123 research outputs found
Accelerated K-Serial Stable Coalition for Dynamic Capture and Resource Defense
Coalition is an important mean of multi-robot systems to collaborate on
common tasks. An effective and adaptive coalition strategy is essential for the
online performance in dynamic and unknown environments. In this work, the
problem of territory defense by large-scale heterogeneous robotic teams is
considered. The tasks include exploration, capture of dynamic targets, and
perimeter defense over valuable resources. Since each robot can choose among
many tasks, it remains a challenging problem to coordinate jointly these robots
such that the overall utility is maximized. This work proposes a generic
coalition strategy called K-serial stable coalition algorithm (KS-COAL).
Different from centralized approaches, it is distributed and complete, meaning
that only local communication is required and a K-serial Stable solution is
ensured. Furthermore, to accelerate adaptation to dynamic targets and resource
distribution that are only perceived online, a heterogeneous graph attention
network (HGAN)-based heuristic is learned to select more appropriate parameters
and promising initial solutions during local optimization. Compared with manual
heuristics or end-to-end predictors, it is shown to both improve online
adaptability and retain the quality guarantee. The proposed methods are
validated rigorously via large-scale simulations with 170 robots and hardware
experiments of 13 robots, against several strong baselines including GreedyNE
and FastMaxSum.Comment: 8 pages, 10 figures, 1 tabl
Isolation of high quality RNA from Polyporus umbellatus (Pers.) Fries
Background: The dried sclerotium of medicinal fungus Polyporus
umbellatus (Pers.) Fries has many pharmacological functions such as
diuretic and anticancer activity, in which high-content polysaccharides
may play an important role. However, RNA isolation is difficult in
filamentous fungi and lacking in P. umbellatus. Results: Five methods
for RNA extraction from five strains collected from four provinces were
assessed for their ability to recover a high-quality RNA applicable for
sequence-related amplification polymorphism (SRAP) PCR and
GDP-D-mannose pyrophosphorylase (GMP) gene expression profiles. Both
A260/A280 and A260/A230 ratios of the best Trizol Plus + RNAiso-mate
for Plant Tissue method are around 2 with a yield of 1122.00 \ub1
0.21 ng \u3bcl-1. The Trizol method also showed good quality with the
yield 469.60 ng \u3bcl-1. The SRAP PCR amplified clear and polymorphic
bands in all five cDNA samples transcribed from RNA by using primer
Me4-Em4. GMP gene fragment (1251 bp) was successfully amplified by
RT-PCR, suggesting the integrity of isolated RNA. Conclusion:All these
results showed that the total RNA isolated by this protocol is of
sufficient quality for subsequent molecular applications
Bloch surface plasmon enhanced blue emission from InGaN/GaN light-emitting diode structures with Al-coated GaN nanorods
InGaN/GaN light-emitting diode structures with Al-coated GaN nanorods were fabricated by using soft ultraviolet nanoimprint lithography. The intensity of light emission was found to be greatly enhanced due to the strong near-fields confined at the interface of Al/GaN and extended to the multiple quantum wells (MQWs) active region. The dynamics of carrier recombination and plasmon-enhanced Raman scattering were also investigated, providing a progressive view on the effective energy transfer between MQWs and surface plasmons.This work was supported by Special Funds for Major State
Basic Research Project (Nos. 2011CB301900 and
2012CB619304), the Hi-tech Research Project (No.
2014AA032605), National Nature Science Foundation of
China (Nos. 11104130, 61274003, 60990311, 61176063, and
61422401), the Program for New Century Excellent Talents
in University (No. NCET-11-0229), Nature Science Foundation
of Jiangsu Province (Nos. BK2011556, BK2011010,
BK2010385, BY2013077, and BE2011132), Funds of Key
Laboratory (No. 9140C140102120C14), Scientific Innovation
Research of College Graduate in Jiangsu Province
(CXZZ12_0052), PAPD, the Fundamental Research Funds
for the Central Universities, the Research Funds from NJUYangzhou
Institute of Opto-electronics, and the Australian
Research Council Discovery Early Career Researcher Award
(DE130101700)
Genome-Wide Association Studies for Dynamic Plant Height and Number of Nodes on the Main Stem in Summer Sowing Soybeans
Plant height (PH) and the number of nodes on the main stem (NN) serve as major plant architecture traits affecting soybean seed yield. Although many quantitative trait loci for the two traits have been reported, their genetic controls at different developmental stages in soybeans remain unclear. Here, 368 soybean breeding lines were genotyped using 62,423 single nucleotide polymorphism (SNP) markers and phenotyped for the two traits at three different developmental stages over two locations in order to identify their quantitative trait nucleotides (QTNs) using compressed mixed linear model (CMLM) and multi-locus random-SNP-effect mixed linear model (mrMLM) approaches. As a result, 11 and 13 QTNs were found by CMLM to be associated with PH and NN, respectively. Among these QTNs, 8, 3, and 4 for PH and 6, 6, and 8 for NN were found at the three stages, and 3 and 6 were repeatedly detected for PH and NN. In addition, 34 and 30 QTNs were found by mrMLM to be associated with PH and NN, respectively. Among these QTNs, 11, 13, and 16 for PH and 11, 15, and 8 for NN were found at the three stages. A majority of these QTNs overlapped with the previously reported loci. Moreover, one QTN within the known E2 locus for flowering time was detected for the two traits at all three stages, and another that overlapped with the Dt1 locus for stem growth habit was also identified for the two traits at the mature stage. This may explain the highly significant correlation between the two traits. Our findings provide evidence for mixed major plus polygenes inheritance for dynamic traits and an extended understanding of their genetic architecture for molecular dissection and breeding utilization in soybeans
Interpreting Deep Learning-Based Networking Systems
While many deep learning (DL)-based networking systems have demonstrated
superior performance, the underlying Deep Neural Networks (DNNs) remain
