42 research outputs found
Bearing-Based Target Entrapping Control of Multiple Uncertain Agents With Arbitrary Maneuvers
This paper is concerned with bearing-based cooperative target entrapping
control of multiple uncertain agents with arbitrary maneuvers including shape
deformation, rotations, scalings, etc. A leader-follower structure is used,
where the leaders move with the predesigned trajectories, and the followers are
steered by an estimation-based control method, integrating a distance estimator
using bearing measurements and a stress matrix-based formation controller. The
signum functions are used to compensate for the uncertainties so that the
agents' accelerations can be piecewise continuous and bounded to track the
desired dynamics. With proper design of the leaders' trajectories and a
geometric configuration, an affine matrix is determined so that the
persistently exciting conditions of the inter-agent relative bearings can be
satisfied since the bearing rates are related to different weighted
combinations of the affine matrix vectors. The asymptotic convergence of the
estimation error and control error is proved using Filipov properties and
cascaded system theories. A sufficient condition for inter-agent collision
avoidance is also proposed. Finally, simulation results are given to validate
the effectiveness of the method in both 2D and 3D cases.Comment: 13 pages, 6 figures, the paper has been accepted by IFAC WC 202
Automatic Conditional Generation of Personalized Social Media Short Texts
Automatic text generation has received much attention owing to rapid
development of deep neural networks. In general, text generation systems based
on statistical language model will not consider anthropomorphic
characteristics, which results in machine-like generated texts. To fill the
gap, we propose a conditional language generation model with Big Five
Personality (BFP) feature vectors as input context, which writes human-like
short texts. The short text generator consists of a layer of long short memory
network (LSTM), where a BFP feature vector is concatenated as one part of input
for each cell. To enable supervised training generation model, a text
classification model based convolution neural network (CNN) has been used to
prepare BFP-tagged Chinese micro-blog corpora. Validated by a BFP linguistic
computational model, our generated Chinese short texts exhibit discriminative
personality styles, which are also syntactically correct and semantically
smooth with appropriate emoticons. With combination of natural language
generation with psychological linguistics, our proposed BFP-dependent text
generation model can be widely used for individualization in machine
translation, image caption, dialogue generation and so on.Comment: published in PRICAI 201
Numerical Analysis on a Perforated Muffler Applied in the Discharge Chamber of a Twin Screw Refrigeration Compressor Based on Fluid-Acoustic Coupling Method
The twin screw compressor has been widely used in the refrigeration systems due to advantages such as compact structure, stable operation, high efficiency and good adaptability. Intermittent gas flow generates gas pulsation that cause serious problems such as structural vibration and noise in the twin screw refrigeration compressor. Because the mechanical noise can be controlled well with the improvement of machining and assembly accuracy, the aerodynamic noise induced by gas pulsation even has become the main noise source of the twin screw refrigeration compressor. In order to reduce the pressure pulsation, a broadband perforated panel muffler applied in the discharge chamber of the twin screw refrigeration compressor is proposed based on the noise spectrum and flow characteristics of the compressor. In order to obtain the noise spectrum of the twin screw refrigeration compressor, the pressure fluctuation in discharge chamber based on a three-dimensional CFD simulation model is calculated, and the acoustical model is established based on fluid-acoustic coupling method. Then the impacts of different structural parameters on the performance of a perforated panel muffler are investigated, including perforation rate, perforation diameter and panel thickness. Through the optimization of the perforated muffler, a better reduction effect of broadband noise can be achieved. Results of fluid-acoustic coupled analysis can provide guidance on the design and optimization of the perforated muffler and noise reduction of the twin screw refrigeration compressor
Parental Burnout and Prosocial Behavior among Chinese Adolescents: The Role of Empathy
peer reviewedParental burnout refers to exhaustion caused by the parenting role. This devastating negative emotion can have repercussions for adolescent social development. Nevertheless, much remains unclear about the association between parental burnout and adolescent prosocial behavior and the potential mechanisms underlying this relationship. Based on theoretical and empirical evidence, the current study examined the relationship between parental burnout and adolescent prosocial behavior by using a sequential mediation model that included both parental empathy and adolescent empathy as potential mediators. A total of 488 parent–adolescent dyads (for adolescents: 45.7% men, 54.3% women, Mage = 15.28 ± 1.67 years; for parents: 36.5% fathers, 63.5% mothers, Mage = 41.30 ± 3.79 years) completed questionnaires regarding demographics, social desirability, parental burnout, parental empathy, adolescent empathy, and adolescent prosocial behavior. After controlling for demographic covariates and social desirability, the results showed that parental burnout had a negative effect on adolescent-reported prosocial behavior through parental cognitive empathy and adolescent other-oriented empathy (adolescent cognitive empathy and empathic concern) sequentially. These findings contribute to our understanding of the role of parental burnout as a family environmental factor detrimental to the positive functioning of adolescents through parental reactions to their children’s emotions and children’s own social competence
