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281 results on '"Su, Jianyu"'

61. A Robust Filtering Method for X-Ray Pulsar Navigation in the Situation of Strong Noises and Large State Model Errors

Author

Su Jianyu, Haiyan Fang, Sun Haifeng, Yanming Liu, Li Zhang, Shen Lirong, and Xiaoping Li

Subjects
020301 aerospace & aeronautics, General Computer Science, Spacecraft, Computer science, business.industry, General Engineering, 020206 networking & telecommunications, 02 engineering and technology, robustness, X-ray pulsar-based navigation, 0203 mechanical engineering, Pulsar, Robustness (computer science), 0202 electrical engineering, electronic engineering, information engineering, State model error, General Materials Science, lcsh:Electrical engineering. Electronics. Nuclear engineering, strong noise, business, Algorithm, lcsh:TK1-9971, X-ray pulsar
Abstract

X-ray pulsar-based navigation (XPNAV) is one of the perfect ways for autonomous deep-space navigation in the future. Due to spacecraft state model errors and strong cosmic background noises, low navigation accuracy is one of the main problems in XPNAV. This paper proposes a robust navigation filtering method to reduce the serious effect of spacecraft state model errors and strong noises on XPNAV. This method uses state model errors and pulsar observation errors to estimate and correct the state model. And then, to predict the spacecraft’ state in the next moment with high precision, the gain matrix is adjusted in quasi real-time by using the fading factor to ensure a minimized state estimation error variance in the next moment and an orthogonal residual sequence at different times. Finally, experimental results of multi-group simulations show that the proposed method had significantly improved navigation accuracy. And the accuracy of the proposed method is better than that of $\text{H}\infty $ robust filter and STUKF, especially when the state model errors and noise are great. Under the same conditions, compared with the other two methods, the proposed method has the minimum navigation filtering error and the strongest robustness.

Published
2019

62. Magnetic field regulation of mouse bone marrow mesenchymal stem cell behaviours on TiO2 nanotubes via surface potential mediated by Terfenol‐D/P(VDF‐TrFE) film.

Author

Qi, Haisheng, Ke, Qi, Tang, Qiwen, Yin, Lei, Yang, Lixin, Ning, Chengyun, Su, Jianyu, and Fang, Liming

Subjects
BIOMATERIALS, MAGNETOELECTRIC effect, MAGNETOSTRICTION, PIEZOELECTRICITY, SURFACE potential, TITANIUM dioxide
Abstract

It is challenging to match the mutual interactions between implant and host because the biomaterials usually cannot actively adjust their performance to the changing microenvironment. Surface potential is one of the critical factors affecting the bioactivity of biomaterials, but it is difficult to be directly controlled in vivo. Magnetic stimulation has attracted much attention due to its deep penetrability, good reliability, and convenient operability. Here, titanium dioxide (TiO2) nanotubes and Terfenol‐D/P(VDF‐TrFE) composite film are prepared by anodic oxidation and solution casting methods on opposite sides of a titanium sheet, respectively. Terfenol‐D magnetostrictive microparticles deform under a magnetic field, generating surface potential on the P(VDF‐TrFE) piezoelectric matrix through magneto‐electric coupling. Correspondingly, equal opposite charges are induced on the surface of TiO2 nanotubes. Stem cells cultured on TiO2 nanotubes show that cell adhesion, proliferation, and differentiation abilities can be regulated by magnetic strength, which correlates with the absorption of charged proteins. Therefore, a cascade coupling of magnetic, mechanical, electric, biochemical, and cellular effects is established. This work demonstrates the feasibility of regulating the bioactivity of biomaterials in vivo through a magnetic field. [ABSTRACT FROM AUTHOR]

Published
2022
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68. Spoilage Lactic Acid Bacteria in the Brewing Industry

Author

Xu, Zhenbo, primary, Luo, Yuting, additional, Mao, Yuzhu, additional, Peng, Ruixin, additional, Chen, Jinxuan, additional, Soteyome, Thanapop, additional, Bai, Caiying, additional, Chen, Ling, additional, Liang, Yi, additional, Su, Jianyu, additional, Wang, Kan, additional, Liu, Junyan, additional, and Kjellerup, Birthe V, additional

