An adaptive hybrid atom search optimization with particle swarm optimization and its application to optimal no-load PID design of hydro-turbine governor

Zhao Weiguo,Shi Tiancong,Wang Liying,Cao Qingjiao,Zhang Hongfei 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.5

One metaheuristic algorithm recently introduced is atom search optimization (ASO), inspired by the physical movement of atoms based on the molecular dynamics in nature. ASO displays a unique search ability by employing the interaction force from the potential energy and the constraint force. Despite some successful applications, it still suffers from a local optima stagnation and a low search efficiency. To alleviate these disadvantages, a new adaptive hybridized optimizer named AASOPSO is proposed. In this study, the individual and group cognitive components in particle swarm optimization (PSO) are integrated into ASO to accelerate the exploitation phase, and the acceleration coefficients are introduced to adaptively achieve a good balance between exploration and exploitation. Meanwhile, to improve the search performance of the algorithm, each individual atom possesses its own force constant, which is effectively and adaptively adjusted based on the feedback of the fitness of the atom in some sequential steps. The performance of AASOPSO is evaluated on two sets of benchmark functions compared to the other population-based optimizers to show its effectiveness. Additionally, AASOPSO is applied to the optimal no-load PID design of the hydro-turbine governor. The simulation results reveal that AASOPSO is more successful than its competitors in searching the global optimal PID parameters.

Emergy analysis-based study of the sustainable development of Kunming’s urban eco-economic system

Li Hui,Cao Lei,Chen Youbin,Qiu Huiyi,Huang Xue,Guo Wanqi,Wang Shuntao,Sheng Weiguo,Zhou Yilu,Xu Qing 서울시립대학교 도시과학연구원 2023 도시과학국제저널 Vol.27 No.2

We studied Kunming’s urban eco-economic system’s evolution from 2009 to 2018, using the emergy theory and method; with the entropy evaluation method, we analyzed the system’s natural, social and economic subsystems to know its sustainable development capacity. The results show that the system’s emergy structure has clearly improved, and its renewable resources’ emergy has been rationally employed. The environment load ratio, after reaching its peak in 2011, has been decreasing, and the environment stress has becoming lower year by year, as is conducive to sustainable development. Its eco-economic system, however, is highly dependent on the internal resources; its emergy self-sufficiency ratio indicates that it does not see sufficient utilization of imported emergy and feels excessive stress on its internal resources. It witnesses relatively high emergy intensity. The current population is about twice of its renewable resources’ population carrying capacity, and its dramatically growing population is presenting even high pressure on its social subsystems. This indicates that the living standard per capita in Kunming is lower than the national average. All of these factors will hinder the sustainable development of Kunming’s urban eco-economic system. Our analysis of attribute classification shows that it is more appropriate to calculate the tourist revenue by taking into account export emergy. At the same time, the analysis results of sustainable development emergy indexes obtained by ESI, EISD, euehi, euehi’ and entropy method are compared, which shows that the entropy method is able to better reflect the dynamic changes of the sustainable development capacity of its urban eco-economic system because it introduces all indicators of social, economic and natural subsystems for evaluation. In a word, sustainable development capacity represents the outcome of tradeoff and coordination of the three subsystems of society, economy and nature, and we can formulate corresponding strategies based on the above research findings.

An Improved Method of Control Law Design at High Angle of Attack Based on Wind Tunnel Test Data

Yongxi Lyu,Yuyan Cao,Weiguo Zhang,Jingping Shi,Xiaobo Qu 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

This paper presents an improved dynamic inversion (DI) based method, which is further successfully applied to the high angle of attack flight control of the aircraft under the influence of unsteady aerodynamics. On the basis of large oscillation wind tunnel test data, the accurate unsteady aerodynamic model is established by the sequential minimal optimization - support vector regression (SMO-SVR) method. The nonlinear longitudinal aircraft model is created by considering engine model, atmospheric model, actuator model, and so on. In order to solve the problem of large control error and control delay caused by the unsteady aerodynamics, the improved DI method is proposed. The integral is added in the pitch angle rate control, and the control law of angle of attack is designed combining lag correction. The daisy chain allocation method is utilized to obtain the deflections of the control surfaces and the engine vector nozzle. Numerical simulation of Cobra maneuver is employed to demonstrate the advantages and potential practical application of the proposed improved control law design method.