High-dimensional orbital angular momentum entanglement concentration based on Laguerre-Gaussian mode selection
Twisted photons enable the definition of a Hilbert space beyond two dimensions by orbital angular momentum (OAM) eigenstates. Here we propose a feasible entanglement concentration experiment, to enhance the quality of high-dimensional entanglement shared by twisted photon pairs. Our approach is started from the full characterization of entangled spiral bandwidth, and is then based on the careful selection of the Laguerre–Gaussian (LG) modes with specific radial and azimuthal indices p and `. In particular, we demonstrate the possibility of high-dimensional entanglement concentration residing in the OAM subspace of up to 21 dimensions. By means of LabVIEW simulations with spatial light modulators, we show that the Shannon dimensionality could be employed to quantify the quality of the present concentration. Our scheme holds promise in quantum information applications defined in high-dimensional Hilbert space
Recommended from our members
Flow rate of depuration system has minimal impact on Vibrio parahaemolyticus decontamination in Pacific oysters (Crassostrea gigas)
Vibrio parahaemolyticus infections in the United States have been linked to consumption of raw oysters. Depuration has the potential to reduce contamination in live oysters after harvest. This study investigated the impact of depuration flow rate to reduce V. parahaemolyticus in raw oysters. Pacific oysters (n = 35 per trial) were inoculated with a cocktail of V. parahaemolyticus (10290, 10292, 10293, BE 98-2029, and 027-1c1) in freshly prepared artificial seawater (70 L). The inoculated oysters were depurated with flow rates of 15, 20, 25, and 35 L/min at 12.5 degrees C for up to 5 days and V. parahaemolyticus contamination was determined using a three-tube most probable number (MPN) method. V. parahaemolyticus reductions were as flow rate moderately increased from 15 L/min (2.39 log MPN/g reduction in 5 days) to 35 L/min (3.39 log MPN/g reduction). These results suggest that depuration efficacy can be enhanced by increasing depuration flow rate to 35 L/min.
Practical applications
Vibrio parahaemolyticus can contaminate raw shellfish, including oysters, during their production and lead to outbreaks of foodborne illness. Depuration, a post-harvest process, may be used by the shellfish industry to reduce the persistence of V. parahaemolyticus. Previous studies have demonstrated that the depuration process can reduce V. parahaemolyticus in oysters; however, further optimization of the process is necessary to achieve US Food Drug Administration's targeted reduction goal (>3.52 log MPN/g). This study evaluated the impact of depuration flow rate on the reduction of V. parahaemolyticus in Pacific oysters. Increasing flow rates (15-35 L/min) during depuration enhanced the clearance of V. parahaemolyticus in these oysters; however, these conditions were unable to consistently achieve the target of >3.52 log MPN/g reduction. This study provides a reference for the industry on the variability of V. parahaemolyticus in individual oysters and demonstrates that practical modifications (i.e., flow rate) can be implemented in depuration systems to maximize bacterial clearance
Integrative analysis of the metabolome and transcriptome reveals the molecular mechanism of chlorogenic acid synthesis in peach fruit
As the most abundant phenolic acid in peach fruit, chlorogenic acid (CGA) is an important entry point for the development of natural dietary supplements and functional foods. However, the metabolic and regulation mechanisms underlying its accumulation in peach fruits remain unclear. In this study, we evaluated the composition and content of CGAs in mature fruits of 205 peach cultivars. In peach fruits, three forms of CGA (52.57%), neochlorogenic acid (NCGA, 47.13%), and cryptochlorogenic acid (CCGA, 0.30%) were identified. During the growth and development of peach fruits, the content of CGAs generally showed a trend of rising first and then decreasing. Notably, the contents of quinic acid, shikimic acid, p-coumaroyl quinic acid, and caffeoyl shikimic acid all showed similar dynamic patterns to that of CGA, which might provide the precursor material basis for the accumulation of CGA in the later stage. Moreover, CGA, lignin, and anthocyanins might have a certain correlation and these compounds work together to maintain a dynamic balance. By the comparative transcriptome analysis, 8 structural genes (Pp4CL, PpCYP98A, and PpHCT) and 15 regulatory genes (PpMYB, PpWRKY, PpERF, PpbHLH, and PpWD40) were initially screened as candidate genes of CGA biosynthesis. Our findings preliminarily analyzed the metabolic and molecular regulation mechanisms of CGA biosynthesis in peach fruit, which provided a theoretical basis for developing high-CGA content peaches in future breeding programs
