Mental health is an urgent societal issue, and social scientists are increasingly turning to online mental health communities (OMHCs) to analyze user behavior data for early intervention. However, existing sequence mining techniques fall short of the urgent need to explore the behavior progression of different groups (e.g., recovery or deterioration groups) and track the potential long-term impact of behaviors on mental health status. To address this issue, we introduce EMINDS, a visual analytics system built on a novel automatic mining pipeline that extracts distinct behavior stages and assesses the potential impact of frequent stage patterns on mental health status over time. The system includes a set of interactive visualizations that summarize the meaning of each behavior stage and the evolution of different stage patterns. We feature a pattern-centric Sankey diagram to reveal contextual information about the impact of stage patterns on mental health, helping experts understand the specific changes in sequences before and after a stage pattern. We evaluated the effectiveness and usability of EMINDS through two case studies and expert interviews, which examined the potential stage patterns impacting long-term mental health by analyzing user behaviors on Reddit.

This article deals with the investigation of the Martian subsurface in the Utopia Planitia region using Zhurong’s ground-penetrating radar. The low-frequency data recorded along the overall path followed by the rover are processed thanks to a customized signal processing pipeline aiming on one side to minimize the artifacts in the radargrams and, on the other one, to obtain images of the subsoil that aid the following analysis and interpretation stage. The images reveal a three-layer structure beneath the landing area up to the depth of ~40 m. The general scattering characteristics indicate the presence of$5~\sim ~8$-m regolith,$2~\sim ~3$-m fine materials, and$15~\sim ~30$m embedded with blocks generating a significant electromagnetic scattering. The existence of an upward decrease in grain size is resulted from long-term weathering and repeated impacts or the occurrence of flood events. The radargrams depict a distinctive local enhancement of the scattering at the end of the rover route from Sol 292 to Sol 325. Analysis of the layout of barchan dunes and the distribution of craters suggests that the resurfacing activity is the result of a complex combination of tectonic activities and impact events.

This work presents the results of the Lunar Regolith Penetrating Radar (LRPR), installed at the bottom of the Chang’E-5 (CE-5) lander, which is the first antenna-array radar deployed for the investigation of an extraterrestrial body. Radar imaging results unveiled a hyperfine structure for the top 2.5-m-thick lunar regolith with an unprecedented high resolution of 5 cm. The interpretation of the results permitted to state that subsurface regolith is dominated by fine grains with abundant rock fragments. The radar imaging results were also used to drive the drilling process until a fragment jammed the core inlet at about 100-cm underground. Laboratory measurements of the samples returned at Earth allow to estimate the real part of relative permittivity and the loss tangent, which are 3.04 ± 0.02 and 0.014 ± 0.002, respectively.

Chang'e-3 (CE-3) has been the first spacecraft to soft land on the moon since the Soviet Union's Luna 24 in 1976. The spacecraft arrived at Mare Imbrium on December 14, 2013, and the same day, Yutu lunar rover separated from lander to start its exploration of the surface and the subsurface around the landing site. The rover was equipped, among other instruments, with two lunar penetrating radar systems having a working frequency of 60 and 500 MHz. The radars acquired data for about two weeks while the rover was slowly moving along a path of about 114 m. At navigation point N0209, the rover got stacked into the lunar soil and after that only data at a fixed position could be collected. The low-frequency radar data have been analyzed by different authors and published in two different papers, which reported totally controversial interpretations of the radar cross sections. This paper is devoted to resolve such controversy by carefully analyzing and comparing the data collected on the moon by Yutu rover and on earth by a prototype of LPR mounted onboard a model of the CE-3 lunar rover. Such analysis demonstrates that the deep radar features previously ascribed to the lunar shallow stratigraphy are not real reflectors, rather they are signal artifacts probably generated by the system and its electromagnetic interaction with the metallic rover.

This paper concentrates on the multicast service in the next generation (5G) communications system, and develops an opportunistic massive MIMO-NOMA scheme. The proposed scheme superimposes the signal of Non-orthogonal Multiple Access (NOMA) users on the multicast signal, and employs successive interference cancellation (SIC) to separate the signal of NOMA users from the multicast signal. This scheme also applies null space based interference cancellation to eliminate the signal leakage generated by other groups. And multi-user MIMO (MU-MIMO) linear precoding is employed in the unicast group. Numerical results revealed that opportunistic massive MIMO-NOMA system significantly satisfies the requirement of high peak spectral efficiency in typical massive MIMO scenarios.

The research on vital information extraction meets a lot challenges due to the narrow bandwidth and low signal-to-noise ratio of a vital sign in real environment. In this paper, a novel noncontract vital sign detection method based on multiple higher order cumulant is presented. According to the characteristic of vital sign for impulse ultrawideband radar, the quasi-periodic reflected echo in slow-time is analyzed. The novel method is theoretically deduced from fourth-order cumulant. It is proved to be better than the reference fast Fourier transform method by simulation and experiment. By using the new method, the range position and frequency information of life can be extracted accurately and automatically.

The factors influencing on vital signal detection are discussed by introducing Cramer-Rao Low Bound (CRLB) for Ultra Wideband (UWB) in this paper. The CRLB is described on the basis of the impulse UWB sequential signal module and the Maximum Likelihood rule with Fisher Information Matrix (FIM). A novel detection method based on Multifold High Order Cumulant Fast Fourier Transform (MHOC-FFT) is used to process the simulated noisy signal and to estimate respiratory frequency. Simulated results verify the influence of the key parameters on vital detection. And the novel detection method has high Detectability with the capability to improve SNR and reduce higher harmonics.