In this study, a comparative analysis of three different control methods for precise, real-time control of a complex dynamic double-tank liquid level process system was performed. Since the system in question has a time-delayed structure, feedforward proportional integral (FF-PI) control and cascaded nonlinear feedforward proportional integral delayed (CNPIR) controllers were tested on the process system. While the FF-PI controller improved the response time of the system, it showed limitations in handling external disturbances and nonlinearities. On the other hand, the CNPIR controller showed better improvements in control accuracy and lower overshoot compared to the FF-PI controller. Since the process system has a nonlinear model and is affected by external disturbances, these two controllers were inadequate in this study when compared to the fractional order adaptive proportional integral derivative sliding mode controller (FO-APIDSMC). The FO-APIDSMC controller provided fairly good performance in both tracking accuracy and disturbance rejection control for non-chattering, fast finite-time convergence, increased robustness, and uncertain dynamic processes. Experimental results reveal that the FO-APIDSMC controller achieves superior minimized tracking error and outperforms the FF-PI and CNPIR controllers by effectively handling uncertainties and external disturbances.

The systems that use parallel kinematic structures in additive manufacturing technology are particularly notable for their ability to provide exceptional precision and efficiency in the fabrication of intricate geometrically shaped items. This study introduces a novel system paradigm with five degrees of freedom, specifically developed to tackle existing additive manufacturing issues. In the proposed design, by incorporating rotational motions along the x and z axes, contributions were added to the efficiency of typical three-degrees-of-freedom (3-DOF) systems, resulting in a total of five degrees of freedom. In this way, it is aimed at increasing product durability, improving surface integrity, and saving production time. In this study, the conceptual design of the system was defined. Mathematical analyses were then used to determine the kinematic and dynamic models of the system, and a proposed model-based control technique was revealed. To evaluate the axis movement performance of the system, two different control techniques were used, and real-time test studies were conducted. The first control technique was the proportional–integral–derivative (PID) controller, and the second method was the sliding mode control (SMC) method, which was used to increase the performance of the system during trajectory tracking. The experimental results showed that the SMC method provides a reasonably good trajectory tracking response and a steady-state error compared to the classical PID controller.

This study addresses the design of a wide-band microstrip patch antenna for 5G mobile communication systems. To respond to the increasing data rate and wide bandwidth needs in fifth-generation communication systems, it is very important to increase the performance of the antennas used. In this paper, a manufacturable and compact microstrip patch antenna design operating at 28 GHz wave frequency is realized and the simulation results are compared with the measured results. The proposed antenna is designed using a low-cost FR-4 substrate. The primary motivation behind calling the antenna “cost effective” in this study is the choice of the FR-4 substrate, which is significantly more affordable than other high-performance materials commonly used for 5G antennas, such as Rogers RT Duroid. Despite the limitations of FR4 substrate at high frequencies, this study demonstrates that a functional and efficient wide-band antenna can still be achieved through careful design and optimization. The performance of the antenna is evaluated with parameters such as input reflection coefficient (S_11), bandwidth, gain, and radiation efficiency of the antenna. The simulations of the proposed antenna are performed using CST and CEMS programs and the obtained results show that the antenna has a wide bandwidth of 1950 MHz between 26.85 GHz and 28.8 GHz. A parametric study of the antenna is performed to show the effect of substrate thickness and patch size on antenna performance. Numerical and measured results show that the proposed microstrip patch antenna has good performance for 5G communication systems, including wide bandwidth, high gain and low reflection coefficient. The antenna fabricated on the low-cost FR4 substrate can be useful for 5G communication systems with its cost-effectiveness and compact geometric configuration.

Bu çalışmada, özellikle katmanlı üretim sorunlarının üstesinden gelmek için geliştirilmiş, beş serbestlik derecesine sahip yeni bir sistem önerilmiştir. Önerilen sistemde, benzer sistemlerden farklı olarak, X ve Z eksenleri boyunca, sisteme dönme hareketleri dahil edilerek, geleneksel üç serbestlik dereceli yapı, beş serbestlik derecesine çıkarılmıştır. Belirtilen serbestlik derecelerinin sisteme eklenmesiyle, geleneksel sistemlerin aksine, parça yüzey bütünlüğünün iyileştirilmesi, üretim süresinden tasarruf ve üretimde kullanılan destek parça kullanımının azaltılması sağlanacaktır. Çalışmada, öncelikle, sistemin kavramsal tasarımı tanımlanmıştır. Daha sonra sistemin kinematik ve dinamik modellerini belirlemek için matematiksel analizler kullanılmıştır. Sistemin eksen hareket performansını değerlendirmek için oransal-integral-türev (PID) kontrol tekniği kullanılmış ve gerçek zamanlı test çalışmaları yapılmıştır. Bu çalışmanın literatüre temel katkısı, üretim teknolojilerine yeni bir bakış açısı sunmak, sanayideki dönüşümü yönlendirmek, gelecekteki üretim süreçlerini şekillendirmek ve endüstriyel yeniliği tetiklemektir. Önerilen sistem ile geleneksel eklemeli imalat yöntemlerine göre daha esnek, sürdürülebilir, uygun maliyetli, daha hassas ve yüksek iş hızlarına ulaşabilen bir üretim modeli olarak literatüre sunulmaktadır.

This paper presents a compact implantable antenna for reliable biotelemetric communication at 2.45 GHz that maintains stable electromagnetic performance in heterogeneous biological tissues without requiring dielectric encapsulation, active tuning circuits, or impedance matching networks. The proposed design achieves reduced sensitivity to tissue-induced detuning through its geometry and field distribution characteristics, enabling consistent resonance and impedance behavior across variations in tissue composition and implantation depth. A rigorous full-wave analysis is performed using a dispersive finite-difference time-domain (FDTD) formulation incorporating a three-term Debye model, enabling accurate representation of frequency-dependent, lossy biological media in multilayer human tissue environments within a single simulation framework. The antenna performance is evaluated using both homogeneous and multilayer three-dimensional anatomical phantom models representing skin, fat, and muscle tissues, with implantation depths ranging from 5 mm to 30 mm. In addition, a prototype fabricated on a low-cost FR-4 substrate is experimentally validated using minced fat and muscle tissues, showing close agreement with simulation results. The combined numerical and experimental findings demonstrate stable operation around 2.45 GHz with negligible detuning and robust performance across diverse tissue environments, confirming a low-complexity and fabrication-friendly solution for next-generation implantable medical devices requiring reliable in-body wireless communication.