A novel air-to-ground communication paradigm is conceived, where an unmanned aerial vehicle (UAV)-mounted base station (BS) equipped with multiple antennas sends information to ground users (GUs) the aid of a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS). In contrast conventional RIS whose main function reflect incident signals, STAR-RIS capable both impinging signals from either side surface, thereby leading full-space 360 degree coverage. However,...

A reconfigurable intelligent surface (RIS) aided air-to-ground uplink non-orthogonal transmission framework is investigated for next generation multiple access. Occupying the same spectrum resource, unmanned aerial vehicle (UAV) users and ground (GUs) are connected to terrestrial cellular networks via access (NOMA) protocol. As flight safety important employing UAVs in civil airspace, collision avoidance mechanism has be considered during flight. Therefore, a joint optimization problem of...

Flight delay prediction has recently gained growing popularity due to the significant role it plays in efficient airline and airport operation. Most of previous works consider single-airport scenario, which overlooks time-varying spatial interactions hidden networks. In this paper, flight problem is investigated from a network perspective (i.e., multi-airport scenario). To model time-evolving periodic graph-structured information network, approach based on graph convolutional neural (GCN)...

The Chinese air transport system has witnessed an important evolution in the last decade, with a strong increase number of flights operated and consequent reduction their punctuality. In this contribution, we propose modelling process delay propagation by using complex networks, which nodes are associated to airports, links between pairs them assigned when is detected. Delay time series analysed through well-known Granger Causality, allows detecting if one causing dynamics observed second...

A novel framework of the unmanned aerial vehicle (UAV)-mounted active simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) communications with non-orthogonal multiple access (NOMA) is proposed for Internet-of-Things (IoT) networks. In particular, an STAR-RIS deployed onboard to enhance communication link between base station (BS) IoT devices, NOMA utilized supporting multi-device connectivity. Based on framework, a system sum rate maximization problem...

A novel near-field integrated sensing and communications framework for secure unmanned aerial vehicle (UAV) networks with high time efficiency is proposed. ground base station (GBS) large aperture size communicates one communication UAV (C-UAV) under the existence of eavesdropping (E-UAV), where artificial noise (AN) employed both jamming purpose. Given that E-UAV's motion model unknown at GBS, we first propose a localization trajectory tracking scheme. Specifically, exploiting variant...

The novel framework of an integrated aeronautical communication and radar system (IACRS) to realize spectrum sharing is investigated. A non-orthogonal multiple access (NOMA)- motivated multi-input-multi-output (MIMO) scheme proposed for the dual-function system, which able detect aircraft while simultaneously transmitting dedicated messages. Specifically, NOMA-inspired technology utilized enable dual-spectrum sharing. superposition signals facilitated in power domain, with successive...

The novel framework of an integrated aeronautical communication and radar system (IACRS) to realize spectrum sharing is investigated. A non-orthogonal multiple access (NOMA)-motivated multi-input–multi-output (MIMO) scheme proposed for the dual-function system, which able detect aircraft while simultaneously transmitting dedicated messages. Specifically, NOMA-inspired technology utilized enable dual-spectrum sharing. superposition signals facilitated in power domain. Successive interference...

In western China, the terrain and meteorological conditions are so complex that it is not suitable to construct new radar stations. Automatic dependent surveillance-broadcast (ADS-B) a totally surveillance method, before practically applied operated in abundant tests evaluations necessary validate performance of ADS-B guarantee operational security. During flight tests, we collect data radar, high accuracy position compare with based on position. To solve asynchronous problem among data,...

Conflict avoidance (CA) plays a crucial role in guaranteeing the airspace safety. The current approaches, mostly focusing on short-term situation which eliminates conflicts via local adjustment, cannot provide global solution. Recently, long-term conflict are proposed to solutions strategically planning traffic flow from view, have attracted more attentions. With consideration of China, there thousands flights per day and air route network is large complex, makes problem be large-scale...

Abstract The confidence partitioning sampling filter (CPSF) method proposed in this paper is a novel approach for solving the generic nonlinear filtering problem. First, probability space (CPS) defined, which restricts state transition bounded and closed recursive Bayesian filtering. In posterior CPS, weighted grid samples, represented PDF, are obtained by using technique (PST). Each sample treated as an impulse function. approximate expression of key PST implementation, properties function...

The aim of this study was to explore the incidence and risk factors for posterior cage migration (PCM) following decompression instrumented fusion degenerative lumbar disorders, hope provide references in decision making surgical planning spine surgeons. By retrieving medical records from January 2011 December 2015, 286 patients were retrospectively reviewed. According occurrence PCM, divided into 2 groups: PCM group non-PCM (N-PCM). To investigate values 3 categorized analyzed...

Conflict avoidance plays a crucial role in guaranteeing the safety and efficiency of air traffic management system. Recently, strategic conflict (SCA) problem has attracted more attention. Taking into consideration large-scale flight planning global view, SCA can be formulated as combinatorial optimisation with complex constraints tight couplings between variables, which is difficult to solve. In this paper, an approach based on cooperative coevolution algorithm combined new decomposition...

Based on long-term follow-ups, this study was designed to investigate the incidence and risk factors for postoperative adjacent segment degeneration (ASD) after anterior cervical discectomy fusion (ACDF) or total disc replacement (TDR) in treating degenerative diseases. Between January 2000 December 2005, 108 cases undergoing ACDF 78 TDR, were enrolled into study. All medical records retrospectively collected. Every patient followed up at least 10 years. Outcome assessment included visual...