Distributed Adaptive Fault-tolerant Control for Heterogeneous Nonlinear Multi-agent Systems with Actuator Faults

Quan-Yong Fan,Chao Deng,Xin Wang,Cai-Cheng Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

This paper investigates the fuzzy cooperative reliable output regulation (CROR) problem for heterogeneous nonlinear multi-agent systems (MASs) with actuator faults under directed network topology. Compared with the existing CROR results, this paper considers more general heterogeneous nonlinear MASs with actuator faults under directed network topology. To identity the dynamic matrix of the exosystem for each subsystem, distributed finite-time estimators are firstly designed. Then, a novel hierarchical mechanism is introduced for the MASs network such that each subsystem knows its layer in the network. By using the introduced hierarchical variables in the hierarchical mechanism, distributed finite-time observers are proposed to estimate the state of the exosystem. Based on the proposed finite-time observers, a new decentralized fuzzy resilient controller is proposed. It is proved that the developed method can be used to solve the considered problem. Finally, a simulation example is provided to show the effectiveness of the developed method.

Establishment and Validation of a Nomogram for Nasopharyngeal Carcinoma Patients Concerning the Prognostic Effect of Parotid Lymph Node Metastases

Chao Lin,Xue-Song Sun,Sai-Lan Liu,Xiao-Yun Li,Nian Lu,Xin-Ling Li,Lin-Quan Tang,Ling Guo 대한암학회 2020 Cancer Research and Treatment Vol.52 No.3

Purpose The prognosis of nasopharyngeal carcinoma (NPC) patients with parotid lymph node (PLN) metastasis remains unclear. This study was performed to investigate the prognostic significance and optimal staging category of PLN metastasis and develop a nomogram for estimating individual risk. Materials and Methods Clinical data of 7,084 non-metastatic NPC patients were retrospectively reviewed. Overall survival (OS) was the primary endpoint. A nomogram was established based on the Cox proportional hazards regression model. The accuracy and calibration ability of this nomogram was evaluated by C-index and calibration curves with bootstrap validation. Results Totally, 164/7,084 NPC patients (2.3%) presented with PLNs. Multivariate analyses showed that PLN metastasis was a negative prognostic factor for OS, progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRFS). Patients with PLN metastasis had a worse prognosis than N3 disease. Five independent prognostic factors were included in the nomogram, which showed a C-index of 0.743. The calibration curves for probability of 3- and 5-year OS indicated satisfactory agreement between nomogram-based prediction and actual observation. All results were confirmed in the validation cohort. Conclusion NPC patient with PLN metastasis had poorer survival outcome (OS, PFS, DMFS, and LRFS) than N3 disease. We developed a nomogram to provide individual prediction of OS for patients with PLN metastasis.

Experimental Investigation on the Bond Behavior of Deformed Bars in a Class of Structural Expanded Polystyrene (EPS) Concrete

Chao Li,Linchang Miao,Quan You,Lijian Lei,Xiaodong Liang,Junjie Wang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.12

The structural expanded polystyrene (EPS) concrete (above 35 MPa) has the potential to be used as metro track bed to reduce and isolate vibration, but its bond behavior is still unclear. This inhibits its application because it is often used in combination with reinforcing bar. In this paper, a class of structural EPS concrete (above 35 MPa) was developed. Based on this, a series of pull-out tests were conducted and the bond behavior of deformed bars in these structural EPS concretes was investigated. In addition, effects of rebar bond length and rebar diameter were analyzed in detail. Experimental results indicate that the structural EPS concrete suffers splitting failure more easily than the conventional concrete (CC). Increase of EPS replacement, rebar bond length or rebar diameter tends to cause the splitting failure of structural EPS concrete. Moreover, with increase of EPS replacement, the failure process is less explosive and more gradual. The stress-slip relationships of the most specimens show three stages, namely linear ascending, non-linear progression, and descending stages. The bond strength of structural EPS concrete is found depended linearly on the power function of its compressive strength, relative cover thickness (c/d) and relative rebar bond length (L/d), respectively. Accordingly, a bond strength prediction model was formulated, and it can precisely predict the bond strength of deformed bars in structural EPS concrete, specimens failing in splitting or splitting-pull out modes, and no fiber added. The results can provide reference for the design of structural EPS concrete.

