Connecting Link Research Articles

Study on the Development of Cross-border E-commerce by the Policy Trials of the Free Trade Zones (FTZ)

The Pilot Free Trade Zone is a milestone policy for opening up the foreign economy, and plays an important role under the policy orientation of ‘early and pilot implementation’ in China. 2023 will mark the 10th anniversary of the construction of the Pilot Free Trade Zone in Shanghai, and the new development pattern is based on the domestic macro-cycle as the main body, and the domestic and international double-cycle is mutually promoted, and cross-border e-commerce is just an important connection link relying on Internet technology and the emerging trade mode. Cross-border e-commerce, as an emerging trade mode relying on Internet technology, is an important link between the domestic and international double cycle. Exploring the path of enhancement of cross-border e-commerce development by the policy experiment of the Pilot Free Trade Zone can help to build a new development pattern in which the domestic and international double cycles promote each other, and provide a basis for deepening the policy in the future. Under the guidance of trade cost theory, government reengineering theory and cooperation theory, this paper draws the following conclusions, and the FTZ has reduced the trade cost of enterprises and further stimulated the vitality of cross-border e-commerce by continuously optimising the tax policy and simplifying the customs clearance procedures. In the future, it is necessary to aim for high-quality green development, identify strategic positioning, and give full play to regional characteristics, and at the same time, refine and improve the rules and standards for the development of digital trade and implement them fairly and equitably, so as to better promote cross-border e-commerce as well as the sustainable development of the economy as a whole.

Examining the Interconnectedness of State High Court Twitter

AbstractJudges are not the first political officials that come to mind when one considers the role of social media in modern politics. Following in the wake of some prominent judicial personalities adopting Twitter, however, a growing number of state high court judges have adopted and established more public personas on the platform. Judges use Twitter in substantively different ways than traditional elected officials (Curry and Fix 2019); however, little is understood about how the use of such social media platforms affects broader judicial networks. Recognizing that judges, like typical social media users, may aspire to expand their networks to build and appeal to broader audiences, we contend that active participation in judicial Twitterverse could yield personal and professional advantages. Here, we address a currently unexplored question: To what extent have judges formed a distinctive “judicial network,” on Twitter, and what discernible patterns present in these networks? Leveraging the unique structure of social media, we collect comprehensive network data on judging using Twitter and analyze what institutional and social factors impact greater power within the judicial network. We find that early adoption, electoral concerns, and connective links between judges all impact the strength of the judicial network, highlighting the complex motivations driving judicial Twitter engagement, and the significance of network building in judges’ social media strategies and its potential impact on career advancement.

Disclosing Connection Links between Microstructure and Mechanical Performance in Pulsating Current Gas Tungsten Arc Welding of Hastelloy B-2 Superalloy

In this study, welding a Ni-Mo-based superalloy (Hastelloy B-2) was examined in order to characterize the microstructure and mechanical performance of joints along with assessing the effects of current intensity on the microstructure and mechanical responses of different weld zones. The gas tungsten arc welding (GTAW) process was used to weld the samples using ERNiCrMo-2 filler metal. The pulsed current GTAW process was used to weld the superalloy sheets of thickness of 1 mm with background current (Ib) of 20 A and 40 A and peak current (Ip) of 80 A and 60 A. Tensile and Vickers microhardness tests were conducted to evaluate the effect of pulsed current on mechanical properties of the welds along with chemistry and microstructure characterizations. Finally, the fracture surfaces after the tensile test were studied using SEM fractography analysis. The results indicated that increasing Ib and decreasing Ip led to low heat input and high cooling rate resulting in a high thermal gradient. This caused microstructure transition from the columnar dendrites to the coaxial ones in the weld zone; molten metal convection in the fusion zone led to fine grains in the weld zone during welding time. Moreover, a significant decrease in the amount of molybdenum carbides at the interdendritic regions of the weld metal was observed under these conditions. The tensile strength of the weld metal was higher than that of the base metal resulting in the fracture of all welds from the base metal. Additionally, the microhardness results indicated a significant increase for the weld metal compared to both heat-affected zone (HAZ) and base metal. The higher mechanical properties of the weld metal is attributed to the increase in background current and decrease in peak current leading to a fine grain microstructure. Fractography following the tensile test showed a completely ductile fracture.

Learning Interpretable Brain Functional Connectivity via Self-Supervised Triplet Network With Depth-Wise Attention.

