649 research outputs found
Dynamics-Guided Diffusion Model for Robot Manipulator Design
We present Dynamics-Guided Diffusion Model, a data-driven framework for
generating manipulator geometry designs for a given manipulation task. Instead
of training different design models for each task, our approach employs a
learned dynamics network shared across tasks. For a new manipulation task, we
first decompose it into a collection of individual motion targets which we call
target interaction profile, where each individual motion can be modeled by the
shared dynamics network. The design objective constructed from the target and
predicted interaction profiles provides a gradient to guide the refinement of
finger geometry for the task. This refinement process is executed as a
classifier-guided diffusion process, where the design objective acts as the
classifier guidance. We evaluate our framework on various manipulation tasks,
under the sensor-less setting using only an open-loop parallel jaw motion. Our
generated designs outperform optimization-based and unguided diffusion
baselines relatively by 31.5% and 45.3% on average manipulation success rate.
With the ability to generate a design within 0.8 seconds, our framework could
facilitate rapid design iteration and enhance the adoption of data-driven
approaches for robotic mechanism design
A Monte-Carlo-Based Network Method for Source Positioning in Bioluminescence Tomography
We present an approach based on the improved Levenberg
Marquardt (LM) algorithm of backpropagation (BP) neural network to estimate the light source position in bioluminescent imaging. For solving the forward problem, the table-based random sampling algorithm (TBRS), a fast Monte Carlo simulation method we developed before, is employed here. Result shows that BP is an effective method to position the light source
Numerical Simulation and Experimental Study of Deep Bed Corn Drying Based on Water Potential
The concept and the model of water potential, which were widely used in agricultural field, have been proved to be beneficial in the application of vacuum drying model and have provided a new way to explore the grain drying model since being introduced to grain drying and storage fields. Aiming to overcome the shortcomings of traditional deep bed drying model, for instance, the application range of this method is narrow and such method does not apply to systems of which pressure would be an influential factor such as vacuum drying system in a way combining with water potential drying model. This study established a numerical simulation system of deep bed corn drying process which has been proved to be effective according to the results of numerical simulation and corresponding experimental investigation and has revealed that desorption and adsorption coexist in deep bed drying
Integration of a statistical emulator approach with the SCE-UA method for parameter optimization of a hydrological model
Transcriptomic profiling of mature embryo from an elite super-hybrid rice LYP9 and its parental lines
<p>Abstract</p> <p>Background</p> <p>The mature embryo of rice (<it>Oryza sativa, L</it>.) is a synchronized and integrated tissue mass laying the foundation at molecular level for its growth, development, and differentiation toward a developing and ultimately a mature plant. We carried out an EST (expressed-sequence-tags)-based transcriptomic study, aiming at gaining molecular insights into embryonic development of a rice hybrid triad–an elite hybrid rice <it>LYP</it>9 and its parental lines (<it>93-11 </it>and <it>PA64s</it>)–and possible relatedness to heterosis.</p> <p>Results</p> <p>We generated 27,566 high-quality ESTs from cDNA libraries made from mature rice embryos. We classified these ESTs into 7,557 unigenes (2,511 contigs and 5,046 singletons) and 7,250 (95.9%) of them were annotated. We noticed that the high-abundance genes in mature rice embryos belong to two major functional categories, stress-tolerance and preparation-for-development, and we also identified 191 differentially-expressed genes (General Chi-squared test, <it>P</it>-value <= 0.05) between <it>LYP9 </it>and its parental lines, representing typical expression patterns including over-dominance, high- and low-parent dominance, additivity, and under-dominance. In <it>LYP9</it>, the majority of embryo-associated genes were found not only abundantly and specifically enriched but also significantly up-regulated.</p> <p>Conclusion</p> <p>Our results suggested that massively strengthening tissue-(or stage-) characteristic functions may contribute to heterosis rather than a few simple mechanistic explanations at the individual gene level. In addition, the large collection of rice embryonic ESTs provides significant amount of data for future comparative analyses on plant development, especially for the important crops of the grass family.</p
Somatosensory changes at forearm donor sites following three different surgical flap techniques
Effects of 5-aminolevulinic Acid on the Photosynthesis, Antioxidant System, and α-Bisabolol Content of Matricaria recutita
