UKF Based Nonlinear Offset-free Model Predictive Control for Ship Dynamic Positioning under Stochastic Disturbances

Fang Deng,Hua-Lin Yang,Long-Jin Wang,Wei-Min Yang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.12

This paper presents the schemes of nonlinear offset-free model predictive control (MPC) for reference tracking of ship dynamic positioning (DP) systems, in the presence of slow-varying stochastic disturbances and input constraints. Two offset-free MPC strategies for nonlinear DP systems are proposed. The first approach, namely, the target calculation formulation, estimates the disturbance based on the augmented disturbance model, and employs a target calculator to address the MPC optimization problem. The second approach, namely, the delta input formulation, works with the augmented velocity model to lump the effects of disturbances into the input estimates. By successively on-line linearizing the state-space model at the current operating point, the future outputs are explicitly predicted, and then the nonlinear optimization problem becomes an easy quadratic optimization problem. The unscented Kalman filter is adopted for the state estimation. By implementing simulations for two scenarios of disturbances with parametric plant-model mismatch, the effectiveness of the two strategies is demonstrated. Results show that the closed-loop control performance of the delta input formulation method is superior, for its good robustness to the stochastic disturbance.

Adaptive Unscented Kalman Filter Based Estimation and Filtering for Dynamic Positioning with Model Uncertainties

Fang Deng,Hua-Lin Yang,Long-Jin Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.3

A novel adaptive unscented Kalman filter (AUKF) is presented and applied to ship dynamic positioning(DP) system with model uncertainties of time-varying noise statistics, model mismatch and slow varying driftforces. The adaptive algorithm is proposed to simultaneously online adapt the process and measurement noisecovariance by adopting the main principle of covariance matching. The measurement noise covariance is adaptedbased on residual covariance matching method, and then the process noise covariance is adjusted by using adaptivescaling factor. Simulation comparisons among the proposed RQAUKF, the strong tracking UKF (RSTAUKF) andthe standard UKF show that the proposed RQAUKF can effectively improve the estimation accuracy and stability,and can assist the controller to obtain better control performance.

Mesoporous CexZr1−xO2 solid solutions supported CuO nanocatalysts for toluene total oxidation

Qing-Fang Deng,Tie-Zhen Ren,Bao Agula,Yuping Liu,Zhong-Yong Yuan 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Mesoporous CexZr1 xO2 solid solutions were prepared by the surfactant-assisted method and used as support of CuO nanocatalysts for catalytic total oxidation of toluene. The prepared CuO/CexZr1 xO2 catalysts have a wormhole-like mesoporous structure with high surface area and uniform pore size distribution, and the CuO nanoparticles were highly dispersed on the surface of CexZr1 xO2. The doping of ZrO2 in CeO2 promotes the dispersion of active copper species and enhances the reducibility of copper species. The effect of Ce/Zr ratio, calcination temperature and CuO loading amount on the catalytic performance of CuO/CexZr1 xO2 was investigated in detail. The 400 ℃-calcined 8%CuO/Ce0.8Zr0.2O2 catalyst exhibits the highest activity with the complete toluene conversion temperature of 275 ℃ at the condition of GHSH = 33,000 h-1 and the toluene concentration of 4400 ppm. The interfacial interaction between CuO and the CexZr1 xO2 support, highly dispersed CuO nanoparticles and the nature of the support contribute to the high catalytic activity of mesoporous CuO/CexZr1 xO2 nanocatalysts.

