629 research outputs found
On the Quantum Theory of Massless Spin-3/2 Field in Minkowski Spacetime
From the modern viewpoint and by the geometric method, this paper provides a
concise foundation for the quantum theory of massless spin-3/2 field in
Minkowski spacetime, which includes both the one-particle's quantum mechanics
and the many-particle's quantum field theory. The explicit result presented
here is useful for the investigation of spin-3/2 field in various circumstances
such as supergravity, twistor programme, Casimir effect, and quantum
inequality.Comment: 11 pages, typos corrected, accepted for publication in Int.J.Geom.
Methods Mod. Phy
Synchronization Analysis of Two Coupled Complex Networks with Time Delays
This paper studies the synchronized motions between two complex networks with time delays,
which include individual inner synchronization in each network and outer synchronization between
two networks. Based on the Lyapunov stability theory and the linear matrix equality (LMI), a
synchronous criterion for inner synchronization inside each network is derived. Numerical examples
are given which fit the theoretical analysis. In addition, the involved numerical results show that
the delays between two networks have little effect on inner synchronization. It is also shown that
synchronous motions within each network or between two networks are not enhanced if individual
intranetwork connections are allowed
Effective Bug Triage based on Historical Bug-Fix Information
International audienceFor complex and popular software, project teams could receive a large number of bug reports. It is often tedious and costly to manually assign these bug reports to developers who have the expertise to fix the bugs. Many bug triage techniques have been proposed to automate this process. In this pa-per, we describe our study on applying conventional bug triage techniques to projects of different sizes. We find that the effectiveness of a bug triage technique largely depends on the size of a project team (measured in terms of the number of developers). The conventional bug triage methods become less effective when the number of developers increases. To further improve the effectiveness of bug triage for large projects, we propose a novel recommendation method called BugFixer, which recommends developers for a new bug report based on historical bug-fix in-formation. BugFixer constructs a Developer-Component-Bug (DCB) network, which models the relationship between developers and source code components, as well as the relationship be-tween the components and their associated bugs. A DCB network captures the knowledge of "who fixed what, where". For a new bug report, BugFixer uses a DCB network to recommend to triager a list of suitable developers who could fix this bug. We evaluate BugFixer on three large-scale open source projects and two smaller industrial projects. The experimental results show that the proposed method outperforms the existing methods for large projects and achieves comparable performance for small projects
Masked Vision-Language Transformers for Scene Text Recognition
Scene text recognition (STR) enables computers to recognize and read the text
in various real-world scenes. Recent STR models benefit from taking linguistic
information in addition to visual cues into consideration. We propose a novel
Masked Vision-Language Transformers (MVLT) to capture both the explicit and the
implicit linguistic information. Our encoder is a Vision Transformer, and our
decoder is a multi-modal Transformer. MVLT is trained in two stages: in the
first stage, we design a STR-tailored pretraining method based on a masking
strategy; in the second stage, we fine-tune our model and adopt an iterative
correction method to improve the performance. MVLT attains superior results
compared to state-of-the-art STR models on several benchmarks. Our code and
model are available at https://github.com/onealwj/MVLT.Comment: The paper is accepted by the 33rd British Machine Vision Conference
(BMVC 2022
Effect of estrogen application timing on adipose tissue revascularization and immune regulation in rats after autologous fat transplantation
Purpose: To study the effect of timing of estrogen application on adipose tissue revascularization and immune regulation in rats given autologous fat transplantation.Methods: Ninety (90) healthy rats were selected for use in this study. The rats were randomly divided into a study group (n = 45) and control group (n = 45). After ovariectomy, the study group was given estrogen replacement therapy before autologous fat transplantation, while the control group was given estrogen replacement therapy after autologous fat transplantation. The rats were observed for 6 weeks after transplantation. Micro-vessel density, wet weight of transplanted fat, VEGF expression level, levels of M1 and M2 in macrophages, and macrophage infiltration rate were determined 40 days postautologous fat transplantation.Results: Forty days after autologous fat transplantation, microvessel density, wet weight of transplanted fat, expression level of VEGF and levels of M1 and M2 in macrophages were significantly higher in study group rats than in controls (p < 0.05). There was 80 % macrophage infiltration in the study group rats, while the corresponding control value (61 %) was significantly lower (p < 0.05).Conclusion: Estrogen treatment before autologous fat transplantation in rats is helpful for the revascularization of adipose tissue, enhances vascular regeneration, promotes the survival of adipose tissue after transplantation, and activates immune cells. It also promotes the production of immune factors, and improves immunoregulation in adipose tissue. Thus, this therapeutic strategy may be useful in clinical practice, but further clinical trials are required
Study on the Collaborative Design PN-PDDP Model for the Multi-component Coupling Rotor System Based on Petri Nets
AbstractBased on the analysis of the characteristics for the design process in the complex multi-component coupling rotor system, and considering the fact that the multi-components co-design is demanded in the design process of the performance-driven target coupled rotor system, a PN-PDDP (Petri Network for Performance Driven Design Process) model based on the extended Petri nets is presented. The model defines the libraries of the performance and structure characteristics, the traces Token and firing rules. With the model, the flow process of the various coupled information flow is described, and the conflict resolution mechanism for the conflict information is developed. The model also offers guidance on the construction of the related database and design platform, which will provide the important design tools and implementation means for the design of the multi-component coupling turbopump rotor system in the liquid rocket engine
Lipoic acid inhibits nerve cell apoptosis in rats with Parkinson's disease via Erk signaling pathway
Purpose: To investigate the effect of lipoic acid on nerve cell apoptosis in rats with Parkinson's disease via the extracellular signal-regulated kinase (ERK) signaling pathway.Methods: A total of 36 rats were randomly divided into normal group (n = 12), Parkinson's disease model group (n = 12) and lipoic acid group (n = 12). The neuronal morphology was examined by means of Nissl staining, while cell apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay.Results: The neurons were severely damaged in model group, while neuronal morphology and structure were ameliorated in lipoic acid group when compared with those in model group. The p-ERK was lowered significantly (p < 0.05) in model group and lipoic acid group compared with that in normal group. Levels of mRNA, caspase-3 and Bax increased significantly, while Bcl-2 decreased in model group and lipoic acid group when compared with those in normal group (p < 0.05). Lipoic acid treatment significantly reduced mRNA expression of caspase-3 and Bax, but increased Bcl-2 compared with model group. Furthermore, ELISA results indicate that model and lipoic acid groups exhibited raised caspase-3 and Bax but significantly reduced Bcl-2 levels, compared with normal group. The results also showed that the apoptosis was higher in the other two groups than in normal group; on the other hand, it was significantly lower in lipoic acid group than in model group (p < 0.05).Conclusion: Lipoic acid inhibits nerve cell apoptosis in rats with Parkinson's disease by up-regulating ERK signaling pathway. Therefore, lipoic acid is a potential neuroprotective agent for the management of Parkinson’s disease
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