Matricaria recutita is a widely used medicinal plant with broad pharmacological effects, and α-bisabolol is the main active ingredient of this plant. To improve its α-bisabolol content, M. recutita was sprayed with different concentrations (1.0, 2.0,and 4.0 mmol.L−1) of 5-aminolevulinic acid (ALA) or with water as a control to study the effects of ALA treatment on the photosynthesis, antioxidant system, and α-bisabolol content of M. recutita. Results showed that the photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, soluble protein, total amino acids, soluble sugar, and α-bisabolol of M. recutita were significantly increased. Moreover, the activities of superoxide dismutase, peroxidase, and catalase of M. recutita were also enhanced by ALA treatment. Optimal results were obtained when the concentration of ALA was 2.0 mmol.L−1. Results showed that ALA treatment could improve the α-bisabolol content of M. recutita, and the underlying physiological mechanism was analyzed. ALA treatment was an effective measure for improving the medicinal value of M. recutita
Compound Attention and Neighbor Matching Network for Multi-contrast MRI Super-resolution
Multi-contrast magnetic resonance imaging (MRI) reflects information about
human tissue from different perspectives and has many clinical applications. By
utilizing the complementary information among different modalities,
multi-contrast super-resolution (SR) of MRI can achieve better results than
single-image super-resolution. However, existing methods of multi-contrast MRI
SR have the following shortcomings that may limit their performance: First,
existing methods either simply concatenate the reference and degraded features
or exploit global feature-matching between them, which are unsuitable for
multi-contrast MRI SR. Second, although many recent methods employ transformers
to capture long-range dependencies in the spatial dimension, they neglect that
self-attention in the channel dimension is also important for low-level vision
tasks. To address these shortcomings, we proposed a novel network architecture
with compound-attention and neighbor matching (CANM-Net) for multi-contrast MRI
SR: The compound self-attention mechanism effectively captures the dependencies
in both spatial and channel dimension; the neighborhood-based feature-matching
modules are exploited to match degraded features and adjacent reference
features and then fuse them to obtain the high-quality images. We conduct
experiments of SR tasks on the IXI, fastMRI, and real-world scanning datasets.
The CANM-Net outperforms state-of-the-art approaches in both retrospective and
prospective experiments. Moreover, the robustness study in our work shows that
the CANM-Net still achieves good performance when the reference and degraded
images are imperfectly registered, proving good potential in clinical
applications.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
LiveRetro: Visual Analytics for Strategic Retrospect in Livestream E-Commerce
Livestream e-commerce integrates live streaming and online shopping, allowing
viewers to make purchases while watching. However, effective marketing
strategies remain a challenge due to limited empirical research and subjective
biases from the absence of quantitative data. Current tools fail to capture the
interdependence between live performances and feedback. This study identified
computational features, formulated design requirements, and developed
LiveRetro, an interactive visual analytics system. It enables comprehensive
retrospective analysis of livestream e-commerce for streamers, viewers, and
merchandise. LiveRetro employs enhanced visualization and time-series
forecasting models to align performance features and feedback, identifying
influences at channel, merchandise, feature, and segment levels. Through case
studies and expert interviews, the system provides deep insights into the
relationship between live performance and streaming statistics, enabling
efficient strategic analysis from multiple perspectives.Comment: Accepted by IEEE VIS 202
Characterization and expression analysis of four members genes of flavanone 3-hydroxylase families from Chamaemelum nobile
Chamaemelum nobile is a traditional Chinese herbal medicine, whose secondary metabolites used in the pharmacology of Chinese medicine. Among them, the flavonoids have great research value. Flavanone 3-hydroxylase (F3H) is one of the core enzymes in the early steps of flavonoid biosynthesis. This study aimed to elucidate the structures, functions, and expression levels of F3H families from C. nobile. Four members of the F3H family were screened from C. nobile transcriptome data and performed bioinformatics analysis. Results showed that CnF3H1~4 had a high similarity with the other F3H plants, and all genes contained two conserved isopenicillin N synthase-like and oxoglutarate/iron-dependent dioxygenase domains. Further analysis revealed that the four CnF3H proteins contained some differences in binding sites. The results of secondary and 3-D structures displayed that the composition and proportion of the four CnF3H secondary structures were basically the same, and their 3D structures were consistent with the secondary structures. The phylogenetic tree displayed that CnF3H2, CnF3H3, and CnF3H4 were grouped with Asteraceae. The expression patterns of CnF3Hs in the roots, stems, leaves, and flowers of C. nobile were evaluated using the value of RPKM. The results indicated that CnF3Hs had significant difference in the expression of different tissues. Especially, CnF3H1~3 and CnF3H4 had the highest expression levels in the flowers and roots, respectively. Hence, CnF3Hs played a significant role in the flavonoid metabolism
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