1,337 research outputs found
Vertices with the Second Neighborhood Property in Eulerian Digraphs
The Second Neighborhood Conjecture states that every simple digraph has a
vertex whose second out-neighborhood is at least as large as its first
out-neighborhood, i.e. a vertex with the Second Neighborhood Property. A cycle
intersection graph of an even graph is a new graph whose vertices are the
cycles in a cycle decomposition of the original graph and whose edges represent
vertex intersections of the cycles. By using a digraph variant of this concept,
we prove that Eulerian digraphs which admit a simple dicycle intersection graph
have not only adhere to the Second Neighborhood Conjecture, but have a vertex
of minimum outdegree that has the Second Neighborhood Property.Comment: fixed an error in an earlier version and made structural change
Neuro-Modulated Hebbian Learning for Fully Test-Time Adaptation
Fully test-time adaptation aims to adapt the network model based on
sequential analysis of input samples during the inference stage to address the
cross-domain performance degradation problem of deep neural networks. We take
inspiration from the biological plausibility learning where the neuron
responses are tuned based on a local synapse-change procedure and activated by
competitive lateral inhibition rules. Based on these feed-forward learning
rules, we design a soft Hebbian learning process which provides an unsupervised
and effective mechanism for online adaptation. We observe that the performance
of this feed-forward Hebbian learning for fully test-time adaptation can be
significantly improved by incorporating a feedback neuro-modulation layer. It
is able to fine-tune the neuron responses based on the external feedback
generated by the error back-propagation from the top inference layers. This
leads to our proposed neuro-modulated Hebbian learning (NHL) method for fully
test-time adaptation. With the unsupervised feed-forward soft Hebbian learning
being combined with a learned neuro-modulator to capture feedback from external
responses, the source model can be effectively adapted during the testing
process. Experimental results on benchmark datasets demonstrate that our
proposed method can significantly improve the adaptation performance of network
models and outperforms existing state-of-the-art methods.Comment: CVPR2023 accepte
Controlling complex networks: How much energy is needed?
The outstanding problem of controlling complex networks is relevant to many
areas of science and engineering, and has the potential to generate
technological breakthroughs as well. We address the physically important issue
of the energy required for achieving control by deriving and validating scaling
laws for the lower and upper energy bounds. These bounds represent a reasonable
estimate of the energy cost associated with control, and provide a step forward
from the current research on controllability toward ultimate control of complex
networked dynamical systems.Comment: 4 pages paper + 5 pages supplement. accepted for publication in
Physical Review Letters;
http://link.aps.org/doi/10.1103/PhysRevLett.108.21870
Surgical management of a foramen magnum tumor via a far-lateral approach using an oblique straight incision: a case series report and technique note
ObjectiveTo review our single-institution experience in the surgical management of foramen magnum tumors via a far-lateral approach using an oblique straight incision.MethodsFrom October 2023 to January 2024, four cases of tumors in the foramen magnum area treated at the Capital Medical University-affiliated XuanWu hospital neurosurgery department were involved in this study. All cases were managed with a far-lateral approach using an oblique straight incision. We retrospectively reviewed the clinical and imaging data, as well as the surgical strategies employed.ResultsThree cases of foramen magnum meningiomas and one case of glioma of the ventral medulla. All cases underwent a far-lateral approach using an oblique straight incision; all cases had a gross total resection, and the wounds healed well without cerebral fluid leakage or scalp hydrops. Except for one case of right foramen magnum meningioma, which had dysphagia and pneumothorax, the other cases were without any postoperative complications.ConclusionA far-lateral approach using an oblique straight incision can preserve muscle integrity and minimize subcutaneous exposure, allowing for complete anatomical reduction of muscles. This craniectomy method is simple and replicable, making it worthy of further clinical practice
The cosmic ray test of MRPCs for the BESIII ETOF upgrade
In order to improve the particle identification capability of the Beijing
Spectrometer III (BESIII),t is proposed to upgrade the current endcap
time-of-flight (ETOF) detector with multi-gap resistive plate chamber (MRPC)
technology. Aiming at extending ETOF overall time resolution better than 100ps,
the whole system including MRPC detectors, new-designed Front End Electronics
(FEE), CLOCK module, fast control boards and time to digital modules (TDIG),
was built up and operated online 3 months under the cosmic ray. The main
purposes of cosmic ray test are checking the detectors' construction quality,
testing the joint operation of all instruments and guaranteeing the performance
of the system. The results imply MRPC time resolution better than 100,
efficiency is about 98 and the noise rate of strip is lower than
1() at normal threshold range, the details are discussed and
analyzed specifically in this paper. The test indicates that the whole ETOF
system would work well and satisfy the requirements of upgrade
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