BING: Binarized normed gradients for objectness estimation at 300fps

Training a generic objectness measure to produce object proposals has recently become of significant interest. We observe that generic objects with well-defined closed boundaries can be detected by looking at the norm of gradients, with a suitable resizing of their corresponding image windows to a small fixed size. Based on this observation and computational reasons, we propose to resize the window to 8 × 8 and use the norm of the gradients as a simple 64 D feature to describe it, for explicitly training a generic objectness measure. We further show how the binarized version of this feature, namely binarized normed gradients(BING), can be used for efficient objectness estimation, which requires only a few atomic operations(e.g., add, bitwise shift, etc.). To improve localization quality of the proposals while maintaining efficiency, we propose a novel fast segmentation method and demonstrate its effectiveness for improving BING's localization performance, when used in multithresholding straddling expansion(MTSE) postprocessing. On the challenging PASCAL VOC2007 dataset, using 1000 proposals per image and intersectionover-union threshold of 0.5, our proposal method achieves a 95.6% object detection rate and 78.6% mean average best overlap in less than 0.005 second per image.

Progress of Jinping Underground laboratory for Nuclear Astrophysics(JUNA)

Jinping Underground laboratory for Nuclear Astrophysics(JUNA) will take the advantage of the ultra-low background of CJPL lab and high current accelerator based on an ECR source and a highly sensitive detector to directly study for the first time a number of crucial reactions occurring at their relevant stellar energies during the evolution of hydrostatic stars. In its first phase, JUNA aims at the direct measurements of^(25)Mg(p,γ)^(26)Al,^(19)F(p,α)^(16)O,^(13)C(α,n)^(16)O and ^(12)C(α,γ)^(16)O reactions. The experimental setup,which includes an accelerator system with high stability and high intensity, a detector system, and a shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

High peak power femtosecond cylindrical vector beams generation in a chirped-pulse amplification laser system

Cylindrical vector beams(CVBs),with non-uniform state of polarizations,have become an indispensable tool in many areas of science and technology.However,little research has explored high power CVBs at the femtosecond regime.In this paper,we report on tne generation of high quality CVBs with high peak power and femtosecond pulse duration in a fiber chirped-pulse amplification laser system.The radially(azimuthally)polarized vector beam has been obtained with a pulse duration of 4A0 fs[430 fs]and a maximum average output power of 20.36 W[20.12 W].The maximum output pulse energy is〜20μJ at a repetition rate of 1 MHz,corresponding to a high peak power of-46 MW.The comparison between simulated intensity profiles and measured experimental results suggests that the generated CVBs have a remarkable intensity distribution.The proposed configuration of our laser system provides a promising solution for high quality CVBs generation with the characteristics of high peak power,ultrashort pulse duration,and high mode purity.

Heterogeneous integrated phase modulator based on two-dimensional layered materials

Silicon nitride,with ultralow propagation loss and a wide transparency window,offers an exciting platform to explore integrated photonic devices for various emerging applications.It is appealing to combine the intrinsic optical properties of two-dimensional layered materials with high-quality optical waveguides and resonators to achieve functional devices in a single chip.Here we demonstrate a micro-ring resonator-based phase modulator integrated with few-layer MoS_(2).The ionic liquid is employed directly on the surface of MoS_(2) to form a capacitor configuration.The effective index of the composite MoS_(2)–SiN waveguide can be modulated via adjusting bias voltages to achieve different charged doping induced electro-refractive responses in MoS_(2) film.The maximum effective index modulation of the composite MoS_(2)–SiN waveguide can be achieved to 0.45×10^(−3).The phase tuning efficiency is measured to be 29.42 pm/V,corresponding to a V_(π)L of 0.69 V·cm.Since the micro-ring resonator is designed near the critical coupling regime,the coupling condition between the bus waveguide and micro-ring resonator can also be engineered from under-coupling to over-coupling regime during the charged doping process.That can be involved as a degree of freedom for the coupling tailoring.The ability to modulate the effective index with two-dimensional materials and the robust nature of the heterostructure integrated phase modulator could be useful for engineering reliable ultra-compact and low-power-consumption integrated photonic devices.