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Chen Xuefeng,Chen Wentao,Zhang Yifu,Peng Bin,Wang Yuling,Xu Mingwei 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.1
Oil and gas pipeline accidents not only caused personnel casualties, economic losses and environmental pollution but also brought great panic to the public. To provide accurate accident prevention strategies, risk assessment (RA) has been widely used in the oil and gas pipeline industry. It aims to quantify the potential risk due to unexpected eventualities. However, the current RA methods mainly pay attention to the tangible risk (such as the human safety risk, economic risk and environmental risk), and the intangible risk (such as reputation loss risk) is often neglected. This cannot refl ect the real risk for the oil and gas pipeline. To settle existing research limitation, a two-dimensional risk assessment method for oil and gas pipelines based on “accident probability–reputation loss” is proposed. The method mainly involves four steps, namely, risk identifi cation, probability calculation, consequence assessment and risk assessment. The proposed method is used to quantitatively assess a natural gas pipeline in central China. Its results indicate that pipeline risk is unacceptable due to the unacceptability of accident probability and various dimensions of risk. Therefore, this study can enrich and develop the current oil and gas pipeline RA method to refl ect the real risk of oil and gas pipeline accidents.
ShuYu Chen,GuiPing Wang,Jun Liu,MingWei Lin 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1
In order to successfully monitor a large-scale distributed system, it is an important issue that the monitoring function fully covers all the entities in the system. To this end, a key challenge is to efficiently transmit state information of the entities in the system. This paper solves this challenge from two aspects. First, in virtue of the idea of self-organizing networks, this paper proposes a neighborhood organization algorithm, which self-organizes the nodes into several monitoring neighborhoods based on the t distance between nodes. The second aspect focuses on message transmission. There are three common message transmission methods in network, i.e., flooding, multicast and unicast. Flooding may cause high network overhead, while unicast may pose high system delay. Based on the idea of Gossip protocol, this paper proposes a directional message dissemination algorithm (D-Gossip), which is a kind of probabilistic multicast. D-Gossip reduces message dissemination uncertainty of traditional Gossip protocols. It effectively improves the efficiency and coverage of message dissemination, while reducing redundant information in the system due to Gossip protocol. The experimental results show that the neighborhood organization algorithm and the D-Gossip can effectively solve the above challenge.
Quantitative Analysis of Critical Limitation in Using Extended State Observer
Mingwei Sun,Yi Li,Zenghui Wang,Zengqiang Chen 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.3
Active disturbance rejection control (ADRC) has been successfully widely applied. The extended stateobserver (ESO) is a crucial component of ADRC to deal with uncertainties in many control systems. Althoughthe nominal stability of ADRC was proved by adopting a sufficiently fast observer with a performance recoveryprinciple, it is difficult to be employed in practice because severe oscillation or even instability might be triggeredif the fast observer was used. This paper investigates the reason behind this phenomenon within the frameworkof input time-delay sensitivity for a typical first-order system, which can provide an insightful understanding ofADRC. The positive root of the polynomial which determines the maximal input time-delay maintaining closed loopstability is quantitatively analyzed and the relationship among the bandwidth of ESO, other control parametersand the allowable input time-delay is thoroughly studied. Finally, numerical examples are presented to validate thecorresponding theoretical results.
Structure of hercynite prepared with existence of metal Fe
Junhong Chen,Dongfang Liu,Mingwei Yan, Yong Li,Jindong Su,Bin Li,Jialin Sun 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12
In this work, raw materials analytically pure Al2O3 and analytically pure Fe2O3 were mixed in FeO: Al2O3 molar ratio of 1 : 1and pressed into specimens. The specimens were embedded in analytically pure metal Fe powders and fired slowly to 1650 oCin air atmosphere, and then soaked at 1650 oC for 5 hrs. The fired specimens were investigated by XRD, SEM, and EDS. Theresults show that the specimen synthesized at high temperatures in melting Fe is composed of hercynite and wüstite (FenO(n ≤ 1)); FenO disperses in hercynite; hercynite crystals develop well and are mostly perfect octahedron with grain size around50μm. The hercynite has Fe/Al ratio smaller than 1/2, which is non-stoichimetric. With the existence of melting Fe, althoughthe raw materials are theoretically batched according to FeO·Al2O3, FenO is still excess, so the hercynite obtained is Al-rich.
Junhong Chen,Mingwei Yan, Yong Li,Zhijian Li,Jindong Su,Bin Li,Jialin Sun 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.5
Periclase-hercynite bricks were prepared from fused or reaction-sintered hercynite. The microstructure of the obtained brickswas studied and their thermal conductivity in the simulated on-site condition was tested. The results show that the mutualdiffusion of Fe or Al from hercynite and Mg from periclase forms more pores in the material. Compared with the brickprepared from fused hercynite, the brick from reaction-sintered hercynite has smaller pore size. The thermal conductivitysimulation test of the two bricks at 1550 oC shows that the cold end temperature of the brick synthesized from the reactionsinteredhercynite is 40 oC lower than that of the brick from the fused hercynite. Thus, in consideration of reducing the shelltemperature of the cement rotary kilns, the reaction-sintered hercynite is more favorable for the production of periclasehercynitebricks.
Li Wan,Mingwei Yuan,Guowen Xiong,Shunli Shi,Weiming Xiao,Chao Chen,Fanrong Ai 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-
MOF-polymer mixed matrix catalytic membrane has excellent potential for applications in continuousflow separation and catalysis. However, scalable fabrication methods to produce ultra-high flux mixedmatrix catalytic membranes are urgently needed yet to be largely met. Inspired by the honeycomb structure,composite MOF with polymer materials possessing rapidly prepare large area MOF-polymer mixedmatrix catalytic membrane with penetrated honeycomb structure. The bulk loading of MOFs linked thewalls of the honeycomb, endowing the MOF-polymer mixed matrix membrane with large surface areasand abundant pore channels. The porous MOF material links the pore walls of the honeycomb structure,which not only enables the rapid passage of reactants, but also greatly enhances the mutual contact betweenthe membrane and the reactants, achieving rapid passage and efficient catalysis. The 0.6-ZIF-8/Pd-TPU porosity reaches 69% and the specific surface area can reach 828.35 m2/g. The water flux reached3290 L m2 h1 and the treatment efficiency of different dyes and 4-NP under vacuum pump filtrationreached 99%. This preparation method was extended to other porous materials, and membranes weresuccessfully prepared with good catalytic effects. This strategy paves the way for the development of highflux and efficient catalytic membranes.
Grey Wolf Optimization based Active Disturbance Rejection Control Parameter Tuning for Ship Course
Jia Ren,Zengqiang Chen,Yikang Yang,Mingwei Sun,Qinglin Sun,Zenghui Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.3
It is important to control the ship course in complicated ocean environment. In this paper, a Grey Wolf Optimization (GWO) based Active Disturbance Rejection Control (ADRC) tuning method is proposed in the application of the ship course. Here, GWO is used to tune the parameters of ADRC. To validate the performance of the proposed method, some simulations have been carried out and the results are compared with the results of other tuning methods, such as, Harris Hawks Optimization (HHO), Particle Swarm Optimization (PSO), Q-learning and manual tuning. To test the stability of different tuning methods, the cases of no disturbance, constant value disturbance, second-order wave force disturbance, white noise disturbance and mixed disturbance are considered. The robustness of the system for parameters perturbation is analyzed. The research indicates that the GWO based ADRC can achieve better performance than other methods.