Target-free vision-based approach for vibration measurement and damage identification of truss bridges

Jun LI,Dong Tan,Zhenghao Ding,Hong Hao 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.4

This paper presents a vibration displacement measurement and damage identification method for a space truss structure from its vibration videos. Features from Accelerated Segment Test (FAST) algorithm is combined with adaptive threshold strategy to detect the feature points of high quality within the Region of Interest (ROI), around each node of the truss structure. Then these points are tracked by Kanade-Lucas-Tomasi (KLT) algorithm along the video frame sequences to obtain the vibration displacement time histories. For some cases with the image plane not parallel to the truss structural plane, the scale factors cannot be applied directly. Therefore, these videos are processed with homography transformation. After scale factor adaptation, tracking results are expressed in physical units and compared with ground truth data. The main operational frequencies and the corresponding mode shapes are identified by using Subspace Stochastic Identification (SSI) from the obtained vibration displacement responses and compared with ground truth data. Structural damages are quantified by elemental stiffness reductions. A Bayesian inference-based objective function is constructed based on natural frequencies to identify the damage by model updating. The Success-History based Adaptive Differential Evolution with Linear Population Size Reduction (L-SHADE) is applied to minimise the objective function by tuning the damage parameter of each element. The locations and severities of damage in each case are then identified. The accuracy and effectiveness are verified by comparison of the identified results with the ground truth data.

Helicobacter pylori Chaperone-Like Protein CagT Plays an Essential Role in the Translocation of CagA into Host Cells

( Ding Hong Lei ),( Hao Zeng ),( Lin Ping Huang ),( Yan Dong Dong ),( Yi Jun Duan ),( Xu Hu Mao ),( Gang Guo ),( Quan Ming Zou ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.10

Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.

Voltage Regulation System based on ADRC for Doubly Salient Electro-magnetic Generator

Jun Ding,Weili Dai,Hao Tian,Juntao Fei 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

A voltage regulation system based on linear active disturbance rejection control (LADRC) for doubly salient electro-magnetic generator (DSEG) was proposed in this paper. Based on mathematical model and operation principle of the generator, second-order LADRC controller was constructed to keep output dc voltage stable by adjusting exciting current and corresponding operation principle was analyzed in detail. Then, control parameters selection method has been given according to engineer design consideration. Finally, co-simulation models of voltage regulation system for DSEG using LADRC and traditional output voltage feedback plus exciting current feed-forward control were built by electromagnetic finite element analysis and transient solver of control circuit. The steady state and dynamic performance of the generator under different load show that DSEG using LADRC will acquire much better steady and dynamic response characteristic than one using traditional control.

Improved Global Maximum Power Point Tracking Method Based on Voltage Interval for PV Array under Partially Shaded Conditions

Ding, Kun,Wang, Xiang,Zhai, Quan-Xin,Xu, Jun-Wei,Zhang, Jing-Wei,Liu, Hai-Hao The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

The power-voltage (P-V) curve of photovoltaic (PV) arrays connected in parallel to bypass diodes would have several local maximum power points (LMPP) under partial shading conditions (PSC). Conventional maximum power point tracking (MPPT) methods fail to search for the global maximum power point (MPP) because the searched peak point may remain at the LMPP on the P-V curve under PSC. This study proposes an improved MPPT algorithm to ensure that PV arrays operate at global maximum power point (GMPP) under PSC. The proposed algorithm is based on a critical study and a series of observations of PV characteristics under PSC. Results show the regularity of voltage interval between LMPPs. The algorithm has the advantages of rapidly reaching GMPP, maintaining stability, and recovering GMPP quickly when the operating condition changes. Simulation and experimental results demonstrate the feasibility of the proposed algorithm.