Numerical simulation of the effects of the internal components on the uniformity of the flow field in a tubular separator

Quan Li,Zongyong Wang,Ruting Lin,Shuai Li,Chao Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

This paper adopts the standard k-ε model and mixture model of the FLUENT code to numerically analyze the components characteristics of the gravity separator. It intends to involve several combinations of four types of rectifiers and two types of coalescers of corrugated plates to optimize the structure of the components. Numerical simulation analysis is carried out on the synergistic effect of the reflective inlet component, the rectifier of square grids, and the coalescer of perforated corrugated plates under variable working conditions. The results illustrate that when the distance between the rectifier and the separator’s head is L 1 = 3/4 D, the width L 2 = 1/4 D, and the plate spacing L 3 = 1/10 D, the separation effect gets improved. Additionally, the perforated corrugated plates prove better effects of rectification and coalescence. And when the distance between the coalescer and the head is L 4 = 25/183 L and the elevation angle α = 2.5°, the separation performance will be further improved. What’s more, the influence of the Reynolds number (Re i , from 5640 through 8297 in the inlet component) and the volume fraction of the dispersed phase (from 5 % through 30 %) on the separation effects of various combination conditions of the internal components has also been investigated. As the former increases, the combined of reflective inlet component, rectifier and coalescer will perform the best separation effects. As the latter increases, the separation efficiency of low-oil ratio of oil-water mixture of the jointly structured separator will increase the most.

Influence factors of non-uniform phase transformation in hot stamping process of ultra-high-strength steel sheet

Guo-zheng Quan,Chao An,Hui-min Qiu,Le Zhang,Xuan Wang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.7

In the hot stamping process of ultra-high-strength steel sheets, it is a significant issue to reveal the nonuniformity of cooling rate in space–time domain by finite element method and even uncover the inner cause, which contributes to the further adjustment of the phase transformation. In this work, a series of heat transfer experiments between dies and sheets were conducted on the self-developed experimental apparatus. The temperature evolution curves of die and BR1500HS ultra-high-strength steel sheets under different pressures and holding time were obtained. Moreover, the transient heat transfer coefficients (HTC) under different mean interface temperatures and pressures were calculated by the inverse heat transfer algorithm. Subsequently, based on the HTC curves, a thermal–mechanical-phase dynamic coupling finite element model was developed for modeling the hot stamping process, and a series of simulations for analyzing the non-uniform microstructures distribution in hot stamping parts were implemented. Finally, the simulation results were validated by actual hot stamping experiments. Two significant influence factors on the nonuniform distribution of microstructures were summarized as follows: the existence of incomplete contact between steel sheets and dies due to the sheet thickness reduction in sidewall and circular bead regions, and the temperature differences between dies and steel sheets.

한국어 시간관계 연결어미의 중국어 대응 양상 고찰

이초 ( Yi Chao ),전영근 ( Quan Yonggen ) 중국한국(조선)어교육연구학회 2019 한국(조선)어교육연구 Vol.14 No.-

In order to teach the Chinese Korean learners more effectively, this study analyzed the concepts and categories of Korean temporal conjunctive morpheme at first. Then through the Korean-Chinese parallel corpus, it analyzed the Chinese cor-respondence patterns with Korean temporal conjunctive, such as ‘-myeo’, ‘-myeonseo’, ‘-ja’, ‘-jamaja’, ‘-go’, ‘-eoseo’, which are frequently used. On this basis, this study analyzes the characteristics of Chinese correspondence patterns to the Korean temporal conjunctive.

Multi-Variable and Bi-Objective Optimization of Electric Upsetting Process for Grain Refinement and Its Uniform Distribution

Guo-zheng Quan,Le Zhang,Chao An,Zhen-yu Zou 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.6

It is significant to adjust the microstructures of preforms in pursuit of high-quality exhaust valves. This work is a novel attempt to identify the optimum process parameters in electric upsetting of 3Cr20Ni10W2 high-alloy to achieve grain refinement and uniform distribution by multi-objective genetic algorithm (MOGA) optimization. A finite element (FE) model on basis of electric-thermalmechanical and macro-micro sequential multi-physics analysis methods was developed in software MSC. Mar. And different schedules of four independent process variables (heating current (I), clamping length (L), upsetting pressure (Pset) and velocity of the anvil cylinder (v)) were performed aiming to achieve two objective indicators (average grain size (dav) and inhomogeneous degree of grain distribution (σd)). Then, two objective response surfaces were constructed as the functions between the two indicators and the four independent process variables. As per the criterion that simultaneously minimize dav and σd, the processing parameters (Pset, L, v, I) were optimized by MOGA, and corresponding numerical simulation were performed. The results show that both dav and σd are improved significantly at the optimal process condition as verified by the trial-manufacture experiments, which validated the optimal design and corresponding simulation based on grain refinement and uniform distribution by MOGA was credible and effective.