Brain functional connectivity has been widely explored to reveal the functional interaction dynamics between the brain regions. However, conventional connectivity measures rely on deterministic models demanding application-specific empirical analysis, while deep learning approaches focus on finding discriminative features for state classification, having limited capability to capture the interpretable connectivity characteristics. To address the challenges, this study proposes a self-supervised triplet network with depth-wise attention (TripletNet-DA) to generate the functional connectivity: 1) TripletNet-DA firstly utilizes channel-wise transformations for temporal data augmentation, where the correlated & uncorrelated sample pairs are constructed for self-supervised training, 2) Channel encoder is designed with a convolution network to extract the deep features, while similarity estimator is employed to generate the similarity pairs and the functional connectivity representations, 3) TripletNet-DA applies Triplet loss with anchor-negative similarity penalty for model training, where the similarities of uncorrelated sample pairs are minimized to enhance model's learning capability. Experimental results on pathological EEG datasets (Autism Spectrum Disorder, Major Depressive Disorder) indicate that 1) TripletNet-DA demonstrates superiority in both ASD discrimination and MDD classification than the state-of-the-art counterparts, where the connectivity features in beta & gamma bands have respectively achieved the accuracy of 97.05%, 98.32% for ASD discrimination, 89.88%, 91.80% for MDD classification in the eyes-closed condition and 90.90%, 92.26% in the eyes-open condition, 2) TripletNet-DA enables to uncover significant differences of functional connectivity between ASD EEG and TD ones, and the prominent connectivity links are in accordance with the empirical findings, thus providing potential biomarkers for clinical ASD analysis.

A dynamic fire risk assessment method for compact historic villages based on the improved FRAME

There are a large number of high-value heritage sites in the historic villages preserved in the mountainous areas of southern China. These sites are exposed to major fire risks due to their compact layout and wooden building materials. By improving the fire risk assessment method for engineering (FRAME), we proposed a dynamic fire risk assessment method for compact historic villages. On one hand, a balance between universality and pertinence was established regarding the assessment indexes and weighting system by integrating general factors with unique regional factors. On the other hand, a connecting link between prescriptive fire codes and performance-based design adjustments was established through the cyclic operation path of assessment-intervention-reassessment. Xiaozhai village, which has experienced serious fire incidents, was selected as an example. Its original fire risk, established fire interventions, actual fire results, and optimized fire protection plan were compared and analyzed to validate the effectiveness and reliability of the assessment method. This study reveals the correlation between various factors of the village and building fire risk. Among these factors, building proximity, traditional customs, and fire protection layout, which are not included in the original FRAME, have a significant impact on fire risk. The results of this study can serve as a reference for fire prevention in historic villages with similar characteristics worldwide. Additionally, the proposed methodology can provide insights into the development of fire risk assessment methods for various types of historical settlements, thus promoting the sustainable development of built heritage in these settlements.

The Necessary Rapprochement of Negative Affectivity, Personality Disorder, and Depression.

The relationship between depression and personality has long been a topic of interest in the fields of psychiatry and psychology, but consensus remains elusive. This lack of consensus poses a significant challenge in both diagnosis and treatment, especially in situations when otherwise effective therapies for depression fail. Our article aims to address this issue by reviewing the historical and recent conceptualizations of the relationship between depression and personality pathology. Specifically, we focus on the trait domain of negative affectivity found in the International Classification of Diseases, 11th Edition (ICD-11) and the Alternative Model for Personality Disorders (AMPD) as a connecting link between the two phenomena. We review recent empirical studies evaluating the association of negative affectivity, personality, and depression, along with investigations of the relationship between depressive disorders and personality disorders. Additionally, we describe the Hierarchical Taxonomy of Psychopathology (HiTOP) and the AMPD as organizing frameworks for understanding depression within a broader personality framework. Based on the available evidence, we propose that depressive disorders must be assessed within the context of the patient's personality in order to maximize treatment outcomes. Ultimately, this integrated approach can guide clinicians in developing unified treatment protocols and facilitate early detection and intervention for factors contributing to depression in order to minimize treatment resistance.

Development of Graphical User Interface for Link Budget Analysis of Point-to-Point Communications at 5 GHz and 11 GHz

It is well known that simulation tools are essential for the design and optimization of wireless communication systems. This paper proposes a Python script that can be used for planning and predicting a connection link budget by analyzing its basic parameters. Our proposal consists of an application that calculates the connection budget for point-to-point links operating at 5 GHz and 11 GHz, taking into account all the necessary microwave parameters. For validating the efficiency of the proposed tool, this paper presents comprehensive simulation results derived from comparing our tool to a couple of other simulation tools by means of calculating the same parameters.

