Resilient Distributed Filtering for Discrete Time-varying Systems with Missing Measurements and Stochastic Uncertainties

Tianqi Liu,Dongyan Chen,Jun Hu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.5

In this paper, the resilient distributed filtering problem is addressed for discrete stochastic uncertain timevarying systems with missing measurements and stochastic uncertainties over wireless sensor networks. Some random variables governed by the Bernoulli distribution are used to model the missing measurements phenomenon of each sensor node. In addition, the stochastic uncertainties are characterized by the multiplicative noises and stochastic nonlinearities. By using the variance-constrained method, an appropriate filter gain is selected to minimize thetrace of the upper bound for the filter error covariance. Moreover, the resilient distributed filtering algorithm isdesigned and a new matrix simplification technique is introduced to deal with the sparsity of sensor networks topology. Finally, both the feasibility and effectiveness of the resilient distributed filtering algorithm are verified by anumerical simulation.

Commutability Assessment of Candidate External Quality Assessment Materials for Aminotransferase Activity Measurements Based on Different Approaches in China

Long Qichen,Qi Tianqi,Zhang Tianjiao,Wang Jing,Zeng Jie,Ying Yan,Meng Wang,Wei Huang,Haijian Zhao,Wenxiang Chen,Chuanbao Zhang 대한진단검사의학회 2021 Annals of Laboratory Medicine Vol.41 No.1

Background: Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement. Methods: One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the ln-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach). Results: For ALT, all materials were commutable for 14–21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach. Conclusions: Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.

Mast Cells Tryptase Promotes Intestinal Fibrosis in Natural Decellularized Intestinal Scaffolds

Wan Jian,Wu Tianqi,Liu Ying,Yang Muqing,Fichna Jakub,Guo Yibing,Yin Lu,Chen Chunqiu 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Standard two-dimensional (2D) culture has confirmed the mechanism of mast cells (MCs) in the pathogenesis of inflammatory bowel disease (IBD), but the regulation of signaling responses of MCs may well differ in three-dimensional (3D) microenvironments. The aim of the study was to develop a 3D culture model based on decellularized intestinal scaffolds (DIS) and verify how MCs influenced fibroblasts phenotype in the 3D model. METHODS: DIS were achieved using the detergent technique and extracellular matrix (ECM) components were verified by histologic analysis, quantification and scanning electron microscope. After human colon fibroblasts recellularized into the scaffolds and activated by MCs tryptase and TGFb1, the changes in genes and signaling pathways during fibroblasts activation in 3D were studied and compared with the changes in 2D cell culture on plastic plates. RESULTS: Decellularization process effectively removed native cell debris while retaining natural ECM components and structure. The engrafted fibroblasts could penetrate into the scaffolds and maintain its phenotype. No matter whether fibroblasts were cultured in 2D or 3D, MCs tryptase and transforming growth factor b1 (TGF-b1) could promote the differentiation of fibroblasts into fibrotic-phenotype myofibroblasts through Akt and Smad2/3 signaling pathways. Furthermore, the pro-collagen1a1 and fibronectin synthesis of myofibroblasts in 3D was higher than in 2D culture. CONCLUSION: Our results demonstrated that the DIS can be used as a bioactive microenvironment for the study of intestinal fibrosis, providing an innovative platform for future intestinal disease modeling and screening of genes and signaling pathways.

Damping Applications of Ferrofluids

Chuan Huang,Jie Yao,Tianqi Zhang,Yibiao Chen,Huawei Jiang,Decai Li 한국자기학회 2017 Journal of Magnetics Vol.22 No.1

Ferrofluids are a special category of smart nanomaterials which shows normal liquid behavior coupled with superparamagnetic properties. One of the earliest and most prospective applications of ferrofluids is in damping, which has prominent advantages compared with conventional damping devices: simplicity, flexibility and reliability. This paper presents the basic principles that play a major role in the design of ferrofluid damping devices. The characteristics of typical ferrofluid damping devices including dampers, vibration isolators, and dynamic vibration absorbers are compared and summarized, and then recent progress of vibration energy harvesters based on ferrofluid is briefly described. Additionally, we proposed a novel ferrofluid dynamic vibration absorber in this paper, and its damping efficiency was verified with experiments. In the end, the critical problems and research directions of the ferrofluid damping technology in the future are raised.

