New Results on Finite-time Stabilization for Stochastic Systems with Time-varying Delay

Lihua Zhang,Wenhai Qi,Yonggui Kao,Xianwen Gao,Longjiang Zhao 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2

The paper deals with the problem of finite-time stabilization for stochastic systems with time-varying delay by defining a new criterion for finite-time stability. Firstly, by use of more appropriate Lyapunov-Krasovskii functional (LKF), the difficulties of finite-time stability confronted in system analysis and synthesis can be overcome. Then, a state feedback controller is constructed to guarantee the closed-loop system finite-time stable. New conditions for finite-time stability analysis as well as controller synthesis are established in terms of linear matrix inequality (LMI). Finally, two practical examples demonstrate the validity of the main results.

Multiple Periods Minimal Cost Programming Optimization Model for Empty Containers Repositioning with Stock Level

Lihua Lu,Hengzhen Zhang,Xiaofeng Wang,Xiao-Zhi Gao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

The main problem of empty containers repositioning (ECR) is to dispatch the empty containers among the ports meanwhile cut the costs as possible as. According to the actual operations, the stock policy and various constrains are considered together in this paper firstly. Then we build a multiple periods minimal cost programming optimization model with stock to solve this problem. Furthermore, we adopt the heuristic rule to effectively operate the empty containers since there is a large amount of calculation. Finally, some simulate data are given to assess the model. The results show that our proposed model is feasible and efficient to minimize the operation cost as well as satisfy the demand of customers. Moreover by analyzing the data it can guide us to set the inventory of empty containers of ports in different supply and demand scenarios.

Effects of chronic alcohol exposure on ischemia–reperfusion-induced acute kidney injury in mice: the role of β-arrestin 2 and glycogen synthase kinase 3

Lihua Wang,Yifei Zhu,Lili Wang,Jingjing Hou,Yongning Gao,Lei Shen,Jingyu Zhang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Little is known about the effects of chronic alcohol intake on the outcome of acute kidney injury (AKI). Hence, we examined the effects of chronic alcohol intake on the development of renal fibrosis following AKI in an animal model of bilateral renal ischemia–reperfusion (IR) injury. We first found that chronic alcohol exposure exacerbated bilateral IR-induced renal fibrosis and renal function impairment. This phenomenon was associated with increased bilateral IR-induced extracellular matrix deposition and an increased myofibroblast population as well as increased bilateral IR-induced expression of fibrosis-related genes in the kidneys. To explore the mechanisms underlying this phenomenon, we showed that chronic alcohol exposure enhanced β-arrestin 2 (Arrb2) expression and Akt and glycogen synthase kinase-3 (GSK3)β activation in the kidneys. Importantly, pharmacological GSK3 inhibition alleviated bilateral IR-induced renal fibrosis and renal function impairment. Furthermore, we demonstrated that Arrb2− / − mice exhibited resistance to IR-induced renal fibrosis and renal function impairment following chronic alcohol exposure, and these effects were associated with attenuated GSK3β activation in the kidneys. Taken together, our results suggest that chronic alcohol exposure may potentiate AKI via β-arrestin 2/Akt/GSK3β-mediated signaling in the kidney.

Research on metal flow law of micro-riblets based on multi-pass rolling

Xujie Gao,Huihang Wang,Guangming Zhu,Zheng Chang,Nana Guo,Zongshen Wang,Lihua Zhu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

Micro-riblets (grooves) can reduce surface friction in turbulent flow by up to 10 %. Furthermore, roll forming is an effective method for manufacturing large-area groove structures. In this study, the fluidity of metal during the multi-pass rolling of microgrooves was studied, and the reason for the accumulation of materials at the end of rolling was explained. A comparative analysis was conducted between single-pass rolling and multi-pass rolling. Then, according to the distribution of stress field and strain field, the force and flow tendency of the metal during rolling were studied. The gradually changing streamlined roller tooth profile promoted the flow of metal to both sides of the gear hob. Given the same reduction, the forming height of micro-grains during multi-pass rolling was 64.2 % higher than that during single-pass rolling.

