinin olması durumunda köprülerde ekstra hangi etkilerin oldğuna, geliştirilen analiz yöntemlerine ve analizler sonucu elde edilen bulgulara yer verilmiştir. Tez kapsamında deprem dalgalarının rastgele üst üste binmesiyle oluşan uyumsuzluk etkisi ile deprem dalgalarının faz farkından dolayı farklı anlarda köprü ayaklarına ulaşmasıyla oluşan dalga geçiş etkisi incelenmemiştir. TKDY kapsamında da ayrıca bu etkilerin incelenmesi zorunlu tutulmamıştır. Birinci bölümde köprülerin tanımından ve kullanım amaçlarından kısaca bahsedilmiştir. Ayrıca farklı yönetmeliklerdeki tanımından da bahsedilmiştir. Türkiye'de köprülerin sismik analizlerinin hangi yönetmelikler aracılığıyla yapıldığı ve TKDY'nin ne zaman uygulanmaya başlandığından bahsedilmiştir. TKDY'nin göreceli olarak yeni bir yönetmelik olması ve bu yönetmelikle ilgili literatürde yeterli çalışma olmamasından kaynaklı zorluklardan bahsedilmiştir. Bu sorunlardan biri olan DZE'ye değinilmiştir. DZE'nin hangi durumlarda ortaya çıktığına, hangi durumlarda göz önünde bulundurulacağına ve TKDY kapsamında nasıl ele alındığına değinilmiştir.
Biconservative and biharmonic surfaces in Euclid and Minkowski spaces

(Graduate School, 2024-07-02) Yürük, Hazal ; Turgay, Nurettin Cenk ; Şen Yeğin, Rüya ; 509211217 ; Mathematics Engineering

In 1964, Sampson and Eells formulated the concept of biharmonic maps as an extension of harmonic maps while investigating the energy functional $E$ between Riemannian manifolds, a subject of both geometric and physical significance. Subsequently, numerous mathematicians have shown interest in the study of biharmonic mappings.\\ By the definition, the bienergy functional between semi-Riemannian manifolds $(M^m,g)$ and $(N^n,\tilde{g})$ is defined by $$E_2(\varphi)=\frac {1}{2} \int_M \|\tau(\varphi)\|^2 v_g$$ for a smooth map $\varphi:M \to N$, where $\tau(\varphi)$ represents the tension field of $\varphi$. $\varphi:M\to N$ is said to be biconservative if it is a critical point of $E_2$. This condition is equivalent to satisfying the Euler-Lagrange equation associated with the bienergy functional $$\tau_2(\varphi)=0,$$ where $\tau_2$ is the bitension field defined by $$\tau_2(\varphi):=\Delta\tau(\varphi)-\mathrm{tr\,} \tilde{R}(d\varphi,\tau(\varphi))d\varphi.$$\\ In the 1980s, B. Y. Chen conducted research on biharmonic submanifolds within Euclidean spaces as a component of B. Y. Chen's initiative to comprehend submanifolds of finite type in semi-Euclidean spaces. B. Y. Chen proposed an other characterization of biharmonic submanifolds in these spaces. Let $x:M\to \mathbb E^n_r$ be an isometric immersion. By examining normal and tangential parts of $\tau_2(x)$, the following results can be obtained.\\ Let $x: M^m \rightarrow \mathbb E^n_r$ be an isometric immersion of an $n$-dimensional semi-Riemannian submanifold $M^m$ into the semi-Euclidean space $\mathbb E^n_r$. If $x$ satisfies the fourth-order semi-linear PDE system given by the equations $$\Delta^\perp H+\mathrm{trace}h(A_H(\cdot),\cdot)=0$$ and $$m\mathrm{grad} \Vert H \Vert^2 +4\mathrm{trace} A_{\nabla^\perp_\cdot H}(\cdot)=0,$$ then $M^m$ is biharmonic.\\ On the other hand, if a mapping $\varphi: M \to N$ satisfies the weaker condition $$\langle \tau_2(\varphi), d\varphi \rangle = 0,$$ then it is said to be biconservative. Mainly, if $x: M \to N$ is an isometric immersion, then the previous equation is equivalent to $$\tau_2(x)^\top = 0,$$ where $\tau_2(x)^\top$ represents the tangential part of $\tau_2(x)$. In this case, $M$ is said to be a biconservative submanifold of $N$.\\ In this thesis, we mainly focus on biharmonic and biconservative surfaces in four dimensional Euclidean and Minkowski spaces. The first section provides a concise overview of the historical background and underlying principles concerning biharmonic and biconservative submanifolds, as well as an overview of the research conducted far in this field. In the second section, we give some basic notations and basic facts about submanifolds of semi- Euclidean spaces, the definition of biconservative submanifolds and we introduce the rotational surfaces. In the third section, we give biconservative PNMCV surfaces in $\mathbb E^4$. We obtain local parameterizations of these surfaces and demonstrate that they are not biharmonic. In the fourth section, we give biconservative rotational surfaces in $\mathbb E_1^4$. We study with three different class of rotational surfaces and obtain the condition for each of them to be biconservative. In the concluding section, the derived conclusions are presented, along with recommendations regarding possible future researches.
Biharmonic and biconservative submanifolds of lorentizan space forms