Manufacture and Characterization on Three-Dimensional Random Resonators of Porous Silicon/TiO2 Nanowires for Continuous Light Pumping Lasing of Perovskite Quantum Dots

Yining Mu,Tuo Zhang,Tianqi Chen,Fanqi Tang,Jikai Yang,Chunyang Liu,Zhangxiaoxiong Chen,Yiming Zhao,Peng Du,Haibo Fan,Yan Zhu,Guozhen Liu,Ping Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

In recent years, all inorganic bismuth lead-halide perovskite nanocrystals [CsPbX3 (X=Cl, Br, I)] have received extensive attention due to their high performance in fluorescence quantum yield, narrow emission spectrum, and adjustable emission range. However, the disadvantages of high cost and poor stability have greatly limited the development prospects of the material. Here, in order to develop a perovskite quantum dot lasing cavity with high chemical stability, high quality factor and low fabrication cost, we have successfully fabricated a 3D random cavity device based on porous silicon/TiO2 nanowires. A TiO2 nanowire is grown on the porous silicon to form a 3D resonant cavity, and a perovskite quantum dot is spin-coated on the surface of the 3D resonant cavity to form a novel 3D complex film. The novel structure enhances the chemical stability and lasing quality factor of the resonant cavity while the fluorescence generated by the large quantum dots in the spatial interference structure constitutes the feedback loop, which will provide favorable support for the development of information optics.

Design and Research on the Special System for High Efficient Manufacturing of Blisk Based on UG

Yaonan Cheng,Rui Guan,Diange Zuo,Tianqi Chen,Li Liu 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.10

As one of the most important parts of aeroengine, blisk has complex structure and its material is titanium alloy hard to machine. It results in some difficulties in modeling and NC programming. In this paper, from the perspective of application, the secondary development technology of UG/Open Grip is used to design and develop the CAD/CAM module of blisk after analyzing structure feature and milling process of blisk. Firstly, it completes parametric modeling of blisk by establishing CAD module through the optimization of the original data points in NUBRS curve fitting and node interpolation technology; secondly, the inner and outer tolerance algorithm are applied to calculate the cutting step, and the row spacing is determined based on constant scallop height. Besides, tool axis vector is defined. All of these things are done to complete the establishment of the CAM module and realize trajectory planning of semi-finish machining of the blisk. It greatly improves the efficiency of programming and machining in blisks; finally, the module of blisk designed is used to model and program in the machining experiments in five axis machining center to verify correctness and reliability of the system. The results show that this module greatly improves manufacturing efficiency of blisk.

Analysis and improvement of output power drop of dynamic wireless power transfer systems with transmitting coil switching for inspection robots

Yishuo Ding,Jiangui Li,Longyang Wang,Chen Wang,Guofu Zhu,Yuying Cheng,Tianqi Yu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

Dynamic wireless power transfer (DWPT) has received extensive attention due to its advantages of high security, high convenience, and high efficiency. To solve the problems of the mutual inductance and output power drop of DWPT systems for inspection robots, a new DWPT system with a trapezoidal-rectangular coupler has been proposed. First, the DWPT system topology and the switching strategy of the transmitting coil are introduced. Second, the real-time mutual inductances of the coupler in linear and curved motion are derived. Third, a new trapezoidal transmitting coil is presented. Finally, the performance of the DWPT system with the trapezoidal-rectangular coupler (TRC) is tested and compared to the DWPT system with the rectangular-rectangular coupler (RRC). Experimental results show that the minimum mutual inductance of the TRC is increased by 58.71%, and that the minimum output power is more than doubled in curved motion. Moreover, the mutual inductance drop rates of the TRC in linear and curved motion are reduced by 21.23% and 18.42%, respectively. The output power drop rates of the TRC-DWPT system are reduced by 18.99% and 16.12%, respectively. In addition, the Litz wire consumption is reduced by 8.28% in linear motion.