Tie1 contributes to the development of ovarian hyperstimulation syndrome under the regulation of EGR1 in granulosa cells

Sun Lihua,Tian Hui,Xue Songguo,Ye Hongjuan,Xue Xue,Wang Rongxiang,Liu Yu,Zhang Caixia,Chen Qiuju,Gao Shaorong 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

The expression of tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 (Tie1), a transmembrane protein expressed almost exclusively by endothelial cells, has been reported in granulosa cells. However, its significance in ovarian hyperstimulation syndrome (OHSS), which can occur after the injection of gonadotropins in infertile women undergoing controlled ovarian stimulation, is unknown. Here, we report significantly increased Tie1 and vascular endothelial growth factor (VEGF) expression in cultured granulosa cells from OHSS patients, as well as ovaries from rats with experimentally established OHSS, compared to controls, with the levels of both proteins also increasing in granulosa and SVOG cells (a nontumorigenic human granulosa-lutein cell line) treated with an acute dose of human chorionic gonadotropin (hCG). Tie1 silencing abolished the hCG-induced VEGF level in SVOG cells and attenuated the progression of OHSS in rats, as determined by histological analysis. Further studies in SVOG cells revealed that the hCG-induced upregulation of Tie1 expression involved the phosphoinositide 3-kinase/protein kinase B signaling pathway. We also report that early growth response protein 1 (EGR1), whose expression was also upregulated by hCG, bound directly to the Tie1 promoter and activated its transcription. Taken together, our results indicate that Tie1 may be a therapeutic target in cases of moderate-to-severe OHSS. Further studies are needed to address its clinical relevance.

Synthesis and characterization of TiC powders by sol-gel method

Liang Gao,Yun Zhang,Xue Yang,YanBin He,LiHua Song 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.6

TiC powders were successfully synthesized by carbothermal reduction of Ti-O-C precursor in argon at 1,400 °C for 2 h. Andthe Ti-O-C precursor was formed by sol-gel method using titanium butyrate (Ti(OC4H9)4), fructose (C6H12O6), and acetylacetone (acac). Here, acac was used as chemical modifier to control Ti(OC4H9)4 hydrolysis to obtain stable sol. Furthermore,TG-DSC, XRD, FTIR, Raman, SEM, and EDS were employed to characterize the precursor and TiC powders. Moreover, acacas stabilizer was studied using FTIR when reacted with Ti(OC4H9)4 formed stable six-member ring as a result of the existenceof tautomer, prevent the nucleophilic attack of water, which reduced the hydrolysis rate of Ti(OC4H9)4. Besides, the compositionof TiC phase was further understood by the Raman spectra, and the results showed that the peaks at 403 cm−1, 513 cm−1, and 629 cm−1 were ascribed to the characteristic peaks of TiC. Finally, the photomicrograph revealed an equiaxed shape and theaverage grain size of TiC particles was ca. 1 um. The EDS indicated that the particles contain elements of Ti and carbonaccording to dot and line scan.

Seismic behavior of energy dissipation shear wall with CFST column elements

Hao Su,Lihua Zhu,Yaohong Wang,Lei Feng,Zeyu Gao,Yuchen Guo,Longfei Meng,Hanquan Yuan 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.1

To develop high-efficiency lateral force resistance components for high-rise buildings, a novel energy dissipation shear wall with concrete-filled steel tubular (CFST) column elements was proposed. An energy dissipation shear wall specimen with CFST column elements (GZSW) and an ordinary reinforced concrete shear wall (SW) were constructed, and experimented by low-cycle reversed loading. The mechanical characteristics of these two specimens, including the bearing capacity, ductility, energy dissipation, and stiffness degradation process, were analyzed. The finite-element model of the GZSW was established by ABAQUS. Based on this finite-element model, the effect of the placement of steel-plate energy dissipation connectors on the seismic performance of the shear wall was analyzed, and optimization was performed. The experiment results prove that, the GZSW exhibited a superior seismic performance in terms of bearing capacity, ductility, energy dissipation, and stiffness degradation, in comparison with the SW. The results calculated by the ABAQUS finite-elements model of GZSW corresponded well with the results of experiment, and it proved the rationality of the established finite-elements model. In addition, the optimal placement of the steel-plate energy dissipation connectors was obtained by ABAQUS.

