A parametrized compactness theorem under bounded Ricci curvature

We prove a parametrized compactness theorem on manifolds of bounded Ricci curvature, upper bounded diameter and lower bounded injectivity radius.Comment: 17 pages. Final version to appear in Front. Math. China. Reformulation of Theorem B to Corollary 1, adding some remarks, changing the precompactness in Corollary 1.3 (now Corollary 2) to $C^{0,\alpha}$-norm, and correcting some typo

A quadratic bound on the number of boundary slopes of essential surfaces with bounded genus

Let $M$ be an orientable 3-manifold with $\partial M$ a single torus. We show that the number of boundary slopes of immersed essential surfaces with genus at most $g$ is bounded by a quadratic function of $g$. In the hyperbolic case, this was proved earlier by Hass, Rubinstein and Wang.Comment: 11 pages, 1 figur

Moving mesh finite element simulation for phase-field modeling of brittle fracture and convergence of newton's iteration

A moving mesh finite element method is studied for the numerical solution of a phase-field model for brittle fracture. The moving mesh partial differential equation approach is employed to dynamically track crack propagation. Meanwhile, the decomposition of the strain tensor into tensile and compressive components is essential for the success of the phase-field modeling of brittle fracture but results in a non-smooth elastic energy and stronger nonlinearity in the governing equation. This makes the governing equation much more difficult to solve and, in particular, Newton's iteration often to fail to converge. Three regularization methods are proposed to smooth out the decomposition of the strain tensor. Numerical examples of fracture propagation under quasi-static load demonstrate that all of the methods can effectively improve the convergence of Newton's iteration for relatively small values of the regularization parameter but without comprising the accuracy of the numerical solution. They also show that the moving mesh finite element method is able to adaptively concentrate the mesh elements around propagating cracks and handle multiple and complex crack systems.Comment: 32 page

Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields

We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel ionized N2 molecules at various driver wavelengths in the near- and mid-infrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground state and the excited states occur in strong laser fields. The couplings result in the population inversion between the ground and the excited states at the wavelengths near 800 nm, which is verified by our experiment by observing the amplification of a seed at ~391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.Comment: 18 pages, 4 figure

The Development and Exploration of Smart Port

Smart port is the core of the intersection of logistics. According to the data-driven Internet of Things information platform, the logistics chain and value chain are highly integrated to realize intelligent management and decision-making. In the future, smart ports will continue to promote the development prospects of logistics, business innovation and operation, promote the high integration of the port and the shipping industry, and enhance the comprehensive competitiveness of the port. At the same time, the construction of green and smart ports will become an important direction of future development, and promote the development of ports to a greener and more intelligent direction

Research and Prospect of Big Data Audit Technology

In the era of big data, technology is constantly innovated. For the audit industry, the combination of big data technology and audit should be the development trend of The Times. The joint application and combination of various technologies will promote the further development of audit. This paper mainly expounds some basic technologies of big data audit, explores and discusses the problems and corresponding solutions in the development process of big data audit in today’s society, and looks forward to the trend of big data audit in the future

Strategies for Searching Video Content with Text Queries or Video Examples

The large number of user-generated videos uploaded on to the Internet everyday has led to many commercial video search engines, which mainly rely on text metadata for search. However, metadata is often lacking for user-generated videos, thus these videos are unsearchable by current search engines. Therefore, content-based video retrieval (CBVR) tackles this metadata-scarcity problem by directly analyzing the visual and audio streams of each video. CBVR encompasses multiple research topics, including low-level feature design, feature fusion, semantic detector training and video search/reranking. We present novel strategies in these topics to enhance CBVR in both accuracy and speed under different query inputs, including pure textual queries and query by video examples. Our proposed strategies have been incorporated into our submission for the TRECVID 2014 Multimedia Event Detection evaluation, where our system outperformed other submissions in both text queries and video example queries, thus demonstrating the effectiveness of our proposed approaches

An Iterative Approach to Data-Driven Inference for Decoding Oscillator Network Structures

In complex networks, interactions between multiple agents give rise to an array of intricate global dynamics, ranging from synchronization to cluster formations. Decoding the connectivity structure as well as the types of interactions from measurement data is the first step toward understanding these intriguing behaviors. In this paper, we present a bilinear optimization framework to infer both the connectivity and interaction functions of oscillator networks with the identical class of coupling functions. We then propose an iterative algorithm to solve the resulting bilinear problem and illustrate its convergence. We validate our approach on both simulated and noisy experimental datasets, where we demonstrate its effectiveness compared with existing approaches.Comment: 6 pages, 6 Figures, conference pape