Doctor of Philosophy

dissertationThe Communist regime in China survived the collapse of the Soviet Communist Bloc in the early 1990s. Since then, China has sustained rapid economic growth with an annual growth rate of 8%. However, in recent years, we have witnessed increasing social protests in Chinese cities and rural areas. The increasing contentious politics and a stable authoritarian regime puzzles theorists on authoritarian regime and political transition. This dissertation seeks to answer the question, why or how China's authoritarian regime has remained politically stable with increasing social protest. It adopts an institutionalist approach to explore the interaction between contentious politics and political institutional arrangements. It argues that the multilevel reasonability structure is the key to understanding political stability in China. This structure not only can absorb exogenous shock, but also can prevent endogenous subversion and can avoid power disequilibrium

GFF: Gated Fully Fusion for Semantic Segmentation

Semantic segmentation generates comprehensive understanding of scenes through densely predicting the category for each pixel. High-level features from Deep Convolutional Neural Networks already demonstrate their effectiveness in semantic segmentation tasks, however the coarse resolution of high-level features often leads to inferior results for small/thin objects where detailed information is important. It is natural to consider importing low level features to compensate for the lost detailed information in high-level features.Unfortunately, simply combining multi-level features suffers from the semantic gap among them. In this paper, we propose a new architecture, named Gated Fully Fusion (GFF), to selectively fuse features from multiple levels using gates in a fully connected way. Specifically, features at each level are enhanced by higher-level features with stronger semantics and lower-level features with more details, and gates are used to control the propagation of useful information which significantly reduces the noises during fusion. We achieve the state of the art results on four challenging scene parsing datasets including Cityscapes, Pascal Context, COCO-stuff and ADE20K.Comment: accepted by AAAI-2020(oral

Emergency Operations of Sudden Water Pollution Accidents

Emergency operation technologies can help to make reasonable operation measures of hydraulic structures, which are important to control the scope of the effect arising from an event and reduce the harm caused thereby. The main canal of MRP is divided into three parts in case of sudden water pollution accidents: the accident pool, the upstream section of the accident pool, and the downstream section of the accident pool. For each part, the target and strategy for emergency operation technologies are discussed. With regard to an accident pool, multiple kinds of check gate closing methods, synchronous, asynchronous, identical speed, and different speed are put forward; for the upstream section, a new method of equal-volume operation is introduced; and for the downstream section, three emergency operation methods are proposed. The simulation result of case study shows that the methods raised in this chapter can be used to determine suitable emergency operation measures

Effects of Arbuscular Mycorrhizal Fungi on Root Growth and Architecture of Tulip Gesneriana

Arbuscular mycorrhizal fungi(AMF) can promote the absorption of soil water and mineral nutrients, improve photosynthesis, and make host attain higher quality finally by establishing symbiotic relationship between AMF and host root. To improve Tulip gesneriana quality have practical meaning under no bad affect to cultivation soil, in the light of its economical and ecological values. However, some AMF may be diverse from others, the concrete function of AMF on commercial tulip varieties need to explore. Therefore, three different sets of  arbuscular mycorrhizal fungi were inoculated into tulip rhizosphere soil, which were set as 4(Diversispora versiformis), 7(Diversispora spurca) and 1 + 3 + 4 (Rhizophagus intraradias + Funneliformis mosseae + Diversispora versiformis), respectively. The results showed that the activity of most of the measured indices increased, the average root diameter and sucrose content decreased in those three mycorrhizal treatments. Our research provide some theoretical basis for the application of AMF on T.gesneriana ecological cultivation in future

Peeling behavior of a viscoelastic thin-film on a rigid substrate

AbstractIn order to study the adhesion mechanism of a viscoelastic thin-film on a substrate, peeling experiment of a viscoelastic polyvinylchloride (PVC) thin-film on a rigid substrate (glass) is carried out. The effects of peeling rate, peeling angle, film thickness, surface roughness and the interfacial adhesive on the peel-off force are considered. It is found that both the viscoelastic properties of the film and the interfacial adhesive contribute to the rate-dependent peel-off force. For a fixed peeling rate, the peel-off force decreases with the increasing peeling angle. Increasing film thickness or substrate roughness leads to an increase of the peel-off force. Viscoelastic energy release rate in the present experiment can be further predicted by adopting a recently published theoretical model. It is shown that the energy release rate increases with the increase of peeling rates or peeling angles. The results in the present paper should be helpful for understanding the adhesion mechanism of a viscoelastic thin-film