221 research outputs found
Poly(ethylene glycol)-conjugated surfactants promote or inhibit aggregation of phospholipids
AbstractThe calcium-induced aggregation of dilauroyl phosphatidic acid (DLPA) suspensions, with or without added poly(ethylene oxide) (PEO)-conjugated surfactants containing 4 to 30 ethylene oxide subunits, were monitored by turbidity measurement and quasi-elastic light scattering (QLS). The aggregation was inhibited (protected) by the incorporated PEO surfactant for most samples, while a window for promotive effect was found for samples with low surface coverage by the PEO moiety of the incorporated surfactant. Promotion occurs only when the aggregation is slow and at a low level. The promotion is explained by the synergistic effect of PEO and divalent calcium cations when the steric repulsion is weak. The promotion/protection crossover is a display between the PEO/calcium synergistic effect and the steric repulsion
Segatron: Segment-Aware Transformer for Language Modeling and Understanding
Transformers are powerful for sequence modeling. Nearly all state-of-the-art
language models and pre-trained language models are based on the Transformer
architecture. However, it distinguishes sequential tokens only with the token
position index. We hypothesize that better contextual representations can be
generated from the Transformer with richer positional information. To verify
this, we propose a segment-aware Transformer (Segatron), by replacing the
original token position encoding with a combined position encoding of
paragraph, sentence, and token. We first introduce the segment-aware mechanism
to Transformer-XL, which is a popular Transformer-based language model with
memory extension and relative position encoding. We find that our method can
further improve the Transformer-XL base model and large model, achieving 17.1
perplexity on the WikiText-103 dataset. We further investigate the pre-training
masked language modeling task with Segatron. Experimental results show that
BERT pre-trained with Segatron (SegaBERT) can outperform BERT with vanilla
Transformer on various NLP tasks, and outperforms RoBERTa on zero-shot sentence
representation learning.Comment: Accepted by AAAI 202
Progressive Multi-Scale Residual Network for Single Image Super-Resolution
Multi-scale convolutional neural networks (CNNs) achieve significant success
in single image super-resolution (SISR), which considers the comprehensive
information from different receptive fields. However, recent multi-scale
networks usually aim to build the hierarchical exploration with different sizes
of filters, which lead to high computation complexity costs, and seldom focus
on the inherent correlations among different scales. This paper converts the
multi-scale exploration into a sequential manner, and proposes a progressive
multi-scale residual network (PMRN) for SISR problem. Specifically, we devise a
progressive multi-scale residual block (PMRB) to substitute the larger filters
with small filter combinations, and gradually explore the hierarchical
information. Furthermore, channel- and pixel-wise attention mechanism (CPA) is
designed for finding the inherent correlations among image features with
weighting and bias factors, which concentrates more on high-frequency
information. Experimental results show that the proposed PMRN recovers
structural textures more effectively with superior PSNR/SSIM results than other
small networks. The extension model PMRN with self-ensemble achieves
competitive or better results than large networks with much fewer parameters
and lower computation complexity.Comment: This work has been submitted to the IEEE for possible publication.
Copyright may be transferred without notice, after which this version may no
longer be accessibl
Deformable 3D Gaussians for High-Fidelity Monocular Dynamic Scene Reconstruction
Implicit neural representation has opened up new avenues for dynamic scene
reconstruction and rendering. Nonetheless, state-of-the-art methods of dynamic
neural rendering rely heavily on these implicit representations, which
frequently struggle with accurately capturing the intricate details of objects
in the scene. Furthermore, implicit methods struggle to achieve real-time
rendering in general dynamic scenes, limiting their use in a wide range of
tasks. To address the issues, we propose a deformable 3D Gaussians Splatting
method that reconstructs scenes using explicit 3D Gaussians and learns
Gaussians in canonical space with a deformation field to model monocular
dynamic scenes. We also introduced a smoothing training mechanism with no extra
overhead to mitigate the impact of inaccurate poses in real datasets on the
smoothness of time interpolation tasks. Through differential gaussian
rasterization, the deformable 3D Gaussians not only achieve higher rendering
quality but also real-time rendering speed. Experiments show that our method
outperforms existing methods significantly in terms of both rendering quality
and speed, making it well-suited for tasks such as novel-view synthesis, time
synthesis, and real-time rendering
Iterative Network for Image Super-Resolution
Single image super-resolution (SISR), as a traditional ill-conditioned
inverse problem, has been greatly revitalized by the recent development of
convolutional neural networks (CNN). These CNN-based methods generally map a
low-resolution image to its corresponding high-resolution version with
sophisticated network structures and loss functions, showing impressive
performances. This paper proposes a substantially different approach relying on
the iterative optimization on HR space with an iterative super-resolution
network (ISRN). We first analyze the observation model of image SR problem,
inspiring a feasible solution by mimicking and fusing each iteration in a more
general and efficient manner. Considering the drawbacks of batch normalization,
we propose a feature normalization (FNorm) method to regulate the features in
network. Furthermore, a novel block with F-Norm is developed to improve the
network representation, termed as FNB. Residual-in-residual structure is
proposed to form a very deep network, which groups FNBs with a long skip
connection for better information delivery and stabling the training phase.
