Manisa Celal Bayar University

Multiple-Input Multiple-Output (MIMO) technologies utilize multiple antennas at the transceivers and enable enhanced diversity or multiplexing gain. The first implementations of MIMO technology appeared in cellular communication and Wi-Fi systems. One of the main problems with early MIMO systems is their limited performance in meeting the requirements of next generation communication systems. Specifically, the parameters like peak data rates, spectrum efficiency and energy efficiency constraints cannot be met with existing MIMO architectures. Hence, early MIMO techniques evolved to massive MIMO (mMIMO) type of communication as the number of antennas at both transmitters and receivers increased. Included in 5G New Radio standard, mMIMO enabled an increase the spectral efficiency and coverage compared with earlier MIMO techniques. Nowadays, there exists an ever-increasing interest in the application of advanced MIMO technologies in 6G networks. These applications include ultra massive MIMO (mMIMO), holographic MIMO and intelligent reflecting surface (IRS) assisted MIMO. These new advanced MIMO techniques either employ larger number of antennas or extremely large aperture arrays compared with mMIMO and are named as extremely large-scale MIMO. This paper presents a detailed overview of all these techniques. Joint design of wireless communication and radar sensing, named as integrated sensing and communication (ISAC) as well, has shown to improve spectrum efficiency and reduce power consumption. Recent novel research on ISAC exploits the application of MIMO technology specifically in joint communication and radar sensing (JCS) systems. In this aspect, the other objective of this work is to exploit MIMO communication and MIMO radar coexistence. After summarizing the current state of the art on MIMO radar systems, this paper exploits joint application of advanced MIMO communication and radar sensing. Finally, it aims to offer a perspective on future research directions and the potential of overall MIMO systems discussed in the paper.

In historic stone masonry buildings, strong ground motions typically result in out-of-plane failure of the walls before their in-plane strength is reached. This phenomenon is especially pronounced in structures characterized by long unsupported spans perpendicular to their plane, in the absence of a diaphragm effect. In such cases, the strengthening intervention for the historic façade should be selected by considering the principles of conservation. The present study investigates the effectiveness of an innovative reinforcing configuration that builds upon the steel-cord-based techniques available in the literature, using experimental and numerical methods. The applied strengthening consists of no-tensioned steel cords embedded in the bed joints and vertically in both the head joints and the stone bricks of the masonry wall. A large-scale stone masonry wall specimen was designed and constructed to reflect the results of on-site material and dynamic tests performed on a reference historic masonry structure. A series of dynamic and quasi-static cyclic tests was conducted on both the unreinforced and reinforced conditions of the specimen. The proposed method was found to restore the out-of-plane strength without significantly increasing the stiffness of the damaged specimen. Furthermore, it was observed to improve the out-of-plane deformation capacity and overall structural integrity. The finite element models were calibrated based on the test data and exhibited a noteworthy agreement with the experimental results, particularly in terms of load–drift response and damage observations. Some model parameters were also proposed.

Bu çalışma, sosyal medya platformlarının modern hibrit savaş stratejilerindeki kritik rolünü ve dijital diplomasiden siber saldırıya uzanan spektrumdaki işlevlerini analiz etmektedir. Geleneksel güvenlik paradigmalarının dijital çağda yaşadığı dönüşüm, devlet ve devlet dışı aktörlerin sosyal medyayı hem yumuşak güç aracı hem de saldırı vektörü olarak kullanmasını beraberinde getirmiştir. Araştırma, hibrit savaşın teorik çerçevesini sosyal medya dinamikleriyle harmanlayarak güncel vaka analizleri üzerinden konuyu ele almakta, özellikle Rusya ve Çin’in son yıllardaki operasyonlarını incelemektedir. Bulgular, sosyal medya platformlarının algoritmik yapılarının dezenformasyon kampanyalarını hızlandırdığını, mikro-hedefleme teknolojilerinin psikolojik operasyonları daha etkili hale getirdiğini ve koordineli sahte davranışların geleneksel diplomasi kanallarını aştığını göstermektedir. Çalışma, mevcut karşı tedbirlerin yetersizliğini vurgulayarak teknolojik çözümler, hukuki düzenlemeler ve toplumsal direnç geliştirme stratejilerini kapsayan bütüncül bir savunma yaklaşımı önermektedir. Sonuç olarak, sosyal medyanın hibrit savaştaki rolünün sadece bir araç olmaktan çıkarak stratejik bir alan haline geldiği ve gelecekteki güvenlik politikalarının bu gerçekliği dikkate alması gerektiği tespit edilmiştir.