Research on effects of key influencing factors upon fuel injection characteristics of the combination electronic unit pump for diesel engines

Liyun Fan,Quan Dong,Chao Chen,Yun Bai,Wensheng Zhao,Xiuzhen Ma 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

A numerical model of the combination electronic unit pump (CEUP) fuel injection system was developed in AMESim environment. The effects of five key influencing factors, including cam profile velocity, plunger diameter, length of high pressure fuel pipe, inner diameterof high pressure fuel pipe and nozzle flow rate on injection characteristic parameters, were analyzed by using the developed numericalmodel. On the basis, a correlation analysis between the influencing factors and injection characteristics was performed by usingthe design of experiments (DoE) method, and the influences of these factors were quantized accordingly. Relevant results show that boththe single influencing factor and the interaction among these factors correlates with the injection characteristics, and the correlation representsa complex law with the cam rotational speed. The effect of plunger diameter on the injection pressure, cycle fuel injection quantityand injection duration is the most obvious, especially at a cam rotational speed of 500 r/min and the correlation coefficient is up to 0.82. The length of high-pressure pipe (HP pipe) has the most obvious influence on the coefficient of fuel feeding at cam rotational speed of500 r/min and 800 r/min, and the correlation coefficient is negative. Overall, the independent influence of the factors is more significantthan the combined influence of various factors. The CEUP fuel injection system is a complicated multi-input multi-output (MIMO)nonlinear system in fact.

Selection of Reference Genes for Real-time Quantitative PCR Normalization in the Process of Gaeumannomyces graminis var. tritici Infecting Wheat

Li-hua Xie,Xin Quan,Jie Zhang,Yan-yan Yang,Run-hong Sun,Ming-cong Xia,Bao-guo Xue,Chao Wu,Xiao-yun Han,Ya-nan Xue,Li-rong Yang 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.1

Gaeumannomyces graminis var. tritici is a soil borne pathogenic fungus associated with wheat roots. The accurate quantification of gene expression during the process of infection might be helpful to understand the pathogenic molecular mechanism. However, this method requires suitable reference genes for transcript normalization. In this study, nine candidate reference genes were chosen, and the specificity of the primers were investigated by melting curves of PCR products. The expression stability of these nine candidates was determined with three programs-geNorm, Norm Finder, and Best Keeper. TUBβ was identified as the most stable reference gene. Furthermore, the exopolygalacturonase gene (ExoPG) was selected to verify the reliability of TUBβ expression. The expression profile of ExoPG assessed using TUBβ agreed with the results of digital gene expression analysis by RNA-Seq. This study is the first systematic exploration of the optimal reference genes in the infection process of Gaeumannomyces graminis var. tritici.

Compressive-Tensile Mechanics and Energy Consumptions of a Cementitious Composite with High Utilization of Steel Slag

Guohua Sheng,Shengji Jin,Chao Li,Quan Bai,Xiaoyu Wang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.3

In response to the National Development and Reform Commission's “Guiding Opinions on Comprehensive Utilization of Large Solid Wastes during the Fourteenth Five Year Plan”, further expand the use of steel slag as concrete admixture in construction projects and other fields, and gradually improve the comprehensive utilization ratio, a cementitious composite with high utilization of steel slag (CHS) was developed, which is with the cement replaced by high-content super-fine steel slag powder (SSP) (replacement ratio υ ≥ 30%) as the cementitious materials, steel slag sand (SS) as the only aggregate and environmentally basalt fiber (BF) for toughening. It improves the utilization percentage of steel slag (SSP and SS) and reduces the consumption of natural resources such as cement and natural sand. Use BF to achieve better strength and toughness. In order to better understand the performance of CHS and make it better used in the engineering field. Study the influence of each component on the strength and energy consumption of compression and splitting tension, and strive to find the optimal proportion and lay the theoretical foundation for its application. Through the tests, the effects of high replacement ratio υ (30% − 50%), low binder-aggregate ratio γ (0.31 − 0.44), and BF content ρv (0% − 2%) on the aspects of peak strength, force-deformation curve and energy consumption were analyzed. The results show that the standard curing fck and ft,s can reach 40 MPa and 5 MPa respectively. With the increase of υ, the maximum axial compressive strength fck and splitting tensile strength ft,s decreased insignificantly. The γ has an important influence on fck and ft,s. When it increases from 0.31 to 0.44, fck increases linearly by 63.1% to 40.4 MPa, while ft,s increases by 52.8% to 5.18 MPa. As ρv increases, fck and ft,s show a trend of first increasing and then decreasing. ρv exerts a significant impact on the descending segments of stress-strain response curves of the compression which expressed as bilinear and trilinear models with different ρv after normalization. The energy consumptions of peak, total, and residual (Epeak, Edisp, Eres) show a slight downward trend with the increase of υ, a significantly upward trend with the increase of γ. With the increase of γv, Epeak and Edisp increase first and then tend to be flat, while Eres always increases and the percentages of Eres/Edisp in the compressive test increase from 22.6% to 38.5%, reflecting the improvement of the compressivetoughness of BF.