Three-dimensional optical coherence tomography for guidance of percutaneous coronary intervention for coronary bifurcation disease: a review of current clinical applications.

Percutaneous coronary intervention (PCI) for coronary bifurcation disease remains one of the most challenging situations in interventional cardiology in terms of procedural success rates and long-term cardiac events. Optical coherence tomography (OCT), with a higher signal-to-noise ratio and the ability to distinguish plaque components, can display the true condition of bifurcation lesions without overlapping or shortening and achieve detailed visualization of vascular structures, which is superior to those of other imaging modalities. Three-dimensional (3D) reconstruction of OCT images (3D-OCT) helps to gain a more informed understanding of the geometry and morphology of bifurcation lesions and provide additive information on plaque distribution. Following stent implantation, 3D-OCT can also guide the re-crossing of guide wires through stent struts jailing the side branch (SB) ostium and more clearly display the jailing strut configuration, as well as the ideal position of the guidewire recrossing point and stent struct link connection, to confirm the optimal guidewire position and understand interactions between stents and vessel walls, which may improve clinical results after PCI. The present review provides an up-to-date overview of the clinical use of 3D-OCT for accurate assessment of bifurcation anatomy, guiding the optimal guidewire rewiring into SB during bifurcation stenting, and evaluation of post-PCI results, offering novel information about atherosclerotic disease or stenting process.

Estimating the all-terminal signatures for networks by using deep neural network

Computing the signature of a network is both significant and challenging. Addressing the limitations of existing methods in batch processing of large-scale network signatures, in this paper we propose a novel DNN (Deep Neural Network)-based framework for estimating the all-terminal signature and reliability for networks with varying topologies. Our framework involves constructing a DNN model with four efficient and compact network topological features (the numbers of nodes, and links, the node degrees and the link connectivity) as input features and the signature as the response. Additionally, we propose to estimate the all-terminal network reliability based on the signature estimated by the DNN, termed the two-stage DNN approach, which does not require the link reliability as one of the inputs, resulting in better estimation accuracy and generation performance compared to traditional DNN approaches. A case study is conducted and the results show that the estimation accuracy of our DNN model for the signature is satisfactory, and the two-stage DNN approach for network reliability outperforms existing DNN approaches in the literature.

Intracranial Directed Connectivity Links Subregions of the Prefrontal Cortex to Major Depression.

Understanding the neural basis of major depressive disorder (MDD) is vital to guiding neuromodulatory treatments. The available evidence supports the hypothesis that MDD is fundamentally a disease of cortical disinhibition, where breakdowns of inhibitory neural systems lead to diminished emotion regulation and intrusive ruminations. Recent research also points towards network changes in the brain, especially within the prefrontal cortex (PFC), as primary sources of MDD etiology. However, due to limitations in spatiotemporal resolution and clinical opportunities for intracranial recordings, this hypothesis has not been directly tested. We recorded intracranial EEG from the dorsolateral (dlPFC), orbitofrontal (OFC), and anterior cingulate cortices (ACC) in neurosurgical patients with MDD. We measured daily fluctuations in self-reported depression severity alongside directed connectivity between these PFC subregions. We focused primarily on delta oscillations (1-3 Hz), which have been linked to GABAergic inhibitory control and intracortical communication. Depression symptoms worsened when connectivity within the left vs. right PFC became imbalanced. In the left hemisphere, all directed connectivity towards the ACC, from the dlPFC and OFC, was positively correlated with depression severity. In the right hemisphere, directed connectivity between the OFC and dlPFC increased with depression severity as well. This is the first evidence that delta oscillations flowing between prefrontal subregions transiently increase intensity when people are experiencing more negative mood. These findings support the overarching hypothesis that MDD worsens with prefrontal disinhibition.

