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Developing wireless communication technologies is essential to satisfy the requirements of new applications and the increasing proliferation of interconnected devices. This research presents a resilient terahertz (THz)-based secure transmission framework for an active intelligent reflecting surface (IRS)-enabled symbiotic radio (SR) system in the presence of multiple eavesdroppers (Eves). The IRS facilitates secure transmission for the primary transmitter (PT) by intelligently adjusting the phase shifts of the signals from the PT, while simultaneously transmitting its own data to an Internet of Things (IoT) device. In light of the existence of numerous eves and unpredictable channels in real-world situations, we concurrently optimize the active beamforming of the PT and the phase shifts of the IRS to enhance the secrecy of IRS-assisted secure relay networks while adhering to quality-of-service standards and secure communication rates. To address this intricate non-convex stochastic optimization issue, we propose a secure beamforming technique named DDPG-SR, utilizing an effective deep reinforcement learning (DRL)-based deep deterministic policy gradient (DDPG) scheme to determine the optimal beamforming approach against Eves. This method seeks to establish an optimal beamforming strategy to counteract Eves under dynamic environmental circumstances. Comprehensive simulation experiments confirm the effectiveness of our proposed solution, showcasing enhanced performance relative to conventional IRS methods, IRS backscattering-based anti-evesdropping techniques, and other benchmark tactics for secrecy performance.

Unmanned aerial vehicles (UAVs) have attracted much attention for civil and military uses because of their high mobility and adaptable deployment capabilities in open spaces. They facilitate agile communications and ubiquitous connectivity. UAVs benefit from dominant line-of-sight communication links but are more susceptible to adversary eavesdropping attacks. Since upper-layer cryptography methods may be insufficient, physical-layer security (PLS) is an attractive alternative. PLS capitalizes on the inherent randomness of wireless channels to improve information confidentiality, particularly in UAV systems. This article provides a comprehensive overview of PLS in the context of UAV systems, examining various communication channels, including ground-to-air (G2A), ground-to-ground (G2G), air-to-ground (A2G), and air-to-air (A2A). First, we give a general review of UAV communications, emphasizing its functions as user equipment, base station (BS), and mobile relay. Following that, we provide an overview of PLS and its forms. The survey organizes the most advanced PLS techniques against passive wireless eavesdropping regarding the channels they are designed to protect. These schemes are further categorized into optimization and secrecy performance analysis. We examine technical aspects within each sub-category and classify core contributions based on approaches and objectives to improve secrecy performance. Moreover, we added summary tables of the identified schemes considering optimization and secrecy performance analysis domains for each category, providing an in-depth understanding of their technical aspects. In addition, we discuss open research issues and identify future research directions to address evolving threats and requirements in UAV communications to improve information confidentiality.

Background The present research study was made to isolate and identify the pathogenic microorganism from environment of tertiary care hospital Lahore. This study also assessed the microbiological quality and efficacy of four commonly used disinfectants (Alpha Guard, Klortab NaDCC, Spray Off Virugard and UNISEPTA) in Jinnah Hospital Lahore in order to provide sterile environment. Material and Methods The sterilized cotton buds sticks wetted by dipping in normal saline were used to collect samples from various parts of hospital. A sum of 150 samples was obtained as many areas as possible of each surface. Disinfectants efficacy was determined for each isolate using the quantitative suspension test. Results The isolated microbial pathogens of work surfaces before disinfection were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Gram-positive bacilli, Micrococcus luteus and Candida species. All under study disinfectants were competent for disinfection in hospital at tested dilution which was taken as satisfactory on the basis of Log reduction, measured = 5. The Unisepta Plus disinfectant was more potent than Alpha Guard, Klortab NaDCC, and Spray off Virugard on the basis of bactericidal activity and individual killing rate. The bactericidal activity of the four disinfectants was time-dependent. Conclusions The results of this research study represents that there is need of assessing efficacy and quality of disinfectants from time to time to ensure the control of infections by choosing right disinfectant in right concentration for right contact time. [ABSTRACT FROM AUTHOR]