83 research outputs found
Label Mask AutoEncoder(L-MAE): A Pure Transformer Method to Augment Semantic Segmentation Datasets
Semantic segmentation models based on the conventional neural network can
achieve remarkable performance in such tasks, while the dataset is crucial to
the training model process. Significant progress in expanding datasets has been
made in semi-supervised semantic segmentation recently. However, completing the
pixel-level information remains challenging due to possible missing in a label.
Inspired by Mask AutoEncoder, we present a simple yet effective Pixel-Level
completion method, Label Mask AutoEncoder(L-MAE), that fully uses the existing
information in the label to predict results. The proposed model adopts the
fusion strategy that stacks the label and the corresponding image, namely Fuse
Map. Moreover, since some of the image information is lost when masking the
Fuse Map, direct reconstruction may lead to poor performance. Our proposed
Image Patch Supplement algorithm can supplement the missing information, as the
experiment shows, an average of 4.1% mIoU can be improved. The Pascal VOC2012
dataset (224 crop size, 20 classes) and the Cityscape dataset (448 crop size,
19 classes) are used in the comparative experiments. With the Mask Ratio
setting to 50%, in terms of the prediction region, the proposed model achieves
91.0% and 86.4% of mIoU on Pascal VOC 2012 and Cityscape, respectively,
outperforming other current supervised semantic segmentation models. Our code
and models are available at https://github.com/jjrccop/Label-Mask-Auto-Encoder
THEORY RESEARCH ON APPLICATION OF CT TECHNOLOGY TO SHIELDED NUCLEAR MATERIAL DISCRIMINATION
Abstract Smuggling of nuclear material is a serious threat to security of international society. Formal research on nuclear material discrimination can fulfil customs inspection requirement. This paper designs a situation that nuclear material which is packaged and shielded by heavy metal need to be discriminated accurately on the condition that the object being detected cannot be dismantled. Calculation results prove nuclear material could be discriminated accurately while the ideal condition is fulfilled. If multi-energy X-ray source is used the discrimination accuracy is declined. However the accuracy could be improved while energy spectrum shaping technique is used
Magnesium-Rich Calcium Phosphate Derived from Tilapia Bone Has Superior Osteogenic Potential
We extracted magnesium-rich calcium phosphate bioceramics from tilapia bone using a gradient thermal treatment approach and investigated their chemical and physicochemical properties. X-ray diffraction showed that tilapia fish bone-derived hydroxyapatite (FHA) was generated through the first stage of thermal processing at 600â800 °C. Using FHA as a precursor, fish bone biphasic calcium phosphate (FBCP) was produced after the second stage of thermal processing at 900â1200 °C. The beta-tricalcium phosphate content in the FBCP increased with an increasing calcination temperature. The fact that the lattice spacing of the FHA and FBCP was smaller than that of commercial hydroxyapatite (CHA) suggests that Mg-substituted calcium phosphate was produced via the gradient thermal treatment. Both the FHA and FBCP contained considerable quantities of magnesium, with the FHA having a higher concentration. In addition, the FHA and FBCP, particularly the FBCP, degraded faster than the CHA. After one day of degradation, both the FHA and FBCP released Mg2+, with cumulative amounts of 4.38 mg/L and 0.58 mg/L, respectively. Furthermore, the FHA and FBCP demonstrated superior bone-like apatite formation; they are non-toxic and exhibit better osteoconductive activity than the CHA. In light of our findings, bioceramics originating from tilapia bone appear to be promising in biomedical applications such as fabricating tissue engineering scaffolds
Retrievals of Arctic sea ice melt pond depth and underlying ice thickness using optical data
Melt pond is a distinctive characteristic of the summer Arctic, which affects energy balance in the Arctic system. The Delta-Eddington model (BL) and Two-strEam rAdiative transfer model (TEA) are employed to retrieving pond depth Hp and underlying ice thickness Hi according to the ratio X of the melt-pond albedo in two bands. Results showed that when Îť1 = 359 nm and Îť2 = 605 nm, the Pearsonâs correlation coefficient r between X and Hp is 0.99 for the BL model. The result of TEA model was similar to the BL model. The retrievals of Hp for the two models agreed well with field observations. For Hi, the highest r (0.99) was obtained when Îť1 = 447 nm and Îť2 = 470 nm for the BL model, Îť1 = 447 nm and Îť2 = 451 nm for the TEA model. Furthermore, the BL model was more suitable for the retrieval of thick ice (0 < Hi < 3.5 m, R2 = 0.632), while the TEA model is on the contrary (Hi < 1 m, R2 = 0.842). The present results provide a potential method for the remote sensing on melt pond and ice in the Arctic summer
The Maunakea Spectroscopic Explorer Book 2018
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is
intended as a concise reference guide to all aspects of the scientific and
technical design of MSE, for the international astronomy and engineering
communities, and related agencies. The current version is a status report of
MSE's science goals and their practical implementation, following the System
Conceptual Design Review, held in January 2018. MSE is a planned 10-m class,
wide-field, optical and near-infrared facility, designed to enable
transformative science, while filling a critical missing gap in the emerging
international network of large-scale astronomical facilities. MSE is completely
dedicated to multi-object spectroscopy of samples of between thousands and
millions of astrophysical objects. It will lead the world in this arena, due to
its unique design capabilities: it will boast a large (11.25 m) aperture and
wide (1.52 sq. degree) field of view; it will have the capabilities to observe
at a wide range of spectral resolutions, from R2500 to R40,000, with massive
multiplexing (4332 spectra per exposure, with all spectral resolutions
available at all times), and an on-target observing efficiency of more than
80%. MSE will unveil the composition and dynamics of the faint Universe and is
designed to excel at precision studies of faint astrophysical phenomena. It
will also provide critical follow-up for multi-wavelength imaging surveys, such
as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field
Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation
Very Large Array.Comment: 5 chapters, 160 pages, 107 figure
Application of pushover analysis in estimating seismic demands for large-span spatial structure
p. 1987-1994Pushover analysis has been widely adopted in the seismic analysis of low- and medium-rise structures. It needs to be studied whether it is accurate for large-span spatial structure. In this paper, pushover analysis of a large-span spatial structure, Beijing A380 hangar structure at Capital International Airport is introduced. The modal load pattern is adopted to perform pushover analysis for the hangar structure. The pushover analysis results are compared with nonlinear response history analysis results. It is concluded that pushover analysis is accurate enough for large-span spatial structure, provided the modal participating mass ratio is larger than about 0.65.Zhang, W.; Qian, J. (2010). Application of pushover analysis in estimating seismic demands for large-span spatial structure. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/718
Identification and Virulence Assay of the Entomogenous Fungus FE-1 Strain Isolated from Phenacoccus solenoposis
ăObjectiveăThis study aimed to evaluate the biocontrol potential of an entomogenous fungus strain isolated from Phenacoccus solenoposis, for providing the basis of its development as a biocontrol agent.ăMethodăThe strain was isolated and purified from the diseased P.solenoposis using tissue isolation method. Based on the cultural traits, morphological traits and phylogenetic tree analysis, its taxonomic ststus was clarified. The infection mode of strain on P.solenoposis was explored by scanning electron microscope, which clarified its ability to infect P.solenoposis. The pathogenicity of the strain to P.solenoposis was measured by leaf dipping and insect dipping method.ăResultăA strain FE-1 was isolated and purified from the diseased P.solenoposis, the morphological traits results showed that the colony diameter of strain FE-1 ranged from 50 to 60 mm at 5 days on PDA medium, and the colony was orange-white in front. The conidia morphology had two types, which small type was long column shape and large spore was sickle shape. The strain FE-1 was identified as Fusarium equiseti based on cultural traits, morphological traits and phglogenetic tree analysis. The strain FE-1 infected into the insect body cavity of P.solenoposis mainly by conidia germination forming germ tubes at the epidermis for growing horizontally, and the formation of expanded appressorium at the specific contact epidermis, which clarified its ability to infect P.solenoposis. The results of indoor toxicity measuremerts showed that the pathogenicity of strain FE-1 against female adults of P.solenoposis was gradually increased with the concentration of conidial suspension. At the spore concentration of 1Ă108 CFU / mL, LT50 was 3.32 days, while at 7 days after inoculation, the adjusted mortality of P.solenoposis female adults was 87.50Âą1.79%, LC50 was 1.8Ă105 CFU /mL.ăConclusionăA strain FE-1 isolated and purified from the diseased P.solenoposis can form expanded appressorium at the specific contact epidermis for infection, which clarifies its ability to infect P.solenoposis. Meanwhile, the strain FE-1 is highly pathogenic against P.solenoposis, which has great potential for biocontrol and provide original material for the biocontrol research of P.solenoposis
Material discrimination and mixture ratio estimation in nanocomposites via harmonic atomic force microscopy
Harmonic atomic force microscopy (AFM) was employed to discriminate between different materials and to estimate the mixture ratio of the constituent components in nanocomposites. The major influencing factors, namely amplitude feedback set-point, drive frequency and laser spot position along the cantilever beam, were systematically investigated. Employing different set-points induces alternation of tipâsample interaction forces and thus different harmonic responses. The numerical simulations of the cantilever dynamics were well-correlated with the experimental observations. Owing to the deviation of the drive frequency from the fundamental resonance, harmonic amplitude contrast reversal may occur. It was also found that the laser spot position affects the harmonic signal strengths as expected. Based on these investigations, harmonic AFM was employed to identify material components and estimate the mixture ratio in multicomponent materials. The composite samples are composed of different kinds of nanoparticles with almost the same shape and size. Higher harmonic imaging offers better information on the distribution and mixture of different nanoparticles as compared to other techniques, including topography and conventional tapping phase. Therefore, harmonic AFM has potential applications in various fields of nanoscience and nanotechnology
Large-scale fabrication of nanostructure on bio-metallic substrate for surface enhanced raman and fluorescence scattering
The integration of surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF) has attracted increasing interest and is highly probable to improve the sensitivity and reproducibility of spectroscopic investigations in biomedical fields. In this work, dual-mode SERS and SEF hierarchical structures have been developed on a single bio-metallic substrate. The hierarchical structure was composed of micro-grooves, nano-particles, and nano-ripples. The crystal violet was selected as reporter molecule and both the intensity of Raman and fluorescence signals were enhanced because of the dual-mode SERSâSEF phenomena with enhancement factors (EFs) of 7.85 Ă 105 and 14.32, respectively. The Raman and fluorescence signals also exhibited good uniformity with the relative standard deviation value of 2.46% and 5.15%, respectively. Moreover, the substrate exhibited high sensitivity with the limits of detection (LOD) as low as 1 Ă 10â11 mol/L using Raman spectroscopy and 1 Ă 10â10 mol/L by fluorescence spectroscopy. The combined effect of surface plasmon resonance and âhot spotsâ induced by the hierarchical laser induced periodical surface structures (LIPSS) was mainly contributed to the enhancement of Raman and fluorescence signal. We propose that the integration of SERS and SEF in a single bio-metallic substrate is promising to improve the sensitivity and reproducibility of detection in biomedical investigations.Published versio
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