Exhaustive Enumeration of Spatial Prime Structures

Prime structures are link chains with 0 DoF (degrees of freedom), not including subchains with 0 or fewer DoF, which are expected to be used in systematic kinematic and dynamic analyses of link mechanisms. This paper describes the exhaustive enumeration of spatial prime structures with three–five links. There will be more types of spatial prime structures than planar prime structures due to the variety in the DoF of kinematic pairs and the existence of prime structures with idle DoF. In the enumeration, the graphs which represent the connection of links and pairs are used. The vertices of the graphs represent the links of structures, and the edges represent the kinematic pairs. To consider the pair DoF, weights are set on edges. First, the numbers of pairs are calculated using Grübler’s equation. Second, the graphs corresponding to structures are enumerated, without considering pair DoF, and the isomorphic graphs and other inappropriate graphs are eliminated. Then, the combinations of pair DoF arrangement are enumerated, and the isomorphic graphs and graphs which correspond to non-prime structures are eliminated. Finally, prime structures with idle DoF are considered. As a result, 3, 13, and 97 kinds of spatial prime structures for 3, 4, and 5 links, respectively, are obtained.

Abstract Mo129: Elevation in male sex hormone metabolites with increased risk factors for inflammation and clotting in female kidneys following chronic binge drinking

Background: Binge drinking is a major systemic health concern. Binge drinking could alter renal metabolome and induce markers of injury as per our previously published work. Further investigation into the top regulated pathways revealed alterations sex hormone biosynthesis pathway was altered in a sex specific manner following 6 weeks of binge drinking. Our goal is to unveil individual metabolite mediators belonging to sex hormone biosynthesis pathway and to investigate the connecting link to cardiorenal health in both sexes following chronic binge drinking. Materials and Methods: For this work, n=3 male and female mice belonging to either control (water fed) or ethanol (20% fed in water) treatment groups were included. At the age of 8- 10 weeks, mice underwent water or binge (20% ethanol) drinking from Monday to Thursday for 4 hours, in dark cycle. This cycle was repeated for 6 weeks. Renal tissues from our experimental groups were collected at the end of 6 weeks and subjected to untargeted metabolomics. In brief, Ultra Performance Liquid Chromatography (UPLC) with Time-of-flight Mass Spectrometry (ESI-TOF-MS) followed by Mass spectrometry based separation was used to identify significantly altered metabolites. Results: Steroid hormone biosynthesis was the one among the top regulated pathways. Metabolites belonging to male hormone biosynthesis were the significantly altered one but specifically in females. Dehydroepiandrosterone, and it’s downstream 11-hydroxytestosterone were upregulated only in females and not in males. Female binge drinking group demonstrated an increase of 4.24 (fold) and 2.21 (fold) for dehydroepiandrosterone, and 11-hydroxytestosterone respectively as per the Log 2 Fold change values with a statistical significance of P<0.05 . Interestingly, this increase in male hormone metabolites we observed in females were also accompanied by an increase in metabolites of proinflammatory and prothrombotic mediators, thromboxane B3 and 5- Oxo- 12 HETE, of 2.3 (fold) and over 1.6 (fold) respectively as per Log 2 Fold change values and with a statistical difference of P<0.05 . Conclusion: Our data clearly demonstrate a sex specific effect following chronic binge drinking, where females have an increase in male hormones accompanied by an increase in prothrombotic and proinflammatory factors.

블랜디드 러닝 수업을 적용한 칼림바 합주 수업지도 방안 연구: 메타버스 플랫폼 ‘ZEP’을 중심으로

The purpose of this study is to design a Kalimba ensemble teaching plan based on the direction and digital application of the 2022 revised curriculum, and to suggest ways to effectively fulfill the goals of the 2022 revised curriculum in the school setting. The theoretical backgrounds of the Kalimba and the Metaverse were gathered through a review of academic papers and dissertations. The performance domain of the 2022 revised music curriculum was analyzed to design a teaching plan and explore practical methods for implementing a digital-instrument integrated class, as intended by the revised curriculum. The digital elements and music performance classes emphasized in the 2022 revised curriculum were fused so that students could experience the basics of new technologies. To create a student-led participatory class, a virtual reality space and study score were produced directly, enabling students to engage in creative and self-directed learning. To complement this, this study creates a virtual reality space using the Metaverse platform "ZEP" and provides online video and ensemble performance forms using the video link connection function of "ZEP" to foster basic digital literacy and improve music performance. It is hoped that research on instrumental teaching methods using digital media will be further expanded so that students can recognize the sensibility and value of music.

