Secrecy Performance Analysis for Reconfigurable Intelligent Surface aided NOMA Network

Reconfigurable Intelligent Surface (RIS) technology is emerging as a promising performance enhancement for next-generation wireless networks in terms of the quality of service and radio connectivity. Inspired by the promising potential of RIS technology, we investigate the secrecy performance of the downlink RIS-aided non-orthogonal multiple access network. To characterize the network's performance, the expectation of the new channel statistics for the reflected links with Nakagami-m fading is derived. Furthermore, the performance of the proposed network is evaluated according to the secrecy outage probability (SOP). The closed-form expressions of the SOP are derived. To obtain further insights, the asymptotic SOP and secrecy diversity orders are obtained. Our analytical results demonstrate that: 1) the expectation of channel gain for the reflected links is determined by the number of RISs and the Nakagami-m fading parameters; 2) Both the SOP of user Bob1 and the SOP of user Bob2 are 1 when the number of RISs is sufficiently large; 3) The secrecy diversity orders are affected by the number of RISs and Nakagami-m fading parameters

Physical Layer Security of Intelligent Reflective Surface Aided NOMA Networks

Intelligent reflective surface (IRS) technology is emerging as a promising performance enhancement technique for next-generation wireless networks. Hence, we investigate the physical layer security of the downlink in IRS-aided non-orthogonal multiple access networks in the presence of an eavesdropper, where an IRS is deployed for enhancing the quality by assisting the cell-edge user to communicate with the base station. To characterize the network's performance, the expected value of the new channel statistics is derived for the reflected links in the case of Nakagami-m fading. Furthermore, the performance of the proposed network is evaluated both in terms of the secrecy outage probability~(SOP) and the average secrecy capacity (ASC). The closed-form expressions of the SOP and the ASC are derived. We also study the impact of various network parameters on the overall performance of the network considered. To obtain further insights, the secrecy diversity orders and the high signal-to-noise ratio slopes are obtained. We finally show that: 1) the expectation of the channel gain in the reflected links is determined both by the number of IRSs and by the Nakagami- m fading parameters; 2)~The SOP of both receiver 1 and receiver 2 becomes unity, when the number of IRSs is sufficiently high; 3) The secrecy diversity orders are affected both by the number of IRSs and by the Nakagami-m fading parameters, whereas the high-SNR slopes are not affected by these parameters. Our Monte-Carlo simulations perfectly demonstrate the analytical results

A Novel Design of RIS for Enhancing the Physical Layer Security for RIS-aided NOMA Networks.

This letter proposes a novel design of reconfigurable intelligent surface (RIS) to enhance the physical layer security (PLS) in the RIS-aided non orthogonal multiple access (NOMA) network. Under the design of the RIS, the problem of increasing the number of RIS elements damaging the secrecy performance is solved. Besides, it also ensures that the networks can use traditional channel coding schemes to achieve secrecy. Our results show that the novel design of the RIS is ready for enhancing secrecy performance

Comparative studies on the multi-component pharmacokinetics of Aristolochiae Fructus and honey-fried Aristolochiae Fructus extracts after oral administration in rats

PK parameters of 7-OH AA I in rats after oral administration of AF and HAF. (DOC 37 kb

Sexual Knowledge, attitudes and behaviors among unmarried migrant female workers in China: a comparative analysis

<p>Abstract</p> <p>Background</p> <p>In recent years, many studies have focused on adolescent's sex-related issues in China. However, there have been few studies of unmarried migrant females' sexual knowledge, attitudes and behaviors, which is important for sexual health education and promotion.</p> <p>Methods</p> <p>A sample of 5156 unmarried migrant female workers was selected from three manufacturing factories, two located in Shenzhen and one in Guangzhou, China. Demographic data, sexual knowledge, attitudes and behaviors were assessed by self-administered questionnaires. Multivariate logistic regression analysis was conducted to examine the factors associated with premarital sexual intercourse.</p> <p>Results</p> <p>The average age of the unmarried female workers included in the sample was 20.2 years, and majority of them showed a low level of sex-related knowledge. Females from the west of China demonstrated a significant lower level of sex-related knowledge than those from the eastern or central provinces (<it>p </it>< 0.05). Approximately 13% of participants held a favorable attitude towards premarital sexual intercourse, and youths from the east/central were more likely to have favorable attitudes compared with those from the west (<it>p </it>< 0.05). About 17.0% of the unmarried female workers reported having engaged in premarital sexual intercourse, and females from the east/central were more likely to have experienced premarital sexual intercourse than those from the west (<it>p </it>< 0.05). Multivariate analysis revealed that age, education, current residential type, dating, sexual knowledge, attitudes, and pattern of communication were significantly associated with premarital sexual intercourse.</p> <p>Conclusion</p> <p>The unmarried migrant female workers lack sexual knowledge and a substantial proportion of them are engaged in premarital sexual behaviors. Interventions aimed at improving their sexual knowledge and related skills are needed.</p

Preparation and Preliminary Biological Evaluation of Novel &lt;sup&gt;99m&lt;/sup&gt;Tc-Labelled Thymidine Analogs as Tumor Imaging Agents

Two kinds of novel thymidine derivatives, &lt;em&gt;N&lt;/em&gt;-thymidine-yl-&lt;em&gt;N′&lt;/em&gt;-methyl-&lt;em&gt;N′&lt;/em&gt;-{&lt;em&gt;N′′&lt;/em&gt;-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-ethanediamine (TMHEA) and &lt;em&gt;N&lt;/em&gt;-thymidine-yl-&lt;em&gt;N′&lt;/em&gt;-methyl-&lt;em&gt;N′&lt;/em&gt;-{&lt;em&gt;N′′&lt;/em&gt;-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-hexanediamine (TMHHA) were prepared and successfully labeled with &lt;sup&gt;99m&lt;/sup&gt;Tc in high labeling yields. The &lt;em&gt;in vitro &lt;/em&gt;stability and &lt;em&gt;in vivo&lt;/em&gt; biodistribution of &lt;sup&gt;99m&lt;/sup&gt;Tc-TMHEA and &lt;sup&gt;99m&lt;/sup&gt;Tc-TMHHA were investigated and compared. The biodistribution studies indicate that the radiotracer &lt;sup&gt;99m&lt;/sup&gt;Tc-TMHEA displays selective tumor uptake, suggesting it is a potential tumor imaging agent

Casing Damage Prediction Model Based on the Data-Driven Method

Casing damage caused by sand production in unconsolidated sandstone reservoirs often results in oil wells unable to produce normally. However, due to the complex mechanism of sheath damage caused by sand production, there is no more mature technology for predicting the risk of casing damage in advance. Data-driven method can better integrate various factors and use a large amount of historical data to solve complex classification prediction problems. In this paper, XGBoost and LightGBM algorithms are used to establish casing damage prediction models, and 13 model application experiments are carried out to optimize the set of casing damage factors. These two algorithms are used to calculate the feature importance of each factor and determine the final set of factors. The evaluation results of five key metrics show that both prediction models show good performance, and the prediction accuracy is 0.99 for the XGBoost model and 0.94 for the LightGBM model. Applying the established prediction model can determine reasonable range of the maximum daily liquid production of a single layer (Qlmax) to reduce the probability of casing damage. In addition, at certain Qlmax, increasing the perforation density can significantly reduce the probability of casing damage. Therefore, increasing the perforation density can achieve high production without causing casing damage