Aqueous Extract of Lysimachia christinae Hance Prevents Cholesterol Gallstone in Mice by Affecting the Intestinal Microflora

( Shijia Liu ),( Quji Luorong ),( Kaizhi Hu ),( Weiguo Cao ),( Wei Tao ),( Handeng Liu ),( Dan Zhang ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.9

With changes in human dietary patterns, the proportion of high-fat and high-cholesterol foods in the daily diet has increased. As a result, the incidence rate of cholelithiasis is increasing rapidly. Many studies have reported on the crucial role that the intestinal microflora plays in the progression of gallstones. Although the whole herb of Lysimachia christinae, a traditional Chinese medicine, has long been extensively used as a remedy for cholelithiasis in China, its effects on the intestinal microflora remain unknown. Hence, in this study, we investigated the ability of the aqueous extract of L. christinae (LAE) to prevent cholesterol gallstones (CGSs) in model animals by affecting the intestinal microflora. The effects of LAE on body weight, serum lipid profile, visceral organ indexes, and histomorphology were studied in male C57BL/6J mice, which were induced by a lithogenic diet. After the 8-week study, CGSs formation was greatly reduced after LAE treatment. LAE also reduced body weight gain and hyperlipidemia and restored the histomorphological changes. Moreover, the intestinal microflora exhibited significant variation. In the model group fed the lithogenic diet, the abundances of the genera unclassified Porphyromonadaceae, Lactobacillus and Alloprevotella decreased, but in contrast, Akkermansia dramatically increased compared with the control check group, which was fed a normal diet; the administration of LAE reversed these changes. These results imply that L. christinae can be considered an efficient therapy for eliminating CGSs induced by a high-fat and high-cholesterol diet, which may be achieved by influencing the intestinal microflora.

Cyclooxygenase-2 Polymorphisms and Susceptibility to Colorectal Cancer: A Meta-Analysis

Jun Wang,Xufeng Guo,Jixiang Zhang,Jia Song,Mengyao Ji,Shijie Yu,Jing Wang,Zhuo Cao,Weiguo Dong 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.6

Purpose: Four polymorphisms, -765G>C, -1195G>A, 8473T>C, and Val511Ala, in the cyclooxygenase-2 (COX-2) gene were identified to be associated with colorectal cancer (CRC) risk. However, the results are inconsistent. The objective of this meta-analysis was to evaluate the association between these four polymorphisms and the risk of CRC. Materials and Methods: All eligible case-control studies published up to December 2012 on the association between the four polymorphisms of COX-2 and CRC risk were identified by searching PubMed and Web of Science. The CRC risk associated with the four polymorphisms of the COX-2 gene was estimated for each study by odds ratio (OR) together with its 95% confidence interval (CI), respectively. Results: A total of 15 case-control studies were included. Overall, no evidence has indicated that the -1195A allele, -765C allele, 8473C allele, and 511Ala allele are associated with susceptibility to CRC (-1195G>A: OR=1.11, 95% CI: 0.82-1.51, p=0.78; -765G>C: OR=1.08, 95% CI: 0.96-1.21, p=0.07; 8473T>C: OR=1.03, 95% CI: 0.89-1.18, p=0.91; Val511Ala:OR=0.71, 95% CI: 0.46-1.09, p=0.94). However, stratified analysis with ethnicity indicated that individuals with -765GC or GC/CC genotypes had an increased risk of CRC among Asian populations (GC vs. GG: OR=1.05, 95% CI: 0.87-1.28, p=0.03; GC+CC vs. GG: OR=1.08, 95% CI: 0.96-1.21, p=0.07). Conclusion: This meta-analysis indicated that -765G>C polymorphism was significantly associated with susceptibility to CRC in Asian populations.

Fatigue Analysis of 306K Crude Oil Tanker Based on MSC Fatigue

Wei Guo,Dong-Myung Bae,Bo Cao,Da-Long Qi 한국해양공학회 2015 韓國海洋工學會誌 Vol.29 No.6

Fatigue in the metal used as hull material has always been an important issue. The fatigue phenomenongenerally occurs suddenly in a ship hull, and always causesa large number of casualties and economic losses. This paper presents a study of an assessment method for the fatigue life based on Li’s approach using MSC Fatigue. The details of Li’s approach based on MSC Fatigue are provided. Based on the results of this study, it can be concluded that Li’s approach has several advantages: (1) it allows the wide application of different structural details, (2) is easy to use, and (3) provides accurate results. Finally, Li’s approach can be proven to be feasible for a ship’s fatigue analysis.