Viscoelastic analysis of a sleeve based on the BP neural network

Yubin Gao,Haibin Li,Guangmei Wei,Yun He 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

Viscoelastic materials are widely used in aviation, underground engineering, chemical engineering, light textile, construction, machineryand shock-absorbing. The properties of viscoelastic materials present strong non-linear characteristics in the time, temperature andfrequency domains. The objective is to explore the possibility of having a rational understanding of the complex response. The neuralnetwork technique is thus implemented for this purpose. This study presents the differential constitutive equations of viscoelastic materialsbased on the generalized Kelvin model. The viscoelastic response Laplace transform equations of the sleeve structure are derivedunder the condition of plane strain according to the boundary conditions of the viscoelastic sleeve. The orthogonal design test results ofviscoelastic numerical calculations are normalized and trained using a three-layer BP neural network. The trained network can easilyrealize the mapping of the viscoelastic material test set. Simulation results show that the neural network test and numerical solution resultsare close to each other, and the maximum error of all variables is less than 2.8 percent. The results obtained in this research revealthat the neural network technique has a suitable capability in establishing correlations among different loads and corresponding viscoelasticresponses. The developed neural network model can effectively solve the non-linear problems of viscoelastic structures.

Optimization the extraction of anthocyanins from blueberry residue by dual-aqueous phase method and cell damage protection study

Yuan Gao,Yubin Ji,Fuling Wang,Wenlan Li,Xiaomeng Zhang,Zhihui Niu,Zhuo Wang 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.13

Blueberry residue is usually discarded as waste,but has a high anthocyanins content. The extraction methodof anthocyanins from blueberry residue with ultrasonicassisted dual-aqueous phase system was optimized. Interms of the principle of central group and design (CCD)experimental design, three-factor and five-level responsesurface analysis was adopted to optimize the extractionconditions with the extraction rate of anthocyanins. Theoptimum extraction rate of anthocyanin was12.372 ± 0.078 mg/g. Anthocyanin extract could protectthe pBR322 DNA oxidative damage induced by Fentonreagent, increase the superoxide dismutase(SOD) and glutathioneperoxidase (GSH-Px) enzyme activities, anddecrease the H2O2-induced cell apoptosis of human normalliver cell (LO2 cell). The study indicates that the extractionrate of anthocyanin was increased by optimized ultrasonicassisted dual-aqueous phase system. The anthocyaninextract could protect DNA and LO2 cell from oxidativedamage.

Adaptive Variable Impulsive Synchronization of Multi‑agent Systems

Like Gao,Jing Xiao,Xiaoxuan Guo,Shifeng Ou,Yangjun Zhou,Ning Wu,Yubin Feng,Zhiyang Yao 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

This paper is concerned with the adaptive synchronization of multi-agent systems via variable impulsive control method. Based on the theory of impulsive diferential equations, adaptive control technique, Lyapunov stability theory and comparison system method, some novel adaptive synchronization conditions with impulsive time window are given to realize the synchronization of multi-agent nonlinear systems with uncertain parameters. Diferent from the existing investigations of impulsive synchronization of multi-agent systems, the proposed impulsive control protocol with impulsive time window is more efective in practical systems. Finally, two simulation results demonstrate the validity of the theoretical results.

Endophytic Fungi from Dalbergia odorifera T. Chen Producing Naringenin Inhibit the Growth of Staphylococcus aureus by Interfering with Cell Membrane, DNA, and Protein

Yuan Gao,Yubin Ji,Wenlan Li,Fuling Wang,Fuling Wang,Xiaomeng Zhang,Zhihui Niu,Lulu Zhou,Lijun Yan 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.2

This study focused on the antibacterial effects of the endophytic fungi producing naringenin from Dalbergia odorifera T. Chen against Staphylococcus aureus. The antibacterial activity was measured by the inhibition diameters, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The time-killing curve was also used to evaluate its antibacterial efficacy. The results of antibacterial activity determinations showed that endophytic fungi secondary metabolites can inhibit the growth of five pathogenic bacteria (S. aureus, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, and Bacillus subtilis) and the most sensitive strain was S. aureus that had the MIC and MBC values of 0.13 and 0.50 mg/mL, respectively. The membrane permeability study was measured by a DNA leakage assay and electrical conductivity assay. Furthermore, the whole-cell protein lysates and DNA fragmentation assay was evaluated. The morphology of S. aureus treated with the endophytic fungi products was observed by scanning electron microscopy (SEM). The probable antibacterial mechanism of endophytic fungi secondary metabolites was the increased membrane permeability that leads to leaks of nucleic acids and proteins. SEM results further confirmed that the extracts can interfere with the integrity of S. aureus cell membrane and further inhibit the growth of bacteria, resulting in the death of bacteria. This study provides a new perspective for the antibacterial functions of endophytic fungi secondary metabolites for biomedical applications.