(Graduate School, 2022-12-16) Kayhan, Aykut ; Turgay, Nurettin Cenk ; 509172205 ; Mathematical Engineering

In 1964, Eells and Sampson gave the definition of biharmonic maps as a generalization of harmonic maps during they were studying on the energy functional E between Riemannian manifolds which has geometrical and physical interest. Later, many geometers interested in biharmonic maps. By the definition, a biharmonic map φ : M → N between two Semi-Riemannian manifolds is a critical point of the bienergy functional E2(φ) = 1 2 Z M ∥τ(φ)∥ 2 vg, where τ(φ) = trace∇dφ is the tension field of φ that vanishes for harmonic maps. If φ is a biharmonic isometric immersion into N then M is said to be biharmonic submanifold of N. In the middle of 1980's, Chen studied biharmonic submanifolds in Euclidean spaces as a part of his program of understanding finite type submanifolds in Euclidean spaces. He gave an alternative definition of biharmonic submanifolds in Euclidean spaces. That definition is also same for pseudo-Euclidean spaces: If the position vector field x : M → E n satisfies ∆ 2 x = 0 then M is called biharmonic submanifold, where ∆ denote the Laplacian of M. By the well known Laplace-Beltrami identity this equation is equivalent to ∆H = 0, where H is the mean curvature vector of M. In the mean time, independently, Jiang showed that a smooth map φ is biharmonic if and only if its bitension field τ2(φ) (which corresponds the Euler-Lagrange equation of bienergy functional) vanishes identically, i.e., τ2(φ) = 0. Jiang also showed that τ2(φ) = 0 if and only if ∆H = 0 for an isometric immersion φ : M → E n . As a result, definitions given by Chen and Jiang coincide for the class of Euclidean and pseudo-Euclidean submanifolds. Biconservative submanifolds arose from the theory of biharmonic submanifolds. Stress-energy tensor for the energy function described by Hilbert was expanded for the bienergy function as follows S2(X,Y) = 1 2 ∥τ(φ)∥ 2 ⟨X,Y⟩+⟨dφ,∇τ(φ)⟩⟨X,Y⟩ −⟨dφ(X),∇Y τ(φ)⟩ − ⟨dφ(Y),∇Xτ(φ)⟩ xxi satisfying divS2 = −⟨τ2(φ),dφ⟩ . In general, a submanifold is called biconservative if divS2 = 0. It means (τ2(φ))T = 0. Indeed, this is equivalent to (∆H) T = 0 when the ambient space is pseudo-Euclidean. Because, for the isometric immersion into E n 1 , τ(φ) = −mH and τ2(φ) = m∆H. In this thesis we study on the biconservative submanifolds and biconservative hypersurfaces of the Lorentzian space forms and we also obtained some results related biharmonic ones. This work consists of seven sections and these sections were planned as follows: In the first section, we give a brief history and philosophy of biharmonic and biconservative submanifolds and studies has been done so far. In the second section, we give some basic notions of the submanifold theory on Lorentzian inner product space and biharmonic submanifolds. In the third section, biconservative surfaces with constant mean curvature (CMC) in Minkowski 4-space E 4 1 is studied. Firstly, we determine the canonical forms of the shape operator and then we give some examples of such submanifolds in E 4 1 . Later, we classify biconservative CMC submanifolds in E 4 1 . Then, we generalize all results to the CMC surfaces of S 4 1 and H4 1 . In the fourth section, we examine the biconservative hypersurfaces in Minkowski 4-space E 4 1 . In particular, we study hypersurfaces with non-diagonalizable shape operator A satisfying A(∇H) = − nH 2 ∇H, where n and H are the dimension and the mean curvature of the hypersurface, respectively. We determine the canonical forms of the shape operator, the mean curvature, sectional curvature and Levi-Civita connection of this hypersurface. Afterwards we give the necessary and sufficient condition for this hypersurface to be biconservative. Later we classify the biconservative hypersurface in E 4 1 and show the uniquniess of them. In fifth section, we examine the biconservative hypersurfaces with certain shape operator in Minkowski 5 space E 5 1 . We give some non-existence theorems. In the sixth section, we examine the biconservative submanifolds with mean curvature whose gradient is light-like in E n 1 . We give some non-existence results. In the last section, the obtained conclusions are shared and recommendations are made about the future of the problems.
Bir Osmanlı entelektüeli Hamid Vehbi ve Medrese-i Fünûn Dergisi

