207 research outputs found
A Virtual Shaker Table for Predicting Loads in Automotive Powertrain Mounts
In the automotive industry, multi-axis shaker tables are often used to study the damage caused by motion-induced inertia loads to components such as engine mounts or fuel tank strips. To assess the component durability characteristics using this approach, prototype parts must be built and a test rig must be installed. This process is both time and budget consuming, so there is an incentive to reduce the number of physical shaking tests. To that end, this thesis introduces a set of software tools that are capable of conducting virtual shaking simulations with quality output results, i.e., a virtual multi-axial shaker table (VMAST). By refining and reproducing vehicle body acceleration signals collected from the proving grounds, the VMAST is able to replay the body motion of a vehicle. The reproduced motion (drive file) can then be used to drive the virtual dynamic shaking. With the additional consideration of vehicle body local flexibility, the flexible motion can be added to the rigid body motion to improve the simulation accuracy. The dynamic shaking simulation can be done natively in MATLAB, or the drive files derived from MATLAB can be used by other commercial software, such as Altair MotionView. The virtual load data acquisition of the engine bushing mount is implemented during the simulation to predict the fatigue index, which can be referenced in the design procedure. This VMAST provides the automotive engineer with a cost effective tool for analysis, and optimizes the testing process, allowing rapid design iteration
Does Correction Remain A Problem For Large Language Models?
As large language models, such as GPT, continue to advance the capabilities
of natural language processing (NLP), the question arises: does the problem of
correction still persist? This paper investigates the role of correction in the
context of large language models by conducting two experiments. The first
experiment focuses on correction as a standalone task, employing few-shot
learning techniques with GPT-like models for error correction. The second
experiment explores the notion of correction as a preparatory task for other
NLP tasks, examining whether large language models can tolerate and perform
adequately on texts containing certain levels of noise or errors. By addressing
these experiments, we aim to shed light on the significance of correction in
the era of large language models and its implications for various NLP
applications
The genome of\u3ci\u3e Orychophragmus\u3c/i\u3e violaceus provides genomic insights into the evolution of Brassicaceaepolyploidizationandits distinct traits
Orychophragmus violaceus, referred to as ‘‘eryuelan’’ (February orchid) in China, is an early-flowering ornamental plant. The high oil content and abundance of unsaturated fatty acids in O. violaceus seeds make it a potential high-quality oilseed crop. Here, we generated a whole-genome assembly for O. violaceus using Nanopore and Hi-C sequencing technologies. The assembled genome of O. violaceus was ~1.3 Gb in size, with 12 pairs of chromosomes. Through investigation of ancestral genome evolution, we determined that the genome of O. violaceus experienced a tetraploidization event from a diploid progenitor with the translocated proto-Calepineae karyotype. Comparisons between the reconstructed subgenomes of O. violaceus identified indicators of subgenome dominance, indicating that subgenomes likely originated via allotetraploidy. O. violaceus was phylogenetically close to the Brassica genus, and tetraploidy in O. violaceus occurred approximately 8.57 million years ago, close in time to the whole-genome triplication of Brassica that likely arose via an intermediate tetraploid lineage. However, the tetraploidization in Orychophragmus was independent of the hexaploidization in Brassica, as evidenced by the results from detailed phylogenetic analyses and comparisons of the break and fusion points of ancestral genomic blocks. Moreover, identification of multi-copy genes regulating the production of high-quality oil highlighted the contributions of both tetraploidization and tandem duplication to functional innovation in O. violaceus. These findings provide novel insights into the polyploidization evolution of plant species and will promote both functional genomic studies and domestication/breeding efforts in O. violaceus
A de novo Genome of a Chinese Radish Cultivar
AbstractHere, we report a high-quality draft genome of a Chinese radish (Raphanus sativus) cultivar. This draft contains 387.73Mb of assembled scaffolds, 83.93% of the scaffolds were anchored onto nine pseudochromosomes and 95.09% of 43 240 protein-coding genes were functionally annotated. 184.75Mb (47.65%) of repeat sequences was identified in the assembled genome. By comparative analyses of the radish genome against 10 other plant genomes, 2 275 genes in 780 gene families were found unique to R. sativus. This genome is a good reference for genomic study and of great value for genetic improvement of radish
