Numerical simulation of ripple formation

River morphodynamics and sediment transportMechanics of sediment transpor

Calculating Intrinsic and Extrinsic Camera Parameters Based on the PnP Problem

The classical PnP problem is premised on given intrinsic camera parameters. However, for unknown intrinsic camera parameters, given n space points in a world coordinate system and their coordinates in an image coordinate system, the extrinsic camera parameters can be determined. Regarding the existence and uniqueness of a solution for the classical PnP problem, for 4 control points in a plane and an uncalibrated camera, a set of linear equations can be solved based on the correspondence between the space points and the image points. The results show that this approach is feasible and has high calculation precision

The missing link between thermodynamics and structure in F_1-ATPase

F_1F_o-ATP synthase is the enzyme responsible for most of the ATP synthesis in living systems. The catalytic domain F_1 of the F_1F_o complex, F_1-ATPase, has the ability to hydrolyze ATP. A fundamental problem in the development of a detailed mechanism for this enzyme is that it has not been possible to determine experimentally the relation between the ligand binding affinities measured in solution and the different conformations of the catalytic β subunits (β_(TP), β_(DP), β_E) observed in the crystal structures of the mitochondrial enzyme, MF_1. Using free energy difference simulations for the hydrolysis reaction ATP+H_2O → ADP+P_i in the β_(TP) and β_(DP) sites and unisite hydrolysis data, we are able to identify β_(TP) as the “tight” (K_D = 10^(−12) M, MF_1) binding site for ATP and β_(DP) as the “loose” site. An energy decomposition analysis demonstrates how certain residues, some of which have been shown to be important in catalysis, modulate the free energy of the hydrolysis reaction in the β_(TP) and β_(DP) sites, even though their structures are very similar. Combined with the recently published simulations of the rotation cycle of F_1-ATPase, the present results make possible a consistent description of the binding change mechanism of F_1-ATPase at an atomic level of detail

An improve method for Chinese core ontology construction

2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Mining Concepts from Wikipedia for Ontology Construction

An ontology is a structured knowledgebase of concepts organized by relations among them. But concepts are usually mixed with their instances in the corpora for knowledge extraction. Concepts and their corresponding instances share similar features and are difficult to distinguish. In this paper, a novel approach is proposed to comprehensively obtain concepts with the help of definition sentences and Category Labels in Wikipedia pages. N-gram statistics and other NLP knowledge are used to help extracting appropriate concepts. The proposed method identified nearly 50,000 concepts from about 700,000 Wiki pages. The precision reaching 78.5% makes it an effective approach to mine concepts from Wikipedia for ontology construction.Department of Computin

Energy Efficiency Maximization Under Delay-Outage Probability Constraints Using Fluid Antenna Systems

Fluid antenna system (FAS) is a new wireless technology that enables reconfigurable antenna position to enhance communication performance. In wireless networks, spectral efficiency, delay and energy efficiency are some of the most important performance indicators. To jointly optimize these indicators for FAS-assisted point-to-point communication systems, we adopt the energy efficiency (EE) metric which is defined as the delivered data rate divided by the total power consumption. The optimal power allocation strategy is obtained to maximize the EE subject to a delay-outage probability constraint. We then study the effects of delay bounds and the number of FAS's ports on the maximum EE. Simulation results are presented to show the effectiveness of the proposed delay-aware FAS-assisted system

Experimental Diffusion Research on BCC Ti-Al-Sn Ternary Alloys

The interdiffusion behavior of BCC alloys of Ti-Sn binary and Ti-Al-Sn ternary was investigated at 1473 K (1200 °C) by the diffusion-couple technique. The extracted interdiffusion coefficients of Ti-Sn binary was found to gradually increase with increasing the Sn content, whereas those of Ti-Al-Sn ternary, either main or cross, greatly enhance as the content of diffusing species increases. By a way of comparison, Sn diffusion in Ti-Al-Sn ternary was discerned to occur by the vacancy mechanism

RGB Guided Depth Map Super-Resolution with Coupled U-Net

The depth maps captured by RGB-D cameras usually are of low resolution, entailing recent efforts to develop depth super-resolution (DSR) methods. However, several problems remain in existing DSR methods. First, conventional DSR methods often suffer from unexpected artifacts. Secondly, high-resolution (HR) RGB features and low-resolution (LR) depth features are often fused in shallow layers only. Thirdly, only the last layer of features is used for reconstruction. To address the above problems, we propose Coupled U-Net (CU-Net), a new color image guided DSR method built on two U-Net branches for HR color images and LR depth maps, respectively. The CU-Net embeds a dual skip connection structure to leverage the feature interaction of the two branches, and a multi-scale fusion to fuse the deeper and multi-scale features of two branch decoders for more effective feature reconstruction. Moreover, a channel attention module is proposed to eliminate artifacts. Extensive experiments show that the proposed CU-Net outperforms state-of-the-art methods