14,972 research outputs found
Disturbance observer based adaptive sliding mode control for continuous stirred tank reactor
The continuous stirred tank reactor (CSTR) typifies an important class of process control systems. Is is a nonlinear
system and is sensitive to both external disturbances and system uncertainty. Given these challenges, a nonsingular terminal
sliding mode observer is proposed to estimate any external disturbance. Then, a continuous adaptive sliding mode control
method is combined with the proposed disturbance observer. This is found to reduce chattering and improve control accuracy
when compared with other methods. A full Lyapunov stability proof of the resulting closed-loop system is performed and the
effectiveness of the proposed approach is demonstrated by simulation experiments
Graphene-based spintronic components
A major challenge of spintronics is in generating, controlling and detecting
spin-polarized current. Manipulation of spin-polarized current, in particular,
is difficult. We demonstrate here, based on calculated transport properties of
graphene nanoribbons, that nearly +-100% spin-polarized current can be
generated in zigzag graphene nanoribbons (ZGNRs) and tuned by a source-drain
voltage in the bipolar spin diode, in addition to magnetic configurations of
the electrodes. This unusual transport property is attributed to the intrinsic
transmission selection rule of the spin subbands near the Fermi level in ZGNRs.
The simultaneous control of spin current by the bias voltage and the magnetic
configurations of the electrodes provides an opportunity to implement a whole
range of spintronics devices. We propose theoretical designs for a complete set
of basic spintronic devices, including bipolar spin diode, transistor and logic
gates, based on ZGNRs.Comment: 14 pages, 4 figure
Haplo2Ped: a tool using haplotypes as markers for linkage analysis
<p>Abstract</p> <p>Background</p> <p>Generally, SNPs are abundant in the genome; however, they display low power in linkage analysis because of their limited heterozygosity. Haplotype markers, on the other hand, which are composed of many SNPs, greatly increase heterozygosity and have superiority in linkage statistics.</p> <p>Results</p> <p>Here we developed Haplo2Ped to automatically transform SNP data into haplotype markers and then to compute the logarithm (base 10) of odds (LOD) scores of regional haplotypes that are homozygous within the disease co-segregation haploid group. The results are reported as a hypertext file and a 3D figure to help users to obtain the candidate linkage regions. The hypertext file contains parameters of the disease linked regions, candidate genes, and their links to public databases. The 3D figure clearly displays the linkage signals in each chromosome. We tested Haplo2Ped in a simulated SNP dataset and also applied it to data from a real study. It successfully and accurately located the causative genomic regions. Comparison of Haplo2Ped with other existing software for linkage analysis further indicated the high effectiveness of this software.</p> <p>Conclusions</p> <p>Haplo2Ped uses haplotype fragments as mapping markers in whole genome linkage analysis. The advantages of Haplo2Ped over other existing software include straightforward output files, increased accuracy and superior ability to deal with pedigrees showing incomplete penetrance. Haplo2Ped is freely available at: <url>http://bighapmap.big.ac.cn/software.html</url>.</p
Model Test on Impact of Surrounding Rock Deterioration on Segmental Lining Structure for Underwater Shield Tunnel with Large Cross-Section
AbstractBased on Guangzhou Shiziyang Tunnel, a large-scale model test of segment lining structure was conducted to study the impact of surrounding rock deterioration. The results showed the outflow or deterioration of surrounding rock at the hence could make the stress state at the bottom and crown more serious. And it is very important to provide effective surrounding rock resistance to ensure the safety of tunnel structure
Developmental patterns and characteristics of epicardial cell markers Tbx18 and Wt1 in murine embryonic heart
<p>Abstract</p> <p>Background</p> <p>Although recent studies have highlighted the role of epicardial cells during cardiac development and regeneration, their cardiomyogenic potential is still controversial due to the question of lineage tracing of epicardial cells. The present study therefore aimed to examine the the expression of Tbx18 and Wt1 in embryonic heart and to identify whether Tbx18 and Wt1 themselves expressed in the cardiomyocyte.</p> <p>Methods</p> <p>Mouse embryonic hearts were collected at different stages for immunofluorescence costaining with either Tbx18 and the cardiac transcription factor Nkx2.5 or Wilms tumor 1 (Wt1) and Nkx2.5.</p> <p>Results</p> <p>Tbx18 and Wt1, but not Nkx2.5, were expressed in the proepicardium and epicardium. Tbx18 was expressed in cells within the heart from E10.5 to at least E14.5; these Tbx18-expressing cells were Nkx2.5 positive, except for a few cells that were Nkx2.5 negative at E14.5. Wt1 was expressed in cells within the heart from E12.5 to at least E14.5, but these Wt1-expressing cells were Nkx2.5 negative.</p> <p>Conclusion</p> <p>The data obtained in this study demonstrate that Tbx18 is expressed in the cardiomyocytes from E10.5 to at least E14.5, and Wt1 is expressed within the heart from E12.5 to at least E14.5, but not in the cardiomyocyte. These findings may provide new insights on the role of the epicardial cells in cardiac regeneration.</p
Shikra: Unleashing Multimodal LLM's Referential Dialogue Magic
In human conversations, individuals can indicate relevant regions within a
scene while addressing others. In turn, the other person can then respond by
referring to specific regions if necessary. This natural referential ability in
dialogue remains absent in current Multimodal Large Language Models (MLLMs). To
fill this gap, this paper proposes an MLLM called Shikra, which can handle
spatial coordinate inputs and outputs in natural language. Its architecture
consists of a vision encoder, an alignment layer, and a LLM. It is designed to
be straightforward and simple, without the need for extra vocabularies,
position encoder, pre-/post-detection modules, or external plug-in models. All
inputs and outputs are in natural language form. Referential dialogue is a
superset of various vision-language (VL) tasks. Shikra can naturally handle
location-related tasks like REC and PointQA, as well as conventional VL tasks
such as Image Captioning and VQA. Experimental results showcase Shikra's
promising performance. Furthermore, it enables numerous exciting applications,
like providing mentioned objects' coordinates in chains of thoughts and
comparing user-pointed regions similarities. Our code and model are accessed at
https://github.com/shikras/shikra
Neural Interactive Keypoint Detection
This work proposes an end-to-end neural interactive keypoint detection
framework named Click-Pose, which can significantly reduce more than 10 times
labeling costs of 2D keypoint annotation compared with manual-only annotation.
Click-Pose explores how user feedback can cooperate with a neural keypoint
detector to correct the predicted keypoints in an interactive way for a faster
and more effective annotation process. Specifically, we design the pose error
modeling strategy that inputs the ground truth pose combined with four typical
pose errors into the decoder and trains the model to reconstruct the correct
poses, which enhances the self-correction ability of the model. Then, we attach
an interactive human-feedback loop that allows receiving users' clicks to
correct one or several predicted keypoints and iteratively utilizes the decoder
to update all other keypoints with a minimum number of clicks (NoC) for
efficient annotation. We validate Click-Pose in in-domain, out-of-domain
scenes, and a new task of keypoint adaptation. For annotation, Click-Pose only
needs 1.97 and 6.45 NoC@95 (at precision 95%) on COCO and Human-Art, reducing
31.4% and 36.3% efforts than the SOTA model (ViTPose) with manual correction,
respectively. Besides, without user clicks, Click-Pose surpasses the previous
end-to-end model by 1.4 AP on COCO and 3.0 AP on Human-Art. The code is
available at https://github.com/IDEA-Research/Click-Pose.Comment: Accepted to ICCV 202
Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress.
The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition
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