Toward 6G TK Extreme Connectivity: Architecture, Key Technologies and Experiments
Sixth-generation (6G) networks are evolving towards new features and
order-of-magnitude enhancement of systematic performance metrics compared to
the current 5G. In particular, the 6G networks are expected to achieve extreme
connectivity performance with Tbps-scale data rate, Kbps/Hz-scale spectral
efficiency, and s-scale latency. To this end, an original three-layer 6G
network architecture is designed to realise uniform full-spectrum cell-free
radio access and provide task-centric agile proximate support for diverse
applications. The designed architecture is featured by super edge node (SEN)
which integrates connectivity, computing, AI, data, etc. On this basis, a
technological framework of pervasive multi-level (PML) AI is established in the
centralised unit to enable task-centric near-real-time resource allocation and
network automation. We then introduce a radio access network (RAN) architecture
of full spectrum uniform cell-free networks, which is among the most attractive
RAN candidates for 6G TK extreme connectivity. A few most promising key
technologies, i.e., cell-free massive MIMO, photonics-assisted Terahertz
wireless access and spatiotemporal two-dimensional channel coding are further
discussed. A testbed is implemented and extensive trials are conducted to
evaluate innovative technologies and methodologies. The proposed 6G network
architecture and technological framework demonstrate exciting potentials for
full-service and full-scenario applications.Comment: 15 pages, 12 figure
Biased Gene Fractionation and Dominant Gene Expression among the Subgenomes of Brassica rapa
Polyploidization, both ancient and recent, is frequent among plants. A “two-step theory" was proposed to explain the meso-triplication of the Brassica “A" genome: Brassica rapa. By accurately partitioning of this genome, we observed that genes in the less fractioned subgenome (LF) were dominantly expressed over the genes in more fractioned subgenomes (MFs: MF1 and MF2), while the genes in MF1 were slightly dominantly expressed over the genes in MF2. The results indicated that the dominantly expressed genes tended to be resistant against gene fractionation. By re-sequencing two B. rapa accessions: a vegetable turnip (VT117) and a Rapid Cycling line (L144), we found that genes in LF had less non-synonymous or frameshift mutations than genes in MFs; however mutation rates were not significantly different between MF1 and MF2. The differences in gene expression patterns and on-going gene death among the three subgenomes suggest that “two-step" genome triplication and differential subgenome methylation played important roles in the genome evolution of B. rapa
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Characterization of cells from patient-derived fibrovascular membranes in proliferative diabetic retinopathy
Purpose Epiretinal fibrovascular membranes (FVMs) are a hallmark of proliferative diabetic retinopathy (PDR). Surgical removal of FVMs is often indicated to treat tractional retinal detachment. This potentially informative pathological tissue is usually disposed of after surgery without further examination. We developed a method for isolating and characterizing cells derived from FVMs and correlated their expression of specific markers in culture with that in tissue. Methods: FVMs were obtained from 11 patients with PDR during diabetic vitrectomy surgery and were analyzed with electron microscopy (EM), comparative genomic hybridization (CGH), immunohistochemistry, and/or digested with collagenase II for cell isolation and culture. Antibody arrays and enzyme-linked immunosorbent assay (ELISA) were used to profile secreted angiogenesis-related proteins in cell culture supernatants. Results: EM analysis of the FVMs showed abnormal vessels composed of endothelial cells with large nuclei and plasma membrane infoldings, loosely attached perivascular cells, and stromal cells. The cellular constituents of the FVMs lacked major chromosomal aberrations as shown with CGH. Cells derived from FVMs (C-FVMs) could be isolated and maintained in culture. The C-FVMs retained the expression of markers of cell identity in primary culture, which define specific cell populations including CD31-positive, alpha-smooth muscle actin-positive (SMA), and glial fibrillary acidic protein-positive (GFAP) cells. In primary culture, secretion of angiopoietin-1 and thrombospondin-1 was significantly decreased in culture conditions that resemble a diabetic environment in SMA-positive C-FVMs compared to human retinal pericytes derived from a non-diabetic donor. Conclusions: C-FVMs obtained from individuals with PDR can be isolated, cultured, and profiled in vitro and may constitute a unique resource for the discovery of cell signaling mechanisms underlying PDR that extends beyond current animal and cell culture models
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