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.

Terminal sliding mode control of master-slave system with Markovian jump parameters

Xinghua Liu,Guoqi Ma,Hongsheng Xi,Weidong Wang 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

The finite-time synchronization of master-slave system with Markovian jump parameters is investigated in this paper. An equivalent control based terminal sliding mode control is proposed to guarantee the finite-time convergence of error dynamics. By using stochastic theory and Lyapunov method, some conditions are proposed to facilitate the sliding surface design. Furthermore, a desired controller is synthesized to ensure that the trajectory of the closed-loop error system can be driven onto the prescribed sliding mode surface. Finally numerical simulations are presented to illustrate the effectiveness of terminal sliding mode control scheme.

Effects of alfalfa flavonoids on the production performance, immune system, and ruminal fermentation of dairy cows

Zhan, Jinshun,Liu, Mingmei,Su, Xiaoshuang,Zhan, Kang,Zhang, Chungang,Zhao, Guoqi Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.10

Objective: The objective of this study was to examine the effects of alfalfa flavonoids on the production performance, immunity, and ruminal fermentation of dairy cows. Methods: The experiments employed four primiparous Holstein cows fitted with ruminal cannulas, and used a $4{\times}4$ Latin square design. Cattle were fed total mixed ration supplemented with 0 (control group, Con), 20, 60, or 100 mg of alfalfa flavonoids extract (AFE) per kg of dairy cow body weight (BW). Results: The feed intake of the group receiving 60 mg/kg BW of AFE were significantly higher (p<0.05) than that of the group receiving 100 mg/kg BW. Milk yields and the fat, protein and lactose of milk were unaffected by AFE, while the total solids content of milk reduced (p = 0.05) linearly as AFE supplementation was increased. The somatic cell count of milk in group receiving 60 mg/kg BW of AFE was significantly lower (p<0.05) than that of the control group. Apparent total-tract digestibility of neutral detergent fiber and crude protein showed a tendency to increase (0.05<$p{\leq}0.10$) with ingestion of AFE. Methane dicarboxylic aldehyde concentration decreased (p = 0.03) linearly, whereas superoxide dismutase activity showed a tendency to increase (p = 0.10) quadratically, with increasing levels of AFE supplementation. The lymphocyte count and the proportion of lymphocytes decreased (p = 0.03) linearly, whereas the proportion of neutrophil granulocytes increased (p = 0.01) linearly with increasing levels of dietary AFE supplementation. The valeric acid/total volatile fatty acid (TVFA) ratio was increased (p = 0.01) linearly with increasing of the level of AFE supplementation, the other ruminal fermentation parameters were not affected by AFE supplementation. Relative levels of the rumen microbe Ruminococcus flavefaciens tended to decrease (p = 0.09) quadratically, whereas those of Butyrivibrio fibrisolvens showed a tendency to increase (p = 0.07) quadratically in response to AFE supplementation. Conclusion: The results of this study demonstrate that AFE supplementation can alter composition of milk, and may also have an increase tendency of nutrient digestion by regulating populations of microbes in the rumen, improve antioxidant properties by increasing antioxidant enzyme activities, and affect immunity by altering the proportions of lymphocyte and neutrophil granulocytes in dairy cows. The addition of 60 mg/kg BW of AFE to the diet of dairy cows was shown to be beneficial in this study.

Set-membership Estimation for Event-triggered 2-D Systems Based on Zonotopes

Xudong Wang,Guoqi Wang,Liu Yang,Jitao Li 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

This article discusses the interval estimation for 2-D systems in Roesser model with amplitude-boundedenvironmental disturbance and measurement noise. To save the limited capacity of communication network, anevent-triggered communication strategy is adopted to reduce the amount of packets transmitted through the network. Considering the amplitude-bounded uncertainties, an observer design criterion with peak-to-peak norm boundis deduced to suppress the influence of uncertainties on estimation error. A zonotope-based interval estimation approach is derived such that the actual state of 2-D Roesser system is enclosed within the estimated intervals on thebasis of the obtained observer. Finally, a numerical example is presented to verify the effectiveness of the proposedalgorithm

Boundary-compensated Lesion Aware Transformer for Polyp Segmentation

Yuan Ju,Bingxin Wei,Guoqi Liu,Haewoon Nam 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

Allocating Minimum Number of Leaders for Seeking Consensus over Directed Networks with Time-varying Nonlinear Multi-agents

Leitao Gao,Guangshe Zhao,Guoqi Li,Yuming Liu,Jiangshuai Huang,Changyun Wen 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.1

In this paper, we consider how to determine the minimum number of leaders with allocation and how toachieve consensus over directed networks consisting of time-varying nonlinear multi-agents. Firstly, the problemof finding minimum number of leaders is formulated as a minimum spanning forest problem, i.e., finding theminimum population of trees in the network. By introducing a toll station connecting with each agent, this problemis converted to a minimum spanning tree problem. In this way, the minimum number of leaders is determined andthese leaders are found locating at the roots of each tree in the obtained spanning forest. Secondly, we describe avirtual leader connected with the allocated leaders, which indicates that the number of edges connected the followeragents with the virtual leader is the least in an arbitrary directed network. This method is different from the existingconsensus problem of redundant leaders or edges that connect the follower with one leader in special networks. A distributed consensus protocol is revisited for achieving final global consensus of all agents. It is theoreticallyshown that such a protocol indeed ensures consensus. Simulation examples in real-life networks are also providedto show the effectiveness of the proposed methodology. Our works enable studying and extending application ofconsensus problems in various complex networks.

