A Method for Rapid Detection and Evaluation of Position Errors of Patterns of Small Holes on Complex Curved and Freeform Surface

Xiaomei Chen,Andrew Longstaff,Simon Parkinson,Alan Myers 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

This paper presents an evaluation method for the rapid and automatic detection of position errors of arrays of small holes on complex-curved and freeform surfaces that can satisfy the special demands of the aviation and automobile industries. The evaluation is based on the dual-sensor autofocusing method. The dual-sensor unit is the combination of a tactile probe and an optical vision sensor. The tactile probe detects the focal position for the optical vision sensor by probing the distance between the objective lens of the microscope and the location of each small hole. The optical vision sensor focuses to this position for capturing the image of the artifact under inspection. As a case study, a pattern of φ 0.5 mm small holes centripetally drilled with equal-angular distribution on the circumference of an elliptical cylinder shell is investigated. The autofocusing errors caused by the radius of the tactile probe and the position errors of the small holes are evaluated mathematically. Subsequently, a standalone dual-sensor autofocusing unit is built and integrated into a user-controllable 3D coordinate test rig. It is used to autofocus and capture the images of small holes. The centroid positions and deviations of the holes are automatically and rapidly detected from the captured images.

Graphitization of graphene oxide films under pressure

Chen, Xianjue,Deng, Xiaomei,Kim, Na Yeon,Wang, Yu,Huang, Yuan,Peng, Li,Huang, Ming,Zhang, Xu,Chen, Xiong,Luo, Da,Wang, Bin,Wu, Xiaozhong,Ma, Yufei,Lee, Zonghoon,Ruoff, Rodney S. Elsevier 2018 Carbon Vol.132 No.-

<P><B>Abstract</B></P> <P>Lightweight, flexible graphite foils that are chemically inert, high-temperature resistant, and highly electrically and thermally conductive can be used as component materials in numerous applications. “Graphenic” foils can be prepared by thermally transforming graphene oxide films. For this transformation, it is desirable to maintain a densely packed film structure at high heating rates as well as to lower the graphitizing temperatures. In this work, we discuss the pressure-assisted thermal decomposition of graphene oxide films by hot pressing at different temperatures (<I>i.e.</I>, 300 °C, 1000 °C, or 2000 °C). The films pressed at 1000 °C or 2000 °C were subsequently heated at 2750 °C to achieve a higher degree of graphitization. The combination of heating and pressing promotes the simultaneous thermal decomposition and graphitic transformation of G-O films. Films pressed at 2000 °C as well as films further graphitized at 2750 °C show high chemical purity, uniformity, and retain their flexibility. For films pressed at 2000 °C and then further heated at 2750 °C, the mechanical performances outperform the reported values of the “graphite” foils prepared by calendering exfoliated graphite flakes; the electrical conductivity is ∼3.1 × 10<SUP>5</SUP> S/m and the in-plane thermal conductivity is ∼1.2 × 10<SUP>3</SUP> W/(m·K).</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Transcriptional Profiling and Dynamical Regulation Analysis Identify Potential Kernel Target Genes of SCYL1-BP1 in HEK293T Cells

Wang, Yang,Chen, Xiaomei,Chen, Xiaojing,Chen, Qilong,Huo, Keke Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.9

SCYL1-BP1 is thought to function in the p53 pathway through Mdm2 and hPirh2, and mutations in SCYL1-BP1 are associated with premature aging syndromes such as Geroderma Osteodysplasticum; however, these mechanisms are unclear. Here, we report significant alterations in miRNA expression levels when SCYL1-BP1 expression was inhibited by RNA interference in HEK293T cells. We functionally characterized the effects of potential kernel miRNA-target genes by miRNA-target network and protein-protein interaction network analysis. Importantly, we showed the diminished SCYL1-BP1 dramatically reduced the expression levels of EEA1, BMPR2 and BRCA2 in HEK293T cells. Thus, we infer that SCYL1-BP1 plays a critical function in HEK293T cell development and directly regulates miRNA-target genes, including, but not limited to, EEA1, BMPR2, and BRCA2, suggesting a new strategy for investigating the molecular mechanism of SCYL1-BP1.

Transcriptional Profiling and Dynamical Regulation Analysis Identify Potential Kernel Target Genes of SCYL1-BP1 in HEK293T Cells

Yang Wang,Xiaomei Chen,Xiaojing Chen,Qilong Chen,Keke Huo 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.9

SCYL1-BP1 is thought to function in the p53 pathway through Mdm2 and hPirh2, and mutations in SCYL1-BP1 are associated with premature aging syndromes such as Geroderma Osteodysplasticum; however, these mechanisms are unclear. Here, we report significant alterations in miRNA expression levels when SCYL1-BP1 expression was inhibited by RNA interference in HEK293T cells. We functionally characterized the effects of potential kernel miRNA-target genes by miRNA-target network and protein-protein interaction network analysis. Importantly, we showed the diminished SCYL1-BP1 dramatically reduced the expression levels of EEA1, BMPR2 and BRCA2 in HEK293T cells. Thus, we infer that SCYL1-BP1 plays a critical function in HEK293T cell development and directly regulates miRNA-target genes, including, but not limited to, EEA1, BMPR2, and BRCA2, suggesting a new strategy for investigating the molecular mechanism of SCYL1-BP1.

Common mode leakage current analysis for Transformerless PV system with long DC side cables

Xiaomei Song,Wenjie Chen,Yang Xuan,Bin Zhang,Jiao Zhang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Due to the advantages of high efficiency and low cost, grid connected inverter based transformerless PV systems have been widespread during the last two decades. The key problem, which arises in absence of galvanic isolation, is the presence of a common mode (CM) leakage current on both AC and DC side of the inverter. In this paper, the influence of long DC side cable to the CM leakage current is taken into account for the first time. Moreover, an improved pai-structure model of the PV panel is proposed. It differs from the traditional single capacitance model in that the panel frame, the mounting rack as well as the connecting wire is all considered. Based upon the proposed model, the common mode leakage current is evaluated in both time domain and frequency domain. Simulation and experimental results give a firm support to the proposed model.