General method of reducing switching voltage stress without extra voltage‑loop control for related switching‑capacitor high‑gain converters

Fan Wang,Yubin Wang,Menghan Chu,Chuhao Gao 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.4

High-gain converters have been used on many occasions as interfaces for multiple energy conversions. Among these converters, a family of switching-capacitor high-gain converters is widely used due to its low cost, small volume, low loss, spontaneous capacitor voltages balance, and spontaneous inductor currents average. However, one or more of the switches in these converters suffer from the issue of withstanding higher voltage stresses than the other switches, which may limit the applications of these converters at high voltages. To solve this issue, a general method for reducing the switching voltage stresses for this high-gain converter family is proposed. This method can improve many kinds of high-gain converters, which can reduce the switching voltage stresses. Based on this method, a two-phase low-stress high-gain converter is proposed. The voltage stresses of all the switches in the proposed converter do not exceed half of the output voltage of the converter. Then, based on the proposed converter feature, a control method is proposed that can make the proposed converter have the automatic capacitor voltage balancing characteristic without an extra voltage-loop control. Finally, the proposed method is verified by prototype experiments.

Direct Chemical Vapor Deposition-Derived Graphene Glasses Targeting Wide Ranged Applications

Sun, Jingyu,Chen, Yubin,Priydarshi, Manish Kr.,Chen, Zhang,Bachmatiuk, Alicja,Zou, Zhiyu,Chen, Zhaolong,Song, Xiuju,Gao, Yanfeng,Rü,mmeli, Mark H.,Zhang, Yanfeng,Liu, Zhongfan American Chemical Society 2015 NANO LETTERS Vol.15 No.9

<P>Direct growth of graphene on traditional glasses is of great importance for various daily life applications. We report herein the catalyst-free atmospheric-pressure chemical vapor deposition approach to directly synthesizing large-area, uniform graphene films on solid glasses. The optical transparency and sheet resistance of such kinds of graphene glasses can be readily adjusted together with the experimentally tunable layer thickness of graphene. More significantly, these graphene glasses find a broad range of real applications by enabling the low-cost construction of heating devices, transparent electrodes, photocatalytic plates, and smart windows. With a practical scalability, the present work will stimulate various applications of transparent, electrically and thermally conductive graphene glasses in real-life scenarios.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-9/acs.nanolett.5b01936/production/images/medium/nl-2015-019367_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5b01936'>ACS Electronic Supporting Info</A></P>

A SPECTRALLY ARBITRARY COMPLEX SIGN PATTERN

Liu, Sujuan,Lei, Yingjie,Gao, Yubin The Korean Society for Computational and Applied M 2010 Journal of applied mathematics & informatics Vol.28 No.1

A spectrally arbitrary complex sign pattern A is a complex sign pattern of order n such that for every monic nth degree polynomial f(x) with coefficients from $\mathbb{C}$, there is a matrix in the qualitative class of A having the characteristic polynomial f(x). In this paper, we show a necessary condition for a spectrally arbitrary complex sign pattern and introduce a minimal spectrally arbitrary complex sign pattern $A_n$ all of whose superpatterns are also spectrally arbitrary for $n\;{\geq}\;2$. Furthermore, we study the minimum number of nonzero parts in a spectrally arbitrary complex sign pattern.

TIGHT UPPER BOUND ON THE EXPONENTS OF A CLASS OF TWO-COLORED DIGRAPHS

Wang, Rong,Shao, Yanling,Gao, Yubin Korean Society of Computational and Applied Mathem 2008 Journal of applied mathematics & informatics Vol.26 No.3-4

A two-colored digraph D is primitive if there exist nonnegative integers hand k with h + k > 0 such that for each pair (i, j) of vertices there exists an (h, k)-walk in D from i to j. The exponent of the primitive two-colored digraph D is the minimum value of h + k taken over all such hand k. In this paper, we give the tight upper bound on the exponents of a class of primitive two-colored digraphs with (s + 1) n-cycles and one (n - 1)-cycle, and the characterizations of the extremal two-colored digraphs.

Tight upper bound on the exponents of a class of two-colored digraphs

Rong Wang,Yanling Shao,Yubin Gao 한국전산응용수학회 2008 Journal of applied mathematics & informatics Vol.26 No.3-4

A two-colored digraph D is primitive if there exist nonnegative integers h and k with h + k > 0 such that for each pair (i, j) of vertices there exists an (h, k)-walk in D from i to j. The exponent of the primitive two-colored digraph D is the minimum value of h + k taken over all such h and k. In this paper, we give the tight upper bound on the exponents of a class of primitive two-colored digraphs with (s + 1) n−cycles and one (n − 1)−cycle, and the characterizations of the extremal two-colored digraphs.

Pore Structure Identification Method for Pervious Concrete based on Improved UNet and Fusion Algorithm

Fan Yu,Kailang Li,Hua Zhang,Rui Zhang,Zhang Gao,Yubin Huang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.11

This paper aims to establish an automatic and accurate pore identification method for pervious concrete. The residual module and mixed loss functions were introduced to the original UNet network to obtain the improved UNet. CT scanning was conducted on the six groups of pervious concrete samples with different aggregate sizes to obtain the initial dataset. The initial dataset was marked and enhanced, and then the pore recognition model was trained. The influence of image brightness and contrast on pore identification was analyzed. The fusion algorithm was used to improve the robustness of the model. The results show that during model training, R-UNet began to converge 20 epochs earlier than UNet and the loss value was smaller. Moreover, the maximum increase of mIoU and mDice was 10.3% and 11.7% respectively, and the maximum decrease of mHD was 14.1%. The fusion algorithm could improve the segmentation accuracy of pores in brightness anomaly images. Compared with threshold segmentation method, the method proposed in this paper could improve the accuracy of pore edge segmentation and the “fine pores” identification, and reduced the pore identification defects. The value of mHD was decreased by 48.7% − 72.4%, and the efficiency of pore identification was greatly improved.