blackboxes and stay uninterpretable for network operators. The lack of
interpretability makes DL-based networking systems prohibitive to deploy in
practice. In this paper, we propose Metis, a framework that provides
interpretability for two general categories of networking problems spanning
local and global control. Accordingly, Metis introduces two different
interpretation methods based on decision tree and hypergraph, where it converts
DNN policies to interpretable rule-based controllers and highlight critical
components based on analysis over hypergraph. We evaluate Metis over several
state-of-the-art DL-based networking systems and show that Metis provides
human-readable interpretations while preserving nearly no degradation in
performance. We further present four concrete use cases of Metis, showcasing
how Metis helps network operators to design, debug, deploy, and ad-hoc adjust
DL-based networking systems.Comment: To appear at ACM SIGCOMM 202
Investigation on Antioxidant Activity and Different Metabolites of Mulberry (Morus spp.) Leaves Depending on the Harvest Months by UPLC–Q-TOF-MS with Multivariate Tools
The changes in active components in mulberry leaves harvested in different months and their antioxidant activities were investigated. Ultra-high-performance liquid chromatography–tandem quadrupole time-of-flight mass spectrometry (UPLC–Q-TOF-MS) with multivariate statistical tools was used to investigate the chemical constituents in the extracts of mulberry leaves. The results indicated that mulberry leaves were rich in phenolic acids, flavonoids, organic acids, and fatty acid derivatives. In addition, 25 different compounds were identified in the different batches of mulberry leaves. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was measured to evaluate the in vitro antioxidant activities of mulberry leaves. Among the four batches, batch A, harvested in December, exhibited the strongest DPPH radical-scavenging activity, while batch B, harvested in March, showed the weakest activity. This was related to the total phenolic content in the mulberry leaves of each batch. The optimal harvest time of mulberry leaves greatly influences the bioactivity and bioavailability of the plant
Vibration and buckling of a carbon nanotube inserted with a carbon chain
An elastic string-elastic shell model is developed to study vibration behaviors of a carbon nanowire. The present model predicts that non-coaxial vibration between the C-chain and the innermost tube does not occur due to negligible bending rigidity of the C-chain. In addition, it is found that the C-chain has most significant effect on the lowest frequency associated with radial vibration mode for circumferential wave-number 2 (n=2). In particular, the effect of the C-chain on axisymmetric radial breathing frequencies (n=0) predicted by the present model is found to be in reasonable agreement with known experimental and modeling results available in the literature. To study the buckling of a carbon nanowire made of the C-chain inserted inside a CNT, not only the elastic string-elastic shell model that used above but also the molecular dynamics (MD) simulation are adopted. For radial buckling, both continuum model and MD simulation predict that C-chain increases buckling stress by more than 40% to (2, 8), (0, 9), (3, 7) and (5, 5) tube. The continuum model predicts that circumferential wave number n=2 at buckling. Related with this, MD simulation shows that the cross-section of CNT is an ellipse at buckling. In particular, the nonlinear effects of vdW interaction have significant influence on the critical buckling loading. For the buckling under axial compression, two different kinds of buckling have been observed and investigated, namely the C-chain\u27s unconditional buckling, and the tube\u27s wall buckling, respectively. After the unconditional buckling, all displacements on the C-chain are in the same plane, and, the wave amplitudes\u27 localization phenomenon appears. To the tube\u27s wall buckling, the C-chain could either increase or decrease axial buckling strain depending on specific CNT chirality and temperature
Contamination Transport in the Coastal Unconfined Aquifer under the Influences of Seawater Intrusion and Inland Freshwater Recharge—Laboratory Experiments and Numerical Simulations
The coupled effect of seawater intrusion and inland freshwater recharge plays an important role in contamination transport in coastal heterogeneous aquifer. In this study, the effects of seawater intrusion and inland recharge on contamination transport were investigated by conducting laboratory experiments and numerical simulations. The laboratory tests were conducted in a sand tank considering two scenarios, namely the conditions of landward and seaward hydraulic gradients. The SEAWAT software was applied for validating the contaminant transport in coastal heterogeneous aquifer. The results indicated that the simulated seawater wedge and contours of the saltwater contaminant matched the observed ones well. The length of the seawater wedge in the scenario of seaward hydraulic gradient was smaller than that in the scenario of landward hydraulic gradient, which reflected that the large quantity of inland recharge have a negative effect on the invasion process of seawater. The plume moved mainly downward in the heterogeneous unconfined aquifer for both scenarios. The pollution plume became concave at the interface between each two layers, which was because the velocity of contaminant plume migration increased gradually from the upper layer to lower layer. The migration direction of the front of the plume was consistent with the direction of hydraulic gradient, which indicated that it was influenced by the water flowing. The maximum area of plume in the scenario of seaward hydraulic gradient was slightly smaller than that in the scenario of landward hydraulic gradient. The maximum area and vertical depth of the pollutant plume were sensitive to the hydraulic conductivity, dispersivity and contamination concentration. This study was of great significance to the controlling of pollution and utilization of freshwater resources in coastal areas
Prediction of protein subcellular location using the information entropy and the auto covariance transformation
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