Beihang University

About: Beihang University is a education organization based out in Beijing, China. It is known for research contribution in the topics: Control theory & Microstructure. The organization has 67002 authors who have published 73507 publications receiving 975691 citations. The organization is also known as: Beijing University of Aeronautics and Astronautics.

Ship Detection in Spaceborne Optical Image With SVD Networks

Abstract: Automatic ship detection on spaceborne optical images is a challenging task, which has attracted wide attention due to its extensive potential applications in maritime security and traffic control. Although some optical image ship detection methods have been proposed in recent years, there are still three obstacles in this task: 1) the inference of clouds and strong waves; 2) difficulties in detecting both inshore and offshore ships; and 3) high computational expenses. In this paper, we propose a novel ship detection method called SVD Networks (SVDNet), which is fast, robust, and structurally compact. SVDNet is designed based on the recent popular convolutional neural networks and the singular value decompensation algorithm. It provides a simple but efficient way to adaptively learn features from remote sensing images. We evaluate our method on some spaceborne optical images of GaoFen-1 and Venezuelan Remote Sensing Satellites. The experimental results demonstrate that our method achieves high detection robustness and a desirable time performance in response to all of the above three problems.

Switchable, dual-wavelength passively mode-locked ultrafast fiber laser based on a single-wall carbon nanotube modelocker and intracavity loss tuning

Abstract: We demonstrate a dual-wavelength passively mode-locked soliton fiber laser based on the single-wall carbon nanotube saturable absorber. By using a simple scheme of adjusting the intracavity loss, the gain profile of the erbium-doped fiber laser is effectively controlled. Besides operating at a single wavelength, the laser is able to simultaneously generate sub-picosecond pulses at both ~1532 and 1557 nm wavelength. The mode-locking wavelength can also be quickly switched from one wavelength to the other by changing the intracavity loss with a tunable attenuator.

Part-Regularized Near-Duplicate Vehicle Re-Identification

Abstract: Vehicle re-identification (Re-ID) has been attracting more interests in computer vision owing to its great contributions in urban surveillance and intelligent transportation. With the development of deep learning approaches, vehicle Re-ID still faces a near-duplicate challenge, which is to distinguish different instances with nearly identical appearances. Previous methods simply rely on the global visual features to handle this problem. In this paper, we proposed a simple but efficient part-regularized discriminative feature preserving method which enhances the perceptive ability of subtle discrepancies. We further develop a novel framework to integrate part constrains with the global Re-ID modules by introducing an detection branch. Our framework is trained end-to-end with combined local and global constrains. Specially, without the part-regularized local constrains in inference step, our Re-ID network outperforms the state-of-the-art method by a large margin on large benchmark datasets VehicleID and VeRi-776.

Black Phosphorus Quantum Dot/Ti3C2 MXene Nanosheet Composites for Efficient Electrochemical Lithium/Sodium‐Ion Storage

Abstract: The exploration of new and efficient energy storage mechanisms through nanostructured electrode design is crucial for the development of high-performance rechargeable batteries. Herein, black phosphorus quantum dots (BPQDs) and Ti3C2 nanosheets (TNSs) are employed as battery and pseudocapacitive components, respectively, to construct BPQD/TNS composite anodes with a novel battery-capacitive dual-model energy storage (DMES) mechanism for lithium-ion and sodium-ion batteries. Specifically, as a battery-type component, BPQDs anchored on the TNSs are endowed with improved conductivity and relieved stress upon cycling, enabling a high-capacity and stable energy storage. Meanwhile, the pseudocapacitive TNS component with further atomic charge polarization induced by POTi interfacial bonds between the two components allows enhanced charge adsorption and efficient interfacial electron transfer, contributing a higher pseudocapacitive value and fast energy storage. The DMES mechanism is evidenced by substantial characterizations of X-ray photoelectron spectroscopy and X-ray absorption fine structure spectroscopy, density functional theory calculations, and kinetics analyses. Consequently, the composite electrode exhibits superior battery performance, especially for lithium storage, such as high capacity (910 mAh g−1 at 100 mA g−1), long cycling stability (2400 cycles with a capacity retention over 100%), and high rate capability, representing the best comprehensive battery performance in BP-based anodes to date.