The Research and Implementation of Temporal Quasi-order Data Index

Xiuqin Deng,Hongyan Xing,Chengyan Fang,Xiaoping Ye 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

This study proposed a quasi-order-based temporal data structure (QOTDS) which differed from conventional, algebraic data management models. Based on this QOTDS, a temporal data index called the temporal quasi-order index (TQOindex) was established. Firstly, the study proposed the concepts of temporal quasi-order (TQO) and linear order partitioning (LOP) of time period sets and discussed the construction algorithm of LOP and the optimum (minimum) properties. On this basis, a temporal data structure was established based on LOP. This structure realized the set-at-a-time data operation-like relational data structure and improved the inquiry efficiency by using multiple threads. Subsequently, in the structural framework of TQO, we discussed the temporal data index (TQOindex) based on quasi-order extensions. This index was effectively applicable to various conventional database platforms depending on the disk (external memory)-based data management and also to big data dynamic index technology relying on the incremental updating mechanism. Finally, a corresponding experimental simulation and comparative evaluation were designed to verify the feasibility and effectiveness of TQOindex. Research and experiments showed that QOTDS were effective at temporal inquiry and management in cases involving the temporal processing and integration mechanisms in new data, such as semantic data, XML data, and moving object data.

Analysis of Factors Influencing Communication Popularity Based on Short Video Information Sources: Audience Trust as a Mediated Research Review

Xin Guo(Guo Xin ),Fang Deng(Deng Fang ) 동북아경상학회 2022 동북아경상연구 Vol.3 No.1

Purpose – In the online environment, the group definition, marginal scope, and transmission methods of short video creators and audiences have all changed, but the centrality of the audiences’ essence will not change. Their thinking characteristics and behaviors ultimately determine the influence of digital products spread in the network. This paper attempts to explore the relationship between audience trust and communication mechanism from the source of information: the trust or suspicion generated by the creator’s identity type information, and explore its influence on the popularity of communication. Design/Methodology/Approach – We systematically reviews the connotation and extension of audience trust in online media, definition and characteristics of network identity, the disclosure of creator identity types, character setting, authentication and supervision of identity, and communication popularity. Findings – The interaction between short video media and audience includes: information dissemination, value judgment and emotional transmission. Audience trust plays a bridge and check position in the dissemination of short video media, which determines the survival and development of short video media. These contents can provide short video creators with basic information that can effectively affect user behavior, provide them with a basis for decisionmaking in the creation process, increase audience trust, and improve the popularity and effectiveness of media communication. Research Implications – It provides a new research perspective for influencing user identification, social recommendation and other fields.

A Hybrid Feature Gene Selection Method based on Fuzzy Neighborhood Rough Set with Information Entropy

Tao Chen,Zenglin Hong,Fang-an Deng,Man Cui 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6

DNA microarray technique can detect tens of thousands of genes activity in cells and has been widely used in clinical diagnosis. However, microarray data has the characteristics of high dimension and small samples, moreover many irrelevant and redundant genes also decrease performance of classification algorithm. Feature gene selection is an effective method to solve this problem. This paper proposes a hybrid feature gene selection method. Firstly, a lot of irrelevant genes from original data were eliminated by using reliefF algorithm, and the candidate feature genes subset is obtained; Secondly, Fuzzy neighborhood rough set with information entropy which deals directly with continuous data is proposed to reduce redundant genes among genes subset above. Here, differential evolution algorithm is used to optimize radius before reduction by using fuzzy neighborhood rough set, because radius of neighborhood greatly affects reduction performance. The simulation results on six microarray datasets indicate that our method can obtain higher classification accuracy by using as few genes as possible, especially feature genes selected are important for understanding microarray data and identifying the pathogenic genes. The results demonstrated that this method is effective and efficient for feature genes selection.

UNICITY OF MERMORPHIC FUNCTIONS CONCERNING SHARED FUNCTIONS WITH THEIR DIFFERENCE

Deng, Bingmao,Fang, Mingliang,Liu, Dan Korean Mathematical Society 2019 대한수학회보 Vol.56 No.6

In this paper, we investigate the uniqueness of meromorphic functions of finite order concerning sharing small functions and prove that if f(z) and ${\Delta}_cf(z)$ share a(z), b(z), ${\infty}$ CM, where a(z), b(z)(${\neq}{\infty}$) are two distinct small functions of f(z), then $f(z){\equiv}{\Delta}_cf(z)$. The result improves the results due to Li et al. ([9]), Cui et al. ([1]) and $L{\ddot{u}}$ et al. ([12]).

