Research on Transferring the National Height System to the Island

Yanxiong LIU,Xinghua ZHOU,Lin PENG,Yongtong WU 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

It is quite difficult to transfer the National Height System 1985 to the island in China. In the study, one feasible and alternative way, which measures synchronally the tide variation at the island and the coast , is firstly introduced. Then, a new method is proposed. This new method combines GPS technique and Quasi-Geoid Determination technique (GQGD). It needs gravity data, GPS data, leveling data and DEM data, together with complex calculation method and the Earth gravity model. After describing the mathematical model and presenting the calculational steps, one experiment has been shown that this method is valid and can achieve accuracy up to 5 cm for the normal height, compared with the results both from the tidal observation and height approximation. Some suggestion is also given in the end.

Studies on control mechanism and performance of a novel pneumatic-driven active dynamic vibration absorber

Kunjie Rong,Xinghua Li,Zheng Lu,Siyuan Wu 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.87 No.2

To efficiently attenuate seismic responses of a structure, a novel pneumatic-driven active dynamic vibration absorber (PD-ADVA) is proposed in this study. PD-ADVA aims to realize closed-loop control using a simple and intuitive control algorithm, which takes the structure velocity response as the input signal and then outputs an inverse control force to primary structure. The corresponding active control theory and phase control mechanism of the system are studied by numerical and theoretical methods, the system’s control performance and amplitude-frequency characteristics under seismic excitations are explored. The capability of the proposed active control system to cope with frequency-varying random excitation is evaluated by comparing with the optimum tuning TMD. The analysis results show that the control algorithm of PD-ADVA ensures the control force always output to the structure in the opposite direction of the velocity response, indicating that the presented system does not produce a negative effect. The phase difference between the response of uncontrolled and controlled structures is zero, while the phase difference between the control force and the harmonic excitation is π, the theoretical and numerical results demonstrate that PD-ADVA always generates beneficial control effects. The PD-ADVA can effectively mitigate the structural seismic responses, and its control performance is insensitive to amplitude. Compared with the optimum tuning TMD, PD-ADVA has better control performance and higher system stability, and will not have negative effects under seismic wave excitations.

Centralized Clustering Routing Based on Improved Sine Cosine Algorithm and Energy Balance in WSNs

Xiaoling Guo,Xinghua Sun,Ling Li,Renjie Wu,Meng Liu 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.1

Centralized hierarchical routing protocols are often used to solve the problems of uneven energy consumptionand short network life in wireless sensor networks (WSNs). Clustering and cluster head election have becomethe focuses of WSNs. In this paper, an energy balanced clustering routing algorithm optimized by sine cosinealgorithm (SCA) is proposed. Firstly, optimal cluster head number per round is determined according tosurviving node, and the candidate cluster head set is formed by selecting high-energy node. Secondly, a randompopulation with a certain scale is constructed to represent a group of cluster head selection scheme, and fitnessfunction is designed according to inter-cluster distance. Thirdly, the SCA algorithm is improved by usingmonotone decreasing convex function, and then a certain number of iterations are carried out to select a groupof individuals with the minimum fitness function value. From simulation experiments, the process from thefirst death node to 80% only needs about 30 rounds. This improved algorithm balances the energy consumptionamong nodes and avoids premature death of some nodes. And it greatly improves the energy utilization andextends the effective life of the whole network.

The behaviors of LNAPL migration and entrapment in a rough-walled vertical fracture

Bin Lu,Shiqiang Wu,Xinghua Xie,Yefei Tan 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.3

The migration of light non-aqueous phase liquids (LNAPLs) and their entrapment in unsaturated vertical fractures exhibit complex behaviors, such as upward LNAPL migration that follows water level rise. In this study, behavior of LNAPL migration and entrapment in a vertical rough-walled fracture was investigated with optical measurement. A series of experiments were preformed, including fracture drainage, LNAPL infiltration and accumulation in an unsaturated fracture, and upward LNAPL migration with water level rise. Experimental results indicate that the fracture aperture significantly influences the LNAPL migration path and entrapped blobs distribution. The LNAPL-filled aperture follows a normal distribution, with the mean aperture ranging 0.253 mm to 0.287 mm, and the standard deviation around 0.13 mm. The characteristics of the entrapment blob morphology indicate that 80% of the individual blob areas are smaller than 20mm2. The irregular structures of discrete blobs increase the ‘LNAPL-water’ interface, which will exacerbate contamination.

