6,262 research outputs found
SSthreshless Start: A Sender-Side TCP Intelligence for Long Fat Network
Measurement shows that 85% of TCP flows in the internet are short-lived flows
that stay most of their operation in the TCP startup phase. However, many
previous studies indicate that the traditional TCP Slow Start algorithm does
not perform well, especially in long fat networks. Two obvious problems are
known to impact the Slow Start performance, which are the blind initial setting
of the Slow Start threshold and the aggressive increase of the probing rate
during the startup phase regardless of the buffer sizes along the path. Current
efforts focusing on tuning the Slow Start threshold and/or probing rate during
the startup phase have not been considered very effective, which has prompted
an investigation with a different approach. In this paper, we present a novel
TCP startup method, called threshold-less slow start or SSthreshless Start,
which does not need the Slow Start threshold to operate. Instead, SSthreshless
Start uses the backlog status at bottleneck buffer to adaptively adjust probing
rate which allows better seizing of the available bandwidth. Comparing to the
traditional and other major modified startup methods, our simulation results
show that SSthreshless Start achieves significant performance improvement
during the startup phase. Moreover, SSthreshless Start scales well with a wide
range of buffer size, propagation delay and network bandwidth. Besides, it
shows excellent friendliness when operating simultaneously with the currently
popular TCP NewReno connections.Comment: 25 pages, 10 figures, 7 table
Visualizing topological edge states of single and double bilayer Bi supported on multibilayer Bi(111) films
Freestanding single-bilayer Bi(111) is a two-dimensional topological
insulator with edge states propagating along its perimeter. Given the
interlayer coupling experimentally, the topological nature of Bi(111) thin
films and the impact of the supporting substrate on the topmost Bi bilayer are
still under debate. Here, combined with scanning tunneling microscopy and
first-principles calculations, we systematically study the electronic
properties of Bi(111) thin films grown on a NbSe2 substrate. Two types of
non-magnetic edge structures, i.e., a conventional zigzag edge and a 2x1
reconstructed edge, coexist alternately at the boundaries of single bilayer
islands, the topological edge states of which exhibit remarkably different
energy and spatial distributions. Prominent edge states are persistently
visualized at the edges of both single and double bilayer Bi islands,
regardless of the underlying thickness of Bi(111) thin films. We provide an
explanation for the topological origin of the observed edge states that is
verified with first-principles calculations. Our paper clarifies the
long-standing controversy regarding the topology of Bi(111) thin films and
reveals the tunability of topological edge states via edge modifications.Comment: 36 pages, 10 figure
Regulated cell death in glioma: promising targets for natural small-molecule compounds
Gliomas are prevalent malignant tumors in adults, which can be categorized as either localized or diffuse gliomas. Glioblastoma is the most aggressive and deadliest form of glioma. Currently, there is no complete cure, and the median survival time is less than one year. The main mechanism of regulated cell death involves organisms coordinating the elimination of damaged cells at risk of tumor transformation or cells hijacked by microorganisms for pathogen replication. This process includes apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis, necrosis, parthanayosis, entosis, lysosome-dependent death, NETosis, oxiptosis, alkaliptosis, and disulfidaptosis. The main goal of clinical oncology is to develop therapies that promote the effective elimination of cancer cells by regulating cell death are the main goal of clinical oncology. Recently, scientists have utilized pertinent regulatory factors and natural small-molecule compounds to induce regulated cell death for the treatment of gliomas. By analyzing the PubMed and Web of Science databases, this paper reviews the research progress on the regulation of cell death and the role of natural small-molecule compounds in glioma. The aim is to provide help for the treatment of glioblastoma
CurveFormer: 3D Lane Detection by Curve Propagation with Curve Queries and Attention
3D lane detection is an integral part of autonomous driving systems. Previous
CNN and Transformer-based methods usually first generate a bird's-eye-view
(BEV) feature map from the front view image, and then use a sub-network with
BEV feature map as input to predict 3D lanes. Such approaches require an
explicit view transformation between BEV and front view, which itself is still
a challenging problem. In this paper, we propose CurveFormer, a single-stage
Transformer-based method that directly calculates 3D lane parameters and can
circumvent the difficult view transformation step. Specifically, we formulate
3D lane detection as a curve propagation problem by using curve queries. A 3D
lane query is represented by a dynamic and ordered anchor point set. In this
way, queries with curve representation in Transformer decoder iteratively
refine the 3D lane detection results. Moreover, a curve cross-attention module
is introduced to compute the similarities between curve queries and image
features. Additionally, a context sampling module that can capture more
relative image features of a curve query is provided to further boost the 3D
lane detection performance. We evaluate our method for 3D lane detection on
both synthetic and real-world datasets, and the experimental results show that
our method achieves promising performance compared with the state-of-the-art
approaches. The effectiveness of each component is validated via ablation
studies as well
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