Periodic Event-triggered State-feedback and Output-feedback Control for Linear Systems

Xia Chen,Fei Hao 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.4

This paper investigates the periodic event-triggered control for linear systems. Both state-feedback and output-feedback controllers are considered. The resulting closed-loop systems are modeled as delay systems and event conditions are constructed in more general forms. The stability analyses rely on the proposed Lyapunov functional and the improving free weighing matrix method. Criteria co-designing the feedback gain matrices and the event condition parameters are established to guarantee the asymptotic stability of the closed-loop systems. Moreover, we can obtain the maximum verifying period by solving a generalized eigenvalue problem. Simulation examples verify the less conservativeness and efficiency of the theoretical results.

SDC4 Gene Silencing Favors Human Papillary Thyroid Carcinoma Cell Apoptosis and Inhibits Epithelial Mesenchymal Transition via Wnt/β-Catenin Pathway

Chen, Liang-Liang,Gao, Ge-Xin,Shen, Fei-Xia,Chen, Xiong,Gong, Xiao-Hua,Wu, Wen-Jun Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.9

As the most common type of endocrine malignancy, papillary thyroid cancer (PTC) accounts for 85-90% of all thyroid cancers. In this study, we presented the hypothesis that SDC4 gene silencing could effectively attenuate epithelial mesenchymal transition (EMT), and promote cell apoptosis via the $Wnt/{\beta}-catenin$ signaling pathway in human PTC cells. Bioinformatics methods were employed to screen the determined differential expression levels of SDC4 in PTC and adjacent normal samples. PTC tissues and adjacent normal tissues were prepared and their respective levels of SDC4 protein positive expression, in addition to the mRNA and protein levels of SDC4, $Wnt/{\beta}-catenin$ signaling pathway, EMT and apoptosis related genes were all detected accordingly. Flow cytometry was applied in order to detect cell cycle entry and apoptosis. Finally, analyses of PTC migration and invasion abilities were assessed by using a Transwell assay and scratch test. In PTC tissues, activated $Wnt/{\beta}-catenin$ signaling pathway, increased EMT and repressed cell apoptosis were determined. Moreover, the PTC K1 and TPC-1 cell lines exhibiting the highest SDC4 expression were selected for further experiments. In vitro experiments revealed that SDC4 gene silencing could suppress cell migration, invasion and EMT, while acting to promote the apoptosis of PTC cells by inhibiting the activation of the $Wnt/{\beta}-catenin$ signaling pathway. Besides, $si-{\beta}-catenin$ was observed to inhibit the promotion of PTC cell migration and invasion caused by SDC4 overexpression. Our study revealed that SDC4 gene silencing represses EMT, and enhances cell apoptosis by suppressing the activation of the $Wnt/{\beta}-catenin$ signaling pathway in human PTC.

A Load Identification Method for ICPT System Utilizing Harmonics

Xia, Chen-Yang,Zhu, Wen-Ting,Ma, Nian,Jia, Ren-Hai,Yu, Qiang The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

Online identification of load parameters is the premise of establishing a stable and highly-efficient ICPT (Inductive Coupled Power Transfer) system. However, compared with pure resistive load, precise identification of composite load, such as resistor-inductance load and resistance-capacitance load, is more difficult. This paper proposes a method for detecting the composite load parameters of ICPT system utilizing harmonics. In this system, the fundamental and harmonic wave channel are connected to the high frequency inverter jointly. The load parameter values can be obtained by setting the load equation based on the induced voltage of secondary-side network, the fundamental wave current, as well as the third harmonic current effective value received by the secondary-side current via Fourier decomposition. This method can achieve precise identification of all kinds of load types without interfering the normal energy transmission and it can not only increase the output power, but also obtain higher efficiency compared with the fundamental wave channel alone. The experimental results with the full-bridge LCCL-S type voltage-fed ICPT system have shown that this method is accurate and reliable.

A Load Identification Method for ICPT System Utilizing Harmonics

Chen-Yang Xia,Wen-Ting Zhu,Nian Ma,Ren-Hai Jia,Qiang Yu 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

Online identification of load parameters is the premise of establishing a stable and highlyefficient ICPT (Inductive Coupled Power Transfer) system. However, compared with pure resistive load, precise identification of composite load, such as resistor-inductance load and resistancecapacitance load, is more difficult. This paper proposes a method for detecting the composite load parameters of ICPT system utilizing harmonics. In this system, the fundamental and harmonic wave channel are connected to the high frequency inverter jointly. The load parameter values can be obtained by setting the load equation based on the induced voltage of secondary-side network, the fundamental wave current, as well as the third harmonic current effective value received by the secondary-side current via Fourier decomposition. This method can achieve precise identification of all kinds of load types without interfering the normal energy transmission and it can not only increase the output power, but also obtain higher efficiency compared with the fundamental wave channel alone. The experimental results with the full-bridge LCCL-S type voltage-fed ICPT system have shown that this method is accurate and reliable.