Seascape genetic study on Laminaria digitata underscores the critical role of sampling schemes

Understanding connectivity patterns exhibited by endangered species living in fragmented habitats is fundamental to improving management and conservation actions. Such improvements can be particularly pressing at the trailing edges of these habitats, where populations are facing the greatest challenges from climate change, and appear even more crucial if the species is commercially harvested. Seascape genetics have been increasingly used to meet these needs. In this study, we examined connectivity patterns among 32 populations of the oarweed kelp Laminaria digitata located at the species’ southern range limit. The distance (or sampling gap) between neighboring populations ranged from a few km to a few 100s of km. By genotyping 11 microsatellite markers, we aimed to (1) refine analyses of population structure; (2) test whether on-shelf islands are genetically more differentiated than mainland populations; (3) evaluate the relative importance of various abiotic conditions in shaping the genetic structure; and (4) evaluate if the relative importance of each environmental factor varied according to sampling schemes. Our analyses revealed a positive relationship between connectivity links and genetic diversity: populations with high levels of connectivity were genetically enriched while isolated populations showed signs of genetic erosion. The genetically impoverished populations corresponded to the southernmost populations as well as populations along the northern coast of Brittany (Locquirec, Saint-Malo Bay) and the northernmost population in Pas-de-Calais. By performing distance-based redundancy analysis on various sampling schemes, geographic distance appeared as the dominant factor influencing connectivity between populations separated by great distances, while hydrodynamic processes were the main factor when analyzing at a final spatial resolution.

FRAGILITY OF GRANULED COMBINED FEEDS

The compound feed industry produces compound feed by combining different ingredients (types of raw materials) in different combinations and proportions. This determines the name "combi feed". Compound feeds are composed in such a way that the disadvantages of some ingredients (low protein content, lack of vitamins, etc.) are compensated by the advantages of other ingredients. The main purpose of compound feed is to produce compound feed that meets the nutritional needs of livestock, domestic animals and poultry and ensures their growth, development and safety. The role of compound feed has increased with the development of industrial agriculture. The demand for compound feed on industrial livestock and poultry farms has increased significantly. Compound feed becomes a connecting link between nature and animals. Animals are kept in cages or stables and are deprived of contact with wild nature, so they receive all the nutrients necessary for growth and development with food. There are different types of compound feed, including loose, granulated and briquetted, characterized by such quality indicators as fragility.

Lactic acid: a narrative review of a promoter of the liver cancer microenvironment.

Lactic acid is a metabolite of glycolysis produced in the body, and its production is thought to be a mechanism by which cancer cells evade immune surveillance. Immune evasion and metabolic changes are well established as basic hallmarks of cancer. Although lactate has long been considered a waste product, it is now generally recognized to be a versatile small-molecule chemical that plays an important part in the tumor microenvironment (TME), with increased lactate production linked to the development of human malignancies. Metabolism in liver cancer is redirected toward glycolysis, which enhances the production of metabolic compounds used by tumor cells to produce proteins, lipids, and nucleotides, enabling them to maintain high proliferation rates and to establish the TME. Dysregulation of metabolic activity in liver cancer may impair antitumor responses owing to the immunosuppressive activity of the lactate produced by anaerobic glycolytic rates in tumor cells. This review primarily explores the link connection between lactic acid and the TME; evaluates the role of lactic acid in the occurrence, metastasis, prognosis, and treatment of liver cancer. Additionally, it investigates the associated pathways as potential targets for liver cancer treatment. Literature searches were conducted in PubMed, Web of Science, and Google Scholar, with the publication date of the most recent article included being January 2024. After eliminating duplicate articles and less relevant articles through titles and abstracts, we selected 113 articles for this review. We categorized references into two categories. One is to classify the content into lactate-related, liver cancer-related and tumor metabolism-related. The other is to classify the article types, which are divided into reviews, research articles and clinical trials. Additionally, we consulted the reference lists of the relevant articles to ensure coverage was comprehensive and unbiased. The connection between lactic acid and the TME has recently become an area of intense research interest, and many related articles have been published in this field. The main finding of this review is to summarize the proven link between lactate and the TME and its possible impact on the TME of liver cancer. And analyzed the potential of lactate in liver cancer treatment and prognosis prediction. Lactate may be key to developing novel approaches in the future treatment of liver cancer. Related research on the combination of classic therapies and molecular targeted drugs may provide innovative medicines that more selectively regulate immune cell activity.