An experimental investigation on the pressure characteristics of high speed self-resonating pulsed waterjets influenced by feeding pipe diameter

Deng Li,Yong Kang,Xiaolong Ding,Xiao-Chuan Wang,Zhenlong Fang 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The destructive power of a continuous waterjet issuing from a nozzle can be greatly enhanced by generating self-resonance in the nozzle assembly to produce a Self-resonating pulsed waterjet (SRPW). To further improve the performance of SRPW, effects of feeding pipe diameter on the pressure characteristics were experimentally investigated by measuring and analyzing the axial pressure oscillation peaks and amplitudes. Four organ-pipe nozzles of different chamber lengths and three feeding pipes of different diameters were employed. Results show that feeding pipe diameter cannot change the feature of SRPW of having an optimum standoff distance, but it slightly changes the oscillating frequency of the jet. It is also found that feeding pipe diameter significantly affects the magnitudes of pressure oscillation peak and amplitude, largely depending on the pump pressure and standoff distance. The enhancement or attenuation of the pressure oscillation peak and amplitude can be differently affected by the same feeding pipe diameter.

NUMERICAL METHODS FOR RECONSTRUCTION OF THE SOURCE TERM OF HEAT EQUATIONS FROM THE FINAL OVERDETERMINATION

DENG, YOUJUN,FANG, XIAOPING,LI, JING Korean Mathematical Society 2015 대한수학회보 Vol.52 No.5

This paper deals with the numerical methods for the reconstruction of the source term in a linear parabolic equation from final overdetermination. We assume that the source term has the form f(x)h(t) and h(t) is given, which guarantees the uniqueness of the inverse problem of determining the source term f(x) from final overdetermination. We present the regularization methods for reconstruction of the source term in the whole real line and with Neumann boundary conditions. Moreover, we show the connection of the solutions between the problem with Neumann boundary conditions and the problem with no boundary conditions (on the whole real line) by using the extension method. Numerical experiments are done for the inverse problem with the boundary conditions.

The Additivity of True or Apparent Phosphorus Digestibility Values in Some Feed Ingredients for Growing Pigs

Fang, R.J.,Li, T.J.,Yin, F.G.,Yin, Y.L.,Kong, X.F.,Wang, K.N.,Yuan, Z.,Wu, G.Y.,He, J.H.,Deng, Z.Y.,Fan, M.Z. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.7

Two experiments were conducted to determine the additivity of apparent or true digestibility of phosphorus (P) in soybean meal (SBM), peas, faba beans, corn, oats, broken rice meal, rough rice meal, buckwheat, and sorghum for growing pigs. Chromic oxide (0.3%) was used as a digestion marker in both experiments. Each experiment lasted for 12 d, which consisted of a 7-d dietary adaptation period followed by a 5-d fecal collection period. Experiment 1 involved 6 diets: the SBM-based control diet; 4 diets with corn, oats, rough rice meal and broken rice meal substituted for SBM; and an additional diet with a representative mixture of the 5 ingredients. In Experiment 2, 6 diets were prepared similarly, except that the tested ingredients besides SBM were faba beans, peas, buckwheat, and sorghum. In each experiment, six barrows with an initial average individual BW of 20.5 kg were fed one of the six diets according to a $6{\times}6$ Latin square design. The apparent and true P digestibility values for the nine tested ingredients were determined by the substitution method. There were no differences (p>0.05) between the determined and the predicted true P digestibility values for the mixture of ingredients in Experiments 1 and 2. However, the determined and the predicted apparent P digestibility values for the mixture of ingredients differed (p = 0.059) in Experiment 1, but not in Experiment 2. These results indicate that true P digestibility values are additive in ingredients containing low levels of phytate phosphorus and anti-nutritional factors, whereas the apparent P digestibility values are not always additive in single feed ingredients for growing pigs.