Transcriptome analysis of male and female mature gonads of Japanese scallop Patinopecten yessonsis

Jun Ding,Dan Yang,Chao Yin,Yaqing Chang,Yan Dou,Zhenlin Hao 한국유전학회 2016 Genes & Genomics Vol.38 No.11

The Japanese scallop Patinopecten yessoensis is an important commercial culture shellfish in China and Japan. In addition to its commercial interest, it has also attracted much attention because of its value in studying sex determination and differentiation mechanisms. Herein, two transcriptome libraries from male and female gonads at maturing stage were constructed. The two libraries were paired-end sequenced using Illumina sequencing techniques. A total of 81,986,898 cleaned reads were obtained, and assembled into 29,897 unigenes by using Trinity software and removing redundancy. Compared with the public Swiss-Prot and NR databases by BlastX, 9354 unigenes were significantly matched to known unique proteins. As determined by GO annotation and KEGG pathway mapping, functional annotation of the unigenes uncovered diverse biological functions and processes. After comparing the two transcriptome libraries, 8652 upregulated and 2973 down-regulated genes were identified in the male gonads. According to annotation information, at least 30 genes related to sex determination and differentiation, such as Dmrt1, Sox9, fem1 and vasa, were identified and characterized. The expression patterns of the random eight genes were then validated by quantitative real-time PCR (qRT-PCR) suggesting the high reliability of RNA-Seq results. The study provides an archive for further studies of molecular mechanisms of bivalve sex determination and differentiation.

Computational study on wind turbine airfoils based on active control for deformable flaps

Wenxing Hao,Chun Li,Zhou Ye,Jun Yang,Qinwei Ding 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

This study numerically investigates the aerodynamic performance of Deformable trailing edge flaps (DTEFs) to reduce the fatigue and ultimate loads of wind turbine blades. A parametric design is adopted to ensure the flexible deformation of the DTEFs. Based on experimental data, a simulation of a baseline airfoil is performed with two methods: A fully coupled viscous/inviscid method employed by the XFOIL program and a Reynolds-averaged Navier–Stokes solver with a Transition SST (T-SST) turbulence model. The static and dynamic performances of DTEFs are then investigated under different flow conditions by using T-SST and maximizing its numerous advantages. Results indicate that under steady conditions, the effects of flap deflection on the integral forces and flow field structures of airfoils vary from attached flow conditions to separated conditions. The gaps between unsteady aerodynamic responses and static values are greater in attached flow and light stall conditions than in deep stall conditions. The ability of DTEFs to control the fatigue loads on wind turbine blades is verified. Specifically, DTEFs effectively alleviate the force fluctuations on blades under gust-induced swinging when wind speed measurements are considered.

Improved Global Maximum Power Point Tracking Method Based on Voltage Interval for PV Array under Partially Shaded Conditions

Kun Ding,Xiang Wang,Quan-Xin Zhai,Jun-Wei Xu,Jing-Wei Zhang,Hai-Hao Liu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

The power?voltage (P?V) curve of photovoltaic (PV) arrays connected in parallel to bypass diodes would have several local maximum power points (LMPP) under partial shading conditions (PSC). Conventional maximum power point tracking (MPPT) methods fail to search for the global maximum power point (MPP) because the searched peak point may remain at the LMPP on the P?V curve under PSC. This study proposes an improved MPPT algorithm to ensure that PV arrays operate at global maximum power point (GMPP) under PSC. The proposed algorithm is based on a critical study and a series of observations of PV characteristics under PSC. Results show the regularity of voltage interval between LMPPs. The algorithm has the advantages of rapidly reaching GMPP, maintaining stability, and recovering GMPP quickly when the operating condition changes. Simulation and experimental results demonstrate the feasibility of the proposed algorithm.

High throughput sequencing of herbaceous peony small RNAs to screen thermo-tolerance related microRNAs

Zhaojun Hao,Ding Liu,Saijie Gong,Daqiu Zhao,Jun Tao 한국유전학회 2017 Genes & Genomics Vol.39 No.4

