121 research outputs found
Few-Shot Medical Image Segmentation via a Region-enhanced Prototypical Transformer
Automated segmentation of large volumes of medical images is often plagued by
the limited availability of fully annotated data and the diversity of organ
surface properties resulting from the use of different acquisition protocols
for different patients. In this paper, we introduce a more promising few-shot
learning-based method named Region-enhanced Prototypical Transformer (RPT) to
mitigate the effects of large intra-class diversity/bias. First, a subdivision
strategy is introduced to produce a collection of regional prototypes from the
foreground of the support prototype. Second, a self-selection mechanism is
proposed to incorporate into the Bias-alleviated Transformer (BaT) block to
suppress or remove interferences present in the query prototype and regional
support prototypes. By stacking BaT blocks, the proposed RPT can iteratively
optimize the generated regional prototypes and finally produce rectified and
more accurate global prototypes for Few-Shot Medical Image Segmentation (FSMS).
Extensive experiments are conducted on three publicly available medical image
datasets, and the obtained results show consistent improvements compared to
state-of-the-art FSMS methods. The source code is available at:
https://github.com/YazhouZhu19/RPT.Comment: Accepted by MICCA
Partition-A-Medical-Image: Extracting Multiple Representative Sub-regions for Few-shot Medical Image Segmentation
Few-shot Medical Image Segmentation (FSMIS) is a more promising solution for
medical image segmentation tasks where high-quality annotations are naturally
scarce. However, current mainstream methods primarily focus on extracting
holistic representations from support images with large intra-class variations
in appearance and background, and encounter difficulties in adapting to query
images. In this work, we present an approach to extract multiple representative
sub-regions from a given support medical image, enabling fine-grained selection
over the generated image regions. Specifically, the foreground of the support
image is decomposed into distinct regions, which are subsequently used to
derive region-level representations via a designed Regional Prototypical
Learning (RPL) module. We then introduce a novel Prototypical Representation
Debiasing (PRD) module based on a two-way elimination mechanism which
suppresses the disturbance of regional representations by a self-support,
Multi-direction Self-debiasing (MS) block, and a support-query, Interactive
Debiasing (ID) block. Finally, an Assembled Prediction (AP) module is devised
to balance and integrate predictions of multiple prototypical representations
learned using stacked PRD modules. Results obtained through extensive
experiments on three publicly accessible medical imaging datasets demonstrate
consistent improvements over the leading FSMIS methods. The source code is
available at https://github.com/YazhouZhu19/PAMI
Experimental Investigation on Residual Stresses in Welded Medium-Walled I-shaped Sections Fabricated from Q460GJ Structural Steel Plates
GJ steel is a new type of high-performance structural steel which has been increasingly adopted in practical engineering. Q460GJ structural steel has a nominal yield strength of 460 MPa, which does not decrease significantly with the increase of steel plate thickness like normal structural steel. Thus, Q460GJ structural steel is normally used in medium-walled welded sections. However, research works on the residual stress in GJ steel members are few though it is one of the vital factors that can affect the member and structural behavior. This article aims to investigate the residual stresses in welded I-shaped sections fabricated from Q460GJ structural steel plates by experimental tests. A total of four full scale welded medium-walled I-shaped sections were tested by sectioning method. Both circular curve correction method and straightening measurement method were adopted in this study to obtain the final magnitude and distribution of the longitudinal residual stresses. In addition, this paper also explores the interaction between flanges and webs. And based on the statistical evaluation of the experimental data, a multilayer residual stress model is proposed
Digital Twin Modeling for Enhanced Operational Reliability: A Case Study on a Dredging Perception System
TEA-PSE 3.0: Tencent-Ethereal-Audio-Lab Personalized Speech Enhancement System For ICASSP 2023 DNS Challenge
This paper introduces the Unbeatable Team's submission to the ICASSP 2023
Deep Noise Suppression (DNS) Challenge. We expand our previous work, TEA-PSE,
to its upgraded version -- TEA-PSE 3.0. Specifically, TEA-PSE 3.0 incorporates
a residual LSTM after squeezed temporal convolution network (S-TCN) to enhance
sequence modeling capabilities. Additionally, the local-global representation
(LGR) structure is introduced to boost speaker information extraction, and
multi-STFT resolution loss is used to effectively capture the time-frequency
characteristics of the speech signals. Moreover, retraining methods are
employed based on the freeze training strategy to fine-tune the system.
