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This paper investigates the physical layer security (PLS) of non-orthogonal multiple access (NOMA)-enabled overlay cognitive radio networks (NOMA-OCRNs), considering multiple non-colluding eavesdroppers. Here PLS is evaluated in terms of: (i) secrecy outage probability (SOP) of primary user (PU) and secondary user (SU) and (ii) system SOP (SSOP), system secrecy throughput (SST) and secrecy energy efficiency (SEE) of the network. Residual hardware impairments arising from non-ideal hardware and imperfect successive interference cancellation conditions are considered. Firstly, we derive new analytical expressions for the SOPs of PU and SU. Numerical evaluation results show that both PU as well as SU suffer very high SOPs that tend to unity in the high transmit power region. Further, RHI and i-SIC have a significant impact on the secrecy performance. To improve the PLS performance, we propose a jamming-assisted framework and develop novel analytical models for determining the SOPs of PU and SU. We derive the asymptotic SOP expressions as well. Detailed analytical and simulation results are presented to demonstrate that the proposed jamming-assisted framework leads to a significant reduction of the SOPs of both PU and SU while exhibiting considerable enhancement of SST and SEE of the network compared to the no-jammer scenario. In the final part of this paper, we utilize a deep learning framework for the precise and fast prediction of the SOPs of PU and SU, that can replace complex mathematical modeling.

This paper investigates the application of non-orthogonal multiple access (NOMA) in a coordinated direct and relay transmission (CDRT) system, where the base station (BS) directly communicates with the near (i.e., cell-centric) user, while it requires the help of a dedicated full duplex (FD) relay to communicate with the far (i.e., cell-edge) user. For the considered NOMA-FD-CDRT system, we derive closed-form expressions for the outage probabilities and ergodic rates experienced by the downlink users, under the realistic assumptions of imperfect channel state information (I-CSI) and imperfect successive interference cancellation (I-SIC). Expressions for system outage probability and ergodic sum rate are also presented. The links are assumed to experience independent, non-identically distributed Nakagami-m fading. The analysis of outage probabilities are carried out for both integer and non-integer values of the fading severity index. Extensive simulation results are described to validate the accuracy of analytical results, and to illustrate the performance gain of the considered system, as compared to NOMA-HD-CDRT system and the orthogonal multiple access (OMA) based CDRT system. Our results show that, both channel estimation error variance and I-SIC factor have significant impact on the performance of the considered NOMA-FD/HD-CDRT system. Further, to ensure fairness in terms of outage, we numerically determine the power allocation coefficient at the BS that provides equal outage performance for both the near and the far users in the presence of I-CSI and I-SIC. Furthermore, we derive closed-form expression for the optimal power allocation (OPA) coefficient at the BS that minimizes the system outage probability of the NOMA-FD/HD-CDRT network under I-CSI. With the help of numerical and simulation investigations, we establish that the proposed OPA significantly reduces the system outage probability, as compared to random (i.e., non-optimal) power allocation at the BS.

Abstract This paper investigates the outage probability and rate performance of multi-hop full duplex (FD) and half duplex (HD) decode-and-forward (DF)-based relay networks. First of all, we derive new closed form equation for the end-to-end outage probability of multi-hop FDR system taking into account the inter-relay interference (IRI), i.e., interference caused by simultaneous transmissions by the nodes in non-orthogonal frequency bands, and the residual self-interference (RSI) present at the full duplex relay (FDR) nodes, in independent non-identical Nakagami-m fading channels. We also derive an approximate expression for the outage probability which is found to be highly accurate. Further, we provide an asymptotic expression as well, for Rayleigh fading channels. Furthermore, we derive exact and approximate expression for the outage probability of multi-hop spectral efficient HDR network that employ two-phase relaying. We then consider optimal power allocation (OPA) for multi-hop FDR and HDR networks that maximizes the end-to-end transmission rate with individual peak power constraint at the nodes. Since the optimization problem is non-convex, we develop an efficient, low-complex and fast-converging iterative algorithm for power allocation based on sequential convex programming. Secondly, we consider OPA for multi-hop FDR and HDR networks that minimizes the end-to-end outage probability with individual peak power constraints at the nodes. We devise geometric programming (GP) to obtain the OPA vector. The results demonstrate that OPA can significantly improve the outage and end-to-end rate performance of both FDR and HDR networks as compared to uniform power allocation policy. The results from the analytical model are validated by extensive Monte Carlo simulations.

In various countries around the world, the emissions of NOX from petrol/gasoline and diesel engine vehicles are restricted by legislation. NOX is produced in the combustion chamber of engines at high temperatures and high pressure. One of the most promising technology for effective control of NOX emissions is Exhaust Gas Recirculation (EGR) and now most modern engines require exhaust gas recirculation to meet emission standards. EGR lowers the presence of oxygen concentration and burn temperature in the combustion chamber and hence controls the NOx. The experimentation was carried out on a 5.2 kW of single cylinder four stroke direct injection diesel engines in computerized mode to investigate the performance, emissions and combustion parameters at different EGR ratios (10, 20 and 30%). From the results, O2, NOX and exhaust temperatures are found to be reduced whereas HC and CO emissions are increased as the EGR concentration increases.

Lesbian, Gay, Bisexual, Transgender, Queer, Intersex and Asexual (LGBTQIA+) people struggle to identify a healthcare service that understands their problems and needs. Additionally, healthcare professionals also find it difficult to care for LGBTQIA+ as very little is studied or heard about management. The article presents a protocol for a pilot study aimed at the development of an LGBTQIA+ care curriculum for health science professionals. The study includes Phase I: The development of a curriculum based on a literature review and focus group discussion among LGBTQIA+ individuals, and Phase II: Pilot testing of LGBTQIA+ care curriculum. The study outcome will reflect the improvement in the knowledge of healthcare professionals on LGBTQIA+ care.

Lesbian, Gay, Bisexual, Transgender, Queer, Intersex and Asexual (LGBTQIA+) people struggle to identify a healthcare service that understands their problems and needs. Additionally, healthcare professionals also find it difficult to care for LGBTQIA+ as very little is studied or heard about management. The article presents a protocol for a pilot study aimed at the development of an LGBTQIA+ care curriculum for health science professionals. The study includes Phase I: The development of a curriculum based on a literature review and focus group discussion among LGBTQIA+ individuals, and Phase II: Pilot testing of LGBTQIA+ care curriculum. The study outcome will reflect the improvement in the knowledge of healthcare professionals on LGBTQIA+ care.