Low-Overhead Feedback Topology Design for the K-User MIMO Interference Alignment

( Jin Jin ),( Xiang-chuan Gao ),( Xingwang Li ),( Charles C. Cavalcante ),( Lihua Li ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11

Since designing a feedback topology is a practical way to implement interference alignment at reduced cost of channel state information (CSI) feedback, six feedback topologies have been presented in prior works for a K-user multiple-input multiple-output interference channel. To fully reveal the potential benefits of the feedback topology in terms of the saving of CSI overhead, we propose a new feedback topology in this paper. By efficiently performing dimensionality-decreasing at the transmitter side and aligning interference signals at a subset of receivers, we show that the proposed feedback topology obtains substantial reduction of feedback cost over the existing six feedback designs under the same antenna configuration.

Stochastic Stability, ℒ1-gain and Control Synthesis for Positive Semi-Markov Jump Systems

Longjiang Zhao,Wenhai Qi,Lihua Zhang,Yonggui Kao,Xianwen Gao 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

This paper treats the problems of stochastic stability, ℒ1-gain and control synthesis for positive semi- Markov jump systems (S-MJSs). The system under consideration involves semi-Markov stochastic process related to Weibull distribution. The main motivation for this paper is that the positive condition sometimes needs to be considered in S-MJSs and the controller design methods in the existing works have some conservation. To deal with these problems, some sufficient conditions for stochastic stability of positive S-MJSs are established by implying the linear co-positive Lyapunov function. Then, some sufficient conditions for ℒ1-gain constraint are also presented, upon which, a state feedback controller is designed by decomposing the controller gain matrix such that the resulting closed-loop system is positive and stochastically stable with ℒ1-gain performance in the form of standard linear programming (LP). The advantages of the new framework lie in the following facts: (1) the weak infinitesimal operator is derived for S-MJSs under the constraint of positive condition and (2) the less conservative stabilizing controller is designed to achieve the desired control performance. Finally, numerical examples are given to demonstrate the validity of the main results.

EDMFEN: Edge detection-based multi-scale feature enhancement Network for low-light image enhancement

Canlin Li,Shun Song,Pengcheng Gao,Wei Huang,Lihua Bi 한국인터넷정보학회 2024 KSII Transactions on Internet and Information Syst Vol.18 No.4

To improve the brightness of images and reveal hidden information in dark areas is the main objective of low-light image enhancement (LLIE). LLIE methods based on deep learning show good performance. However, there are some limitations to these methods, such as the complex network model requires highly configurable environments, and deficient enhancement of edge details leads to blurring of the target content. Single-scale feature extraction results in the insufficient recovery of the hidden content of the enhanced images. This paper proposed an edge detection-based multi-scale feature enhancement network for LLIE (EDMFEN). To reduce the loss of edge details in the enhanced images, an edge extraction module consisting of a Sobel operator is introduced to obtain edge information by computing gradients of images. In addition, a multi-scale feature enhancement module (MSFEM) consisting of multi-scale feature extraction block (MSFEB) and a spatial attention mechanism is proposed to thoroughly recover the hidden content of the enhanced images and obtain richer features. Since the fused features may contain some useless information, the MSFEB is introduced so as to obtain the image features with different perceptual fields. To use the multi-scale features more effectively, a spatial attention mechanism module is used to retain the key features and improve the model performance after fusing multi-scale features. Experimental results on two datasets and five baseline datasets show that EDMFEN has good performance when compared with the state-of-the-art LLIE methods.