According to the official results, TEA-PSE 3.0 ranks 1st in both ICASSP 2023
DNS-Challenge track 1 and track 2.Comment: Accepted by ICASSP 202
Synergistic effect of octadecyl ammonium oxide and oleate amide propyl betaine and development of a foam drainage reagent for natural gas production
Betaine surfactants are used widely in oil field chemistry as well as other industrial applications, but their foaming ability is very poor so that it cannot be used in foaming. In this work, the effect of octadecyl ammonium oxide on the foam properties of oleate amide propyl betaine, a new compound foaming reagent, is studied based on foam performance. Then, a foam drainage reagent of 0.5Â wt% oleate amide propyl betaine and 0.1Â wt% octadecyl ammonium oxide is developed for natural gas production. Its salt resistance, methanol resistance, high temperature resistance, anti-condensate oil performance, and emulsification ability are systematically evaluated. Furthermore, the factors affecting foam performance are analyzed. The results show that the compound foaming reagent has good anti-salt, anti-methanol, and anti-condensate oil properties for meeting application requirements. The microstructures of foams derived from different reagents reveal the stability mechanism. All results reflect the fact that compounding can expand their application range in different environments to various extents, which benefits the design and use of compound surfactants
Influence of heat stress on leaf morphology and nitrogen–carbohydrate metabolisms in two wucai (Brassica campestris L.) genotypes
Heat stress is a major environmental stress that limits plant growth and yield worldwide. The present study was carried out to explore the physiological mechanism of heat tolerant to provide the theoretical basis for heat-tolerant breeding. The changes of leaf morphology, anatomy, nitrogen assimilation, and carbohydrate metabolism in two wucai genotypes (WS-1, heat tolerant; WS-6, heat sensitive) grown under heat stress (40°C/30°C) for 7 days were investigated. Our results showed that heat stress hampered the plant growth and biomass accumulation in certain extent in WS-1 and WS-6. However, the inhibition extent of WS-1 was significantly smaller than WS-6. Thickness of leaf lamina, upper epidermis, and palisade mesophyll were increased by heat in WS-1, which might be contributed to the higher assimilation of photosynthates. During nitrogen assimilation, WS-1 possessed the higher nitrogen-related metabolic enzyme activities, including nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH), which were reflected by higher photosynthetic nitrogen-use efficiency (PNUE) with respect to WS-6. The total amino acids level had no influence in WS-1, whereas it was reduced in WS-6 by heat. And the proline contents of both wucai genotypes were all increased to respond the heat stress. Additionally, among all treatments, the total soluble sugar content of WS-1 by heat got the highest level, including higher contents of sucrose, fructose, and starch than those of WS-6. Moreover, the metabolism efficiency of sucrose to starch in WS-1 was greater than WS-6 under heat stress, proved by higher activities of sucrose phosphate synthase (SPS), sucrose synthase (SuSy), acid invertase (AI), and amylase. These results demonstrated that leaf anatomical alterations resulted in higher nitrogen and carbon assimilation in heat-tolerant genotype WS-1, which exhibited a greater performance to resist heat stress
Modification of sodium dodecyl sulfate and evaluation of foaming activity
In this study, to optimize the foaming activity of sodium dodecyl sulfate (SDS), modified sodium dodecyl sulfate surfactants (MSDS-1 and MSDS-2) are prepared by using methanol and diethanol amine as modifiers by the Mannich reaction. The foaming properties and foam stability of the products are evaluated by the Ross–Miles method and the Waring blender method. The microstructures of the foams produced by three surfactants are compared. The effects of temperature, inorganic salt, methanol, and condensate oil on the foaming activity of SDS, MSDS-1, and MSDS-2 are studied. The results obtained show that the best foaming concentration of all three products is 0.5%. Compared with SDS, the temperature resistance, methanol resistance, salt resistance and anti-condensate oil performance of MSDS-1 and MSDS-2 are improved. Among them, the temperature resistance, salt resistance, and methanol resistance of the MSDS-1 solution are the best. The MSDS-2 solution has the best anti-condensate performance. Besides, the foam size becomes smaller, the foam wall thickens, and the foam stability is improved after modification. The overall performance of SDS as a foaming agent can be improved by the Mannich modification
Modification of sodium dodecyl sulfate and evaluation of foaming activity
In this study, to optimize the foaming activity of sodium dodecyl sulfate (SDS), modified sodium dodecyl sulfate surfactants (MSDS-1 and MSDS-2) are prepared by using methanol and diethanol amine as modifiers by the Mannich reaction. The foaming properties and foam stability of the products are evaluated by the Ross–Miles method and the Waring blender method. The microstructures of the foams produced by three surfactants are compared. The effects of temperature, inorganic salt, methanol, and condensate oil on the foaming activity of SDS, MSDS-1, and MSDS-2 are studied. The results obtained show that the best foaming concentration of all three products is 0.5%. Compared with SDS, the temperature resistance, methanol resistance, salt resistance and anti-condensate oil performance of MSDS-1 and MSDS-2 are improved. Among them, the temperature resistance, salt resistance, and methanol resistance of the MSDS-1 solution are the best. The MSDS-2 solution has the best anti-condensate performance. Besides, the foam size becomes smaller, the foam wall thickens, and the foam stability is improved after modification. The overall performance of SDS as a foaming agent can be improved by the Mannich modification
Synergistic effect of octadecyl ammonium oxide and oleate amide propyl betaine and development of a foam drainage reagent for natural gas production
Betaine surfactants are used widely in oil field chemistry as well as other industrial applications, but their foaming ability is very poor so that it cannot be used in foaming. In this work, the effect of octadecyl ammonium oxide on the foam properties of oleate amide propyl betaine, a new compound foaming reagent, is studied based on foam performance. Then, a foam drainage reagent of 0.5Â wt% oleate amide propyl betaine and 0.1Â wt% octadecyl ammonium oxide is developed for natural gas production. Its salt resistance, methanol resistance, high temperature resistance, anti-condensate oil performance, and emulsification ability are systematically evaluated. Furthermore, the factors affecting foam performance are analyzed. The results show that the compound foaming reagent has good anti-salt, anti-methanol, and anti-condensate oil properties for meeting application requirements. The microstructures of foams derived from different reagents reveal the stability mechanism. All results reflect the fact that compounding can expand their application range in different environments to various extents, which benefits the design and use of compound surfactants
- …