668 research outputs found
Phases of Chiral Gauge Theories
We discuss the behavior of two non-supersymmetric chiral SU(N) gauge
theories, involving fermions in the symmetric and antisymmetric two-index
tensor representations respectively. In addition to global anomaly matching, we
employ a recently proposed inequality constraint on the number of effective low
energy (massless) degrees of freedom of a theory, based on the thermodynamic
free energy. Several possible zero temperature phases are consistent with the
constraints. A simple picture for the phase structure emerges if these theories
choose the phase, consistent with global anomaly matching, that minimizes the
massless degree of freedom count defined through the free energy. This idea
suggests that confinement with the preservation of the global symmetries
through the formation of massless composite fermions is in general not
preferred. While our discussion is restricted mainly to bilinear condensate
formation, higher dimensional condensates are considered for one case. We
conclude by commenting briefly on two related supersymmetric chiral theories.Comment: 23 pages, 2 figures, ReVTeX, improved forma
A Novel Dynamic Event-triggered Mechanism for Dynamic Average Consensus
This paper studies a challenging issue introduced in a recent survey, namely
designing a distributed event-based scheme to solve the dynamic average
consensus (DAC) problem. First, a robust adaptive distributed event-based DAC
algorithm is designed without imposing specific initialization criteria to
perform estimation task under intermittent communication. Second, a novel
adaptive distributed dynamic event-triggered mechanism is proposed to determine
the triggering time when neighboring agents broadcast information to each
other. Compared to the existing event-triggered mechanisms, the novelty of the
proposed dynamic event-triggered mechanism lies in that it guarantees the
existence of a positive and uniform minimum inter-event interval without
sacrificing any accuracy of the estimation, which is much more practical than
only ensuring the exclusion of the Zeno behavior or the boundedness of the
estimation error. Third, a composite adaptive law is developed to update the
adaptive gain employed in the distributed event-based DAC algorithm and dynamic
event-triggered mechanism. Using the composite adaptive update law, the
distributed event-based solution proposed in our work is implemented without
requiring any global information. Finally, numerical simulations are provided
to illustrate the effectiveness of the theoretical results.Comment: 9 pages, 8 figure
A novel dynamic event-triggered mechanism for dynamic average consensus
This paper studies a challenging issue introduced in a recent survey, namely designing a distributed event-based scheme to solve the dynamic average consensus (DAC) problem. First, a robust adaptive distributed event-based DAC algorithm is designed without imposing specific initialization criteria to perform estimation task under intermittent communication. Second, a novel adaptive distributed dynamic event-triggered mechanism is proposed to determine the triggering time when neighboring agents broadcast information to each other. Compared to the existing event-triggered mechanisms, the novelty of the proposed dynamic event-triggered mechanism lies in that it guarantees the existence of a positive and uniform minimum inter-event interval without sacrificing any accuracy of the estimation, which is much more practical than only ensuring the exclusion of the Zeno behavior or the boundedness of the estimation error. Third, a composite adaptive law is developed to update the adaptive gain employed in the distributed event-based DAC algorithm and dynamic event-triggered mechanism. Using the composite adaptive update law, the distributed event-based solution proposed in our work is implemented without requiring any global information. Finally, numerical simulations are provided to illustrate the effectiveness of the theoretical results.</p
Adaptive Distributed Formation-Containment Control on Switching Directed Networks:A Dynamic Triggering Framework
This article addresses the time-varying formation-containment control problem for networked second-order systems with unknown nonlinear dynamics. The communication topology among agents is switching and directed. To simultaneously achieve formation configuration for leaders and accomplish containment behavior for followers, adaptive distributed formation and containment control schemes are developed. In the control framework design, the neural-network control technique is utilized to approximate the unknown nonlinear dynamics. The update frequency and computation resources of the controllers are reduced by dynamic triggering mechanisms. It is proved that no agent exhibits the Zeno behavior on the time-varying asymmetric communication topology. Moreover, no prior knowledge of global information is needed in controller and triggering mechanism implementations. All system parameters can be easily and flexibly chosen. Finally, numerical examples are presented to illustrate the effectiveness of the proposed control schemes.</p
Electroweak Physics for Color Superconductivity
We construct the effective theories describing the electroweak interactions
for the low energy excitations associated with the color superconductive phases
of QCD at high matter density. The main result, for the 3 flavor case, is that
the quasiparticle Goldstone boson decay into two physical massless
photons is identical to the zero density case once we use the new Goldstone