Mutation of Cellulose Synthase Gene Improves the Nutritive Value of Rice Straw

Su, Yanjing,Zhao, Guoqi,Wei, Zhenwu,Yan, Changjie,Liu, Sujiao Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.6

Rice straw is an important roughage resource for ruminants in many rice-producing countries. In this study, a rice brittle mutant (BM, mutation in OsCesA4, encoding cellulose synthase) and its wild type (WT) were employed to investigate the effects of a cellulose synthase gene mutation on rice straw morphological fractions, chemical composition, stem histological structure and in situ digestibility. The morphological fractions investigation showed that BM had a higher leaf sheath proportion (43.70% vs 38.21%, p<0.01) and a lower leaf blade proportion (25.21% vs 32.14%, p<0.01) than WT. Chemical composition analysis showed that BM rice straw was significantly (p<0.01) higher in CP (crude protein), hemicellulose and acid insoluble ash (AIA) contents, but lower in dry matter (DM), acid detergent fiber (ADFom) and cellulose contents when compared to WT. No significant difference (p>0.05) was detected in neutral detergent fiber (NDFom) and ADL contents for both strains. Histological structure observation indicated that BM stems had fewer sclerenchyma cells and a thinner sclerenchyma cell wall than WT. The results of in situ digestion showed that BM had higher DM, NDFom, cellulose and hemicellulose disappearance at 24 or 48 h of incubation (p<0.05). The effective digestibility of BM rice straw DM and NDFom was greater than that of WT (31.4% vs 26.7% for DM, 29.1% vs 24.3% for NDFom, p<0.05), but the rate of digestion of the slowly digested fraction of BM rice straw DM and NDF was decreased. These results indicated that the mutation in the cellulose synthase gene could improve the nutritive value of rice straw for ruminants.

Shorter Telomere Length Is Associated with Increased Breast Cancer Risk in a Chinese Han Population: A Case-Control Analysis

Zhaoxia Wang,Zhenxing Zhang,Yanling Guo,Huifeng Shui,Guoqi Liu,Tianbo Jin,Huijie Wang 한국유방암학회 2018 Journal of breast cancer Vol.21 No.4

Purpose: The aim of this study was to investigate the association of telomere length with breast cancer risk. We simultaneously explored the association between telomerase reverse transcriptase gene polymorphisms and telomere length. Methods: We used real-time quantitative polymerase chain reaction to measure relative telomere length (RTL) in genomic DNA extracted from peripheral blood from 183 breast cancer cases and 191 healthy controls. Genotyping was performed using the Sequenom MassARRAY platform. Results: Our results show that breast cancer patients had significantly shorter RTLs than control subjects (p< 0.05). When the RTLs were categorized into tertiles, we found that the lowest RTL was significantly associated with increased breast cancer risk compared with the highest RTL (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.40–3.90; p=0.001). Subgroup analyses indicated that risk of breast cancer was also significantly increased in the lowest RTL compared with the highest RTL in age >40 years (OR, 2.41; 95% CI, 1.31–4.43; p=0.005), body mass index ≤24 kg/m2 (OR, 2.81; 95% CI, 1.55–5.10; p=0.001), and postmenopausal women (OR, 3.94; 95% CI, 1.63–9.51; p=0.002), respectively. In addition, individuals with the AA genotype of rs2853677 have longer telomeres than those of breast cancer patients with the AG genotype (p= 0.011). Conclusion: Our results suggest that shorter RTL was associated with an increased risk of breast cancer. An association was found between the AA genotype of rs2853677 and longer RTLs in the case group. Functional studies are warranted to validate this association and further investigate our findings.

Carnosic acid protects against acetaminophen-induced hepatotoxicity by potentiating Nrf2-mediated antioxidant capacity in mice

Guo, Qi,Shen, Zhiyang,Yu, Hongxia,Lu, Gaofeng,Yu, Yong,Liu, Xia,Zheng, Pengyuan The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.1

Acetaminophen (APAP) overdose is one of the most common causes of acute liver failure. The study aimed to investigate the protective effect of carnosic acid (CA) on APAP-induced acute hepatotoxicity and its underlying mechanism in mice. To induce hepatotoxicity, APAP solution (400 mg/kg) was administered into mice by intraperitoneal injection. Histological analysis revealed that CA treatment significantly ameliorated APAP-induced hepatic necrosis. The levels of both alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were reduced by CA treatment. Moreover, CA treatment significantly inhibited APAP-induced hepatocytes necrosis and lactate dehydrogenase (LDH) releasing. Western blot analysis showed that CA abrogated APAP-induced cleaved caspase-3, Bax and phosphorylated JNK protein expression. Further results showed that CA treatment markedly inhibited APAP-induced pro-inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 mRNA expression and the levels of phosphorylated $I{\kappa}B{\alpha}$ and p65 protein in the liver. In addition, CA treatment reduced APAP- induced hepatic malondialdehyde (MDA) contents and reactive oxygen species (ROS) accumulation. Conversely, hepatic glutathione (GSH) level was increased by administration of CA in APAP-treated mice. Mechanistically, CA facilitated Nrf2 translocation into nuclear through blocking the interaction between Nrf2 and Keap1, which, in turn, upregulated anti-oxidant genes mRNA expression. Taken together, our results indicate that CA facilitates Nrf2 nuclear translocation, causing induction of Nrf2-dependent genes, which contributes to protection from acetaminophen hepatotoxicity.