Mechanisms of Bushenyiqi decoction in the treatment of asthma: an investigation based on network pharmacology with experimental validation
Background and purpose: The Bushenyiqi decoction (BYD), a contemporary prescription of traditional Chinese medicine (TCM), has been observed to significantly ameliorate asthma symptoms in patients based on clinical observations. Although multi-component and multi-target characteristics are important attributes of BYD treatment, its pharmacological effect on asthma and the underlying mechanism of action remain unclear.Method: Network pharmacology: the asthma-related genes were retrieved from the GeneCards and OMIM database. The active constituents of BYD and their corresponding target genes were collected from the TCMSP database. The underlying pathways associated with overlapping targets between BYD and asthma were identified through GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis. Experimental validation: pulmonary function tests, enzyme-linked immunosorbent assay (ELISA), Hematoxylin and eosin (HE), periodic acid-Schiff (PAS), and Masson’s trichrome stainings were conducted to validate the efficacy of BYD in ameliorating airway inflammation in allergic asthma mice. Western blot (WB) and molecular docking were performed to confirm the involvement of the underlying pathway in BYD treatment of asthma.Results: The results of animal experiments demonstrated that BYD may improve airway responsiveness and suppress airway inflammation in allergic asthma mice. The network pharmacological analysis revealed the involvement of 11 potentially key active components, 9 potential key targets, and the phosphatidylinositol3 kinase-RAC-α serine/threonine-protein kinase (PI3K/AKT) signaling pathway in the mechanism of action of BYD for asthma treatment. Our findings have confirmed that BYD effectively alleviated airway inflammation by targeting interleukin 6 (IL-6), epidermal growth factor receptor (EGFR), and hypoxia inducible factor 1 alpha (HIF1A), with quercetin, kaempferol, and luteolin performing as the pivotal active constituents. BYD may potentially reduce inflammatory cell infiltration in lung tissues by regulating the PI3K/AKT signaling pathway.Conclusion: In conclusion, the integration of network pharmacology and biological experiments has demonstrated that key constituents of BYD, such as quercetin, kaempferol, and luteolin, exhibit targeted effects on IL-6, EGFR, and HIF1A in combating asthma-related inflammation through inhibition of the PI3K/AKT signaling pathway. The findings of this investigation provide evidence supporting the effectiveness of TCM’s “bushenyiqi” therapy in asthma management, as corroborated by contemporary medical technology
Patterns in leaf traits of woody species and their environmental determinants in a humid karstic forest in southwest China
IntroductionLeaf functional traits constitute a crucial component of plant functionality, providing insights into plants’ adaptability to the environment and their regulatory capacity in complex habitats. The response of leaf traits to environmental factors at the community level has garnered significant attention. Nevertheless, an examination of the environmental factors determining the spatial distribution of leaf traits in the karst region of southwest China remains absent.MethodsIn this study, we established a 25 ha plot within a karst forest and collected leaf samples from 144 woody species. We measured 14 leaf traits, including leaf area (LA), leaf thicknes (LT), specific leaf area (SLA), leaf length to width ratio (LW), leaf tissue density (LTD), leaf carbon concentration (LC), leaf nitrogen concentration (LN), and leaf phosphorus concentration (LP), leaf potassium concentration (LK), leaf calcium concentration (LCa), leaf magnesium Concentration (LMg), leaf carbon to nitrogen ratio (C/N), leaf carbon to phosphorus ratio (C/P), and leaf nitrogen to phosphorus ratio (N/P), to investigate the spatial distribution of community-level leaf traits and the response of the leaf trait community-weighted mean (CWM) to topographic, soil, and spatial factors.ResultsResults showed that the CWM of leaf traits display different spatial patterns, first, the highest CWM values for LT, LTD, C/N, and C/P at hilltops, second, the highest CWM values for LA, SLA, LW, LC, LN, LP, and LK at depressions, and third, the highest CWM values for LCa, LMg, and N/P at slopes. The correlation analysis showed that topographic factors were more correlated with leaf trait CWM than soil factors, with elevation and slope being the strongest correlations. RDA analysis showed that topographic factors explained higher percentage of leaf trait CWM than soil factors, with the highest percentage of 19.96% being explained by elevation among topographic factors. Variance Partitioning Analysis showed that the spatial distribution of leaf traits is predominantly influenced by the combined effects of topography and spatial factors (37%-47% explained), followed by purely spatial factors (24%-36% explained).DiscussionThe results could improve our understanding of community functional traits and their influencing factors in the karst region, which will contribute to a deeper understanding of the mechanisms that shape plant communities