(Lisansüstü Eğitim Enstitüsü, 2023-07-13) Çırpan, Mustafa ; Zorlu, Tuncay ; 422191059 ; Bilim ve Teknoloji Tarihi

Osmanlının art arda yaşadığı askeri yenilgiler, askeri olduğu kadar bilim ve teknoloji konusunda da Osmanlının Avrupalı çağdaşlarının katettiği ilerlemelerin çok gerisinde kaldığını ispat etmiştir. Aradaki farkı gören ve kabul eden Osmanlılar başta askeri alanda olmak üzere bilimsel ve teknik reformlara imza atmış, bu reformlar 19. yüzyıla gelindiğinde i vme ve süreklilik kazanmıştır. Osmanlının bilimsel gelişmelere adapte olması kapsamlı ve çok yönlü bir süreç olup bu süreçte başta eğitim olmak üzere çeşitli modern kurumlar ortaya çıkmıştır. Bu dönemde kurulan modern okullar, diğer kurumlar ve yayınlar d evletin bu yüzyılda geçirdiği değişim ve dönüşümün en belirgin örneklerini oluşturmaktadır. . Osmanlı'da bilimsel gelişmeler neticesinde ortaya çıkan bu modern eğitim kurumlarını bu kurumların müfredatlarına kaynak ihtiyacı, encümenler, bilimsel cemiyetler; bu cemiyetlerin yayın organlarını ise bilimsel dergilerin ortaya çıkışı ve yaygınlaşması tak ip etmiştir . 19. yüzyılda çıkarılan bilim dergilerinden biri olan Hamid Vehbi'nin Medresei Fünûn adlı dergisi, Osmanlı dünyasında yayınlanmış diğer bilim dergilerinde olduğu gibi yalnız döneminin bilimsel gelişmeleri ve yayınları değil dönemin üzerinde görece az durul muş birtakım koşullarını yansıtması açısından da tarih çalışmaları içerisinde oldukça kıymetli bir yere sahiptir. Bunlar aynı zamanda; dönemin, özellikle de 19. yüzyılın ikinci yarısının oluşturduğu Osmanlı entelektüelliği ve Osmanlı bilim ve düşünce tarihinin daha iyi anlaşılması açısından büyük önem arz etmektedir. Bu çalışma, Medrese i Fünûn dergisi ve Hamid Vehbi üzerine yoğunlaşarak literatürdeki bu boşluğu doldurmak ve Osmanlı tarihinin diğer dallarına nazaran geri planda kalmış olan Osmanlı bilim ve düşünce tarihi alanındaki literatüre daha fazla çalışma kazandırılması için bir adım atmayı amaçlamaktadır. 19. yüzyılın ikinci yarısında çıkarılmış olan Medresei Fünûn dergis7i ve dergiyi çıkaran İstanbullu Hamid Vehbi'nin bir Osmanlı entelektüeli olarak incelemesini yaparak kısa yayın hayatıyla görece arka planda kalmış olan Medrese kazandırılmasını amaçlanmaktadır.
Bulanık doğrusal programlama ile feldspat karışım optimizasyonu

(Lisansüstü Eğitim Enstitüsü, 2024-07-02) Çelebi, İrem ; Kabak, Özgür ; 507211215 ; Mühendislik Yönetimi

