129 research outputs found
SAR Ship Target Recognition Via Multi-Scale Feature Attention and Adaptive-Weighed Classifier
Maritime surveillance is indispensable for civilian fields, including
national maritime safeguarding, channel monitoring, and so on, in which
synthetic aperture radar (SAR) ship target recognition is a crucial research
field. The core problem to realizing accurate SAR ship target recognition is
the large inner-class variance and inter-class overlap of SAR ship features,
which limits the recognition performance. Most existing methods plainly extract
multi-scale features of the network and utilize equally each feature scale in
the classification stage. However, the shallow multi-scale features are not
discriminative enough, and each scale feature is not equally effective for
recognition. These factors lead to the limitation of recognition performance.
Therefore, we proposed a SAR ship recognition method via multi-scale feature
attention and adaptive-weighted classifier to enhance features in each scale,
and adaptively choose the effective feature scale for accurate recognition. We
first construct an in-network feature pyramid to extract multi-scale features
from SAR ship images. Then, the multi-scale feature attention can extract and
enhance the principal components from the multi-scale features with more
inner-class compactness and inter-class separability. Finally, the adaptive
weighted classifier chooses the effective feature scales in the feature pyramid
to achieve the final precise recognition. Through experiments and comparisons
under OpenSARship data set, the proposed method is validated to achieve
state-of-the-art performance for SAR ship recognition
Boosting Multi-Modal E-commerce Attribute Value Extraction via Unified Learning Scheme and Dynamic Range Minimization
With the prosperity of e-commerce industry, various modalities, e.g., vision
and language, are utilized to describe product items. It is an enormous
challenge to understand such diversified data, especially via extracting the
attribute-value pairs in text sequences with the aid of helpful image regions.
Although a series of previous works have been dedicated to this task, there
remain seldomly investigated obstacles that hinder further improvements: 1)
Parameters from up-stream single-modal pretraining are inadequately applied,
without proper jointly fine-tuning in a down-stream multi-modal task. 2) To
select descriptive parts of images, a simple late fusion is widely applied,
regardless of priori knowledge that language-related information should be
encoded into a common linguistic embedding space by stronger encoders. 3) Due
to diversity across products, their attribute sets tend to vary greatly, but
current approaches predict with an unnecessary maximal range and lead to more
potential false positives. To address these issues, we propose in this paper a
novel approach to boost multi-modal e-commerce attribute value extraction via
unified learning scheme and dynamic range minimization: 1) Firstly, a unified
scheme is designed to jointly train a multi-modal task with pretrained
single-modal parameters. 2) Secondly, a text-guided information range
minimization method is proposed to adaptively encode descriptive parts of each
modality into an identical space with a powerful pretrained linguistic model.
3) Moreover, a prototype-guided attribute range minimization method is proposed
to first determine the proper attribute set of the current product, and then
select prototypes to guide the prediction of the chosen attributes. Experiments
on the popular multi-modal e-commerce benchmarks show that our approach
achieves superior performance over the other state-of-the-art techniques
Identification and Characterization of an Efficient acyl-CoA:Diacylglycerol Acyltransferase 1 (\u3cem\u3eDGAT1\u3c/em\u3e) Gene from the Microalga \u3cem\u3eChlorella ellipsoidea\u3c/em\u3e
Background: Oil in the form of triacylglycerols (TAGs) is quantitatively the most important storage form of energy for eukaryotic cells. Diacylglycerol acyltransferase (DGAT) is considered the rate-limiting enzyme for TAG accumulation. Chlorella, a unicellular eukaryotic green alga, has attracted much attention as a potential feedstock for renewable energy production. However, the function of DGAT1 in Chlorella has not been reported.
Results: A full-length cDNA encoding a putative diacylglycerol acyltransferase 1 (DGAT1, EC 2.3.1.20) was obtained from Chlorella ellipsoidea. The 2,142 bp open reading frame of this cDNA, designated CeDGAT1, encodes a protein of 713 amino acids showing no more than 40% identity with DGAT1s of higher plants. Transcript analysis showed that the expression level of CeDGAT1 markedly increased under nitrogen starvation, which led to significant triacylglycerol (TAG) accumulation. CeDGAT1 activity was confirmed in the yeast quadruple mutant strain H1246 by restoring its ability to produce TAG. Upon expression of CeDGAT1, the total fatty acid content in wild-type yeast (INVSc1) increased by 142%, significantly higher than that transformed with DGAT1s from higher plants, including even the oil crop soybean. The over-expression of CeDGAT1 under the NOS promoter in wild-type Arabidopsis thaliana and Brassica napus var. Westar significantly increased the oil content by 8β37% and 12β18% and the average 1,000-seed weight by 9β15% and 6β29%, respectively, but did not alter the fatty acid composition of the seed oil. The net increase in the 1,000-seed total lipid content was up to 25β50% in both transgenic Arabidopsis and B. napus.
