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In this paper, we explore the development of an explainability system for air combat agents trained with reinforcement learning, thus addressing a crucial need in the dynamic and complex realm of air combat. The safety-critical nature of air combat demands not only improved performance but also a deep understanding of artificial intelligence (AI) decision-making processes. Although AI has been applied significantly to air combat, a gap remains in comprehensively explaining an AI agent’s decisions, which is essential for their effective integration and for fostering trust in their actions. Our research involves the creation of an explainability system tailored for agents trained in an air combat environment. Using reinforcement learning, combined with a reward decomposition approach, the system clarifies the agent’s decision making in various tactical situations. This transparency allows for a nuanced understanding of the agent’s behavior, thereby uncovering their strategic preferences and operational patterns. The findings reveal that our system effectively identifies the strengths and weaknesses of an agent’s tactics in different air combat scenarios. This knowledge is essential for debugging and refining the agent’s performance and to ensure that AI agents operate optimally within their intended contexts. The insights gained from our study highlight the crucial role of explainability in improving the integration of AI technologies within air combat systems, thus facilitating more informed tactical decisions and potential advancements in air combat strategies.

In this study, the effects of cracks in the columns of a single degree of freedom (SDOF) steel structure model on the system responses due to the decrease in the equivalent spring coefficient were investigated. The crack in the columns was modeled as an edge crack, and the crack was thought to behave like a spring. The crack is considered as the mode I crack type (opening mode) specified in linear fracture mechanics. In order to examine the responses of the system under the influence of different excitations, the changes in displacement, acceleration, and power spectral density responses under the influence of harmonic excitation at a frequency equal to the fundamental frequency of the SDOF model and six different earthquake excitations were examined.

The aim of this study was to determine the views of secondary and high school students regarding the distance education activities carried out during the coronavirus disease 2019 (COVID-19) pandemic, the blended learning activities conducted afterwards, and the post-pandemic back-to-school process. The study consisted of 982 students and was conducted utilizing the descriptive survey method, one of the quantitative research methods. Data were collected using the “Scale of Evaluating Instruction in Pandemic Process”. The findings indicated that most of the students used smartphones alone for distance education during the pandemic process and most of them participated in distance education only via live lessons. In addition, no significant difference was found between genders with regard to students’ satisfaction with the distance education process and their expectations. On the other hand, most of the students did not receive sufficient psychological and academic support during this process. It was also noted that the students with internet access were more satisfied with the instruction activities in this process and that their access to the internet and technologies were higher than the students without internet access. Based on our findings, we recommend that students should be provided with academic and psychological support, security precautions should be tightened in schools to minimize the effects of the pandemic, and equal opportunities should be provided to students regarding hardware and internet support.

Advanced Air Mobility (AAM) is a concept that is expected to transform the current air transportation system and provide more flexibility, agility, and accessibility by extending the operations to urban environments. This study focuses on flight test, integration, and analysis considerations for the feasibility of the future AAM concept and showcases the outputs of the Air Mobility Urban-Large Experimental Demonstration (AMU-LED) project demonstrations at Cranfield University. The purpose of the Cranfield demonstrations is to explore the integrated decentralized architecture of the AAM concept with layered airspace structure through various use cases within a co-simulation environment consisting of real and simulated standard-performing vehicle (SPV) and high-performing vehicle (HPV) flights, manned, and general aviation flights. Throughout the real and simulated flights, advanced U-space services are demonstrated and contingency management activities, including emergency operations and landing, are tested within the developed co-simulation environment. Moreover, flight tests are verified and validated through key performance indicator analysis, along with a social acceptance study. Future recommendations on relevant industrial and regulative activities are provided.

The emerging field of Advanced Air Mobility (AAM) holds great promise for revolutionizing transportation by enabling the efficient, safe, and sustainable movement of people and goods in urban and regional environments. AAM encompasses a wide range of electric vertical take-off and landing (eVTOL) aircraft and infrastructure that support their operations. In this work, we first present a new airspace structure by considering different layers for standard-performing vehicles (SPVs) and high-performing vehicles (HPVs), new AAM services for accommodating such a structure, and a holistic contingency management concept for a safe and efficient traffic environment. We then identify the requirements and development process of a testing and simulation infrastructure for AAM demonstrations, which specifically aim to explore the decentralized architecture of the proposed concept and its use cases. To demonstrate the full capability of AAM, we develop an infrastructure that includes advanced U-space services, real and simulated platforms that are suitable for future AAM use cases such as air cargo delivery and air taxi operations, and a co-simulation environment that allows all of the AAM elements to interact with each other in harmony. The considered infrastructure is envisioned to be used in AAM integration-related efforts, especially those focusing on U-space service deployment over a complex traffic environment and those analyzing the interaction between the operator, the U-space service provider (USSP), and the air traffic controller (ATC).

Bu çalışmada fonksiyonel derecelendirilmiş malzemeden yapılmış silindirik olarak eğri eksenli kirişin elastik davranışı analitik olarak incelenmiştir. Çalışmada elastisite modülü üstel kuvvete bağlı olarak kirişin kalınlığı boyunca değiştiği varsayılmaktadır. Aynı zamanda genel lineer karışım kanunu uygulanarak, diğer özellikleri de (ısıl genleşme katsayısı, ısı iletim katsayısı, akma dayanımı) üstel kuvvete göre değişmektedir. Poisson oranı ise sabit kalmakta değişmemektedir. Kirişe uygulanan sıcaklık dağılımı kirişin kalınlığı doğrultusunda ve radyal koordinatın bir fonksiyonu olarak değişmektedir. Kiriş düzlem gerilme durumunda olduğu varsayılmaktadır. Elastik davranışı belirlemek için von Mises akma kriteri kullanılmıştır. Kirişe pozitif, negatif ve homojen sıcaklıklar uygulanmış ve akmanın iç yüzeyde, dış yüzeyde ve aynı anda her iki yüzeyde başladığı görülmüştür.

Metanollü yakıt hücreleri için yüksek sıralı ve kaliteli TiO2 nano-tüpler (TiO2-NTs) katalizör desteği olarak hazırlanmıştır. Sıralı TiO2-NTs hazırlandıktan sonra yüzeyine küçük miktarlarda nikel (Ni) nanotanecikleri (TiO2-NTs-Ni) elektrokimyasal olarak çöktürülmüştür. Bu şekilde hazırlanan anot katalizörlerinin yüzey ve kristal yapısı sırasıyla taramalı elektron mikroskobu (SEM), dönüşümlü voltametri (CV) ve X-ışını kırınımı (XRD) ile karakterize edilmiştir. Hazırlanan TiO2-NTs-Ni anot katalizörlerinin metanol oksidasyonu için katalitik aktiviteleri 1 M KOH içeren 1 M Metanol çözeltisinde CV ve zamanla kararlılıkları ve dayanıklıkları kronoamperometri (CA) tekniği ile araştırılmıştır. Elde edilen sonuçlara göre TiO2-NTs metanollü ortamda aktivite göstermemiş bununla beraber yüzeyi az miktarda Ni ile kaplanması metanol oksidasyonunu arttırmıştır. Katalizör yüzeyindeki Ni miktarı arttıkça oksidasyon hızı artmaktadır. CV tarama hızı arttıkça oksidasyon pik akımlarında artış gözlemlenmiştir. CA sonuçlarına göre hazırlanan katalizörler bir saat boyunca çalışılan ortamda kararlı ve dayanıklı yapı sergilemiştir. Hazırlanan TiO2-NTs-Ni metanollü yakıt hücreleri için etkin bir anot katalizörü olarak kullanılabilir.