163 research outputs found
A Novel Projection Distortion Correction Method on Patient's Body Surface
In this paper, the projection distortion correction method of patient's body surface is studied. First, the applicability of four typical projection image distortion correction methods to different surfaces were compared. Secondly, Based on the correction method based on quadratic surface fitting, and a correction method based on point cloud mapping was designed, which uses structured light to extract the point cloud information on the surface of the projection screen for coordinate transformation. Combined with the depth information, it solves the distortion problem of complex surface projection images, expands the surface applicability of the correction method, and improves the correction accuracy and real-time performance. The projection distortion correction of different types of surfaces is realized by simulation, and the correction effect of the two methods is compared. The correction time is shortened from 67s to 7s by the correction method based on point cloud mapping. Finally, organ simulation experiment was used to verify the intraoperative feasibility, and the virtual "perspective" display effect was presented as a whole
Landscape of RNA polyadenylation in E-coli
Polyadenylation is thought to be involved in the degradation and quality control of bacterial RNAs but relatively few examples have been investigated. We used a combination of 5 '-tagRACE and RNA-seq to analyze the total RNA content from a wild-type strain and from a poly(A) polymerase deleted Mutant. A total of 178 transcripts were either up- or down-regulated in the mutant when compared to the wild-type strain. Poly(A) polymerase up-regulates the expression of all genes related to the FliA regulon and several previously unknown transcripts, including numerous transporters. Notable down-regulation of genes in the expression of antigen 43 and components of the type 1 fimbriae was detected. The major consequence of the absence of poly(A) polymerase was the accumulation of numerous sRNAs, antisense transcripts, REP sequences and RNA fragments resulting from the processing of entire transcripts. A new algorithm to analyze the position and composition of post-transcriptional modifications based on the sequence of unencoded 3 '-ends, was developed to identify polyadenylated molecules. Overall our results shed new light on the broad spectrum of action of polyadenylation on gene expression and demonstrate the importance of poly(A) dependent degradation to remove structured RNA fragments.Peer reviewe
Panoptic Scene Graph Generation
Existing research addresses scene graph generation (SGG) -- a critical
technology for scene understanding in images -- from a detection perspective,
i.e., objects are detected using bounding boxes followed by prediction of their
pairwise relationships. We argue that such a paradigm causes several problems
that impede the progress of the field. For instance, bounding box-based labels
in current datasets usually contain redundant classes like hairs, and leave out
background information that is crucial to the understanding of context. In this
work, we introduce panoptic scene graph generation (PSG), a new problem task
that requires the model to generate a more comprehensive scene graph
representation based on panoptic segmentations rather than rigid bounding
boxes. A high-quality PSG dataset, which contains 49k well-annotated
overlapping images from COCO and Visual Genome, is created for the community to
keep track of its progress. For benchmarking, we build four two-stage
baselines, which are modified from classic methods in SGG, and two one-stage
baselines called PSGTR and PSGFormer, which are based on the efficient
Transformer-based detector, i.e., DETR. While PSGTR uses a set of queries to
directly learn triplets, PSGFormer separately models the objects and relations
in the form of queries from two Transformer decoders, followed by a
prompting-like relation-object matching mechanism. In the end, we share
insights on open challenges and future directions.Comment: Accepted to ECCV'22 (Paper ID #222, Final Score 2222). Project Page:
https://psgdataset.org/. OpenPSG Codebase:
https://github.com/Jingkang50/OpenPS
On-Device Domain Generalization
We present a systematic study of domain generalization (DG) for tiny neural
networks. This problem is critical to on-device machine learning applications
but has been overlooked in the literature where research has been merely
focused on large models. Tiny neural networks have much fewer parameters and
lower complexity and therefore should not be trained the same way as their
large counterparts for DG applications. By conducting extensive experiments, we
find that knowledge distillation (KD), a well-known technique for model
compression, is much better for tackling the on-device DG problem than
conventional DG methods. Another interesting observation is that the
teacher-student gap on out-of-distribution data is bigger than that on
in-distribution data, which highlights the capacity mismatch issue as well as
the shortcoming of KD. We further propose a method called out-of-distribution
knowledge distillation (OKD) where the idea is to teach the student how the
teacher handles out-of-distribution data synthesized via disruptive data
augmentation. Without adding any extra parameter to the model -- hence keeping
the deployment cost unchanged -- OKD significantly improves DG performance for
tiny neural networks in a variety of on-device DG scenarios for image and
speech applications. We also contribute a scalable approach for synthesizing
visual domain shifts, along with a new suite of DG datasets to complement
existing testbeds.Comment: Preprin
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