This paper presents a longitudinal evaluation through four studies of Cubic Gantt Chart (CGC), which is a three-dimensional version of Gantt chart designed to visualize individual student e-learning log data. Across four system versions and four user studies through desktop to VR environments, this paper traces the CGC's development from an initial prototype through an enhanced desktop system, a collaborative VR environment. The central finding across these evaluations is that each function increased users' confidence in their analytical judgements but a ground-truth verification in the final study revealed that this confidence did not correspond to statistical validity. The in-situ statistical test feature designed for integrating into participants' analytical workflow to confirm their analysis is used sparsely and exploratorily. These findings suggest that visual analytics tools can enhance user confidence without a corresponding mechanism ensuring that confidence tracks correctness and need active workflow support beyond the availability of a validation capability.
The rapid development of Unmanned Aerial Vehicle (UAV) technologies has brought non-negligible information security risks. Existing research literature lacks structured and systematic review and summary. From the perspective of key management, this paper reviews representative relevant studies in recent years, constructs a typical conceptual model for UAV key management, and conducts comparative and classified analysis from four dimensions: application scenarios, cryptographic mechanisms, security properties, and evaluation methods. On this basis, it summarizes the core unsolved problems in current theoretical research and scheme design and prospects the key research directions in the future.
To address the critical challenge of ensuring reliable disaster data backhaul under frequent natural disasters and fragile ground communication infrastructures, a backpressure-aware collaborative learning empowered data flow backhaul framework for aerial-ground integrated networks (AGIN) is proposed. First, a data flow backhaul architecture is established by leveraging cooperative networking between unmanned aerial vehicles (UAVs) and ground facilities. Second, a QoS guarantee mechanism based on queue priorities dynamically coordinates resources to ensure low-latency backhaul for high-priority services. Thirdly, a data flow backhaul optimization approach based on backpressure-aware collaborative learning incorporates queue backlog differences into the reward function to prevent accumulation and adds a global conflict penalty to facilitate multi-UAV coordination and mitigate next-hop selection conflicts. Simulation results indicate that the proposed approach enables low-latency, energy-efficient, and high-throughput data flow backhaul under dynamic networks.
The 13.56 MHz RFID system is a short-range wireless communication technology that uses magnetic fields. The Radio Law restricts the intensity of the magnetic field used for communication to a low level, limiting the communication area of 13.56 MHz RFID system. Furthermore, communication performance is easily degraded by the surrounding environment. For some applications, such as paying for all items in a shopping cart at once, it is desirable to expand the communication range. To solve this problem, the authors investigate a simple method for improving the system's communication performance by adding a parasitic coil to 13.56 MHz RFID system. In this paper, they evaluate the communication performance when one or two parasitic coils are placed between a table-type 13.56 MHz RFID reader/writer and a tag.
With the increasing frequency of extreme weather and natural disasters, traditional ground communication networks struggle to meet emergency demands due to inadequate coverage and slow recovery. Complex terrain and inefficient resource allocation also lead to spatial-domain coverage holes, impacting fault location accuracy and emergency repair efficiency. To address these issues, a low-latency service bearing architecture for space-air-ground integrated networks is constructed, which accounts for spatial-domain coverage holes. Secondly, a low-latency service bearing and access control method for space-air-ground integrated networks is proposed considering spatial-domain coverage holes. Furthermore, a low-latency unmanned aerial vehicle (UAV) relay dispatch and channel joint selection algorithm based on coverage hole-aware Q-matching is proposed. Simulation results demonstrate that the proposed method significantly mitigates spatial-domain coverage holes and reduces average queuing delay for critical service bearing.