Macrozoobenthos in the estuary of the small salmon river of Sakhalin Island on example of the Gornaya River

Estuaries as a connecting link between freshwater and marine ecosystems play a special role in salmon rivers. The success of adaptation of juvenile salmonids during the transition to the marine period of life depends on the conditions in estuaries. The work continues the previously started series of publications on the rivers of Sakhalin Island. Using the example of one of the small watercourses in the southeastern part of the island, the hydrological parameters and the structural organization of benthos communities in the atypical estuary have been considered. In the absence of storm surges, penetration of sea water into the water body does not occur; at high tide, water with a salinity of more than 12 psu is observed only at the mouth at the bottom; at low tide, the estuary is completely filled with water with a salinity of 0.1 psu and lower. Studies of the hydrological regime and composition of the bottom fauna were carried out in July 2022. Zoobenthos samples were taken along the longitudinal profile of the estuary at five sections (75 samples in total). Most of the estuarine reach is inhabited by species characteristic of the lower parts of the island watercourses. High environmental variability determines the formation in the estuary of young and unstable benthos communities represented by rapidly reproducing small-sized species.

Dynamic Delay-Sensitive Observation-Data-Processing Task Offloading for Satellite Edge Computing: A Fully-Decentralized Approach

Satellite edge computing (SEC) plays an increasing role in earth observation, due to its global coverage and low-latency computing service. In SEC, it is pivotal to offload diverse observation-data-processing tasks to the appropriate satellites. Nevertheless, due to the sparse intersatellite link (ISL) connections, it is hard to gather complete information from all satellites. Moreover, the dynamic arriving tasks will also influence the obtained offloading assignment. Therefore, one daunting challenge in SEC is achieving optimal offloading assignments with consideration of the dynamic delay-sensitive tasks. In this paper, we formulate task offloading in SEC with delay-sensitive tasks as a mixed-integer linear programming problem, aiming to minimize the weighted sum of deadline violations and energy consumption. Due to the limited ISLs, we propose a fully-decentralized method, called the PI-based task offloading (PITO) algorithm. The PITO operates on each satellite in parallel and only relies on local communication via ISLs. Tasks can be directly offloaded on board without depending on any central server. To further handle the dynamic arriving tasks, we propose a re-offloading mechanism based on the match-up strategy, which reduces the tasks involved and avoids unnecessary insertion attempts by pruning. Finally, extensive experiments demonstrate that PITO outperforms state-of-the-art algorithms when solving task offloading in SEC, and the proposed re-offloading mechanism is significantly more efficient than existing methods.

Deployment of efficient MANET testbed using aggregation based archive population optimization

In today’s 6G era, Mobile ad hoc networks (MANETs) have been enhanced by rapid technological advancement in the wireless communication industry to better support a wide range of domains, including military operations, emergency operations, urban settings, and natural crisesmanagement. In MANET, self-organizing mobile nodes collaborate to build a flexible network architecture. With a MANET, data must transit through numerous intermediate nodes even before reaches its destination node. Local link connectivity is essential for the establishment and preservation of routes. To decrease energy usage, these findings suggest the Aggregation-based Archive Population Optimization(AAPO) along with Ad-hoc On-demand Distance Vector (AODV) Routing Protocol. For both local and global optimal routes, the proposed optimized modelgives top priority. There existtwo different types of rules used by AAPO to evaluate the quality of a route before using it for data transmission. Instead of relying on just one path for transmitting data, AAPO leverages many paths. Also, it minimizes the issue of the network nodes being suddenly inaccessible, which eliminates interruptions in transmissions. However, the suggested optimal routing system considers mobility and energy availability when responding to queries, resulting in significant performance improvements, utilizing 42.69 % of the scenario’s power and functioning at 208.6 kbps with an average PDR of 87.1 %. Also, detailed simulations are conducted using the Matlab (R2021b)software to assess the suggested approach. Furthermore, the suggested protocol outperforms the current methods in terms of effectiveness.

Security Performance Analysis of Full-Duplex UAV Assisted Relay System Based on SWIPT Technology

In this paper, a new methodology is developed for modeling and analyzing a full-duplex UAV-assisted relay system to facilitate solving the problems of UAV energy constraints and the vulnerability of UAVs to eavesdropping in the air. Combining simultaneous wireless information and power transfer (SWIPT) technology, we model the downlink UAV eavesdropping channel and propose a secure transmission protocol for a full-duplex UAV-assisted relay system. Using this transmission protocol, we analyze and derive the connectivity and security of the entire communication link, including connection probability and lower bounds on secrecy outage probability. A key intermediate step in our analysis is to derive the signal-to-digital noise ratio of the destination and eavesdropping nodes of the full-duplex UAV relay link. The analyses show that the power allocation factor λ is a trade-off between system connectivity and security, while greater eavesdropping interference needs to be sacrificed for an equal magnitude of security performance improvement under high security demand conditions.