Herbaceous peony (Paeonia lactiflora Pall.) is an ornamental flower with wide applications for landscape. However, its application potential is greatly restricted because it is prone to heat stress injury. Although there are some studies about thermo-tolerance of P. lactiflora which focused on physiological and transcriptional level, the information on post-transcriptional level is lacked. Here, we chose a thermo-tolerant cultivar ‘Zifengyu’ and a moderately thermo-tolerant cultivar ‘Hongyanzhenghui’ under the natural long summer heat to investigate heat responsive miRNAs by miRNA sequencing. A total of 24,008,974 and 21,981,360 raw reads were generated from ‘Zifengyu’ and ‘Hongyanzhenghui’, respectively, as well as 45,016,796 total sRNAs and 6,297,111 unique sRNAs were obtained. Then 271 conserved and 9 novel miRNAs were identified in ‘Zifengyu’, while 236 conserved and 11 novel miRNAs were identified in ‘Hongyanzhenghui’. Among them, 71 known miRNAs with 272 potential target genes and 3 novel miRNAs with 4 potential target genes were significantly differentially expressed. Expression analysis of the 7 candidate miRNAs previously reported to be regulated by heat stress and their target genes were performed. It showed that miR172c-3p, miR395a, miR397a, miR408-5p and miR827 were up-regulated by heat stress, and expressed much higher in thermo-tolerant cultivar ‘Zifengyu’, suggesting that they might be involved in heat stress response at the post-transcriptional level. These results could provide a better understanding about the thermos-tolerant mechanism of P. lactiflora on post-transcriptional level.

Identification of copy number variations using high density whole-genome single nucleotide polymorphism markers in Chinese Dongxiang spotted pigs

Chengbin Wang,Hao Chen,Xiaopeng Wang,Zhongping Wu,Weiwei Liu,Yuanmei Guo,Jun Ren,Nengshui Ding 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.12

Objective: Copy number variations (CNVs) are a major source of genetic diversity complementary to single nucleotide polymorphism (SNP) in animals. The aim of the study was to perform a comprehensive genomic analysis of CNVs based on high density whole-genome SNP markers in Chinese Dongxiang spotted pigs. Methods: We used customized Affymetrix Axiom Pig1.4M array plates containing 1.4 million SNPs and the PennCNV algorithm to identify porcine CNVs on autosomes in Chinese Dongxiang spotted pigs. Then, the next generation sequence data was used to confirm the detected CNVs. Next, functional analysis was performed for gene contents in copy number variation regions (CNVRs). In addition, we compared the identified CNVRs with those reported ones and quantitative trait loci (QTL) in the pig QTL database. Results: We identified 871 putative CNVs belonging to 2,221 CNVRs on 17 autosomes. We further discarded CNVRs that were detected only in one individual, leaving us 166 CNVRs in total. The 166 CNVRs ranged from 2.89 kb to 617.53 kb with a mean value of 93.65 kb and a genome coverage of 15.55 Mb, corresponding to 0.58% of the pig genome. A total of 119 (71.69%) of the identified CNVRs were confirmed by next generation sequence data. Moreover, functional annotation showed that these CNVRs are involved in a variety of molecular functions. More than half (56.63%) of the CNVRs (n = 94) have been reported in previous studies, while 72 CNVRs are reported for the first time. In addition, 162 (97.59%) CNVRs were found to overlap with 2,765 previously reported QTLs affecting 378 phenotypic traits. Conclusion: The findings improve the catalog of pig CNVs and provide insights and novel molecular markers for further genetic analyses of Chinese indigenous pigs.

Extraction of density-of-states in amorphous InGaZnO thin-film transistors from temperature stress studies

Xing-Wei Ding,Jianhua Zhang,Weimin Shi,Hao Zhang,Chuanxin Huang,Jun Li,Xueyin Jiang,Zhilin Zhang 한국물리학회 2014 Current Applied Physics Vol.14 No.12

The instability of amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) with different active layer thicknesses under temperature stress has been investigated through using the density-of-states (DOS). Interestingly, the a-IGZO TFT with 22 nm active layer thickness showed a better stability than the others, which was observed from the decrease of interfacial and semiconductor bulk trap densities. The DOS was calculated based on the experimentally-obtained activation energy (EA), which can explain the experimental observations. We developed the high-performance Al2O3 TFT with 22 nm IGZO channel layer (a high mobility of 7.4 cm2/V, a small threshold voltage of 2.8 V, a high Ion/Ioff 1.8 107, and a small SS of 0.16 V/dec), which can be used as driving devices in the next-generation flat panel displays.