General Aircraft Material Demand Forecast Based on Modified PSO Optimized BP Neural Network

Xia Chen,Tuo Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.6

Corporate Social Responsibility and Unsecured Debt: Evidence from China

Xia CHEN,Zhe MA,Jiayu SHI,Bingyan TU,Songtao XU 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

This study aims to investigate whether Corporate Social Responsibility (CSR) performance can help companies gain more bank unsecured loans. Additionally, this study analyzes the moderating effect of firm size and industry characteristics. Data was collected through the case of companies listed on the Shanghai Stock Exchange or the Shenzhen Stock Exchange in China between 2009 and 2018 with 5373 firmyear observations. The results of multivariable regression analysis show that good CSR performance exhibits a strong positive impact on unsecured debt, including short-term, long-term, and total unsecured debt, which indicates that corporate with good CSR performance can borrow more unsecured debt. further research shows that this effect is more pronounced for small enterprises and firms operating in heavy-polluting industries. Additionally, research on the impact mechanism finds that good CSR performance can help mitigate information asymmetry between borrower and lender, reduce moral hazard of borrower, and obtain support from key stakeholders, and therefore reduces the risk of default. The findings of this study suggest that firms with good CSR performance exhibit a preference for unsecured debt, but decline to provide collateral for debt. Overall, we emphasize and illustrate the important role of corporate CSR in bank credit financing.

Retrospective Study of Adjuvant Chemotherapy Effects on Survival Rate after Three-Field Lymph Node Dissection for Stage IIA Esophageal Cancer

Chen, Hua-Xia,Wang, Zhou Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

To determine the efficacy of postoperative adjuvant chemotherapy with paclitaxel plus cisplatin (Taxol + DDP, TP therapy) for stage IIA esophageal squamous cell carcinoma (ESCC) and to investigate the expression of RUNX3 in lymph node metastasis-negative esophageal cancer and its relationship with medical prognosis, a retrospective summary of clinical treatment of 143 cases of stage IIA esophageal squamous cell carcinoma patients was made. The patients were divided into two groups, a surgery alone control group (52 patients) and a chemotherapy group that received postoperative TP therapy (91 patients). The disease-free and 5 year survival rates were compared between the groups and a multivariate analysis of prognostic factors was performed. The same analysis was performed for cases classified as RUNX3 positive and negative, with post-operative specimens assessed by immunohistochemistry. Although the disease-free and 5 year survival rates in control and chemotherapy groups did not significantly differ and there was no significance in RUNX3 negative cases, postoperative adjuvant chemotherapy in the chemotherapy group was shown to improve disease-free and 5 year survival rate compared to the control group in RUNX3 positive cases. On Cox regression multivariate analysis, postoperative adjuvant chemotherapy (P<0.01) was an independent prognostic factor for RUNX3 positive cases, suggesting that postoperative TP may be effective as adjuvant chemotherapy for stage IIA esophageal cancer patients with RUNX3 positive lesions.

Overexpression of RUNX3 Inhibits Malignant Behaviour of Eca109 Cells in Vitro and Vivo

Chen, Hua-Xia,Wang, Shuai,Wang, Zhou,Zhang, Zhi-Ping,Shi, Shan-Shan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

Radiation induced grain boundary segregation in ferritic/martensitic steels

Xia, L.D.,Ji, Y.Z.,Liu, W.B.,Chen, H.,Yang, Z.G.,Zhang, C.,Chen, L.Q. Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.1

The radiation induced segregation of Cr at grain boundaries (GBs) in Ferritic/Martensitic steels was modeled assuming vacancy and interstitialcy diffusion mechanisms. In particular, the dependence of segregation on temperature and grain boundary misorientation angle was analyzed. It is found that Cr enriches at grain boundaries at low temperatures primarily through the interstitialcy mechanism while depletes at high temperatures predominantly through the vacancy mechanism. There is a crossover from Cr enrichment to depletion at an intermediate temperature where the Cr:Fe vacancy and interstitialcy diffusion coefficient ratios intersect. The bell-shape Cr enrichment response is attributed to the decreasing void sinks inside the grains as temperature rises. It is also shown that low angle grain boundaries (LAGBs) and special Σ coincidence-site lattice (CSL) grain boundaries exhibit suppressed radiation induced segregation (RIS) response while high angle grain boundaries (HAGBs) have high RIS segregation. This different behavior is attributed to the variations in dislocation density at different grain boundaries.

Unconventional Flatband Line States in Photonic Lieb Lattices

Xia, Shiqi,Ramachandran, Ajith,Xia, Shiqiang,Li, Denghui,Liu, Xiuying,Tang, Liqin,Hu, Yi,Song, Daohong,Xu, Jingjun,Leykam, Daniel,Flach, Sergej,Chen, Zhigang American Physical Society 2018 Physical review letters Vol.121 No.26