Extensive experimental results on testing benchmarks with bicubic (BI)
degradation show our ISRN can not only recover more structural information, but
also achieve competitive or better PSNR/SSIM results with much fewer parameters
compared to other works. Besides BI, we simulate the real-world degradation
with blur-downscale (BD) and downscalenoise (DN). ISRN and its extension ISRN+
both achieve better performance than others with BD and DN degradation models.Comment: 12 pages, 14 figure
An efficient approach to separate CO2 using supersonic flows for carbon capture and storage
The mitigation of CO2 emissions is an effective measure to solve the climate change issue. In the present study, we propose an alternative approach for CO2 capture by employing supersonic flows. For this purpose, we first develop a computational fluid dynamics (CFD) model to predict the CO2 condensing flow in a supersonic nozzle. Adding two transport equations to describe the liquid fraction and droplet number, the detailed numerical model can describe the heat and mass transfer characteristics during the CO2 phase change process under the supersonic expansion conditions. A comparative study is performed to evaluate the effect of CO2 condensation using the condensation model and dry gas assumption. The results show that the developed CFD model predicts accurately the distribution of the static temperature contrary to the dry gas assumption. Furthermore, the condensing flow model predicts a CO2 liquid fraction up to 18.6% of the total mass, which leads to the release of the latent heat to the vapour phase. The investigation performed in this study suggests that the CO2 condensation in supersonic flows provides an efficient and eco-friendly way to mitigate the CO2 emissions to the environment
Effect of superabsorbent polymer on mechanical properties of cement stabilized base and its mechanism
Superabsorbent polymers (SAPs) are cross-linked polymers that can absorb and retain large amounts of water. In recent years, a growing interest was seen in applying SAPs in concrete to improve its performance due to its efficiency in mitigating shrinkage. This paper presents findings in a study on effect of SAPs on performance of cement-treated base (CTB), using the experience of internal curing of concrete. CTB specimens with and without SAPs were prepared and tested in the laboratory. Tests conducted include mechanical property testing, dry shrinkage testing, differential thermal analysis, mercury intrusion porosimetry and scanning electron microscope testing. It was found that 7-day and 28-day unconfined compressive strength of CTB specimens with SAPs was higher than regular CTB specimens. 28d compressive strength of CTB specimens with SAPs made by Static pressure method was 5.87 MPa, which is 27% higher than that of regular CTB specimens. Drying shrinkage of CTB specimens with SAPs was decreased by 52.5% comparing with regular CTB specimens. Through the microstructure analysis it was found that CTB specimens with SAPs could produce more hydration products, which is also the reason for the strength improvement
A Framework for Calculating the Failure Probability of Natural Gas Pipeline
Reliability based design and assessment (RBDA) technique is a developing direction of natural gas pipeline design method. In this paper, a framework for calculating the failure probability of natural gas pipeline is proposed. First, Java reflection mechanism is used in the management of the limit state functions, which enables the separation of the limit state algorithms and the calculations of the failure probability. Under this framework, more newly developed equations can be add into the library of the software readily. Second, a Monte Carlo reliability analysis algorithm capable of incorporating the basic input parameters and limit state functions is used to calculate failure probability of pipelines. Third, a post data processing algorithm is used to improve the efficiency. Finally, an example on natural gas pipeline is presented to illustrate the availability and effectiveness of the software. Experimental results indicate the ability of the proposed framework for pipeline quality control
ADriver-I: A General World Model for Autonomous Driving
Typically, autonomous driving adopts a modular design, which divides the full
stack into perception, prediction, planning and control parts. Though
interpretable, such modular design tends to introduce a substantial amount of
redundancy. Recently, multimodal large language models (MLLM) and diffusion
techniques have demonstrated their superior performance on comprehension and
generation ability. In this paper, we first introduce the concept of
interleaved vision-action pair, which unifies the format of visual features and
control signals. Based on the vision-action pairs, we construct a general world
model based on MLLM and diffusion model for autonomous driving, termed
ADriver-I. It takes the vision-action pairs as inputs and autoregressively
predicts the control signal of the current frame. The generated control signals
together with the historical vision-action pairs are further conditioned to
predict the future frames. With the predicted next frame, ADriver-I performs
further control signal prediction. Such a process can be repeated infinite
times, ADriver-I achieves autonomous driving in the world created by itself.
Extensive experiments are conducted on nuScenes and our large-scale private
datasets. ADriver-I shows impressive performance compared to several
constructed baselines. We hope our ADriver-I can provide some new insights for
future autonomous driving and embodied intelligence.Comment: Tech Repor
Recommended from our members
Culture-related grief beliefs of Chinese Shidu parents: Development and psychometric properties of a new scale
Background: In China, parents whose only-child dies and who have no living or adopted child are called Shidu parents. Negative thinking is assumed to contribute to the development of emotional problems in bereavement. Because grief cognitions are likely influenced by the concepts of Chinese traditional culture (e.g., family continuation), Shidu parents may hold specific culture-related grief beliefs about themselves or the world, which, in turn, could impede their recovery. Objective: This study developed a questionnaire assessing the culture-related grief beliefs of Shidu parents and examined its psychometric properties. Methods: This newly developed questionnaire was administered to the combined sample of 313 Shidu parents. Exploratory (n = 164) and confirmatory factor analysis (n = 149) were conducted. Psychometric properties of the questionnaire were evaluated. Results: Exploratory factor analysis revealed three distinct factors (filial piety belief, destiny belief and perceived stigma), generating a nine-item culture-related grief beliefs of Shidu parents questionnaire (CBSQ). Confirmatory factor analysis verified the three-factor structure (chi(2)(24) = 39.103, p = 0.027, chi(2)/df = 1.630, CFI = .980, TLI = .970, RMSEA = .065, SRMR = .052). Internal consistency and temporal stability were adequate. Convergent, discriminant and concurrent validity were supported. Conclusions: This study highlights the importance of extending the concept of grief cognitions to include culture-specific beliefs, and provides a first measurement tool to assess culture-related grief beliefs after only-child loss, which can be used in future research with Shidu parents.National Social Science Fund of China [16ZDA233]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
- …