Published
2020
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75. Building the Crab Pulsar Timing Model with XPNAV-1 Observations

Author

Liang Zhao, Haiyan Fang, Su Jianyu, Zhi-wei Liu, and Sun Haifeng

Subjects
Physics, Pulsar, Crab Pulsar, Astrophysics::High Energy Astrophysical Phenomena, Maximum likelihood, Phase (waves), Estimator, Satellite, Statistical physics, Fourier series, Pulse time
Abstract

This paper addresses the problem of building the X-ray pulsar timing model that is an essential work for X-ray pulsar navigation (XNAV). We propose a theoretical discussion of the differences between the X-ray and radio pulsar timing and develop a complete processing framework. In this framework, the \( Z_{m}^{2} \)-test method is deduced by the theory of the Fourier Series Estimator (FSE) in the complex form. A fast maximum likelihood (FAML) estimator is applied for the estimation of pulse time of arrival (TOA). Then the model parameters are deduced based on a least-squares strategy. To sustain this framework, about 173 ks observations with X-ray pulsar navigation-I (XPNAV-1) satellite over 30 days are utilized for experimental studies. The results show that the proposed framework is valid, and the phase residuals with the X-ray model parameters is 2.57 milliperiods.

Published
2018

81. Transcriptomics Study on Staphylococcus aureus Biofilm Under Low Concentration of Ampicillin

Author

Liu, Junyan, primary, Yang, Ling, additional, Hou, Yuchao, additional, Soteyome, Thanapop, additional, Zeng, Bingbing, additional, Su, Jianyu, additional, Li, Lin, additional, Li, Bing, additional, Chen, Dingqiang, additional, Li, Yanyan, additional, Wu, Aiwu, additional, Shirtliff, Mark E., additional, Harro, Janette M., additional, Xu, Zhenbo, additional, and Peters, Brian M., additional

Published
2018
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90. Antibiotic Susceptibility, Biofilm-Forming Ability, and Incidence of Class 1 Integron of Salmonellaspp., Escherichia coli, and Staphylococcus aureusIsolated from Various Foods in a School Canteen in China

Author

Wang, Wen, Wang, Li, Su, Jianyu, and Xu, Zhenbo

Abstract

In recent years, the food poisoning incidents from school canteens have aroused widespread concern in China. Microbial contamination to the foods is the main factor responsible for these food poisoning events. In this study, identification of microbial pathogens including Salmonellaspp., Escherichia coli, and Staphylococcus aureusin samples (frozen pork, fresh pork, fresh chicken, and different fresh vegetables) of a school canteen in China during 2017 to 2018 was performed. The antibiotic susceptibility pattern, class 1 integron, and biofilm formation ability of the isolated pathogens were also investigated. In total, 96 strains were isolated (32 Salmonellaspp., 32 E. coli, and 32 S. aureus). The antibiogram study results demonstrated that 61.5% strains were found resistant to at least one type of antibiotics, and 17.7% were resistant to three or more antibiotics. In addition, 31.3% strains possessed class 1 integron. Among the integron-positive isolates, 38.9% Salmonellaspp. and 87.5% E. colicontained ∼800 or/and 1500 bp size gene cassette within the integrons. However, four S. aureusstrains possessing class 1 integron without gene cassette were found. Although none of the isolated strains were found strong biofilm producer, 44.8% were found to have weak or moderate biofilm formation ability. Despite biofilm formation ability or not, the Salmonellaspp. containing positive class 1 integron showed significant resistance to cefazolin and gentamicin. In addition, class 1 integron-positive E. coliisolates having the biofilm formation ability hardly showed sensitive to four antibiotics, such as amikacin, amoxicillin–clavulanate, cefazolin, and gentamicin. Therefore, it is necessary to reduce the prevalence of antibiotic resistance gene cassettes containing antibiotic resistance genes by the prudent use of antibiotics in livestock farms, and the improvement of food processing and storage environment.

Published
2020
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