Approximate Bisimulations for Constrained Discrete-Time Linear Systems

Guoqi Ma,Linlin Qin,Xinghua Liu,Chun Shi,Gang Wu 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

In this paper, we consider the problem of approximate bisimulations for constrained discrete-time linear systems. First, we develop a theory of approximation for transition systems with nondeterministic evolution. Then observation metrics are used to describe the bounded distance between system observations. Furthermore, we utilize a class of Lyapunov-like functions, called bisimulation functions, to characterize the approximate bisimulation relations. For the class of discrete-time linear systems with constrained inputs, we convert the problem of computing bisimulation functions to linear matrix inequalities (LMIs) and optimization problems. Finally, a numerical example is performed to verify the effectiveness of the approximation bisimulation framework design technique, and using multi-parametric toolbox (MPT), we also demonstrate the application to safety verification.

Short-Term Prediction of Disturbance Inputs of the Greenhouse System

Guoqi Ma,Linlin Qin,Xinghua Liu,Chun Shi,Gang Wu 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

Greenhouse microclimate control system is a typical hybrid system, in which the discrete (or logical) variables and continuous variables interact. The existence of outside measurable but uncontrollable disturbance inputs including outside temperature, humidity, wind speed, solar radiation, and et al, makes the control problem of greenhouse microclimate a challenging one and some conventional control methods not applicable, which motivates us to investigate the prediction problem of disturbance inputs of greenhouse control system. First, grey prediction model GM (1, 1) and time series model ARIMA (p, d, q) are adopted to predict the outside humidity over the next four hours, respectively. Then, considering the nonstationary property of the humidity sequence, wavelet analysis theory is applied to decompose the humidity sequence into different scales in order to reduce the randomness of the original sequence. Furthermore, the low frequency signal and high frequency one are predicted by GM (1, 1) and time series model ARIMA (p, d, q), respectively. Finally, simulation studies are carried out to compare the three prediction methods.

Local Hyperthermia Affects Murine Contact Hypersensitivity around Elicitation Phase

( Yan Sun ),( Lan Zhang ),( Qian An ),( Yuxiao Hong ),( Yan Wu ),( Xinghua Gao ) 대한피부과학회 2018 Annals of Dermatology Vol.30 No.1

Three-dimensional thermal-hydraulics/neutronics coupling analysis on the full-scale module of helium-cooled tritium-breeding blanket

Lian Qiang,Tang Simiao,Zhu Longxiang,Zhang Luteng,Sun Wan,Bu Shanshan,Pan Liangming,Tian Wenxi,Qiu Suizheng,Su G.H.,Wu Xinghua,Wang Xiaoyu 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11

Blanket is of vital importance for engineering application of the fusion reactor. Nuclear heat deposition in materials is the main heat source in blanket structure. In this paper, the three-dimensional method for thermalhydraulics/ neutronics coupling analysis is developed and applied for the full-scale module of the helium-cooled ceramic breeder tritium breeding blanket (HCCB TBB) designed for China Fusion Engineering Test Reactor (CFETR). The explicit coupling scheme is used to support data transfer for coupling analysis based on cell-to-cell mapping method. The coupling algorithm is realized by the user-defined function compiled in Fluent. The threedimensional model is established, and then the coupling analysis is performed using the paralleled Coupling Analysis of Thermal-hydraulics and Neutronics Interface Code (CATNIC). The results reveal the relatively small influence of the coupling analysis compared to the traditional method using the radial fitting function of internal heat source. However, the coupling analysis method is quite important considering the nonuniform distribution of the neutron wall loading (NWL) along the poloidal direction. Finally, the structure optimization of the blanket is carried out using the coupling method to satisfy the thermal requirement of all materials. The nonlinear effect between thermal-hydraulics and neutronics is found during the blanket structure optimization, and the tritium production performance is slightly reduced after optimization. Such an adverse effect should be thoroughly evaluated in the future work.