1,068 research outputs found
The Performance Analysis of Spectrum Sharing between UAV enabled Wireless Mesh Networks and Ground Networks
Unmanned aerial vehicle (UAV) has the advantages of large coverage and
flexibility, which could be applied in disaster management to provide wireless
services to the rescuers and victims. When UAVs forms an aerial mesh network,
line-of-sight (LoS) air-to-air (A2A) communications have long transmission
distance, which extends the coverage of multiple UAVs. However, the capacity of
UAV is constrained due to the multiple hop transmissions in aerial mesh
networks. In this paper, spectrum sharing between UAV enabled wireless mesh
networks and ground networks is studied to improve the capacity of UAV
networks. Considering two-dimensional (2D) and three-dimensional (3D)
homogeneous Poisson point process (PPP) modeling for the distribution of UAVs
within a vertical range {\Delta}h, stochastic geometry is applied to analyze
the impact of the height of UAVs, the transmit power of UAVs, the density of
UAVs and the vertical range, etc., on the coverage probability of ground
network user and UAV network user. Besides, performance improvement of spectrum
sharing with directional antenna is verified. With the object function of
maximizing the transmission capacity, the optimal altitude of UAVs is obtained.
This paper provides a theoretical guideline for the spectrum sharing of UAV
enabled wireless mesh networks, which may contribute significant value to the
study of spectrum sharing mechanisms for UAV enabled wireless mesh networks.Comment: 12 pages, 13 figures, IEEE Sensors Journa
Spectrum Sharing between UAV-based Wireless Mesh Networks and Ground Networks
The unmanned aerial vehicle (UAV)-based wireless mesh networks can
economically provide wireless services for the areas with disasters. However,
the capacity of air-to-air communications is limited due to the multi-hop
transmissions. In this paper, the spectrum sharing between UAV-based wireless
mesh networks and ground networks is studied to improve the capacity of the UAV
networks. Considering the distribution of UAVs as a three-dimensional (3D)
homogeneous Poisson point process (PPP) within a vertical range, the stochastic
geometry is applied to analyze the impact of the height of UAVs, the transmit
power of UAVs, the density of UAVs and the vertical range, etc., on the
coverage probability of ground network user and UAV network user, respectively.
The optimal height of UAVs is numerically achieved in maximizing the capacity
of UAV networks with the constraint of the coverage probability of ground
network user. This paper provides a basic guideline for the deployment of
UAV-based wireless mesh networks.Comment: 6 pages, 6 figure
A model local interpretation routine for deep learning based radio galaxy classification
Radio galaxy morphological classification is one of the critical steps when
producing source catalogues for large-scale radio continuum surveys. While many
recent studies attempted to classify source radio morphology from survey image
data using deep learning algorithms (i.e., Convolutional Neural Networks), they
concentrated on model robustness most time. It is unclear whether a model
similarly makes predictions as radio astronomers did. In this work, we used
Local Interpretable Model-agnostic Explanation (LIME), an state-of-the-art
eXplainable Artificial Intelligence (XAI) technique to explain model prediction
behaviour and thus examine the hypothesis in a proof-of-concept manner. In what
follows, we describe how \textbf{LIME} generally works and early results about
how it helped explain predictions of a radio galaxy classification model using
this technique.Comment: 4 pages, 1 figure, accepted summary paper for URSI GASS 2023 J0
Genetic Regulation of N6-Methyladenosine-RNA in Mammalian Gametogenesis and Embryonic Development
Emerging evidence shows that m(6)A is the most abundant modification in eukaryotic RNA molecules. It has only recently been found that this epigenetic modification plays an important role in many physiological and pathological processes, such as cell fate commitment, immune response, obesity, tumorigenesis, and relevant for the present review, gametogenesis. Notably the RNA metabolism process mediated by m(6)A is controlled and regulated by a series of proteins termed writers, readers and erasers that are highly expressed in germ cells and somatic cells of gonads. Here, we review and discuss the expression and the functional emerging roles of m(6)A in gametogenesis and early embryogenesis of mammals. Besides updated references about such new topics, readers might find in the present work inspiration and clues to elucidate epigenetic molecular mechanisms of reproductive dysfunction and perspectives for future research
Do people become more proactive at work as they grow older? Examining the mediating roles of intrinsic motivation, emotional exhaustion, and career aspiration
Today, there is an increasingly aging workforce. Previous studies have examined whether aged people exhibit more positive attitudes, better health, and better performance. However, the relationship between age and proactive work behavior has seldom been examined, which is unfortunate since organizations need employee proactivity to deal with uncertainty and unpredictability. Based on socioemotional selectivity theory, we propose that age might be positively related to proactive work behavior through intrinsic motivation and emotional exhaustion because older people tend to manage their emotions and obtain intrinsic enjoyment. But age might be negatively related to proactive work behavior through career aspiration because older people focus less on future development. With a sample of 393 people, we revealed intrinsic motivation and career aspiration. The findings could help us better understand how age is related to organizational outcomes and individual differences in proactive work behavior. They could also further reduce age-related discrimination and encourage organizations to manage older people in wise and better ways
Copy Number Variation Pattern for Discriminating MACROD2 States of Colorectal Cancer Subtypes
Elevated serum platelet count inhibits the effects of brain functional changes on cognitive function in patients with mild cognitive impairment: A resting-state functional magnetic resonance imaging study
ObjectiveBrain function remodeling has been observed in patients with mild cognitive impairment (MCI) and is closely associated with cognitive performance. However, it is not clear if this relationship is influenced by complete blood counts. This study investigated the role of complete blood counts in the relationship between brain function and cognitive performance.MethodsTwenty-two MCI patients and eighteen controls were enrolled. All subjects underwent resting-state functional magnetic resonance imaging. A neuropsychological battery [Mini-Mental Status Examination, Auditory Verbal Learning Test (AVLT), Symbol Digit Modalities Test, Boston Naming Test (BNT), Shape Trails Test B (STT-B), Rey Complex Figure Test (RCFT), Hamilton Anxiety Rating Scale (HAMA), and Hamilton Depression Scale] was used to assess cognitive function, and MCI patients received complete blood counts tests for red blood cells (RBC), white blood cells, hemoglobin (HGB), monocytes, and platelet counts (PLT).ResultsCompared with controls, MCI patients demonstrated significantly decreased amplitude of low-frequency fluctuation (ALFF) values in the left dorsolateral superior frontal gyrus, left post orbitofrontal cortex, right medial superior frontal gyrus, right insula, and left triangular inferior frontal gyrus. In the MCI group, there were associations between ALFF values of the left hippocampus (HIP.L) and AVLT (p = 0.003) and AVLT-N5 scores (p = 0.001); ALFF values of the right supramarginal gyrus (SMG.R) and BNT scores (p = 0.044); ALFF values of the right superior temporal gyrus (STG.R) and BNT scores (p = 0.022); ALFF values of the left precuneus (PCUN.L) and STT-B time (p = 0.012); and ALFF values of the left caudate nucleus (CAU.L) and RCFT-time (p = 0.036). Moreover, the HAMA scores were negatively correlated with RBC and HGB levels, and positively correlated with monocyte count. The PLT count was positively correlated with STT-B time. Additionally, high PLT count inhibited the effect of ALFF values of the PCUN. L on STT-B performance in MCI patients (p = 0.0207).ConclusionALFF values of the HIP. L, SMG.R, STG. R, PCUN.L, and CAU. L were associated with decreased memory, language, executive function, and visuospatial ability in MCI patients. Notably, elevated PLT count could inhibit the effect of brain functional changes in the PCUN.L on executive function in MCI patients
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