106 research outputs found
Improving Scene Text Image Super-resolution via Dual Prior Modulation Network
Scene text image super-resolution (STISR) aims to simultaneously increase the
resolution and legibility of the text images, and the resulting images will
significantly affect the performance of downstream tasks. Although numerous
progress has been made, existing approaches raise two crucial issues: (1) They
neglect the global structure of the text, which bounds the semantic determinism
of the scene text. (2) The priors, e.g., text prior or stroke prior, employed
in existing works, are extracted from pre-trained text recognizers. That said,
such priors suffer from the domain gap including low resolution and blurriness
caused by poor imaging conditions, leading to incorrect guidance. Our work
addresses these gaps and proposes a plug-and-play module dubbed Dual Prior
Modulation Network (DPMN), which leverages dual image-level priors to bring
performance gain over existing approaches. Specifically, two types of
prior-guided refinement modules, each using the text mask or graphic
recognition result of the low-quality SR image from the preceding layer, are
designed to improve the structural clarity and semantic accuracy of the text,
respectively. The following attention mechanism hence modulates two
quality-enhanced images to attain a superior SR result. Extensive experiments
validate that our method improves the image quality and boosts the performance
of downstream tasks over five typical approaches on the benchmark. Substantial
visualizations and ablation studies demonstrate the advantages of the proposed
DPMN. Code is available at: https://github.com/jdfxzzy/DPMN.Comment: Accepted by AAAI-202
A new type seismic intensity meter
Abstract:A new type of seismic intensity meter based on MEMS accelerometer is introduced. It employs STM32F107 as the data processing core and detects the changes of acceleration with triaxial MEMS LIS344ALH and uses ADS1248 for 24 bit data sampling. The test on vibration table shows that the linearity of the meter is δL = ± 1.4%, and the sensitivity is Kc = 0.9671V/g with zero deviation of 0.0043g. The seismic intensity meter has the advantages of simple structure and stable performance and it is appropriate for intensive layout on a large scale
Progress of the satellite laser ranging system TROS1000
AbstractThe mobile satellite laser ranging system TROS1000, successfully developed in 2010, achieves a high repetition rate and enables daytime laser ranging. Its measurement range has reached up to 36000Â km with an accuracy as precise as 1Â cm. Using recent observations in Wuhan, Jiufeng, Xianning, and Rongcheng, Shandong, we introduce the progress made using this mobile observation system
p21-activated kinase is involved in the sporulation, pathogenicity, and stress response of Arthrobotrys oligospora under the indirect regulation of Rho GTPase-activating protein
The p21-GTPase-activated protein kinases (PAKs) participate in signal transduction downstream of Rho GTPases, which are regulated by Rho GTPase-activating proteins (Rho-GAP). Herein, we characterized two orthologous Rho-GAPs (AoRga1 and AoRga2) and two PAKs (AoPak1 and AoPak2) through bioinformatics analysis and reverse genetics in Arthrobotrys oligospora, a typical nematode-trapping (NT) fungus. The transcription analyses performed at different development stages suggested that Aopaks and Aorga1 play a crucial role during sporulation and trap formation, respectively. In addition, we successfully deleted Aopak1 and Aorga1 via the homologous recombination method. The disruption of Aopak1 and Aorga1 caused a remarkable reduction in spore yield and the number of nuclei per cell, but did not affect mycelial growth. In ∆Aopak1 mutants, the trap number was decreased at 48 h after the introduction of nematodes, but nematode predatory efficiency was not affected because the extracellular proteolytic activity was increased. On the contrary, the number of traps in ∆Aorga1 mutants was significantly increased at 36 h and 48 h. In addition, Aopak1 and Aorga1 had different effects on the sensitivity to cell-wall-disturbing reagent and oxidant. A yeast two-hybrid assay revealed that AoPak1 and AoRga1 both interacted with AoRac, and AoPak1 also interacted with AoCdc42. Furthermore, the Aopaks were up-regulated in ∆Aorga1 mutants, and Aorga1 was down-regulated in ∆Aopak1 mutants. These results reveal that AoRga1 indirectly regulated AoPAKs by regulating small GTPases
Efficient Comb Elliptic Curve Multiplication Methods Resistant to Power Analysis
Elliptic Curve Cryptography (ECC) has found wide applications in
smart cards and embedded systems. Point multiplication plays a
critical role in ECC. Many efficient point multiplication methods
have been proposed. One of them is the comb method which
is much more efficient than other methods if precomputation points
are calculated in advance or elsewhere. Unfortunately, Many
efficient point multiplication methods including the comb method are
vulnerable to power-analysis attacks. Various algorithms to make
elliptic curve point multiplication secure to power-analysis attacks
have been proposed recently, such as the double-and-add-always
method, Möller\u27s window method, Okeya
et al.\u27s odd-only window method, and Hedabou et al.\u27s
comb method. In this paper, we first present a novel comb
recoding algorithm which converts an integer to a sequence of
signed, odd-only comb bit-columns. Using this recoding algorithm, we
then present several comb methods, both Simple Power Analysis
(SPA)-nonresistant and SPA-resistant, for point multiplication.