Madencilik, insanlık tarihinin en eski ve en temel endüstrilerinden biridir. Tarih boyunca medeniyetlerin gelişiminde ve ekonomilerin büyümesinde kritik bir rol oynamıştır. Dünya geliştikçe ve nüfus arttıkça, maden rezervlerinin kullanımı da artmış ve bu durum, maden yataklarının tükenmesi tehlikesini beraberinde getirmiştir. Maden yataklarının azalmasıyla birlikte, daha düşük kaliteli cevherlerden yararlanma zorunluluğu ortaya çıkmıştır. Bu eğilim, zamanla verimliliğin düşmesine ve maden ürünlerinin fiyatlarının yükselmesine sebep olmaktadır. Bu çalışma, dünya çapında yaygın olarak bulunan ve çeşitli endüstrilerde kritik bir hammadde olarak kullanılan feldspat madenine odaklanmaktadır. Feldspat; seramik, cam ve boya endüstrilerinde geniş bir kullanım alanı bulan ve sodyum, potasyum, kalsiyum, lityum, baryum, sezyum gibi elementler ile bu elementlerin izomorfik birleşimlerinden oluşan önemli bir mineral grubudur. Feldspat rezervlerinin kesin miktarını belirlemek mümkün olmamakla birlikte, Türkiye'nin zengin feldspat yataklarına sahip olduğu bilinmektedir; dünya üzerindeki kaliteli feldspat rezervlerinin yaklaşık %14'ü Türkiye'de yer almaktadır. Bu durum, Türkiye'yi feldspat açısından zengin maden rezervlerine sahip ülkeler arasında önemli bir konuma taşımaktadır. Feldspat Türkiye'de en yaygın bulunan mineral gruplarından biri olmasına karşın bulunduğu her kayaçtan ekonomik olarak fayda sağlamak mümkün değildir. Feldspat madenlerinde bulunan demir ve titan gibi kimyasal elementler, mineralin saflığını bozar ve kalitesini düşürür. Bu durum, endüstriyel uygulamalarda renk değişimi, kırılganlık gibi istenmeyen sonuçlara neden olur. İşletmeler, daha saf ve kaliteli feldspat kaynaklarını tercih ederken, safsızlıkların varlığıyla başa çıkma yöntemleri geliştirebilirler. Düşük kalitedeki feldspatlar, bazı zenginleştirme veya saflaştırma yöntemlerine tabi tutularak ticari açıdan faydalı hale getirilebilir. Bu süreçlerden biri olan flotasyon, feldspatın saflaştırılması için sıkça kullanılan bir yöntemdir. Ancak, flotasyon gibi zenginleştirme işlemlerinin maliyeti yüksek olabilir ve bu da ticari karlılığı etkileyebilir. Feldspat madeninde istenilen kalite standartlarının sağlanması ve safsızlık etkilerinin dengelemesi amacıyla başvurulan bir yöntem de harmanlama işlemidir. Safsızlık yaratan minerallerin tamamen ortadan kaldırılması pratikte mümkün olmayabilir, bu nedenle bunların belirli kabul edilebilir sınırlar içinde tutulması tercih edilir. Bu bağlamda, çeşitli bölgelerden farklı değerlere sahip hammaddelerin karıştırılması hedeflenen kalite seviyelerine ulaşmak için stratejik bir yaklaşım olarak kabul edilir. Harmanlama süreci, endüstriyel gereksinimlerin ve kalite standartlarının karşılanmasında önemli bir rol oynar, aynı zamanda feldspatın ticari ve endüstriyel kullanımının sürdürülebilirliğini destekler. Bu noktada, harmanlama sürecinin dikkatle yönetilmesi ve hammaddelerin uygun kombinasyonlarının seçilmesi hayati önem taşır. Türkiye'de feldspat üretimi yoğun olarak Aydın, Muğla ve Bilecik bölgelerinde gerçekleşmektedir. Bu çalışma, Muğla'da faaliyet gösteren bir maden şirketinde ele alınan bir harmanlama problemine odaklanmaktadır. Harmanlama problemi, çeşitli hammadde veya bileşenlerin belirli oranlarda karıştırılmasıyla nihai ürünün elde edilmesini hedefler. Basılı olarak karşımıza çıkan ilk Doğrusal Programlama (DP) problemi olan diyet probleminin genelleştirilmiş bir versiyonudur. Bu tür problemler, optimal kaynak kullanımını sağlamak ve maliyetleri minimize etmek amacıyla endüstriyel süreçlerde yaygın olarak kullanılmaktadır. Bu çalışma, feldspat madeninin harmanlanması sürecinde kullanılacak reçetelerin belirlenmesine yönelik olarak geliştirilen matematiksel modelleri içermektedir. Araştırma kapsamında, farklı kimyasal bileşen kısıtlamalarına sahip ve farklı amaç fonksiyonlarını içeren, modeldeki belirsizlikleri farklı yaklaşımlarla ele alan, birden fazla ürünün dahil edildiği bir çoklu harmanlama problemi detaylı bir şekilde incelenmiştir. Çalışma ile çeşitli ürünler için optimal harmanlama stratejilerinin