Conclusions: We identified a gene encoding DGAT1 in C. ellipsoidea and confirmed that it plays an important role in TAG accumulation. This is the first functional analysis of DGAT1 in Chlorella. This information is important for understanding lipid synthesis and accumulation in Chlorella and for genetic engineering to enhance oil production in microalgae and oil plants
Identification and characterization of an efficient acyl-CoA: diacylglycerol acyltransferase 1 (DGAT1) gene from the microalga Chlorella ellipsoidea
RT-PCR detection of DGAT1 genes in transgenic yeast (INVSc1). The yeast actin was used as an internal control. 1, The yeast transformed with pYES2.0; 2Γ’ΒΒ5, the yeast expressing AtDGAT1, GmDGAT1, BnDGAT1 and CeDGAT1, respectively. (DOCX 55ΓΒ kb
Zero-1-to-3: Domain-level Zero-shot Cognitive Diagnosis via One Batch of Early-bird Students towards Three Diagnostic Objectives
Cognitive diagnosis seeks to estimate the cognitive states of students by
exploring their logged practice quiz data. It plays a pivotal role in
personalized learning guidance within intelligent education systems. In this
paper, we focus on an important, practical, yet often underexplored task:
domain-level zero-shot cognitive diagnosis (DZCD), which arises due to the
absence of student practice logs in newly launched domains. Recent cross-domain
diagnostic models have been demonstrated to be a promising strategy for DZCD.
These methods primarily focus on how to transfer student states across domains.
However, they might inadvertently incorporate non-transferable information into
student representations, thereby limiting the efficacy of knowledge transfer.
To tackle this, we propose Zero-1-to-3, a domain-level zero-shot cognitive
diagnosis framework via one batch of early-bird students towards three
diagnostic objectives. Our approach initiates with pre-training a diagnosis
model with dual regularizers, which decouples student states into domain-shared
and domain-specific parts. The shared cognitive signals can be transferred to
the target domain, enriching the cognitive priors for the new domain, which
ensures the cognitive state propagation objective. Subsequently, we devise a
strategy to generate simulated practice logs for cold-start students through
analyzing the behavioral patterns from early-bird students, fulfilling the
domain-adaption goal. Consequently, we refine the cognitive states of
cold-start students as diagnostic outcomes via virtual data, aligning with the
diagnosis-oriented goal. Finally, extensive experiments on six real-world
datasets highlight the efficacy of our model for DZCD and its practical
application in question recommendation. The code is publicly available at
https://github.com/bigdata-ustc/Zero-1-to-3.Comment: Accepted by AAAI202
Extraction Optimization of Water-Extracted Mycelial Polysaccharide from Endophytic Fungus Fusarium oxysporum Dzf17 by Response Surface Methodology
Water-extracted mycelial polysaccharide (WPS) from the endophytic fungus Fusarium oxysporum Dzf17 isolated from Dioscorea zingiberensis was found to be an efficient elicitor to enhance diosgenin accumulation in D. zingigerensis cultures, and also demonstrated antioxidant activity. In this study, response surface methodology (RSM) was employed to optimize the extraction process of WPS from F. oxysporum Dzf17 using Box-Behnken design (BBD). The ranges of the factors investigated were 1β3 h for extraction time (X1), 80β100 Β°C for extraction temperature (X2), and 20β40 (v/w) for ratio of water volume (mL) to raw material weight (g) (X3). The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis. Statistical analysis showed that the polynomial regression model was in good agreement with the experimental results with the determination coefficient (R2) of 0.9978. By solving the regression equation and analyzing the response surface contour plots, the extraction parameters were optimized as 1.7 h for extraction time, 95 Β°C for extraction temperature, 39 (v/w) for ratio of water volume (mL) to raw material weight (g), and with 2 extractions. The maximum value (10.862%) of WPS yield was obtained when the WPS extraction process was conducted under the optimal conditions
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