These comb methods are more efficient than the original
SPA-nonresistant comb method and Hedabou et al.\u27s SPA-resistant comb
method. Our comb methods inherit the advantage of a comb method,
running much faster than Möller\u27s window method and Okeya et
al.\u27s odd-only window method, as well as other window methods such
as the efficient signed -ary window method, if only the
evaluation phase is taken into account. Combined with randomization
projective coordinates or other randomization techniques and certain
precautions in selecting elliptic curves and parameters, our
SPA-resistant comb methods are resistant to all power-analysis
attacks
Physical Characterization and Volatile Organic Compound Monitoring of Recycled Polyethylene Terephthalate under Mechanical Recycling
In this study, physical characterization and monitoring of volatile organic compounds (VOCs) were investigated on recycled polyethylene terephthalate (rPET) from a mechanical recycling process and rPET bottles made with different rPET contents, with the aim of tracing the source of rPET and assessing its safety when use as a food contact material. It was found that rPET had a similar thermal stability to that of virgin PET (vPET). rPET bottles did not show any significant changes in groups or structure and exhibit similar crystallization and melting behaviors to vPET. However, there were minor mechanical scratches in the surface micromorphology of rPET bottles, and the color of rPET bottles became darker, greener and yellower as the content of recycled material increased. The solid-state polycondensation process was found to play an important role in the removal of VOCs, as detected by headspace gas chromatography-mass spectrometry (HS-GC-MS), resulting in a very small amount of residual VOCs in rPET. Four VOCs (acetaldehyde, glycol and nonanal at levels less than 1.00 mg/kg; 2-methyl-1,3 dioxolane at levels of 1.72-5.76 mg/kg) were detected in the rPET bottles. This study shows that rPET bottles are qualified for reuse in food contact in terms of thermal properties, structure, morphology and VOC residues, although there is variability in color
Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution
Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst
Autocatalytic reduction-assisted synthesis of segmented porous PtTe nanochains for enhancing methanol oxidation reaction
Morphology engineering has been developed as one of the most widely used strategies for improving the performance of electrocatalysts. However, the harsh reaction conditions and cumbersome reaction steps during the nanomaterials synthesis still limit their industrial applications. Herein, one-dimensional (1D) novel-segmented PtTe porous nanochains (PNCs) were successfully synthesized by the template methods assisted by Pt autocatalytic reduction. The PtTe PNCs consist of consecutive mesoporous architectures that provide a large electrochemical surface area (ECSA) and abundant active sites to enhance methanol oxidation reaction (MOR). Furthermore, 1D nanostructure as a robust sustaining frame can maintain a high mass/charge transfer rate in a long-term durability test. After 2,000 cyclic voltammetry (CV) cycles, the ECSA value of PtTe PNCs remained as high as 44.47 m2·gPt–1, which was much larger than that of commercial Pt/C (3.95 m2·gPt–1). The high catalytic activity and durability of PtTe PNCs are also supported by CO stripping test and density functional theory calculation. This autocatalytic reduction-assisted synthesis provides new insights for designing efficient low-dimensional nanocatalysts
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