geliştirilmesini destekleyerek, daha verimli ve etkili üretim süreçlerinin tasarlanmasına katkı sağlanması amaçlanmıştır. Feldspat madeni hakkındaki araştırmalar, madendeki kimyasal bileşiklere ait değerlerin belirsizlik taşıdığını ortaya koymaktadır. Bu belirsizlikler, maden yataklarındaki doğal varyasyonlardan kaynaklanmakta olup, aynı ocaktan çıkarılan madenler arasında bile damarlar arasında nitelik farklılıkları gözlemlenebilmektedir. Bu tür değişkenlikler, son ürün kalitesini doğrudan etkilediğinden, harmanlama süreçlerinde dikkate alınması zorunludur. Araştırma kapsamında belirlenen belirsizlikler, farklı yaklaşımlar kullanılarak ele alınmıştır. İlk olarak, sistemdeki belirsizlikleri doğrudan modele entegre etmek yerine, bu belirsizliklerden kaynaklanabilecek potansiyel olumsuz etkilerden korunma amacıyla daha güvenilir çözüm uzayları tanımlanmıştır. Bu yaklaşımda, klasik DP tekniklerinden yararlanılmıştır. Ancak bu modeller belirsizlikleri tam anlamıyla modele dahil etmemektedir. Modellerde kısıtlara belirli güvenlik oranları ekleyerek potansiyel riskler sınırlanmaktır. Optimizasyon çalışmalarında, belirsizlik faktörlerinin etkin bir şekilde yönetilmesini gerekir. Bu kapsamda, çeşitli metodolojiler ve teknikler geliştirilmiştir. 1965 yılında Lotfi A. Zadeh tarafından tanımlanan bulanık mantık, belirsizlikleri modellemekte kullanılan öncü tekniklerden biri olarak kabul edilir. Bulanık mantık, belirsizlikleri belirli bir belirsizlik derecesi ile ifade eder ve geleneksel ikili mantık sistemlerinin sınırlarını aşarak daha esnek çözüm yolları sunar. Bu yaklaşım, belirsiz koşullar altında bile optimal kararların alınabilmesi için matematiksel bir temel sağlar ve özellikle karmaşık sistemlerde karar verme süreçlerini iyileştirmek için kullanılmaktadır. Çalışmada bulanık mantık yaklaşımına dayanan bir Bulanık Doğrusal Programlama (BDP) modeli geliştirilmiş ve belirsizlik unsurlarını matematiksel olarak modele entegre edilerek, gerçek dünya koşulları daha doğru bir şekilde yansıtılmıştır. Çalışmada bulanık olarak tanımlanan teknoloji ve kaynak katsayıları sırasıyla Üçgen Bulanık Sayı (ÜBS) ve Yamuk Bulanık Sayı (YBS) olarak temsil edilmiş ve BDP modeli parametrik DP modeline dönüştürülerek çözülmüştür. Çalışma sonucunda klasik DP ve BDP metodolojileriyle geliştirilen modellerin sonuçları karşılaştırılmış ve bu karşılaştırma, bulanık mantık kullanılarak gerçekleştirilen modelleme sürecinin, karışım problemlerindeki belirsizlik faktörlerini etkin bir şekilde yönetebildiğini göstermiştir. Klasik DP modeli ile elde edilen sonuçların, BDP modelinde hangi üyelik derecesine eşdeğer olduğu üründen ürüne farklılık göstermiştir. Bu durum, klasik DP modelinde kısıtlara sabit bir güvenlik oranı ekleyerek sonuçlar üretilmiş olsa da sonuçların güvenilirliğinin ürüne göre değişebildiğini göstermektedir. BDP modeli, üyelik derecelerindeki değişimlere paralel olarak sonuçların nasıl değiştiğini kullanıcılara açıkça göstermiştir. Bu, kullanıcıların elde edilen bilgilere dayanarak ne kadar güvenli bir alanda kalacaklarını değerlendirebilmeleri için önemli bir imkândır. Ayrıca, BDP modeli sayesinde üyelik derecesinin yükselmesiyle birlikte ürünü oluşturan hammaddelerin toplam maliyetindeki artış gözlemlenebilir olmuştur. Üyelik derecelerine göre değişen çözümlerin maliyetleri arasındaki farklar nispeten düşük olduğunda daha yüksek üyelik derecelerine ait çözümler tercih edilerek risk almamak mantıklı olabilirken, daha yüksek maliyet farkları söz konusu olduğunda firma, bu ek maliyeti üstlenerek daha yüksek bir riski göze almayı tercih edebilir. Model, kullanıcıların belirsizliklerle dolu ortamlarda daha bilinçli kararlar almalarına olanak tanıyarak, sonuçların olası etkilerini öngörebilmeleri için bir temel sağlamıştır. Sonuç olarak bulanık mantık temelli oluşturulmuş BDP modeli ile karışım problemindeki belirsizlikler etkin bir şekilde yönetilmiş ve kullanıcıların kararlarının sonuçlarını daha iyi anlamalarını ve bu doğrultuda stratejik planlamalar yapabilmelerini desteklemiştir.

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