2,696 research outputs found
Non-Hermitian Stark Many-Body Localization
Utilizing exact diagonalization (ED) techniques, we investigate a
one-dimensional, non-reciprocal, interacting hard-core boson model under a
Stark potential with tail curvature. By employing the non-zero imaginary
eigenenergies ratio, half-chain entanglement entropy, and eigenstate
instability, we numerically confirm that the critical points of spectral
real-complex (RC) transition and many-body localization (MBL) phase transition
are not identical, and an examination of the phase diagrams reveals that the
spectral RC transition arises before the MBL phase transition, which suggests
the existence of a novel non-MBL-driven spectral RC transition. These findings
are quite unexpected, and they are entirely different from observations in
disorder-driven interacting non-Hermitian systems. This work provides a useful
reference for further research on phase transitions in disorder-free
interacting non-Hermitian systems.Comment: Any comments or suggestions are welcome
CCR: Facial Image Editing with Continuity, Consistency and Reversibility
Three problems exist in sequential facial image editing: incontinuous
editing, inconsistent editing, and irreversible editing. Incontinuous editing
is that the current editing can not retain the previously edited attributes.
Inconsistent editing is that swapping the attribute editing orders can not
yield the same results. Irreversible editing means that operating on a facial
image is irreversible, especially in sequential facial image editing. In this
work, we put forward three concepts and corresponding definitions: editing
continuity, consistency, and reversibility. Then, we propose a novel model to
achieve the goal of editing continuity, consistency, and reversibility. A
sufficient criterion is defined to determine whether a model is continuous,
consistent, and reversible. Extensive qualitative and quantitative experimental
results validate our proposed model and show that a continuous, consistent and
reversible editing model has a more flexible editing function while preserving
facial identity. Furthermore, we think that our proposed definitions and model
will have wide and promising applications in multimedia processing. Code and
data are available at https://github.com/mickoluan/CCR.Comment: 10 pages, 11 figure
Clinical Characteristics of Recurrent Nasopharyngeal Carcinoma in High-Incidence Area
Background. To describe the clinical characteristics of the patients who suffered from relapse after conventional irradiation for nasopharyngeal carcinoma (NPC). Methods. Three hundred and fifty-one consecutive patients with first-time recurrent NPC between January 1999 and July 2005 were included. The patients' clinical data were reviewed, including recurrent interval time, symptoms, signs, imaging characteristics, pathologic features, and restaging. Results. The median interval of relapse was 26.0 months. The most common symptoms in symptomatic patients were nasal bloody discharge (37.9%) and headache (31.1%). Local recurrence alone accounted for 73.5%. Most patients were restaged as stage III (23.1%) and stage IV (51.1%). Subgroup analysis suggested a significantly higher proportion of the long-latent relapses originated from early primary. A series of postreirradiation complications were more frequent in patients with longer latency at reception. Conclusions. Most recurrent nasopharyngeal carcinoma is advanced disease. Patients with different recurrent interval time show different nature behavior
A Study on Maneuvering Obstacle Motion State Estimation for Intelligent Vehicle Using Adaptive Kalman Filter Based on Current Statistical Model
Far-field Super-resolution Chemical Microscopy
Far-field chemical microscopy providing molecular electronic or vibrational
fingerprint information opens a new window for the study of three-dimensional
biological, material, and chemical systems. Chemical microscopy provides a
nondestructive way of chemical identification without exterior labels. However,
the diffraction limit of optics hindered it from discovering more details under
the resolution limit. Recent development of super-resolution techniques gives
enlightenment to open this door behind far-field chemical microscopy. Here, we
review recent advances that have pushed the boundary of far-field chemical
microscopy in terms of spatial resolution. We further highlight applications in
biomedical research, material characterization, environmental study, cultural
heritage conservation, and integrated chip inspection.Comment: 34 pages, 8 figures,1 tabl
Mask-Attention-Free Transformer for 3D Instance Segmentation
Recently, transformer-based methods have dominated 3D instance segmentation,
where mask attention is commonly involved. Specifically, object queries are
guided by the initial instance masks in the first cross-attention, and then
iteratively refine themselves in a similar manner. However, we observe that the
mask-attention pipeline usually leads to slow convergence due to low-recall
initial instance masks. Therefore, we abandon the mask attention design and
resort to an auxiliary center regression task instead. Through center
regression, we effectively overcome the low-recall issue and perform
cross-attention by imposing positional prior. To reach this goal, we develop a
series of position-aware designs. First, we learn a spatial distribution of 3D
locations as the initial position queries. They spread over the 3D space
densely, and thus can easily capture the objects in a scene with a high recall.
Moreover, we present relative position encoding for the cross-attention and
iterative refinement for more accurate position queries. Experiments show that
our approach converges 4x faster than existing work, sets a new state of the
art on ScanNetv2 3D instance segmentation benchmark, and also demonstrates
superior performance across various datasets. Code and models are available at
https://github.com/dvlab-research/Mask-Attention-Free-Transformer.Comment: Accepted to ICCV 2023. Code and models are available at
https://github.com/dvlab-research/Mask-Attention-Free-Transforme
Enhancement of polar phases in PVDF by forming PVDF/SiC nanowire composite
Different contents of silicon carbide (SiC) nanowires were mixed with Poly(vinylidene fluoride) (PVDF) to facilitate the polar phase crystallization. It was shown that the annealing temperature and SiC content affected on the phase and crystalline structures of PVDF/SiC samples. Furthermore, the addition of SiC nanowire enhanced the transformation of non-polar α phase to polar phases and increased the relative fraction of β phase in PVDF. Due to the nucleating agent mechanism of SiC nanowires, the ion-dipole interaction between the negatively charged surface of SiC nanowires and the positive CH2 groups in PVDF facilitated the formation of polar phases in PVDF
Generation of Oligodendrocyte Progenitor Cells From Mouse Bone Marrow Cells.
Oligodendrocyte progenitor cells (OPCs) are a subtype of glial cells responsible for myelin regeneration. Oligodendrocytes (OLGs) originate from OPCs and are the myelinating cells in the central nervous system (CNS). OLGs play an important role in the context of lesions in which myelin loss occurs. Even though many protocols for isolating OPCs have been published, their cellular yield remains a limit for clinical application. The protocol proposed here is novel and has practical value; in fact, OPCs can be generated from a source of autologous cells without gene manipulation. Our method represents a rapid, and high-efficiency differentiation protocol for generating mouse OLGs from bone marrow-derived cells using growth-factor defined media. With this protocol, it is possible to obtain mature OLGs in 7-8 weeks. Within 2-3 weeks from bone marrow (BM) isolation, after neurospheres formed, the cells differentiate into Nestin+ Sox2+ neural stem cells (NSCs), around 30 days. OPCs specific markers start to be expressed around day 38, followed by RIP+O4+ around day 42. CNPase+ mature OLGs are finally obtained around 7-8 weeks. Further, bone marrow-derived OPCs exhibited therapeutic effect in shiverer (Shi) mice, promoting myelin regeneration and reducing the tremor. Here, we propose a method by which OLGs can be generated starting from BM cells and have similar abilities to subventricular zone (SVZ)-derived cells. This protocol significantly decreases the timing and costs of the OLGs differentiation within 2 months of culture
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