Bearing Fault Diagnosis Using One-Dimensional Convolutional Neural Network

Zhanyuan Gao,Zhennan Wei,Yuan Chen,Tianqi Ying,Haojie Gao 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

In this paper, a fault diagnosis strategy using one-dimensional convolutional neural network (CNN) is developed for rolling bearing. Firstly, each basic unit in the CNN model to be proposed is introduced in detail, and the optimization algorithm required for the CNN is described to show the working principle, which provides a theoretical basis for the onedimensional CNN model. Next, a series of preprocessing such as overlap sampling and unique thermal coding are performed on the rolling bearing dataset from Case Western Reserve University, and a batch normalization algorithm is proposed to improve the training efficiency and performance of the CNN model. Finally, the designed one-dimensional CNN model is trained, the adaptive ability of the model with variable load is tested, and good results are obtained.

Identification of a 193 bp promoter region of TaNRX1‑D gene from common wheat that contributes to osmotic or ABA stress inducibility in transgenic Arabidopsis

Cheng Jie,Wei Fan,Zhang Mingfei,Li Nan,Song Tianqi,Wang Yong,Chen Dongsheng,Xiang Jishan,Zhang Xiaoke 한국유전학회 2021 Genes & Genomics Vol.43 No.9

Background Cloning and characterizing the drought-inducible promoters is essential for their use in crop resistance’s genetic improvement. Previous studies have shown that the TaNRX1-D gene participates in regulating the response of wheat to drought stress. However, its promoter has not yet been identifed. Objective In this study, we aimed to characterize the promoter of the TaNRX1-D gene. Methods The promoter of TaNRX1-D (named P0, 2081 bp) was isolated from common wheat with several cis-acting elements that regulate in response to abiotic stresses and some core cis-acting elements. Functional verifcation of the promoter, eight 5′-deletion fragments of TaNRX1-D promoter, was fused to the β-glucuronidase (GUS) gene P0::GUS~P7::GUS and transformed into Arabidopsis, respectively. Agrobacterium-mediated GUS transient assay the P6a and P6b promoter regions in tobacco leaves under normal, osmotic or ABA stress. Results Activity analysis of the full-length promoter (P0) showed that the intensity of stronger β-glucuronidase (GUS) staining in the roots and leaves was obtained during the growth of transgenic Arabidopsis. P0::GUS displayed the GUS activity was much higher in the roots and leaves than in other parts of the transgenic plant under normal conditions, which was similarly within wheat. Analysis of the 5′-deletion fragments revealed that P0::GUS~P6::GUS responded well upon exposure to osmotic (polyethylene glycol-6000, PEG6000) and abscisic acid (ABA) stress treatments and expressed signifcantly higher GUS activity than the CaMV35S promoter (35S::GUS), while P7::GUS did not. GUS transient assay in tobacco leaves showed that the GUS activities of P6a and P6b were lower than P6 in the PEG6000 and ABA stresses. Conclusion The 193 bp (P6) segment was considered the core region of TaNRX1-D responding to PEG6000 or ABA treatment. GUS activity assay in transgenic Arabidopsis showed that this segment was sufcient for the PEG6000 or ABA stress response. The identifed 193 bp promoter of TaNRX1-D in this study will help breed osmotic or ABA tolerant crops. The 36 bp segment between P6 and P6b (−193 to −157 bp) was considered the critical sequence for the TaNRX1-D gene responding to PEG6000 or ABA treatment.