decay constant and the modified electric charge ,
with and the strong coupling constant. For 2
flavors we find that the coupling of the quarks to the neutral vector boson
is modified with respect to the zero density case. We finally point out
possible applications of our result to the physics of compact objects.Comment: 23 pages, 1 Figure, RevTex. More discussion and references adde
Application of Fast Deviation Correction Algorithm Based on Shape Matching Algorithm in Component Placement
For contradiction PC template matching between accuracy and speed, combined with the advantages of FPGA high speed parallel computing. This paper presents a FPGA-based rapid correction shape matching algorithm. Mainly in the FPGA, using shape matching and least squares method to calculate the angular deviation chip components. Use single instruction stream algorithm acceleration. Experimental results show that compared with traditional PC template matching algorithms, this algorithm to further improve the correction accuracy and greatly reducing correction time. And SMT machine vision correction can be obtained in a stable and efficient use
Low Energy Theory for 2 flavors at High Density QCD
We construct the effective Lagrangian describing the low energy excitations
for Quantum Chromodynamics with two flavors at high density. The non-linear
realization framework is employed to properly construct the low energy
effective theory. The light degrees of freedom, as required by 't Hooft anomaly
conditions, contain massless fermions which we properly include in the
effective Lagrangian. We also provide a discussion of the linearly realized
Lagrangian.Comment: 17 pages, RevTeX format, references added. To appear in Phys. Rev.
HGCLIP: Exploring Vision-Language Models with Graph Representations for Hierarchical Understanding
Object categories are typically organized into a multi-granularity taxonomic
hierarchy. When classifying categories at different hierarchy levels,
traditional uni-modal approaches focus primarily on image features, revealing
limitations in complex scenarios. Recent studies integrating Vision-Language
Models (VLMs) with class hierarchies have shown promise, yet they fall short of
fully exploiting the hierarchical relationships. These efforts are constrained
by their inability to perform effectively across varied granularity of
categories. To tackle this issue, we propose a novel framework (HGCLIP) that
effectively combines CLIP with a deeper exploitation of the Hierarchical class
structure via Graph representation learning. We explore constructing the class
hierarchy into a graph, with its nodes representing the textual or image
features of each category. After passing through a graph encoder, the textual
features incorporate hierarchical structure information, while the image
features emphasize class-aware features derived from prototypes through the
attention mechanism. Our approach demonstrates significant improvements on 11
diverse visual recognition benchmarks. Our codes are fully available at
https://github.com/richard-peng-xia/HGCLIP
DM-MIMO: Diffusion Models for Robust Semantic Communications over MIMO Channels
This paper investigates robust semantic communications over multiple-input multiple-output (MIMO) fading channels. Current semantic communications over MIMO channels mainly focus on channel adaptive encoding and decoding, which lacks exploration of signal distribution. To leverage the potential of signal distribution in signal space denoising, we develop a diffusion model over MIMO channels (DM-MIMO), a plugin module at the receiver side in conjunction with singular value decomposition (SVD) based precoding and equalization. Specifically, due to the significant variations in effective noise power over distinct sub-channels, we determine the effective sampling steps accordingly and devise a joint sampling algorithm. Utilizing a three-stage training algorithm, DM-MIMO learns the distribution of the encoded signal, which enables noise elimination over all sub-channels. Experimental results demonstrate that the DM-MIMO effectively reduces the mean square errors (MSE) of the equalized signal and the DM-MIMO semantic communication system (DM-MIMO-JSCC) outperforms the JSCC-based semantic communication system in image reconstruction
Selective protein degradation through tetrazine ligation of genetically incorporated unnatural amino acids
Small molecule‐responsive tags for targeted protein degradation are valuable tools for fundamental research and drug target validation. Here, we show that genetically incorporated unnatural amino acids bearing a strained alkene or alkyne functionality can act as a minimalist tag for targeted protein degradation. Specifically, we observed the degradation of strained alkene‐ or alkyne‐containing kinases and E2 ubiquitin‐conjugating enzymes upon treatment with hydrophobic tetrazine conjugates. The extent of the induced protein degradation depends on the identity of the target protein, unnatural amino acid, and tetrazine conjugate, as well as the site of the unnatural amino acid in the target protein. Mechanistic studies revealed proteins undergo proteasomal degradation after tetrazine tethering, and the identity of tetrazine conjugates influences the dependence of ubiquitination on protein degradation. This work provides an alternative approach for targeted protein degradation and mechanistic insight, facilitating the future development of more effective targeted protein degradation strategies
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