Beijing University of Technology

About: Beijing University of Technology is a education organization based out in Beijing, Beijing, China. It is known for research contribution in the topics: Microstructure & Laser. The organization has 31929 authors who have published 31987 publications receiving 352112 citations. The organization is also known as: Běijīng Gōngyè Dàxué & Beijing Polytechnic University.

No-Reference Quality Assessment of Screen Content Pictures

Abstract: Recent years have witnessed a growing number of image and video centric applications on mobile, vehicular, and cloud platforms, involving a wide variety of digital screen content images Unlike natural scene images captured with modern high fidelity cameras, screen content images are typically composed of fewer colors, simpler shapes, and a larger frequency of thin lines In this paper, we develop a novel blind/no-reference (NR) model for accessing the perceptual quality of screen content pictures with big data learning The new model extracts four types of features descriptive of the picture complexity, of screen content statistics, of global brightness quality, and of the sharpness of details Comparative experiments verify the efficacy of the new model as compared with existing relevant blind picture quality assessment algorithms applied on screen content image databases A regression module is trained on a considerable number of training samples labeled with objective visual quality predictions delivered by a high-performance full-reference method designed for screen content image quality assessment (IQA) This results in an opinion-unaware NR blind screen content IQA algorithm Our proposed model delivers computational efficiency and promising performance The source code of the new model will be available at: https://sitesgooglecom/site/guke198701/publications

Advances in chitosan-based drug delivery vehicles

Abstract: Within the past few years, chitosan-based drug delivery vehicles have become some of the most attractive to be studied. In contrast to all other polysaccharides, chitosan has demonstrated its unique characteristics for drug delivery platforms, including its active primary amino groups for chemical modification, simple and mild preparation methods for the encapsulation of biomolecules or drugs, mucoadhesion to facilitate transport across mucosal barriers and so on. In this review, an overview of the various types of chitosan-based drug delivery systems is provided, with special focus on polymeric drug conjugates and drug nanocarriers. The first part of the review is concerned with the development and applications of polymeric chitosan–drug conjugates. Then the chitosan-based nanocarrier systems as well as their preparation methods and applications are further discussed.

Stable nanosecond pulse generation from a graphene-based passively Q-switched Yb-doped fiber laser.

Abstract: We demonstrate stable 70 ns pulse generation from a Yb-doped fiber laser passively Q-switched by a graphene-based saturable absorber mirror in a short linear cavity. The maximum output power was 12 mW and the highest single pulse energy was 46 nJ. The repetition rate of the fiber laser can be widely tuned from 140 to 257 kHz along with the increase of the pump power. To the best of our knowledge, this is the first report for passively Q-switched sub-100-ns pulse operation of a graphene-based saturable absorber in a Yb-doped fiber laser.