Crack Detection Based on Generative Adversarial Networks and Deep Learning

Gongfa Chen,Shuai Teng,Mansheng Lin,Xiaomei Yang,Xiaoli Sun 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

This paper proposes a novel crack detection method using the three-stages detection model. Deep learning technology has been a focus of attention in the field of crack detection; however, it needs big data to train the corresponding network model. More training samples and the combination of multiple deep learning algorithms help to improve the detection performance. Therefore, this paper employed a generative adversarial network (GAN) model to generate abundant virtual crack images with similar features to real images, these virtual images are used to train the CNN classifier and DeepLab_v3+ respectively, and then the real images are used to evaluate the performance of the three-stages detection method. The results show that the proposed three-stages detection method has excellent detection effect on the crack detection is better than that of the control experiment (the NI_MIoU, NI_Accuracy, NI_F-score and NI_MCC are increased by 22.1% − 55.6%, 5.2% − 9.8%, 37.4% − 40.0% and 6.2% − 11.1%, respectively)). These results demonstrate that the three-stages detection model has made a beneficial contribution to the crack detection.

Vitamin D Supplementation is Beneficial for Children with Autism Spectrum Disorder: A Meta-analysis

Liyao Song,Xiaomei Luo,Qing Jiang,Zhi Chen,Lifang Zhou,Dan Wang,Ai Chen 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.2

Objective: We conducted a meta-analysis of randomized controlled trials to explore whether vitamin D supplementation is beneficial for symptom improvement in children with autism spectrum disorder. Methods: We systematically searched the PubMed database, EMBASE, Cochrane Library, Web of Science, Sino-Med, Wanfang Data, and China National Knowledge Infrastructure mainly up to September 2019. Using a fixed effects model, we calculated the standard mean difference with 95% confidence interval. Furthermore, we analyzed baseline serum 25-hydroxyvitamin D levels and outcome scores including the Social Responsiveness Scale and Child Autism Rating Scale scores after vitamin D supplementation. Results: There was no significant difference in baseline serum 25-hydroxyvitamin D levels among 203 children included from three studies in the meta-analysis. After vitamin D supplementation, the outcome scores in the experimental group were dramatically elevated compared with those in the control group (p = 0.03). Conclusion: Vitamin D supplementation improves the typical symptoms of autism spectrum disorder, as indicated by reduced Social Responsiveness Scale and Child Autism Rating Scale scores; thus, it is beneficial for children with autism spectrum disorder.

Characterization and antioxidant properties of chitosan/ethyl-vanillin edible films produced via Schiff-base reaction

Jianfei Zhu,Xiaomei Chen,Tingting Huang,Dongling Tian,Ruiping Gao 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.2

In this paper, chitosan/ethyl-vanillin (CS-EV) Schiff-base edible films with CS and EV at different concentrations and ratios were successfully prepared. The optical barrier properties, water contact angle, mechanical performance, water vapor transmission, antioxidant properties, thermal properties, and morphological structure of the films were compared. The results suggested that the tensile strength (TS) attained a maximum value of 64.63 MPa at a concentration of 4% EV. Moreover, water diffusion was prevented through the compact structure of the CS-EV edible film. Additionally, the two sides of the CS-EV film show different textures due to their different hydrophilicity/hydrophobicity. In particular, the films of CS possessed superior thermal stability, while those of CS-EV exhibited higher antioxidant activity.

Impulsive Functional Observers for Linear Systems

Wu-Hua Chen,Dan-Xia Li,Xiaomei Lu 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.5

The impulsive functional observer design problem for linear systems is addressed. Piecewise differentiable Lyapunov functions are introduced to analyze the stability of the error dynamics. Sufficient conditions for the existence of the impulsive functional observers that are capable of expo-nentially estimating any given function of the state vector are derived. Numerical examples are pre-sented to demonstrate the effectiveness of the proposed results.

Complete genome sequence of the sesame pathogen Ralstonia solanacearum strain SEPPX 05

Xinshen Li,Xiaomei Huang,Gongyou Chen,Lifang Zou,Lingen Wei,Juling Hua 한국유전학회 2018 Genes & Genomics Vol.40 No.6

Ralstonia solanacearum is a soil-borne phytopathogen associated with bacterial wilt disease of sesame. R. solanacearum is the predominant agent causing damping-off from tropical to temperate regions. Because bacterial wilt has decreased the sesame industry yield, we sequenced the SEPPX05 genome using PacBio and Illumina HiSeq 2500 systems and revealed that R. solanacearum strain SEPPX05 carries a bipartite genome consisting of a 3,930,849 bp chromosome and a 2,066,085 bp megaplasmid with 66.84% G+C content that harbors 5,427 coding sequences. Based on the whole genome, phylogenetic analysis showed that strain SEPPX05 is grouped with two phylotype I strains (EP1 and GMI1000). Pan-genomic analysis shows that R. solanacearum is a complex species with high biological diversity and was able to colonize various environments during evolution. Despite deletions, insertions, and inversions, most genes of strain SEPPX05 have relatively high levels of synteny compared with strain GMI1000. We identified 104 genes involved in virulence-related factors in the SEPPX05 genome and eight absent genes encoding T3Es of GMI1000. Comparing SEPPX05 with other species, we found highly conserved secretion systems central to modulating interactions of host bacteria. These data may provide important clues for understanding underlying pathogenic mechanisms of R. solanacearum and help in the control of sesame bacterial wilt.