This paper investigates the optimization of reconfigurable intelligent surface (RIS) in an integrated sensing and communication (ISAC) system. To meet the demand of growing number of devices, power domain non-orthogonal multiple access (NOMA) is considered. However, traditional NOMA with a large number of devices is challenging due to large decoding delay and propagation error introduced by successive interference cancellation (SIC). Thus, OMA is integrated into NOMA to support more devices. We formulate a max-min problem to optimize the sensing beampattern with constraints on communication rate, through joint power allocation, active beamforming and RIS phase shift design. To solve the non-convex problem with a non-smooth objective function, we propose a low complexity alternating optimization (AO) algorithm, where a closed form expression for the intra-cluster power allocation (intra-CPA) is derived, and penalty and successive convex approximation (SCA) methods are used to optimize the beamforming and phase shift design. Simulation results show the effectiveness of the proposed algorithm in terms of improving minimum beampattern gain (MBPG) compared with other baselines. Furthermore, the trade-off between sensing and communication is analyzed and demonstrated in the simulation results.
What is already known about this topic?There are 4,000 new HIV infections every day worldwide, and 31% of which are in adolescents aged 15-24 years old. However, previous study is not aware of the distribution of out-of-school youth among this age group.
What is added by this report?The crude reporting rate of HIV/AIDS among out-ofschool youth aged 15-24 years old increased from 5.25 per 100,000 persons in 2010 to 13.75 per 100,000 persons in 2020 with a weakly aggregated spatial distribution. Local hotspots spread from southwestern China to the central, eastern, and northeastern areas.
What are the implications for public health practice?In the future, HIV/AIDS awareness among out-ofschool youth and research on epidemic characteristics should be strengthened.In 2020, there was a daily increase of 4,000 new human immunodeficiency virus (HIV) infections globally, and 31% of which would be among adolescents aged 15-24 years old (1), defined as the youth by the United Nations (UN) (2). More importantly, a proportion of the youth are sexually active. Due to the lack of school-based HIV education and prevention services, out-of-school youth become more vulnerable to HIV infection than students. This study described the crude reporting rate of out-ofschool youth aged 15-24 and illustrated the spatial distribution characteristics using global spatial autocorrelation and hot spot analysis, which was based on case-reporting areas. The objective of this study was to understand the epidemiological situation and spatial distribution of out-of-school youth. The crude reporting rate of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/ AIDS) among out-of-school youth increased from 5.25 per 100,000 persons in 2010 to 13.75 per 100,000 persons in 2020 with a weakly aggregated spatial distribution. In addition, local hotspots gradually China CDC Weekly
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