Atasözleri bir milletin düşünce yapısı, yaratıcılığı, kıvrak zekâsı ve kültürel katmanları gibi birçok konuda bilgi içeren halkın ortak ürünü olan kalıplaşmış sözlerdir. Anonim bir özelliğe sahip olan atasözleri, günlük konuşma dilinde ve yazılı eserlerde kullanılması bakımından yaygın bir kullanım alanına sahiptir. Birçok kişi tarafından derlenip kitap olarak yayınlanan atasözlerinin bir bölümü de sözlü kaynaklar yoluyla günümüze kadar aktarılmıştır. Atasözleriyle ilgili yapılan çalışmalar arasında 19. yüzyılın sonlarında kaleme alınan Tekezâde Mehmed Said’in Durûb-ı Emsâl-i Türkiyye yâhûd Atalar Sözü isimli eseri bulunmaktadır. Bu çalışmada önce Tekezâde Mehmed Said’in hayatı ve eserleri hakkında bilgi verdikten sonra Durûb-ı Emsâl-i Türkiyye yâhûd Atalar Sözü isimli eserinin incelemesi yapılmıştır. Eser incelenirken şekil özellikleri başlığında; eserin iç ve dış yapısı, şekil olarak metinlere hangi düzene göre yer verildiği, metinlerin hacim ve nazım birimi gibi özellikleri üzerinde durulmuştur. Yaratım-aktarım özellikleri başlığında; eserin nasıl meydana getirildiği, metinlerin hangi düzene göre sıralandığı, metin içinde kullanılan noktalama işaretleri, anlatım teknikleri, dipnot sisteminin nasıl kullanıldığı, metin içinde gönderme yapılan ifadeler ile bunun hangi şekilde yapıldığı ve atasözlerinin şiirlerde kullanılan örnekleri el alınmıştır. İnceleme içinde verilen metin aktarımında metne bağlı kalınmış, transkripsiyon işaretleri kullanılmayıp sadece uzunluklar belirtilmiştir.

Shear wave velocity (Vs30) is a critical parameter for geophysical investigations, site classifications, and seismic microzonation studies. This study aims to establish empirical relationships between Vs30 obtained from the MASW (Multiple Analysis of Surface Waves) method and Standard Penetration Test blow counts (SPT-N). Correlations were developed separately for sandy, clayey, and all soil types, yielding moderate determination coefficients (R² = 0.596–0.675), indicating the reliability and applicability of the proposed correlations. The relationships between SPT-N and shear wave velocity allow for the reliable estimation of Vs30 in areas where direct measurements cannot be performed. This is particularly beneficial in urbanized regions, as such estimations support engineering and geotechnical applications and contribute to the understanding of soil behavior. The present study demonstrates the practical applicability of empirical correlations between Vs30 and SPT-N for geotechnical and seismic site characterization purposes.

Mosaicplasty is an established cartilage repair technique; however, postoperative rehabilitation remains challenging in athletes requiring high neuromuscular control and functional performance. This case study examined the effects of an integrated robotic and sensor-based rehabilitation program using the Cyberdyne Hybrid Assistive Limb Single Joint and TecnoBody systems in a 33-year-old professional soccer player following medial femoral condyle mosaicplasty. The intervention was applied five days per week for three months. Gait parameters, balance, functional mobility, and lower extremity strength were assessed using validated TecnoBody systems and clinical tests. Post-intervention, static balance improved by 19.82% and 13.95% under eyes-open and eyes-closed conditions, respectively, while 10-meter walk and Timed Up and Go test times decreased by 46.40% and 45.89%. Step length increased bilaterally, accompanied by improvements in joint flexion angles and sit-to-stand performance. These findings support the feasibility and potential clinical value of integrated robotic rehabilitation following mosaicplasty in athletes (NCT06516380).

Abstract The use of electric vehicles is rapidly increasing, but their range remains limited due to battery capacity constraints. This paper presents the thermodynamic analysis results of a novel type ejector-assisted heat pump designed for air-conditioning cycle (AC) for electric vehicles. Ejectors are used in cars to reduce compressor energy consumption in AC systems, which is crucial for improving electric vehicle battery efficiency. A chiller unit and an ejector were added to the heat pump system to increase the system’s efficiency. In the proposed system, environmentally friendly fluids with low global warming potential (R290, R1234yf, R1234ze, R600, R717, R744) were tested as alternatives to the refrigerants that are being phased out due to their negative effects on the environment. After applying the first and second law analyses of thermodynamics to the proposed system, an average coefficient of performance (COP) increase of 32.75% was found. According to the analysis results, among the examined fluids, R290 has the maximum COP value of 2.81. At the specified temperature values, the system using R290 as the refrigerant achieved the highest exergy efficiency, with a value of 0.24.