Makale Koleksiyonu | Elektrik-Elektronik Mühendisliği Bölümü / Department of Electrical-Electronics EngineeringElektrik-Elektronik Mühendisliği Bölümüne ait makale koleksiyonunu içerir.https://hdl.handle.net/11729/49012024-03-28T19:48:59Z2024-03-28T19:48:59ZImaging of rough surfaces by RTM methodSefer, AhmetYapar, AliYelkenci, Tanjuhttps://hdl.handle.net/11729/59322024-03-19T14:50:19Z2024-01-01T00:00:00ZImaging of rough surfaces by RTM method
Sefer, Ahmet; Yapar, Ali; Yelkenci, Tanju
An electromagnetic imaging framework is implemented utilizing a single frequency reverse time migration (RTM) technique to accurately reconstruct inaccessible two-dimensional (2D) rough surface profiles from the knowledge of scattered field data. The unknown surface profile, which is expressed as a 1D height function, is either perfectly electric conducting (PEC) or an interface between two penetrable media. For both cases, it is assumed that the surface is illuminated by a number of line sources located in the upper medium. The scattered fields, which should be collected by real measurements in practical applications, are obtained synthetically by solving the associated direct scattering problem through the surface integral equations. RTM is subsequently applied to generate a cross-correlation imaging functional which is evaluated numerically and provides a 2D image of the region of interest. A high correlation is observed by the functional in the regions where the transitions between two media occur. Hence, it results in the acquisition of the unknown surface profile at the sites where the functional attains its highest values. The efficiency of the proposed method is comprehensively tested by numerical examples covering various types of scattering scenarios.
2024-01-01T00:00:00ZEngineering four-qubit fuel states for protecting quantum thermalization machine from decoherenceÖzaydın, FatihSarkar, RamitaBayrakçı, VeyselBayındır, CihanAltıntaş, Azmi AliMüstecaplıoğlu, Özgür E.https://hdl.handle.net/11729/58922024-02-12T06:29:01Z2024-01-10T00:00:00ZEngineering four-qubit fuel states for protecting quantum thermalization machine from decoherence
Özaydın, Fatih; Sarkar, Ramita; Bayrakçı, Veysel; Bayındır, Cihan; Altıntaş, Azmi Ali; Müstecaplıoğlu, Özgür E.
Decoherence is a major issue in quantum information processing, degrading the performance of tasks or even precluding them. Quantum error-correcting codes, creating decoherence-free subspaces, and the quantum Zeno effect are among the major means for protecting quantum systems from decoherence. Increasing the number of qubits of a quantum system to be utilized in a quantum information task as a resource expands the quantum state space. This creates the opportunity to engineer the quantum state of the system in a way that improves the performance of the task and even to protect the system against decoherence. Here, we consider a quantum thermalization machine and four-qubit atomic states as its resource. Taking into account the realistic conditions such as cavity loss and atomic decoherence due to ambient temperature, we design a quantum state for the atomic resource as a classical mixture of Dicke and W states. We show that using the mixture probability as the control parameter, the negative effects of the inevitable decoherence on the machine performance almost vanish. Our work paves the way for optimizing resource systems consisting of a higher number of atoms.
This research was funded by the Personal Research Fund of Tokyo International University, Turkish Academy of Sciences (TÜBA)-Outstanding Young Scientist Award (GEBİP), and the Research Fund of the Istanbul Technical University with project codes: MGA-2022-43528, MDK-2021-42849.
2024-01-10T00:00:00ZA review of recent innovations in remote health monitoringDalloul, Ahmed HanyMiramirkhani, FarshadKouhalvandi, Lidahttps://hdl.handle.net/11729/58662024-01-12T17:39:13Z2023-12-01T00:00:00ZA review of recent innovations in remote health monitoring
Dalloul, Ahmed Hany; Miramirkhani, Farshad; Kouhalvandi, Lida
The development of remote health monitoring systems has focused on enhancing healthcare services’ efficiency and quality, particularly in chronic disease management and elderly care. These systems employ a range of sensors and wearable devices to track patients’ health status and offer real-time feedback to healthcare providers. This facilitates prompt interventions and reduces hospitalization rates. The aim of this study is to explore the latest developments in the realm of remote health monitoring systems. In this paper, we explore a wide range of domains, spanning antenna designs, small implantable antennas, on-body wearable solutions, and adaptable detection and imaging systems. Our research also delves into the methodological approaches used in monitoring systems, including the analysis of channel characteristics, advancements in wireless capsule endoscopy, and insightful investigations into sensing and imaging techniques. These advancements hold the potential to improve the accuracy and efficiency of monitoring, ultimately contributing to enhanced health outcomes for patients.
2023-12-01T00:00:00ZIEEE 802.11BB reference channel models for light communicationsMiramirkhani, FarshadBaykaş, TunçerElamassie, MohammedUysal, Murathttps://hdl.handle.net/11729/58422024-01-03T14:38:11Z2023-12-01T00:00:00ZIEEE 802.11BB reference channel models for light communications
Miramirkhani, Farshad; Baykaş, Tunçer; Elamassie, Mohammed; Uysal, Murat
Increasing industrial attention to visible light communications (VLC) technology led the IEEE 802.11 to establish the task group 802.11bb 'Light Communications' (LC) for the development of a VLC standard. As a part of the standard development process, the development of realistic channel models according to possible use cases is of critical importance for physical layer system design. This article presents the reference channel models for the mandatory usage models adopted by IEEE 802.11bb for the evaluation of system proposals. The use cases include industrial, medical, enterprise, and residential scenarios. Channel impulse responses and corresponding frequency responses are obtained for each use case using a ray tracing approach based on realistic specifications for transmitters and receivers, and optical characterization of the environment.
The work of M. Uysal and T. Baykas was supported by the Turkish Scientific and Research Council (TUBITAK) under Grant 215E311.
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