121 research outputs found

    Ensemble Joint Sparse Low Rank Matrix Decomposition for Thermography Diagnosis System

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    Composite is widely used in the aircraft industry and it is essential for manufacturers to monitor its health and quality. The most commonly found defects of composite are debonds and delamination. Different inner defects with complex irregular shape is difficult to be diagnosed by using conventional thermal imaging methods. In this paper, an ensemble joint sparse low rank matrix decomposition (EJSLRMD) algorithm is proposed by applying the optical pulse thermography (OPT) diagnosis system. The proposed algorithm jointly models the low rank and sparse pattern by using concatenated feature space. In particular, the weak defects information can be separated from strong noise and the resolution contrast of the defects has significantly been improved. Ensemble iterative sparse modelling are conducted to further enhance the weak information as well as reducing the computational cost. In order to show the robustness and efficacy of the model, experiments are conducted to detect the inner debond on multiple carbon fiber reinforced polymer (CFRP) composites. A comparative analysis is presented with general OPT algorithms. Not withstand above, the proposed model has been evaluated on synthetic data and compared with other low rank and sparse matrix decomposition algorithms

    Generation of Biotechnology-Derived Flavobacterium columnare Ghosts by PhiX174 Gene E-Mediated Inactivation and the Potential as Vaccine Candidates against Infection in Grass Carp

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    Flavobacterium columnare is a bacterial pathogen causing high mortality rates for many freshwater fish species. Fish vaccination with a safe and effective vaccine is a potential approach for prevention and control of fish disease. Here, in order to produce bacterial ghost vaccine, a specific Flavobacterium lysis plasmid pBV-E-cat was constructed by cloning PhiX174 lysis gene E and the cat gene with the promoter of F. columnare into the prokaryotic expression vector pBV220. The plasmid was successfully electroporated into the strain F. columnare G4cpN22 after curing of its endogenous plasmid. F. columnare G4cpN22 ghosts (FCGs) were generated for the first time by gene E-mediated lysis, and the vaccine potential of FCG was investigated in grass carp (Ctenopharyngodon idellus) by intraperitoneal route. Fish immunized with FCG showed significantly higher serum agglutination titers and bactericidal activity than fish immunized with FKC or PBS. Most importantly, after challenge with the parent strain G4, the relative percent survival (RPS) of fish in FCG group (70.9%) was significantly higher than FKC group (41.9%). These results showed that FCG could confer immune protection against F. columnare infection. As a nonliving whole cell envelope preparation, FCG may provide an ideal alternative to pathogen-based vaccines against columnaris in aquaculture

    The relationship between BSP mRNA expression and 25(OH)D/OPG in peripheral blood of newly diagnosed T2DM patients with different bone mass

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    Introduction: The objective of the study was to detect the levels of osteoprotegerin (OPG) and 25-hydroxyvitamin D [25(OH)D], as well as the expression of bone sialoprotein (BSP) mRNA, in the peripheral blood of patients with newly diagnosed type 2 diabetes mellitus (T2DM) under different bone mass conditions, and to explore its role and significance in the development process of T2DM combined with osteoporosis (OP). Material and methods: A total of 225 patients hospitalised in the Endocrinology Department and General Department from May 2017 to May 2018 were enrolled and categorised into five groups: the pure T2DM group (group A, 45 patients), the bone mass reduction group (group B, 45 patients), the T2DM + bone mass reduction group (group C, 45 patients), the OP group (group D, 45 patients), and the T2DM + OP group (group E, 45 patients); meanwhile, age-matched healthy subjects undergoing physical examination in our hospital were collected as the normal control group (group NC, 45 cases). Logistic regression analysis was used to analyse the influencing factors of bone mass in patients with T2DM. Results: Compared with group B, the expression levels of glycated haemoglobin (HbA1c), 25(OH)D, N-terminal propeptide of type I procollagen (PINP), fasting plasma glucose (FPG), fasting plasma insulin (FINS), high-density lipoprotein cholesterol (HDL-C), and BSP mRNA were significantly increased while OPG and b-collagen degradation products (b-CTX) were significantly decreased in group A. Conclusion: The expression of BSP mRNA and the decrease of 25(OH)D and OPG in peripheral blood may participate in the development of diabetes and osteoporosis

    The cross-level influence of ethical leadership on employee’s OCBE: a two-wave study based on the social identity approach

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    The importance of organizational citizenship behavior for the environment (OCBE) has received increasing attention in recent years because organizations face increasing pressure from environmental deterioration. The purpose of this study is to use social identity theory to construct a cross-level theoretical model of ethical leadership on OCBE, and to explore the cross-level influential mechanisms of ethical leadership on OCBE. Data collection was conducted via a two-wave distribution of leader-employee paired questionnaires in 20 manufacturing companies in China. In the first wave, data about OCBE and team environmental atmosphere were collected from leaders. Subsequently, 2 months later, we conducted the second wave of data collection when data about ethical leadership and leader identity were obtained from their employees. The results showed that at the individual level, ethical leadership has a significant positive impact on employees’ OCBE, and such relationship is partially mediated by employees’ leader identity and positively moderated by team environmental atmosphere across levels. At the team level, ethical leadership has a significant positive impact on employees’ OCBE, and such relationship is completely mediated by team environmental atmosphere. This study investigates the cross-level influential mechanism of ethical leadership on OCBE in China and provides theoretical guidance for enterprises to promote OCBE effectively

    Sub-structure characteristic mode analysis of microstrip antennas using a global multi-trace formulation

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    A characteristic mode (CM) method that relies on a global multi-trace formulation (MTF) of surface integral equations is proposed to compute the modes and the resonance frequencies of microstrip patch antennas with finite dielectric substrates and ground planes. Compared to the coupled formulation of electric field and Poggio-Miller-Chang-Harrington-Wu-Tsai integral equations, global MTF allows for more direct implementation of a sub-structure CM method. This is achieved by representing the coupling of the electromagnetic fields on the substrate and ground plane in the form of a numerical Green function matrix, which yields a more compact generalized eigenvalue equation. The resulting sub-structure CM method avoids the cumbersome computation of the multilayered medium Green function (unlike the CM methods that rely on mixed-potential integral equations) and the volumetric discretization of the substrate (unlike the CM methods that rely on volume-surface integral equations), and numerical results show that it is a reliable and accurate approach to predicting the modal behavior of electromagnetic fields on practical microstrip antennas
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